LDPE Moisture Barrier Bag Suppliers, Manufacturers India
What is LDPE ?• Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethene.
What is a Polymer ?• The macromolecular that are formed by combination of one or more than two types of innumerable simple molecules by chemical bond formation are called Polymers.• One or more than two type of innumerable simple organic molecules that combine with one another & form a polymer are called monomers.• The reaction process of one or more than two innumerable simple organic molecules that combine with each other by Chemical bond formation is called Polymerisation
Types of Polymer SubstancePolymer substance are classified in different types.• Naturally occurring Polymer Substances- The polymers obtained from nature (plants and animals) are called natural polymers. These polymers are very essential for life. For e.g.: Cellulose, Proteins, Starch, Nucleic acid- DNA & RNA• Semisynthetic Polymer Substances-Semisynthetic Polymer are obtained by chemical reaction with Polymeric substance occurring in nature. The rubber with improved properties obtained by vulcanization of natural rubber is used in the formation of tyres.• Synthetic Polymer Substance -The polymers which are prepared in the laboratories are called synthetic polymers. These are also called man made polymers. For e.g.: polyethene, PVC nylon, teflon, bakelite terylene, synthetic rubber etc.
Classification of PolymersHOMOPOLYMER & CO-POLYMER• Homopolymers: These consist of chains with identical bonding linkages to each monomer unit. These may be represented as: -[A-A-A-A]-• Copolymer : These consist of chains with two or more linkages usually implying two or more different type of monomer units. Thes may be respresented as:-[A-B-A-B-A-B]-
Polymer Classified by mode of Polymerzation• Addition Polymers: The monomer molecules bond to each other without the loss of any other atoms. Eg : Ethylene--- CH2=CH2 ----->~~CH2-CH2-CH2-CH2~~ Polyethylene (PE)• Condensation Polymers: Usually two different monomer combine with the loss of a small molecule, usually water. Eg :
Classification of PolymersThermoplastics.Thermosets.Elastomers.
• Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethene. Structure
Types of Polyethene• Low Density Polyethylene (LDPE)• Linear Low Density Polyethylene (LLDPE)• Medium Density Polyethylene (MDPE)• High Density Polyethylene (HDPE, aka HD)
Properties of LDPE MECHANICAL PROPERTIES OF LDPE• It has more open structure due to presence of a small amount of branching in the chain (on about 2% of the carbon molecule). It is translucent to opaque, strong, tough & enough to be virtually unbreakable and at the same time quite flexible. CHEMICAL PROPERTIES• Chemically LDPE is uncreative at room temperature, slowly attacked by strong oxidizing agents and some solvents will cause softening or swelling.• It may be used at temperatures up to 95° Celsius for short periods and at 80° Celsius continuously.
Surface Property Modifiers• Sleep & Blocking Agent – Prevent film & sheet sticky• Anti Static Agent – Prevent static charges on surface• Anti Fogging Agent – Disperse moisture droplets on film
Aesthetic property• Dyes and pigments - impart color• Odorants - add fragrance• Deodorants - prevent development of odor
Other LDPE Properties• Films are soft and clear• Good for heat-sealing• Fair moisture barrier, very poor oxygen barrier.• Very high elongation (desirable for stretch wrap)• Translucent, very tough, weatherproof, good chemical resistance, low water absorption.
Applications of LDPE• Agriculture – for protection of delicate crops from extreme weather conditions.• Lining of Canal, reservoir, ponds from leakage loss.• Packaging and wrapping.• Water roofing for terrace gardens.• For protection of food grains, fertilizers, cotton, chemicals, cement, constructions etc.
Testing Procedure of LDPE Bags• A tensile test, also known as tension test and it is most fundamental type of mechanical test which can perform on material. By pulling on something, very quickly determine how the material will react to forces being applied in tension. As the material is being pulled, one can find its strength and stretch.
• Tear Strength Test (Tear Testers) Tear testing is a measurement of the resistance of sheet type materials to tearing. A common approach is to apply a tension load to a sample that has been prepared with a cut to begin the controlled tear. Dart Impact Test Falling dart impact is a traditional method for evaluating the impact strength or toughness of a plastic film. This test uses a single dart configuration and a single drop height, while change the weight of the dart. Test results can be used either as a quality control evaluation or for end use comparisons.
Recycling• After individuals drop LDPE products off at a recycling center, the recycling company melts the plastic to eliminate contaminants.• After putting the low density polyethylene under heat, the material is fashioned into thin plastic sheets, which the recycling company then sells to manufacturers.