The document discusses stretched tapes (raffia) and monofilaments made from polypropylene. It describes the manufacturing processes which involve extruding the polymer resin, quenching, slitting into tapes, orienting the tapes through stretching while heated, and annealing. It discusses key processing parameters and their effects on the physical properties of the final products. The principal stages of monofilament production are also outlined, involving extrusion, quenching, drawing, heat setting, and winding. Common polymer resins used and their characteristics are provided.
Extrusion is a high-volume manufacturing process where plastic material is melted and forced through a die to create a continuous profile. There are various types of extrusion processes depending on the final product, such as sheet/film extrusion, tubing extrusion, and wire coating. Extruders use either single or twin screws to melt, mix, and convey the plastic material. The processing section of the extruder subjects the material to different conditions like melting, mixing, venting and homogenization. Wear of extruder components can reduce efficiency over time. Final products are cut into pellets using various pelletizing systems after exiting the die.
An Introduction to Lohia Corp Ltd, IndiaDeven Mehta
Lohia Corp Ltd brings 3 decades of experience and expertise in supplying complete range of machines for producing Plastic Woven Fabric used for flexible packaging solutions and other industrial applications like cement bags, sacks, tarpaulins, FIBC Jumbo bags, carpet backing, leno bags & many more.
The projects supplied by the company are running successfully in over 70 countries around the world and this accomplishment has been possible due to the Group’s continuous emphasis on quality and innovation. With offices in China, Brazil, UAE, US & worldwide network of sales agents supported by top quality professionals, supports the customers for delivery of the machinery & services. The state-of-art infrastructure with strong In-House R&D Centre helps in delivering innovative market-focused solutions at competitive costs.
Our Product Portfolio includes:
Tape extrusion lines
Tape winding solutions
Circular weaving machines (Circular Looms)
Extrusion coating lines
Printing machines
Bag conversion system
Multifilament yarn spinning lines
To know more about us please email us at deven.mehta@lohiagroup.com
The document discusses the calendaring process for producing plastic sheets. It involves passing a plastic melt between heated counter-rotating rolls to form a continuous film or sheet. Key steps include compounding the plastic with additives, fluxing the compound, feeding it to heated calendar rolls, and winding the cooled sheet. Parameters like roll temperature, speed, and nip gap are controlled. Common applications of calendared sheets include packaging, medical products, flooring, and automotive parts.
Monofilaments are produced through an extrusion process where polymer material is melted, extruded through a die, quenched, stretched and oriented to enhance tensile properties, annealed, and wound. Common materials used are nylon, polypropylene, polystyrene, polyethylene, and PVC. Monofilaments have applications as toothbrush bristles, plastic ropes, fish nets, and other netting. The production process involves extrusion through a circular or T-die, quenching in a water bath, stretching using godet rolls, annealing, and winding onto spools.
Phase change materials (PCMs) can absorb and release large amounts of heat during phase changes from solid to liquid and back. When incorporated into textiles, PCMs provide thermal regulation to improve comfort. There are over 500 natural and synthetic PCMs that differ in phase change temperatures and heat storage capacities. PCMs are added to textiles through microencapsulation, coating, or lamination methods. Research shows PCM textiles increase thermal comfort during exercise by regulating temperature and humidity levels. Current PCM sportswear on the market includes products from Outlast and Comfortemp that claim thermoregulation benefits. Further development needs standardized testing methods and improving durability of PCMs under washing and usage conditions
Elastomeric materials that meet tough challenges
----------------------------------------------
Author: Dr. Banja Junhasavasdikul
Published: August 2022
----------------------------------------------
Rubber is a miracle elastomeric material for which there are hardly any alternatives
because of its elastomeric properties. Natural rubber and synthetic rubbers have been
developed to serve man-kind in sealing, transporting, conveying and containing solid, liquid
and gas that other materials find difficult to do.
How could we live in this world without rubber? How would we drive our cars without
rubber? Rubber products are everywhere and offer practical solutions for a wide variety of
design challenges.
This document describes a procedure for measuring the melt flow index (MFI) of various polymer samples using an extrusion plastometer. The MFI is a measure of viscosity and molecular weight, with higher MFI indicating lower viscosity and molecular weight. Samples of polystyrene, ABS, and three grades of polypropylene are tested under different temperature and load conditions. The procedure involves heating samples in the plastometer, applying a load to extrude the melt, and weighing extrudate collected over time to calculate the MFI. Questions address trends in MFI values and how properties vary between polymers and polymer grades.
This document presents information about ring spinning. Md. Yousuf Hossain from Green University of Bangladesh introduces the topic and defines key terms like fiber, spinning and yarn. It then describes the ring spinning process which involves blow room, carding, draw frame and speed frame before the roving reaches the ring frame. Here, it is drafted and twisted to produce yarn, which is then wound onto bobbins. The document focuses on the drafting zone of the ring frame and explains how higher drafts are applied. It also provides details about how the yarn travels through the traveller and onto the cop during winding. In closing, advantages and limitations of ring spinning are mentioned.
Extrusion is a high-volume manufacturing process where plastic material is melted and forced through a die to create a continuous profile. There are various types of extrusion processes depending on the final product, such as sheet/film extrusion, tubing extrusion, and wire coating. Extruders use either single or twin screws to melt, mix, and convey the plastic material. The processing section of the extruder subjects the material to different conditions like melting, mixing, venting and homogenization. Wear of extruder components can reduce efficiency over time. Final products are cut into pellets using various pelletizing systems after exiting the die.
An Introduction to Lohia Corp Ltd, IndiaDeven Mehta
Lohia Corp Ltd brings 3 decades of experience and expertise in supplying complete range of machines for producing Plastic Woven Fabric used for flexible packaging solutions and other industrial applications like cement bags, sacks, tarpaulins, FIBC Jumbo bags, carpet backing, leno bags & many more.
The projects supplied by the company are running successfully in over 70 countries around the world and this accomplishment has been possible due to the Group’s continuous emphasis on quality and innovation. With offices in China, Brazil, UAE, US & worldwide network of sales agents supported by top quality professionals, supports the customers for delivery of the machinery & services. The state-of-art infrastructure with strong In-House R&D Centre helps in delivering innovative market-focused solutions at competitive costs.
Our Product Portfolio includes:
Tape extrusion lines
Tape winding solutions
Circular weaving machines (Circular Looms)
Extrusion coating lines
Printing machines
Bag conversion system
Multifilament yarn spinning lines
To know more about us please email us at deven.mehta@lohiagroup.com
The document discusses the calendaring process for producing plastic sheets. It involves passing a plastic melt between heated counter-rotating rolls to form a continuous film or sheet. Key steps include compounding the plastic with additives, fluxing the compound, feeding it to heated calendar rolls, and winding the cooled sheet. Parameters like roll temperature, speed, and nip gap are controlled. Common applications of calendared sheets include packaging, medical products, flooring, and automotive parts.
Monofilaments are produced through an extrusion process where polymer material is melted, extruded through a die, quenched, stretched and oriented to enhance tensile properties, annealed, and wound. Common materials used are nylon, polypropylene, polystyrene, polyethylene, and PVC. Monofilaments have applications as toothbrush bristles, plastic ropes, fish nets, and other netting. The production process involves extrusion through a circular or T-die, quenching in a water bath, stretching using godet rolls, annealing, and winding onto spools.
Phase change materials (PCMs) can absorb and release large amounts of heat during phase changes from solid to liquid and back. When incorporated into textiles, PCMs provide thermal regulation to improve comfort. There are over 500 natural and synthetic PCMs that differ in phase change temperatures and heat storage capacities. PCMs are added to textiles through microencapsulation, coating, or lamination methods. Research shows PCM textiles increase thermal comfort during exercise by regulating temperature and humidity levels. Current PCM sportswear on the market includes products from Outlast and Comfortemp that claim thermoregulation benefits. Further development needs standardized testing methods and improving durability of PCMs under washing and usage conditions
Elastomeric materials that meet tough challenges
----------------------------------------------
Author: Dr. Banja Junhasavasdikul
Published: August 2022
----------------------------------------------
Rubber is a miracle elastomeric material for which there are hardly any alternatives
because of its elastomeric properties. Natural rubber and synthetic rubbers have been
developed to serve man-kind in sealing, transporting, conveying and containing solid, liquid
and gas that other materials find difficult to do.
