Special Machines Unit 1 PPT - Manufacturing of Plastic Components and Composite Manufacturing
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Thanks and Regards... Mr. U. ARAVIND, B.E., M.I.S.T.E., LECTURER / MECHANICAL ENGINEERING LAKSHMI AMMAL POLYTECHNIC COLLEGE K.R. NAGAR, KOVILPATTI - 628 503 THOOTHUKUDI DISTRICT, TN Mobile No: 9943244068 Email Id: aravindulaganathanmech@gmail.com aravindmech@lapc.in MANUFACTURING OF PLASTIC COMPONENTS Plastic Components: Types of plastics - Engineering plastics – thermosets – composite - structural foam, elastomers - polymer alloys and liquid crystal polymers. Factors Influencing the Selection Of Plastics - Mechanical properties – degradation - wear resistance - frictional properties - special properties –processing – cost Processing of Plastics: Extrusion-general features of single screw extrusion -twin screw extruders. Injection moulding types: Plunger type - Reciprocating screw injection - details of injection mould - structural foam injection mould - sandwich moulding - gas injection moulding - injection moulding of thermosetting materials - calendaring and rotational moulding. Design consideration for plastic components.Composite manufacturing: Introduction – characteristics of composite manufacturing - constituents – Glass fibers manufacturing process – hand laminating process – autoclave processing – filament winding – pultrusion process – liquid composite process – working principles by schematic diagram only – advantages – disadvantages.
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Special Machines Unit 1 PPT - Manufacturing of Plastic Components and Composite Manufacturing
- 1. 1 Lakshmi Ammal Polytechnic College Department of Mechanical Engineering Subject Name : Special Machines Subject Code : 32042 Year & Semester : II / IV Scheme : M U. Aravind Lecturer/Mech LAPC K.R. Nagar
- 3. UNIT – 1 MANUFACTURING OF PLASTIC COMPONENTS 26-04-2021 LAPC 3
- 4. Important Terms • Plastic - Synthetic Organic Polymer • Composite - Combination of two dissimilar materials ( Reinforcement + Matrix) • Elastomers - Thermoplastic Rubber • Engineering Plastics - Used in Engineering Applications • LCP - Liquid Crystal Polymer (Aromatic Polyesters) • Thermosets - Thermosetting Plastics • Polymer - Combination of Monomers • Degradation - Brake down of Chemical Structure • Twin screw Extruder - Two Screw Extruder
- 5. • Fatigue - Brittle Crack • Runner - Flow path of Molten material • Sandwich Moulding - Two different polymers injected one after another • Calendaring - Plastic film producing process • Filament - Single Fiber • Strands - Bundle of filaments • Prepregs - Pre-Impregnated ( Flexible Sheet of Fibers & Resin) • Glass Fiber - Amorphous Material • Epoxy Resin - Polymerizable thermosetting resins 26-04-2021 LAPC 5
- 6. • Autoclave - Pressurized Oven • Bleeder Material - Absorb Excess Resin • Breather Material - Remove Excess Air • Bagging Film - Form vacuum bag • Barrier Film – Control the resin flow • Filament winding - Process of Making Hollow Section Components • Pultrusion - Process of Making Straight shape of Constant Cross-sectioned Components • LCM - Liquid Composite Moulding • RTM - Resin Transfer Moulding • COI - Critical Oxygen Index • Kevlar - Aramid Fibers 26-04-2021 LAPC 6
- 7. • Tow - Untwisted bundle of continuous filaments • Yarn - Twisted bundle of tow • Roving - Number of Untwisted bundle of yarns 26-04-2021 LAPC 7
- 8. I. Plastic Components Plastics: Plastics is an organic resin or synthetic resin which can be moulded to any required shape It contains Oxygen , Hydrogen , Carbon and Nitrogen 26-04-2021 8 LAPC
- 10. Classification of Plastics 26-04-2021 10 LAPC Thermoplastics Thermosetting Plastics
- 11. Thermoplastics: It Can Be Softened By Heating And Hardened By Cooling It can be remoulded Ex: PVC, Polyester Uses: Insulating Tapes, Toys. 26-04-2021 11 LAPC
- 12. Thermosetting Plastics It Cannot Be Softened On Heating , Once hardened and set It cannot be remoulded Ex: Duroplast, Epoxy resin Uses: Automobile Parts, Electric Plugs 26-04-2021 12 LAPC
- 14. Types of Plastics Engineering Plastics Thermosets Composites structural foam Elastomers Liquid Crystal Polymers 26-04-2021 14 LAPC
- 15. Factors Influencing The Selection Of Plastics I. Mechanical Properties Strength Stiffness Fatigue Toughness Ductility 26-04-2021 15 LAPC
- 16. II. Degradation Brake down of chemical structure by heat stress and radiation III. Wear resistance and Frictional Properties IV. Special Properties Optical properties Electrical properties Flammability V. Processing Cost VI. Processing Methods 26-04-2021 16 LAPC