How could we live in this world without rubber? How would we drive our cars without
rubber? Rubber products are everywhere and offer practical solutions for a wide variety of
design challenges.
This document describes a procedure for measuring the melt flow index (MFI) of various polymer samples using an extrusion plastometer. The MFI is a measure of viscosity and molecular weight, with higher MFI indicating lower viscosity and molecular weight. Samples of polystyrene, ABS, and three grades of polypropylene are tested under different temperature and load conditions. The procedure involves heating samples in the plastometer, applying a load to extrude the melt, and weighing extrudate collected over time to calculate the MFI. Questions address trends in MFI values and how properties vary between polymers and polymer grades.
This document presents information about ring spinning. Md. Yousuf Hossain from Green University of Bangladesh introduces the topic and defines key terms like fiber, spinning and yarn. It then describes the ring spinning process which involves blow room, carding, draw frame and speed frame before the roving reaches the ring frame. Here, it is drafted and twisted to produce yarn, which is then wound onto bobbins. The document focuses on the drafting zone of the ring frame and explains how higher drafts are applied. It also provides details about how the yarn travels through the traveller and onto the cop during winding. In closing, advantages and limitations of ring spinning are mentioned.
The objective of this presentation is to give an overview of rubber compounding. We will briefly focus on:
Elastomer System
Filler System
Protection system
Process Aids
Cure System
This document discusses various technologies for producing innovative nonwoven materials, including nanofibers produced through electrospinning, bicomponent fibers, meltblown and spunlace processes, and nonwoven spacer fabrics. It also covers applications of nonwovens such as abrasives, insulation, phase change materials, stretchable fabrics, and flushable wipes that meet industry standards. The document contains images to illustrate the different production processes and material structures.
This document discusses flame retardant finishes for textiles. It begins by introducing different types of textile finishing processes and their purposes. It then focuses on flame retardant finishes, explaining their importance for fire safety. Various flame retardant chemistries are described, including how they work by interrupting the combustion cycle. Specific flame retardants for common fibers like cellulose, wool, polyester and blends are outlined. The document also covers topics like durability, toxicity concerns, testing methods, and differences between flame retardant and fireproof properties. It concludes by comparing permanent versus non-permanent flame retardant application methods.
The document discusses extrusion principles and components used in extruding thermoplastics into various products. It contains the following key points:
- Extrusion is a continuous process where thermoplastics are melted and shaped using a screw and die. Common products made via extrusion include films, pipes, sheets, fibers and filaments.
- The main components of an extruder are the hopper, barrel/screw, and die. The hopper feeds plastic granules into the barrel. The screw conveys the melted plastic to the die, which shapes the final product.
- Screw design depends on the material, with PVC screws having deeper channels to prevent thermal degradation, and PE/PP
The document summarizes the effects of stock treatment, drying, and recycling on fiber properties. It discusses how mill pulps have shorter, less uniformly delignified fibers than laboratory pulps due to mechanical damage. Drying fibers causes further strength loss. Recycled fibers have even lower strength due to increased damage. Refining improves fiber bonding but also causes defects. Proper electrostatic conditions and minimizing turbulence can improve strength. Fiber fines and properties like length, fibrillation, and curl strongly influence paper strength.
This document provides a review of coating and lamination processes and applications in the textile industry. It discusses various coating methods like direct coating, foamed coating, transfer coating, hot melt extrusion coating, and calender coating. It also discusses coating formulations using polymers like PVC, PU, acrylic and their applications in products like waterproof clothing, tarpaulins, upholstery, and more. Recent developments discussed include phase change materials and conductive coatings. In summary, the document reviews coating and lamination techniques, formulations and applications in textiles as well as recent innovations in the field.
Heat setting is a heat treatment process that imparts shape retention, crease resistance, resilience and elasticity to fibers. It involves four phases: heating, penetration, transition and stretch, and cooling. Heat setting can be carried out at different stages - in grey condition, after scouring, or after dyeing. Different methods are used for heat setting including contact, steam, hydro, tenter frame, and selective infrared methods. Heat setting results in structural and chemical modifications of fibers that change properties like strength, stretchability, softness, dyeability and sometimes color.
This document discusses coating and laminating processes for paper and films. It describes several methods including extrusion coating, thermal laminating, wet bond laminating, dry bonding, solventless laminating, and extrusion laminating. Extrusion coating is commonly used to apply polyethylene to paperboard with benefits over wax coating like greater strength and moisture resistance. Laminating combines webs using thermal or chemical bonding with adhesives. Thermal laminating uses heat to bond adhesives while wet bond laminating relies on water or solvent. Dry bonding and solventless laminating avoid volatile organic compounds. The document also discusses factors in dry surface treatment coating like particle size and heat treatment to achieve an adequate coating layer.
This document discusses different molding processes including structural foam molding, sandwich molding, and their advantages and disadvantages. Structural foam molding is a low pressure injection molding process where gas is introduced into molten polymer to reduce density and weight. It requires less pressure than other molding processes. Sandwich molding involves injecting two or more polymers one after another through the same gate to form a layered part with different materials for the core and skin. This allows for weight reduction and various material combinations. Advantages of these processes include lower costs, weight reduction, design flexibility, and strength to weight ratios. Disadvantages include potential for air bubbles or shrinkage.
This document summarizes man-made fiber spinning technology. There are three main types of spinning - melt, dry, and wet spinning. Melt spinning involves melting the polymer and extruding it through spinnerets. Dry spinning uses a volatile solvent to dissolve the polymer before extrusion. Wet spinning extrudes the polymer solution into a coagulating bath. Each method has advantages and disadvantages related to investment cost, hazard level, heat requirement, and production speed. The document also discusses properties required for fiber-forming polymers and the basic spinning system components like spinnerets.
Polymer processing, characterisation and applicationsAvinash Singh
This document discusses various types of polymers, plastics, elastomers and fibers. It describes the key differences between thermosetting and thermoplastic polymers. Important thermoplastics like polyethylene, PVC and Teflon are explained. Phenol-formaldehyde is provided as an example of a thermosetting resin. Natural rubber and synthetic diene elastomers like SBR and nitrile rubber are outlined. The document also discusses the manufacturing of polymers and how they are compounded and molded into end products using various molding techniques.
Calendering is a process that compresses fabric by passing it through rollers under controlled temperature and pressure. It is done to make fabric smoother and more lustrous after dyeing by reducing crimping and waviness. There are several types of calendering machines that use different roller materials and configurations to impart qualities like opacity, air permeability, thickness, and various degrees of luster. Calendering is commonly used to upgrade fabric hand feel and appearance for textiles.
Kevlar is a high-performance synthetic fiber made from para-aramid polymers. It is exceptionally strong for its weight, with high tensile strength and modulus. Kevlar fibers are produced through a solution spinning process using concentrated sulfuric acid and result in highly oriented molecular chains arranged in liquid crystalline domains. The fiber has high strength, stiffness, and heat resistance and is used in applications like bulletproof vests, composites, ropes, and tires due to its unique properties. Aramid fibers like Kevlar and Twaron are resistant to chemicals but can be degraded by strong acids and bases.
The document discusses various polymer processing techniques. It begins by explaining that the main goal of polymer processing is to produce usable objects and lists the necessary parameters for processing including flow, heat transfer, mass transfer, and chemical reactions. It then focuses on extrusion, describing it as shaping material by forcing it through a die. Various extrusion techniques are discussed including single screw extrusion, twin screw extrusion, blown film extrusion, co-extrusion, and injection molding. Other processing methods summarized include thermoforming, vacuum forming, rotational molding, calendering, and spinning.
Spunlacing, also known as hydroentanglement, is a process for bonding nonwoven fabrics using high-pressure water jets. Precursor webs made of fibers like cellulose are passed through multiple rows of water jets that entangle the fibers. This produces a bonded nonwoven fabric with properties like softness and absorbency. Key aspects of the process include forming the precursor web, passing it through water entanglement units with fine jet nozzles, and drying the saturated fabric. The process produces fabrics widely used in applications such as wipes, towels, and medical and protective clothing due to its strength and lack of binders.
This document provides an overview of styrene-butadiene rubber (SBR), including its history, raw materials, manufacturing processes, properties, structure, and applications. Some key points:
- SBR is a random copolymer of styrene and butadiene that accounts for around half of global synthetic rubber production. Its main use is in tire manufacturing.
- SBR was developed in the 1920s-1930s as a replacement for natural rubber. Modern solution and emulsion polymerization techniques were established in the 1950s.
- SBR can be produced via emulsion or solution polymerization. Emulsion SBR dominates tire applications due to its oil-extendability and dynamic properties.
This document discusses additives used in biaxially oriented polypropylene (BOPP) film manufacturing. It describes the BOPP film production process and common film properties required by the market. It then summarizes various additive types used in BOPP films, including antiblock, slip, antistatic, and antioxidant additives. White and pearlescent masterbatch additives for BOPP films are also overviewed along with future trends in BOPP additive technologies.
Styrene-butadiene rubber (SBR) is a synthetic rubber derived from styrene and butadiene monomers. There are two main types - emulsion polymerized SBR (E-SBR) and solution polymerized SBR (S-SBR). E-SBR accounts for over 50% of car tire production and is also used in conveyor belts, footwear, adhesives and more. S-SBR offers improved properties for tires and is increasingly used. The document discusses the production, properties and applications of SBR.
The document discusses acrylonitrile butadiene styrene (ABS) copolymers. It describes the production of ABS polymers through the polymerization of styrene and acrylonitrile in the presence of polybutadiene. ABS has advantages like high impact strength, stiffness, colorability and dimensional stability at high temperatures. The document also summarizes various applications of ABS and discusses ways to improve its properties through blending or reinforcing it with fibers and nanomaterials.
The document discusses different types of spinning processes used to create polymer fibers. It describes melt spinning, dry spinning, and wet spinning. In melt spinning, polymers are melted and extruded through a spinneret, then cooled. Dry spinning uses a volatile solvent and evaporates it using hot air. Wet spinning uses a non-volatile solvent and extrudes the solution into a coagulation bath to solidify the fibers. The document provides details of the processes, examples of polymers used for each type, and their advantages and disadvantages.
This document provides calculations and formulas related to yarn count, twist, winding, warping, sizing, weaving, and yarn quality parameters. It discusses three systems for calculating yarn count: indirect, direct, and universal. It also covers formulas for twist per inch, multi-filament yarns, winding calculations, warping calculations, sizing calculations, weaving calculations, and parameters for assessing yarn appearance, unevenness, linear density, and single thread strength.
HOW MONO AND TAPE FABRIC IS MANUFACTUREDMohsin Ahmed
1) The manufacturing process begins with mixing HDPE, masterbatch, and UV granules according to a recipe to form a mixture.
2) The recipe is processed in mono and tape yarn machines to form the yarn.
3) The mono yarn is converted into beams while the tape yarn is processed into crill. Then the beams and crill are used to form fabric using raschel knit and waterjet machinery.
The objective of this presentation is to give an overview of rubber compounding. We will briefly focus on:
Elastomer System
Filler System
Protection system
Process Aids
Cure System
This document discusses various technologies for producing innovative nonwoven materials, including nanofibers produced through electrospinning, bicomponent fibers, meltblown and spunlace processes, and nonwoven spacer fabrics. It also covers applications of nonwovens such as abrasives, insulation, phase change materials, stretchable fabrics, and flushable wipes that meet industry standards. The document contains images to illustrate the different production processes and material structures.
This document discusses flame retardant finishes for textiles. It begins by introducing different types of textile finishing processes and their purposes. It then focuses on flame retardant finishes, explaining their importance for fire safety. Various flame retardant chemistries are described, including how they work by interrupting the combustion cycle. Specific flame retardants for common fibers like cellulose, wool, polyester and blends are outlined. The document also covers topics like durability, toxicity concerns, testing methods, and differences between flame retardant and fireproof properties. It concludes by comparing permanent versus non-permanent flame retardant application methods.
The document discusses extrusion principles and components used in extruding thermoplastics into various products. It contains the following key points:
- Extrusion is a continuous process where thermoplastics are melted and shaped using a screw and die. Common products made via extrusion include films, pipes, sheets, fibers and filaments.
- The main components of an extruder are the hopper, barrel/screw, and die. The hopper feeds plastic granules into the barrel. The screw conveys the melted plastic to the die, which shapes the final product.
- Screw design depends on the material, with PVC screws having deeper channels to prevent thermal degradation, and PE/PP
The document summarizes the effects of stock treatment, drying, and recycling on fiber properties. It discusses how mill pulps have shorter, less uniformly delignified fibers than laboratory pulps due to mechanical damage. Drying fibers causes further strength loss. Recycled fibers have even lower strength due to increased damage. Refining improves fiber bonding but also causes defects. Proper electrostatic conditions and minimizing turbulence can improve strength. Fiber fines and properties like length, fibrillation, and curl strongly influence paper strength.
This document provides a review of coating and lamination processes and applications in the textile industry. It discusses various coating methods like direct coating, foamed coating, transfer coating, hot melt extrusion coating, and calender coating. It also discusses coating formulations using polymers like PVC, PU, acrylic and their applications in products like waterproof clothing, tarpaulins, upholstery, and more. Recent developments discussed include phase change materials and conductive coatings. In summary, the document reviews coating and lamination techniques, formulations and applications in textiles as well as recent innovations in the field.
Heat setting is a heat treatment process that imparts shape retention, crease resistance, resilience and elasticity to fibers. It involves four phases: heating, penetration, transition and stretch, and cooling. Heat setting can be carried out at different stages - in grey condition, after scouring, or after dyeing. Different methods are used for heat setting including contact, steam, hydro, tenter frame, and selective infrared methods. Heat setting results in structural and chemical modifications of fibers that change properties like strength, stretchability, softness, dyeability and sometimes color.
This document discusses coating and laminating processes for paper and films. It describes several methods including extrusion coating, thermal laminating, wet bond laminating, dry bonding, solventless laminating, and extrusion laminating. Extrusion coating is commonly used to apply polyethylene to paperboard with benefits over wax coating like greater strength and moisture resistance. Laminating combines webs using thermal or chemical bonding with adhesives. Thermal laminating uses heat to bond adhesives while wet bond laminating relies on water or solvent. Dry bonding and solventless laminating avoid volatile organic compounds. The document also discusses factors in dry surface treatment coating like particle size and heat treatment to achieve an adequate coating layer.
This document discusses different molding processes including structural foam molding, sandwich molding, and their advantages and disadvantages. Structural foam molding is a low pressure injection molding process where gas is introduced into molten polymer to reduce density and weight. It requires less pressure than other molding processes. Sandwich molding involves injecting two or more polymers one after another through the same gate to form a layered part with different materials for the core and skin. This allows for weight reduction and various material combinations. Advantages of these processes include lower costs, weight reduction, design flexibility, and strength to weight ratios. Disadvantages include potential for air bubbles or shrinkage.
This document summarizes man-made fiber spinning technology. There are three main types of spinning - melt, dry, and wet spinning. Melt spinning involves melting the polymer and extruding it through spinnerets. Dry spinning uses a volatile solvent to dissolve the polymer before extrusion. Wet spinning extrudes the polymer solution into a coagulating bath. Each method has advantages and disadvantages related to investment cost, hazard level, heat requirement, and production speed. The document also discusses properties required for fiber-forming polymers and the basic spinning system components like spinnerets.
Polymer processing, characterisation and applicationsAvinash Singh
This document discusses various types of polymers, plastics, elastomers and fibers. It describes the key differences between thermosetting and thermoplastic polymers. Important thermoplastics like polyethylene, PVC and Teflon are explained. Phenol-formaldehyde is provided as an example of a thermosetting resin. Natural rubber and synthetic diene elastomers like SBR and nitrile rubber are outlined. The document also discusses the manufacturing of polymers and how they are compounded and molded into end products using various molding techniques.