- 17. Processing of Plastics Extrusion Thermoforming Moulding Processes Calendaring Casting Twin Screw Extruder Single Screw Extruder Compression Moulding Roto Moulding Injection Moulding Expandable Bead Moulding Blow Moulding Gas Injection Moulding Sandwich Moulding Structural Foam Reciprocating Screw Ram or Plunger Type 26-04-2021 17 LAPC
- 18. SINGLE SCREW EXTRUDER It has Three Zones Feed Zone Compression Zone Metering Zone Application: • It is used to make tubes, sheets, ropes 26-04-2021 18 LAPC
- 24. TWIN SCREW EXTRUDES Types: Intermeshing counter rotating Intermeshing co-rotating Non- Intermeshing counter rotating Non- Intermeshing co-rotating Advantages: Output rate is high Mixing efficiency is more 26-04-2021 24 LAPC
- 25. RAM or PLUNGER TYPE INJECTION MOULDING Advantages Complicated shapes of various sizes of products can be produced Good dimensional accuracy Disadvantages High tooling cost Suitable for mass production only High production rate 26-04-2021 LAPC 25
- 31. Extruder screw rotates in the normal way to transport, melt and pressurize the material in the barrel Extruder screw moves forward like plunger to inject melt into the mould Advantages High production rate. Low cost. 26-04-2021 31 LAPC
- 32. STRUCTURAL FOAM INJECTION MOULDING Advantages: These plastics are rigid one. Free form shrinkage. Cost of the mould is less. Very thick sections can be moulded. 26-04-2021 32 LAPC
- 35. SANDWICH INJECTION MOULD Sandwich moulding is defined as two or more polymers are injected one after the other through the dame gate in one or cavities. Advantages: Material, weight and cost is saved. Increased stability and strength. Decorative effects. Combination of characteristics. 26-04-2021 35 LAPC
- 39. GAS INJECTION MOULDING • The gas-assisted injection molding process begins with a partial or full injection of polymer melt into the mold cavity. Compressed gas is then injected into the core of the polymer melt to help fill and pack the mold Advantages: Lower cycle time. No surface imperfections Clamping forces are much lower 26-04-2021 39 LAPC
- 43. INJECTION MOULDING FOR THERMOSETTING MATERIALS Thermosets molding is the reverse process of thermoplastic. Special barrel and screw are used in this process. Advantages: Fastest cycle. Efficient pre heating material Easiest finishing Mould cost is low. 26-04-2021 43 LAPC
- 45. CALENDARING Calendaring is the process of producing the sheet of materials by rolling the plastics between multiple rollers. & Its only for thermoplastic Applications: • Thermoplastic films • Sheets & Coatings Advantages: • High accuracy • High rate of production 26-04-2021 45 LAPC
- 49. ROTATIONAL MOULDING Used for producing hollow plastics. Advantages This process is suitable for making the products with complicated shapes and size. Less expanse than injection moulding. Less expanse for manufacturing few parts than the other process. Disadvantages This process is suitable for manufacturing hollow parts only. Cycle time is slow. It is not easy to get varying wall thickness within a part. Only limited number of materials only can be mould. 26-04-2021 49 LAPC
- 52. 26-04-2021 LAPC 52 Applications: • Used for producing toys in PVC • Used to make petrol tank
- 54. DESIGN CONSIDERATIONS FOR PLASTIC COMPONENTS 1) Avoid under cuts. 2) Provide shrinkage allowance. 3) Avoid sharp corners. 4) long cored holes should be avoided. 5) Location of the parting surface of the mould should be in one plane 6) Maintain uniform wall thickness 7) Ribs provided for increase strength 26-04-2021 LAPC 54
- 55. 8) try to design projections to have circular cross sections 9) Use suitable size inserts 10) Considered material properties 26-04-2021 LAPC 55
- 56. COMPOSITE MANUFACTURING A combination of two or more materials to form a new material with enhanced material properties. Ex: Wood, Concrete, Brick 26-04-2021 LAPC 56
- 57. CONSTITUENTS OF COMPOSITE 26-04-2021 LAPC 57 Characteristics: Provide strength & Stiffness Reinforcement Composite Matrix Forms: Fibers, Filament Forms: Polymers, Metals, Ceramics. Characteristics: Provide Toughness Materials: Metals, Ceramics, Polymer Materials: Glass Fibers, Carbon , Graphite, Kevlar
- 58. CHARACTERISTICS OF COMPOSITE MANUFACTURING • Good Bonding between Fibers and Matrix • Proper Orientation of the fibers • Uniform Distribution • Good dimensional Control 26-04-2021 LAPC 58
- 59. APPLICATIONS OF COMPOSITE MATERIALS • Automotive Applications • Aerospace Applications • Marine Applications • Construction Applications • Sanitary Applications • Building Applications • Sports Applications 26-04-2021 LAPC 59