Calendering is a process that compresses fabric by passing it through rollers under controlled temperature and pressure. It is done to make fabric smoother and more lustrous after dyeing by reducing crimping and waviness. There are several types of calendering machines that use different roller materials and configurations to impart qualities like opacity, air permeability, thickness, and various degrees of luster. Calendering is commonly used to upgrade fabric hand feel and appearance for textiles.
Kevlar is a high-performance synthetic fiber made from para-aramid polymers. It is exceptionally strong for its weight, with high tensile strength and modulus. Kevlar fibers are produced through a solution spinning process using concentrated sulfuric acid and result in highly oriented molecular chains arranged in liquid crystalline domains. The fiber has high strength, stiffness, and heat resistance and is used in applications like bulletproof vests, composites, ropes, and tires due to its unique properties. Aramid fibers like Kevlar and Twaron are resistant to chemicals but can be degraded by strong acids and bases.
The document discusses various polymer processing techniques. It begins by explaining that the main goal of polymer processing is to produce usable objects and lists the necessary parameters for processing including flow, heat transfer, mass transfer, and chemical reactions. It then focuses on extrusion, describing it as shaping material by forcing it through a die. Various extrusion techniques are discussed including single screw extrusion, twin screw extrusion, blown film extrusion, co-extrusion, and injection molding. Other processing methods summarized include thermoforming, vacuum forming, rotational molding, calendering, and spinning.
Spunlacing, also known as hydroentanglement, is a process for bonding nonwoven fabrics using high-pressure water jets. Precursor webs made of fibers like cellulose are passed through multiple rows of water jets that entangle the fibers. This produces a bonded nonwoven fabric with properties like softness and absorbency. Key aspects of the process include forming the precursor web, passing it through water entanglement units with fine jet nozzles, and drying the saturated fabric. The process produces fabrics widely used in applications such as wipes, towels, and medical and protective clothing due to its strength and lack of binders.
This document provides an overview of styrene-butadiene rubber (SBR), including its history, raw materials, manufacturing processes, properties, structure, and applications. Some key points:
- SBR is a random copolymer of styrene and butadiene that accounts for around half of global synthetic rubber production. Its main use is in tire manufacturing.
- SBR was developed in the 1920s-1930s as a replacement for natural rubber. Modern solution and emulsion polymerization techniques were established in the 1950s.
- SBR can be produced via emulsion or solution polymerization. Emulsion SBR dominates tire applications due to its oil-extendability and dynamic properties.
This document discusses additives used in biaxially oriented polypropylene (BOPP) film manufacturing. It describes the BOPP film production process and common film properties required by the market. It then summarizes various additive types used in BOPP films, including antiblock, slip, antistatic, and antioxidant additives. White and pearlescent masterbatch additives for BOPP films are also overviewed along with future trends in BOPP additive technologies.
Styrene-butadiene rubber (SBR) is a synthetic rubber derived from styrene and butadiene monomers. There are two main types - emulsion polymerized SBR (E-SBR) and solution polymerized SBR (S-SBR). E-SBR accounts for over 50% of car tire production and is also used in conveyor belts, footwear, adhesives and more. S-SBR offers improved properties for tires and is increasingly used. The document discusses the production, properties and applications of SBR.
The document discusses acrylonitrile butadiene styrene (ABS) copolymers. It describes the production of ABS polymers through the polymerization of styrene and acrylonitrile in the presence of polybutadiene. ABS has advantages like high impact strength, stiffness, colorability and dimensional stability at high temperatures. The document also summarizes various applications of ABS and discusses ways to improve its properties through blending or reinforcing it with fibers and nanomaterials.
The document discusses different types of spinning processes used to create polymer fibers. It describes melt spinning, dry spinning, and wet spinning. In melt spinning, polymers are melted and extruded through a spinneret, then cooled. Dry spinning uses a volatile solvent and evaporates it using hot air. Wet spinning uses a non-volatile solvent and extrudes the solution into a coagulation bath to solidify the fibers. The document provides details of the processes, examples of polymers used for each type, and their advantages and disadvantages.
This document provides calculations and formulas related to yarn count, twist, winding, warping, sizing, weaving, and yarn quality parameters. It discusses three systems for calculating yarn count: indirect, direct, and universal. It also covers formulas for twist per inch, multi-filament yarns, winding calculations, warping calculations, sizing calculations, weaving calculations, and parameters for assessing yarn appearance, unevenness, linear density, and single thread strength.
HOW MONO AND TAPE FABRIC IS MANUFACTUREDMohsin Ahmed
1) The manufacturing process begins with mixing HDPE, masterbatch, and UV granules according to a recipe to form a mixture.
2) The recipe is processed in mono and tape yarn machines to form the yarn.
3) The mono yarn is converted into beams while the tape yarn is processed into crill. Then the beams and crill are used to form fabric using raschel knit and waterjet machinery.
Este documento describe el proceso de extrusión de termoplásticos. Explica que la extrusión implica forzar un material a pasar a través de un orificio bajo presión para darle forma. Luego describe las partes principales de un extrusor, incluyendo el husillo, camisa y cabezal, y explica cómo funciona para transportar, fundir y bombear el material plástico. También cubre conceptos clave como las temperaturas de transición vítrea y fusión de los plásticos y cómo esto afecta sus temperaturas de
EU: Tyre Cord Fabric of High Tenacity Yarn – Market Report. Analysis and Fore...IndexBox Marketing
IndexBox Marketing has just published its report: “EU: Tyre Cord Fabric of High Tenacity Yarn - Market Report. Analysis And Forecast To 2020”. This report focuses on the EU tyre cord fabric market, providing a comprehensive analysis and the most recent data on its market size and volume, EU trade, price dynamics, domestic production, and turnover in the industry. The market trends section reveals the main issues and uncertainties concerning the industry, while the medium-term outlook uncovers market prospects. The attractivity index (IB Index) summarizes the source of existing opportunities as they appear in this market, as well as an interpretation of the trade figures.
Este documento describe sacos de rafia que son necesarios y versátiles para trabajos de retirada de escombros, jardinería para recoger hojas y ramas, y para almacenar todo tipo de materiales. Se venden en bolsas de 10 sacos cada una.
Sewing thread is a smooth, hard twisted yarn that undergoes a special finishing process to make it resistant to stresses when passing through needles and during sewing operations. It is spun evenly and used for seaming and stitching fabrics.
This document discusses various polymer processing techniques. It begins by outlining three general phases of plastics processes: heating, shaping/forming under constraint, and cooling. It then describes specific processes like thermoforming, compression and transfer molding, rotational molding, extrusion and extrusion-based processes, injection molding, and blow molding. For each process, it provides details on how it works, its advantages and disadvantages, and common applications.
This document discusses different types of sewing threads, including their compositions and applications. Natural fibres like cotton are discussed as well as synthetic fibres like polyester. Specific thread types covered include spun polyester, corespun threads, and textured threads. The benefits of corespun threads for strength and sewability are highlighted. Various yarn counting systems and their applications are also summarized.
This document discusses different types of extrusion dies used in plastic extrusion processes. It classifies dies into five main categories: sheet dies, flat-film and blown-film dies, pipe and tubing dies, profile extrusion dies, and coextrusion dies. For each category, the document provides a brief description and schematic diagrams to illustrate key features. It highlights important design considerations for dies like dealing with non-uniform die swell in profile dies. The benefits of using stack plate dies for better quality and material savings are also noted.
Spun Laid Process, Melt Blown Process, Differences between spun laid Process ...MD. SAJJADUL KARIM BHUIYAN
The document provides information on the spun laid and melt blown processes for producing nonwoven fabrics from polymers. In the spun laid process, polymers are extruded through spinnerets to form fine filaments, which are then deposited randomly onto a conveyor belt and bonded. The melt blown process extrudes polymers through a die containing many small holes, and high-velocity air streams attenuate the extruded fibers to form very fine fibers that are deposited onto a collector. Key differences between the processes are that the spun laid process produces thicker fibers that are later bonded, while the melt blown process produces very fine fibers through fiber attenuation using hot air streams.
CPP is a non-oriented plastic film that has better tear strength, impact resistance at low temperatures, and dimensional stability compared to other plastics like BOPP. It is produced through an extrusion process where plastic pellets are melted, filtered, layered and cast onto a chill roll to solidify. The film thickness is measured and controlled before the film undergoes surface treatment and winding onto rolls.