- 61. Light weight High strength High stiffness High corrosion resistance Low ductility More expensive Difficult in manufacturing Slow manufacturing process 26-04-2021 LAPC 61 ADVANTAGES OF COMPOSITE MATERIALS DISADVANTAGES COMPOSITE MATERIALS
- 62. GLASS FIBER MANUFACTURING PROCESS Raw materials : Silica sand Boric acid Minor ingredients (clay, coal) 26-04-2021 LAPC 62
- 63. Raw Materials Mixed & Weighed Fed into Furnace In Furnace , At refining stage - 1425°C In Furnace, At forehearth stage - 1260°C Sizing Chemical is Added Finish Chemical is Added Filaments Are Bundled Together In Furnace, At melting stage - 1540°C Smaller Filaments Formed Filaments Formed Through Batch unit Molten glass flows through Platinum plate Tiny holes Pulled Mechanically Strands Formed
- 67. HAND LAMINATING PROCESS • Simplest Method of Composite manufacturing • Glass fiber & epoxy resin common material Advantages: Simple process Low cost Disadvantages: Time consuming Not suitable for mass production 26-04-2021 LAPC 67
- 70. 26-04-2021 LAPC 70 Applications: Boats Tanks Bath Ware Housings RV/Truck/Auto Components Architectural Products
- 71. FILAMENT WINDING • Used For Making Hollow , Circular, Oval Sectioned Components Like Pipes, Storage Tanks, Pressure Vessel Advantages • Economic Process • Very Fast Process Disadvantages • Poor Surface Finish • Complex Shapes Difficult To Produce 26-04-2021 LAPC 71
- 76. PULTRUSION PROCESS • Continues process used to produce long, straight, constant cross section products like beams, rods, pipes. Advantages: Automated process Continuous & high speed process Disadvantages: Expensive die Difficult to produce thin wall , tapered, complex shape products LAPC 76
- 80. LIQUID COMPOSITE MOULDING 26-04-2021 LAPC 80 • It is also called as Resin Transfer Moulding (RTM) • It is used to produce Small complex aircraft and automotive components, train seats • It is cost effective process • Consists of Injection ports, Air vents, Guide Pins & gaskets
- 82. Advantages • Good moulded surface • High production rate • Low initial cost • Low manufacturing cost Disadvantages • Limited to smaller components • Tooling is expensive 26-04-2021 LAPC 82
- 87. AUTOCLAVE PROCESSING 26-04-2021 LAPC 87 Materials Used: Reinforcement: Glass & Kevlar fibers Matrix: Polypropylene Mould tool: Stainless Steel Or Aluminium Autoclave - Pressurized Oven Prepregs - Pre-Impregnated Materials
- 88. Processing Steps Prepregs Preparation Mould Preparation Laying Up Prepregs Vacuum Bag Curing
- 93. 26-04-2021 LAPC 93 Advantages: • Simple • Mould tool design • Flexible method • Better surface finish Disadvantages: • High capital cost • Skill laminators need • High maintenance cost
- 94. BOARD EXAM QUESTIONS Part A&B 1. Write the Advantages of Structural Foam Injection Moulding 2. Sketch &Show the parts of Calendaring 3. Differentiate between thermoplastics & thermosetting plastics 4. What are Engineering Plastics? Give Example. 5. Define Autoclave Processing 6. What is Filament Winding? 26-04-2021 LAPC 94
- 95. 7. What is Liquid Composite Moulding? 8. Write the Advantages and Disadvantages of Pultrusion process 9. Define Pultrusion 10. List out Various Matrix materials 11. What is Elastomers? 12. Define Composite 13. Mention the Application of Filament Winding 14. List out the Constituents of Composite 15. Name the Different Composite manufacturing Techniques 16. What are the two major types of plastics? LAPC
- 96. 17. Write the properties of plastics 18. What are the design consideration of plastic components? 19. What are the two types of twin screw extruder? 20. What are the frictional properties of plastics? 26-04-2021 LAPC 96
- 97. Part C 1. With a simple sketch, Explain Rotational Moulding 2. Explain the manufacturing Process of Glass Fibers with a schematic diagram. 3. Explain with neat sketch the Single Screw Extruder 4. Explain with neat sketch the Plunger type Extrusion 5. Explain the Reciprocating Screw Injection Moulding 6. Explain the Gas Injection Moulding process 7. With a neat sketch explain Calendaring Process
- 98. 8. Explain the various types of Plastics available 9. Explain the various factors to be considered for the selection of Plastic Material 10.With a neat sketch explain the functioning of twin screw extruder 11.Briefly explain the characteristics of Composite Manufacturing 12.With a neat sketch, Explain the Filament Winding Process 13.Explain the Pultrusion process of composite manufacturing with neat sketch 14.Write the short notes on (i) Structural Foam Injection Moulding (ii) Rotational Moulding 26-04-2021 LAPC 98
- 99. 26-04-2021 99