The document discusses multi-layer composite films and the extrusion process used to produce them. It describes how multiple polymer layers from different extruders can be combined into a single film through a multi-manifold die. The film is then cooled on chill rollers before undergoing slitting, gauging, and winding into rolls. Properties like optical clarity and barrier performance can be optimized through adjustments to materials, temperatures, and processing speeds. Common polymers used include polyolefins like polyethylene and polypropylene.
This document provides an overview of the cast film extrusion process. It describes the main components of a cast film extrusion line including gravimetric feeders, extruders, filtration systems, flat dies, cooling units, gauge control systems, corona treatment, and winders. It explains the functions of each component and how they work together to produce cast films which are used in various packaging applications.
The document discusses the polymer processing technique of extrusion. It begins with an overview of extrusion and the main components of an extruder. It then describes in detail the different zones of a single screw extruder and how polymer pellets are softened, melted and shaped as they pass through each zone. Common issues like die swelling, melt fracture and surging during extrusion are also explained along with methods to reduce them. Finally, modified extrusion techniques like co-extrusion, blown film extrusion and crosshead extrusion are briefly introduced.
INTRODUCTION
The ring spinning will continue to be the most widely used form of spinning machine in the near future, because it exhibits significant advantages in comparison with the new spinning processes.
Following are the advantages of ring spinning frame
• It is universally applicable, i.e. any material can be spun to any required count
• It delivers a material with optimum characteristics, especially with regard to structure and strength.
• It is simple and easy to master
• The know-how is well established and accessible for everyone
Extrusion is a process that uses compression to form materials through a die into a continuous shape of fixed cross-section. It can produce parts with complex cross-sections from brittle materials. There are two main types - direct extrusion where the ram pushes against the material, and indirect extrusion where the die is stationary and the container moves. Materials commonly extruded include metals, polymers, food, and ceramics. Extrusion is used in many applications like construction, automotive, and food processing.
Ekeeda Provides Online Engineering Subjects Video Lectures and Tutorials of Mumbai University (MU) Courses. Visit us: https://ekeeda.com/streamdetails/University/Mumbai-University
Ekeeda Provides Online Engineering Subjects Video Lectures and Tutorials of Mumbai University (MU) Courses. Visit us: https://ekeeda.com/streamdetails/University/Mumbai-University
This document discusses the process of extrusion for forming polymer products. It describes how extrusion involves forcing molten polymer through a die to form the desired shape. Viscosity and melt flow index are important properties that determine the speed of extrusion. A single screw extruder uses a rotating screw inside a heated barrel to convey, melt, and force the polymer through a die. The screw has three zones - a feed zone to preheat the polymer, a compression zone to compact it, and a metering zone to homogenize the melt before exiting through the die.
This type of moulding is helpful to make containers ,jars ,water bottles and many more so please kindly go through this process .With the help of this type of moulding we can perform our experiment of our daily used water cans e.g: 5ltrs ,10ltrs ,20ltrs ,25ltrs ect.
1. Carding is the process of reducing tufts of entangled fibers into a filmy web of individual fibers using machines called cards. There are three main types of cards used for cotton, wool, and man-made fibers.
2. The carding process opens fibers, removes impurities, disentangles neps, blends fibers, orients fibers, and forms slivers for further processing. It transforms a fiber batt into a uniform web of individual fibers.
3. Fiber batts are fed to the carding machine using either a lap feed system or a flock feed system. The chute feed system aims to feed a fiber sheet of uniform packing density and linear density.
Hot melt adhesives are thermoplastic polymers that become liquid when heated above 80-220°C and solidify when cooled. They are applied in liquid state without solvents or water, allowing for precise application. Common polymers used include styrene copolymers, polyamides, and polyacrylates. Hot melts have advantages like being solvent-free, producing less waste, and allowing for adjustment of viscosity through temperature variation.
it is PDF are typed of myself. study triks & short & sweet (Technical manual) Of Diploma in Plastics technology(DPT-DPMT). All machine knowlage in plastics processing.
Er. Naresh Dhaker
(8890881858)
(CIPET JAIPUR)
This document discusses various types of polymers and polymer processing techniques. It begins by defining polymers as substances made of repeating molecular units called mers. Polymers are classified as thermoplastics or thermosets depending on whether they can be remelted or undergo further chemical reactions. Common polymer processing techniques include extrusion, injection molding, blow molding, thermoforming, and composites fabrication. The document provides details on the basic mechanisms and applications of these important industrial polymer processes.
The document discusses the vacuum pressure impregnation (VPI) process for insulating the windings of large electric machines like turbo generators. It describes how VPI eliminates air gaps in windings to reduce hot spots and lower operating temperatures. VPI seals the machine against environmental conditions and bonds insulation components for strength. This reduces noise and increases the dielectric capability of the machine. The document reviews the existing VPI system and materials used, including resins, tapes and the heating/cooling cycle. It provides details on mixing resins and the sizes of tanks used in the VPI process.
Sizing is the process of applying an adhesive coating to yarn to improve properties like strength and smoothness. The objectives of sizing include protecting yarn from abrasion and decreasing static electricity. A sizing machine coats yarn with size ingredients like adhesives and lubricants in the size box, then dries the yarn on cylinders before winding it onto beams. Key components are creels for unwinding yarn, size boxes for coating, drying cylinders, and headstocks for winding yarn onto beams. Process parameters like size viscosity and squeezing pressure affect the amount of size picked up by the yarn.
[1] O documento descreve os diferentes tipos de tecidos, incluindo tecidos planos, malha e não-tecido. [2] Detalha os processos de fabricação de tecidos de malha de trama e urdume, assim como suas propriedades e aplicações. [3] Fornece ilustrações dos diferentes tipos de estruturas têxteis.
O documento descreve os principais processos e conceitos da indústria têxtil, incluindo a produção de fibras, fiação, tecelagem, malharia e beneficiamento. Também discute a cadeia produtiva têxtil no Brasil, as transformações recentes no setor e normas técnicas relevantes.
Este documento descreve operações físicas e bioquímicas de preparação têxtil, incluindo navalhagem, chamuscagem, pré-fixação e desengomagem. A navalhagem e a chamuscagem são processos para remover fibrilas salientes das fibras, enquanto a pré-fixação serve para fixar as dimensões do tecido antes de outros processos úmidos. A desengomagem tem como objetivo remover engomantes adicionados durante o tear para aumentar a rigidez dos fios.
O documento discute o polipropileno, um plástico de alto crescimento devido às suas propriedades versáteis. É produzido através da polimerização do propeno usando um catalisador que forma longas cadeias de polímero. Pode ser moldado em diversos produtos através de processos como injeção, sopro e extrusão. Apresenta características como leveza, resistência química e mecânica que o tornam útil em muitas aplicações.
Technical fabrics are fabrics manufactured for their technical performance properties rather than aesthetic qualities. They are produced through various methods including weaving, knitting, felting, and non-woven processes. Key specifications that define technical fabrics include construction, area density, cover factor, weave type, crimp, width, and thickness. Common weaves are plain, twill, satin, and sateen weaves. Technical fabrics have a wide range of applications including conveyor belts, filters, parachutes, tires, and more.
Apostila de Ciências das Fibras-Professora Maria Adelina-FATEC AmericanaJosé Carlos de Castro
O documento descreve as propriedades e características de várias fibras têxteis, incluindo algodão, paina, banana, coco e juta. Detalha a origem, obtenção, composição química, comportamento térmico, resistência e aplicações de cada fibra. Fornece informações técnicas valiosas sobre as fibras para fins têxteis e industriais.
1. O documento discute os fundamentos do controle de qualidade no processo de fiação, com foco na utilização do Controle Estatístico do Processo (CEP).
2. A utilização do CEP na indústria têxtil proporcionou uma redução de 38,4% na variabilidade dos dados de profundidade de trabalho média e um aumento de 45% nos dados desejados.
3. O documento defende que o CEP tem grande potencial para melhorar a qualidade e produtividade na indústria têxtil.
This document provides an overview of carpet construction and specification. It discusses carpet fibers, yarns, coloring techniques, fabrication methods like tufting and weaving, finishing techniques, backing systems, and considerations for specification like aesthetics and functionality. The document is copyrighted by the Carpet and Rug Institute and covers topics like fiber types, yarn production methods, pre-dyeing and post-dyeing coloration, tufting and weaving processes, protective treatments, backing components, and factors in carpet selection like insulation value.
2. Stretched Tapes (Raffia) and Monofilaments
Introduction
Stretched tapes are uniaxially oriented thermoplastic semi finished products with a high
width to thickness ratio. These tapes can be converted into twines, ropes, woven and
knitted fabrics. A range of applications for stretched tapes have expanded considerably
from woven sacks to tarpaulins, primary carpet backing, industrial fabric, carpet yarn,
ropes, geotextile fabrics, concrete reinforcement etc.
Monofilaments are uniaxially oriented wirelike polymer strands having a circular cross
section. They are manufactured by melt spinning process. The use of monofilaments has
steadily increased as a substitute for natural fibres. The size of monofilaments ranges
from 0.1mm to 2.5mm in diameter depending upon the end use application.
Polyethylene, polypropylene, nylon and polyesters are commonly used raw materials for
making monofilaments. Polypropylene has emerged as a leader in the monofilament
industry because of its light weight, ease of extrusion and orientation, higher strength and
low cost.
Monofilaments and multifilaments can be distinguished by the filament size. The size of
monofilaments varies from 0.1mm to 2mm whereas that of a single filament in
multifilaments ranges from 5 microns to 50 microns.
Theory of orientation
Partially crystalline thermoplastics, namely eg. Polyethylene (HDPE) and Polypropylene
(PP) are ideal materials for making oriented products. In a stretching process, the macro
molecules are given an orientation in the direction of draw. The orienting ability of
polymer is determined by its spherulite structure. When tension is applied, amorphous
regions get oriented first between folded lamellae and the spherulite boundaries. During
drawing or stretching, energy conversion takes place. The oriented structure is heated
nearly to its melting temperature to reduce amorphous region tension and subsequent
shrinkage of tapes is avoided.
Manufacture of Tapes
The principal stages involved in tape manufacture are :
• Extrusion of film
• Quenching of film
• Slitting of film into tapes
• Orientation of tapes
• Annealing of tapes
• Winding
2
3. The equipment and processing requirements for conversion of PP into tapes are quite
similar to those for HDPE. Although the blown film process has not phased out
completely, more and more processors are shifting to the cast film process owing to its
better gauge control and higher outputs.
Equipment for Cast Film Extrusion
Extruder
PP can be processed on conventional extruders with three zone screws viz. feed,
compression and metering. The output obtained from PP depends upon the L/D ratio
(Length to Diameter Ratio). Higher the L/D ratio, higher will be the output per
revolution of screw. For good melt homogeniety and optimum output, extruders with
L/D ratios of 24:1 upto 30:1 are preferred, whilst compression ratio's between 3.0 - 3.5
should be used. Screw diameters range from 65 upwards. An illustration of a typical
stretched tape plant is given in Fig. 1.
Die
The type of die used is referred to as a coat hanger die / T-die which provides a good
streamlined flow.
Quenching of the film
The polymer melt is partly oriented during extrusion through a die. To prevent melt
relaxation the melt is quenched rapidly after exiting from the die. Fast cooling promotes
a finer crystalline structure of polymer in the film which in turn improves the
performance of film during the stretching operation, apart from rendering better
physicals.
In cast film, the cooling is done by quenching the film in a water tank. The film from the
die is directly taken into the tank filled with water. Film quality and performance of the
resulting tapes mainly depend on the quenching conditions. During quenching, the
significant parameters which control the physicals of the tapes are die-water distance (air
gap) and quench water temperature.
Operation with a lower air gap will reduce the time for melt relaxation and result in films,
with higher strength. A very fast rate of quench will result in a very fine crystal structure
in the film, which will give higher clarity and strength, than a film which is quenched at
slower rates. To achieve optimum strength and elongation, air gap of 20-35 mm and
quench water temperature of 30-40°C is recommended.
3
4. Slitting of film into tapes
The flat film after quenching is slit into tapes of specific width according to the end use
requirements. The slitting tools generally used are industrial or surgical blades with
sharp edges. Blunt blades produce poor cuts, which lead to problems in drawing,
winding and weaving of tapes. The blades are equally placed on a bar using spacers and
are set at an angle of 30 ° and 60 ° with the film. Initial tape width is adjusted by selecting
appropriate spacer.
Orientation of tapes
Orientation is accomplished by stretching the tapes while passing them through a hot air
oven or over a hot plate, maintained at a temperature just below the melting temperature
of PP. PP has a higher melting point (160-165 °C) than HDPE. Hence, it needs to be
oriented at a higher temperatures than that for HDPE to fully develop the mechanical
properties in stretched products. Stretching of tapes is done by passing them over two
sets of rollers, called godet rollers, placed on either side of the hot air oven / hot plate and
operating at different speeds. Ratio of speed of second set of rollers, operating at higher
speed, to that of first set is termed as stretch ratio. Stretching of tapes in presence of heat
media results in molecular / chain orientation and thus greatly increases the mechanical
strength of tapes. PP tapes have to be oriented at a stretch ratio of 5-6 and temperature of
135-155°C in hot air oven or at 125-160 °C on a hot plate.
Hot Air Oven
Tapes from the first set of godet are taken through an oven on to the second godet rollers.
Hot air is blown in the oven, counter current to the movement of tapes, and recirculated
through a blower - heater system at linear flow rate of 10-30 mtrs/sec. Higher flow rate
of circulating air is preferred as it enables faster and more uniform heating of the tapes
and lower the risk of leaving some areas in tapes undrawn or underdrawn. Once the
required tape properties are obtained, the orientation temperature and the stretch ratio are
kept constant and checked randomly throughout the process.
In hot air oven system, uniform heating of the tapes takes place, which ensures better tape
properties compared to the Hot plate system. The length of this unit is around 3 meters
and its width is slightly more than that of the godet rolls, for all the tapes to traverse
freely. A good temperature control system with an accuracy of atleast ± 5 °C is required.
Hot air circulation in the oven should be adequately controlled to avoid excessive
turbulence.
4
5. Hot Plate
Hot plate is heated electrically or by circulating hot oil. In this system, tapes are in close
contact with the hot metal surface while they are oriented. The upper and lower hot plate
design is preferred as it provides enough contact for uniform distribution of the tapes,
since half the tapes can be stretched over top surface while the other half are stretched
over lower surface, giving better heat transfer to all tapes and less variations in
mechanical properties.
Although hot plate offers 25% saving in terms of energy requirement, the hot air
circulating ovens provide uniform heating to the tapes, thereby enabling the converter to
exploit the superior mechanicals of PP.
Annealing of tapes
Drawn tapes are "annealed" immediately after stretching operation. This helps to
minimize tape shrinkage which may occur as a result of residual stresses in the oriented
tapes. Annealing is done by heating the stretched tapes while they are passing over from
second goddet rollers to third godet rollers; the latter being maintained at a slightly lower
speed (5% less) than the former. The annealing ratio is a function of second and third
goddet rollers. The annealing temperature is slightly lower (5-10°C) than the orientation
temperature. For PP, it is between 125-145 °C, while for HDPE it is between 100-110 °C.
Alternatively, tapes can be annealed by using hot goddet rolls, which are usually heated
electrically or by circulating hot oil. Relaxation takes place over a short gap (the distance
between the rolls).
Winding
After the final goddet stand, the tape proceeds to a winder stand and is taken up by the
bobbins. For good winding, controlled tension is essential.
5
9. Manufacture of monofilaments
The process essentially consists of the following steps
• Extrusion
• Forming (Quenching)
• Drawing
• Heat setting
• Winding
Extrusion
Conventional extruders are used for extrusion of monofilaments. Usually these extruders
have screw dia of 65, 90 or 110mm. For good melt homogeneity and optimum output,
screw of L/D ratio from 24:1 to 30:1 is preferred with compression ratio of 3 to 3.5
The homogenised melt from the extruder is fed to a circular die or spinneret which is at
90° to the axis of the extruder. The die is threaded on to the head which is connected to
the extruder through an adaptor or neck. The filterpack and breaker plate are mounted on
the head. The filter ensures that a contaminant free melt is fed to the die, which may
otherwise lead to breakage of filaments.
Monofilament dies usually have 180 to 200 holes which are even distributed on 2 or 3
pitch circles (concentric to one another). The L/D ratio of the die is usually 8 to 10mm.
These holes are precisely machined to get a smooth and uniform monofilament surface.
A cone with a smooth surface is fixed onto the die to ensure smooth and uniform flow of
melt to all the holes. Circular dies are preferred for uniform pressure drop throughout the
die.
9
10. Spinning pumps
Monofilament lines usually include a spinning pump. It is a gear pump which maintains
a constant supply of melt to the die and isolates it from surging effects which can lead to
denier or size variation and even filament breakage.
Usually higher pump inlet pressures are set to ensure proper filling of the pump and also
to increase extruder counter pressure which results in better homogenisation of melt.
Some lines also incorporate on line screen changes prior to the spinning pump.
Forming
The monofilaments emerging from the die are taken into a quench bath. The quench
medium is water which is maintained at around 25-35°C. The purpose of quenching is to
have a finer crystallite size which will facilitate stretching to produce high tenacity
filament. The filaments are taken over a deflecting roll in the quench bath and are drawn
continuously by Godet I.
Quench baths used are height adjustable to alter the distance between the die face and the
water surface which is called hot distance or air gap. The hot distance influences the
tenacity and stretchability of the filaments. Normally it is maintained between 25-40mm.
At the quench bath outlet, the filaments are taken over a roll where the filaments are
separated. Absorbant cotton pads or brushes are also used to reduce water carry over.
Separators avoids entanglement of filament which also leads to considerable breakages.
Drawing
The drawing zone of a monofilament line consists of the first godet, a hot air oven and a
fast godet (2nd godet). Stretching is effected by the speed differential between the 1st and
IInd godet. The filaments are heated to just below their softening point in the hot air
oven (145-160 °C) and drawn. Stretch ratio of 8 to 10 are set for PP filament. Normally,
line speeds are between 130mpm to 160 mpm.
Setting
Monofilaments are subjected to heat setting to stabilise the orientation and residual
stresses which lead to shrinkage. This is effected with godet three which runs at a speed
of 10% lower than that of the 2nd godet and by passing the filaments through a setting
oven which is usually at 80-100°C.
Winding
In most of the extrusion lines, the filaments are wound individually on separate spools or
bobbins. Each winder is fitted with a separate torque motor. Winding tension is
electronically set to get a good package.
The winders also have a large bobbin winder at the end to wind all the filaments together
during start up.
10
11. Resin Selection
The advantages of using synthetic materials instead of natural fibres are better physical
properties, chemical and thermal resistance, negligible water absorption resistance to
rotting and fungus attack.
PP belongs to the family of polyolefin polymers comprising of low and high density
polyethylenes, polybutylenes etc. Although both HDPE & PP compete in the
manufacturing of stretched tapes, a number of factors are in favour of PP. The density of
PP is the lowest among all the synthetic polymers. Moreover, PP has a higher softening
point which gives it the advantage when it comes to hot filling of certain products in
woven sacks. PP being stiffer than HDPE and fabric made from PP has a higher
coefficient of friction, giving it the advantage of higher stackability during storage. On
the other hand, PP tapes tend to fibrillate during processing but this can be avoided by
adding antifibrillating additive.
For polymer to work well in a tape processing environment, it has to meet certain basic
requirements.
These are :
• Capability of being processed easily into film
• Good processing stability and melt strength to eliminate melt flow breaks and thus
deteriorating physical properties
• Polymer cleanliness to eliminate filter pack blockage and tape flaws
• Very little water carry over for processes using quench baths. However this is most
commonly related to the additive package
• The capability to orient readily to eliminate tape breakage while drawing
• Good end use stability, particularly for outdoor use
Resin Characteristics
• MFI : 2 to 4
• Moderately broad molecular weight distribution
• Free of gels and fish eyes
• Low water carry over in water bath quench
• Consistent processability
• Good colour and processing stability
Repol Grades
• Repol H030SG : This is a 3MFI, homopolymer grade with a general additive package
ie. antioxidants and acid acceptor. This grade is recommended for raffia tapes used in
making woven fabric for sacking, carpet backing, industrial fabric and geotextile
application.
• Repol H030SU : This is a UV stabilized version of Repol H030SG and its
recommended for outdoor applications.
11
12. Effect of polymer variables on properties
A) Molecular weight (Melt flow) : Molecular weight of PP has a significant effect on
processing and tape properties. Melt flow index is an indication of molecular weight.
As molecular weight increases (melt flow decreases) tenacity increase and %
elongation decreases at a particular draw ratio. However as molecular weight
decreases, tenacity and % elongation decreases.
Polypropylene grades of higher melt flow tend to process easier than lower melt flow
grades ie. extrusion pressures are lower for a given extrusion rate.
Repol H030SG has a melt flow index of 3 gm/10min by virtue of which it gives an
optimum balance of tape properties and processability.
B) Molecular weight distribution (MWD) : Molecular weight distribution is a function
of catalyst system and polymerisation process. Molten PP is shear sensitive ie.
apparent viscosity decreases as applied pressure increases. PP with broad MWD is
more shear sensitive than the one with narrow MWD. Hence broad MWD PP's are
easier to process than one with narrow MWD. MWD is found to have little effect on
physical properties of PP.
Repol H030SG is a moderately broad molecular weight distribution polymer. Hence it
exhibits good processability.
(C) Stereoregularity : Polypropylene has a methyl group attached to every other carbon
atom. Unless these methyl groups are arranged in one position relative to the chain
(isotactic arrangement), PP cannot crystallise. The crystallinity is responsible for the
strength, stiffness and solvent resistance of PP. Higher the isotactic content, better the
physical properties of the tape. Hence isotactic PP is preferred.
Xylene solubles determines the percentage of lower molecular weight fraction in
polypropylene. Higher xylene solubles will lead to decreased tenacity, increased
shrinkage, stickiness and weaving problems. On the other hand, lower solubles will lead
to tape splitting and drawbreaks.
Additives
Repol H030SG incorporates a general additive package consisting of
• Antioxidants
• Acid acceptors
12
13. Effect of processing variables on physical properties :-
A) Draw / Stretch Ratio : As draw ratio increases, tenacity increases and % elongation
decreases. Higher draw ratio increases the alignment of the polymer molecules.
A draw ratio between 5:1 to 6:1 is optimum for obtaining a tape with good combination
of mechanical properties, non fibrillating tendency and curl free tapes. The draw ratio
also determines initial cross-section of the slit strip/monofilament which is required for
obtaining final width of the tape or size of monofilament.
B) Temperature : Extrusion temperature ie. the temperature profile on the extruder
affects the melt temperature and extruder output.
Quench temperature is also another important variable as the rate of cooling has a
significant effect on the strength and characteristics of the product. In the stretched tape
process, rapid cooling with low quench temperature produces a film of higher
crystallinity which results in poor orientation. Also the tendency to fibrillate is less.
The effect of orientation temperature on stretched tape properties is shown in the
following Fig. 3
13
14. As the orientation temperature increases, tenacity increases and % elongation remains
relatively constant. Eventually a temperature is reached where tenacity decreases rapidly,
with corresponding increase in % elongation.
Effect of orientation temperature on shrinkage is shown in Figure 4. As orientation
temperature is increased, the residual shrinkage decreases.
Desired Characteristics of PP Tapes
Tapes are required to be produced as per IS 11197 1985 (Spec. for mono-axially oriented
tape. As per IS 11197, finished tapes should have the following characteristics :-
Finished tape width (mm) : 5 mm (max)
Linear density (denier) : 600 (min)
Tenacity (g/denier) : 4.2
Elongation at break (%) : 15-25
In general, tapes with tenacity of 5.0-6.0 g/d and elongation of 20-25% are preferred.
14
15. Applications
Raffia Tapes
1. Packaging applications
Woven Sacks - Cement Packaging
Polypropylene woven sacks have increasingly replaced jute bags and paper bags for
packing cement. They offer distinct advantages such as high strength, lower bag weight,
low cost, fungus attack and low seepage of cement as compared to jute bags.
In comparison to paper bags, polypropylene woven sacks offer advantages such as better
bursting strength, low weight and low cost, but paper bags exhibit better printability and
lower seepage than PP bags.
Previously HDPE woven sacks were predominantly used for packing cement, but most of
the end users have shifted to polypropylene due to the following advantages :-
• Polypropylene has a lower density (0.90 g/cc) than HDPE (0.952 g/cc) therefore
giving higher yield per unit weight
• Polypropylene exhibits higher service temperature than HDPE, hence when cement is
filled at a temp.. of 85 °C-90 °C at a pressure of 6 kg/cm2 , the performance of PP
woven sacks is better in terms of bursting strength
• Polypropylene has higher tensile strength than HDPE
• Easy availability
Unlaminated gussetted polypropylene bags with a valve for filling cement are normally
used. Cement is usually packed in 50 kg bags. The fabric used has a mesh size of 10x10
and the bag weight is @70 gms. The bags are not laminated to facilitate breathing of air
during filling.
Fertilizer Packing
Laminated HDPE bags are predominantly used for packing fertilizers. Since HDPE
exhibits better outdoor stability than PP and also because PE lamination grades are easily
available, PP till recent times did not make in roads into this sector due to unavailability
of a suitable PP lamination grade.
New Applications for PP Woven Sacks
• Sugar bags
• Postal bags
• Tea bags
15
16. Flexible Intermediate Bulk Containers (FIBC) / Jumbo bags
Polypropylene woven fabric is used to fabricate FIBC's or jumbo bags. These bags have
carrying capacities of 500 kgs to 4000 kgs. The design and fabric of these bags varies
depending upon the requisite container strength.
These bags are used for packing agro products, chemicals, detergent, plastic raw
materials, petrochemical products and fertilizers.
UV stabilised PP grades are used for this application. The tape denier ranges from
2100D to 2600D for Jumbo bags.
2. Tarpaulins
Tarpaulins are usually produced from HDPE woven fabric, cross laminated PE film,
heavy duty LDPE/LLDPE films and cotton canvas.
Constructions of woven sack tarpaulin range from 90 gsm to 200 gsm. Cost of cotton
canvas tarpaulin is comparative to low gsm HDPE tarpaulins, but they soil easily and are
not weather proof and rot proof.
Some applications of woven fabric tarpaulins are :-
• Water proof liners for trucks
• Railway wagon covers
• Floor linings for storage
• Shed, warehouse covering
• Agricultural farms
• Construction sites - stock pile cover for cement
• Poultry shadding
• Automobile covers
• Baling cloth
HDPE is preferred for tarpaulins due to superior stability to outdoor exposure. UV
stabilised PP can be used for tarpaulins but the cost of it is higher than HDPE tarpaulins.
3. Geotextiles
Geotextile is a woven or non woven fabric that is designed to stop water erosion,
cracking in roads, soil embankments and other construction application. It works by
reducing amount of water in contact with the structure and preventing soil erosion.
HDPE/PP woven sacks are mainly used for :-
• Separation
• Reinforcement
• Drainage and filtration
• Erosion control
16
17. 4. Concrete reinforcement
Fibrillated PP tapes can be blended with concrete to reinforce non load bearing structures.
Advantages of PP reinforced concrete are impact strength, some residual strength after
cracking and improved flexural strength. It also gives saving in construction and
transportation cost.
Monofilaments
Ropes : Ropes are usually manufactured from PP or HDPE but both these materials cater
to different markets.
PP exhibits very good tensile strength and abrasion resistance due to which PP ropes
cater to high performance application. PP is also popular because of its low density. PP
ropes are used for industrial application like cargo handling, marine application (mooring
ropes), ropes for trawling, mountaineering etc. On the other hand, HDPE ropes are used
for domestic application like decorative household uses, furniture and light fishing
activities.
Denier of monofilaments used for ropes and nets is usually between 500 to 800 and
tenacity between 5.5 to 6 gpd.
Nets : PP and HDPE monofilaments are used for making nets. PP nets are used for high
strength application due to its good tensile strength, wear resistance and knot strength.
eg. cargo handling net, safety nets, nets for defence application. HDPE nets are mainly
preferred for fishing. PP nets are stiff and can damage the catch.
PP monofilaments are used for making bristles.
17
18. Trouble - Shooting Guide - Tape Plant
Sr. Problem Suggested Remedy
No.
1. Film puncture Clean die lip
Optimise temperature profile
2. Tape breakage See under film puncture
Check hot plate temperature
Reduce stretch ratio
Reduce quench tank temperature
Set die gap
3. Low tenacity Increase stretch ratio
(Tensile strength) Increase oven/hot plate temperature
4. High elongation Reduce quench tank temperature
Increase oven/hot plate temperature
Increase stretch ratio
Reduce air gap
5. Denier variation Adjust die gap and clean die if required to get
uniform film thickness
Check uniformity of temperature on hot plate
Check spacer thickness with Vernier
Check pressure roller and its pressure
6. Fibrillation of tapes Check sharpness of blades on spacer
Reduce stretch ratio
Check for wrinkles in the tape
Check winder tension
Check traverse guides of winders for damages
7. Shrinkage of tapes Increase annealing temp, check speed of godet 3
Improve heat conduction during annealing
18
19. Trouble - Shooting Guide - Monofilaments
Sr. No. Problem Suggested Remedy
1. Filament breakage a) Surging in extruder. Run at higher pressure, or
with better-mixing screw, or with cooled
screw, or with gear pump, or more slowly. Try
to determine period of the surging, and relate
to drive, controllers etc.
b) One or more holes partially blocked. The same
filament(s) will break every time
c) Uneven temperature or distribution of material
in head and die. The same group of filaments
will break every time. Look at blueprint of die,
to find asymmetrical construction, if any,
which could cause the uneven patterns
d) Melt too cold. Not enough ductility to draw
down. Raise temperature
e) Melt too hot. Too fluid to hold together under
drawing tension. Reduce temperature
f) Drawdown too great (use smaller holes in die)
or drawdown too fast (slow down whole
system)
g) Moisture in material. Use a hopper-dryer
h) Contamination in material. Inspect feed, stop
using reground or reworked plastic
i) Oxidation and weakening of filament surface.
Run at lower temperature, or reduce the gap
between die and quench bath
j) Decomposition in extruder, head, or die. Bits
of decomposed material clog holes, or come
through them but weaken the filaments. Clean
die, run at lower temperature; examine die
design for possible stagnation spots, change die
or head if necessary, use better-stabilized
plastic
k) Too much orientation. Ratio of roll speeds
may be too high causing excessive tensile
stress in orientation stage
l) Too cold orientation. If plastics is not hot
enough, too much tensile stress will be
produced in the filaments
m) Too hot orientation (air oven). If plastic
becomes too hot, it loses ductility and will
break under the normal orientation stresses
n) Nicks or abrasive areas or any of the rolls.
Grind them smooth, or wrap them with tape
19
20. o) Erratic drive. Check smoothness of operation
of all moving parts
2. All filaments varying in a) Surging in extruder, drawdown too much or
diameter too fast, or erratic drive. See (a), (f) and (o)
above
3. Some filaments different a) Temperature gradients in die. Unequal flow in
from others, in size die. Check for drafts, burned-out heaters, poor
and/or strength die design. See (c) above
4. Poor surface appearance a) Moisture in material or any pigment. Dry the
feed
b) Melt fracture. Reduce linear speed, or use
larger holes (more drawdown), or reduce
entrance angle into die holes, or use lower
viscosity compound, or run hotter
c) Plastic too cold. Run hotter
d) Compound inherently dull. Change
compound, or run hotter, or flame polish
5. Low tenacity a) Not enough orientation. Increase ratio of roll
speeds. Use proper orientation temperature.
Note that changes of orientation may also
change the filament size, requiring
compensating adjustments elsewhere
b) Degraded plastic. Use lower material
temperature, requiring compensating
adjustments formula
c) Nicks or cuts in filaments. Examine breaks
and examine unbroken filaments. Look for a
repetitive pattern and examine take-off for the
source
20