Post on 04-Jun-2018
8/13/2019 LDPE Bags - Pharma Grade
1/21
LDPE
8/13/2019 LDPE Bags - Pharma Grade
2/21
What is LDPE ?
Low-density polyethylene(LDPE) is
a thermoplasticmade from
the monomerethene.
http://en.wikipedia.org/wiki/Thermoplastichttp://en.wikipedia.org/wiki/Monomerhttp://en.wikipedia.org/wiki/Ethylenehttp://en.wikipedia.org/wiki/Ethylenehttp://en.wikipedia.org/wiki/Monomerhttp://en.wikipedia.org/wiki/Thermoplastic8/13/2019 LDPE Bags - Pharma Grade
3/21
What is a Polymer ?
The macromolecular that are formed bycombination of one or more than two types ofinnumerable simple molecules by chemical bondformation are called Polymers.
One or more than two type of innumerablesimple organic molecules that combine with oneanother & form a polymer are called monomers.
The reaction process of one or more than two
innumerable simple organic molecules thatcombine with each other by Chemical bondformation is called Polymerisation
8/13/2019 LDPE Bags - Pharma Grade
4/21
Types of Polymer Substance
Polymer substance are classified in different types.
Naturally occurring Polymer Substances- The polymers obtainedfrom nature (plants and animals) are called natural polymers. Thesepolymers 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 occurringin nature. The rubber with improved properties obtained byvulcanization of natural rubber is used in the formation of tyres.
Synthetic Polymer Substance -The polymers which are prepared inthe laboratories are called synthetic polymers. These are also calledman made polymers. For e.g.: polyethene, PVC nylon, teflon,bakelite terylene, synthetic rubber etc.
8/13/2019 LDPE Bags - Pharma Grade
5/21
Classification of Polymers
HOMOPOLYMER & 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]-
8/13/2019 LDPE Bags - Pharma Grade
6/21
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 :
8/13/2019 LDPE Bags - Pharma Grade
7/21
Thermoplastics.
Thermosets.
Elastomers.
Classification of Polymers
8/13/2019 LDPE Bags - Pharma Grade
8/21
Low-density polyethylene(LDPE) is
a thermoplasticmade from
the monomerethene.
Structure
http://en.wikipedia.org/wiki/Thermoplastichttp://en.wikipedia.org/wiki/Monomerhttp://en.wikipedia.org/wiki/Ethylenehttp://en.wikipedia.org/wiki/Ethylenehttp://en.wikipedia.org/wiki/Monomerhttp://en.wikipedia.org/wiki/Thermoplastic8/13/2019 LDPE Bags - Pharma Grade
9/21
Types of Polyethene
Low Density Polyethylene (LDPE)
Linear Low Density Polyethylene
(LLDPE)
Medium Density Polyethylene
(MDPE) High Density Polyethylene (HDPE,
aka HD)
8/13/2019 LDPE Bags - Pharma Grade
10/21
Properties of LDPE
MECHANICAL PROPERTIES OF LDPE
It has more open structuredue to presence of a small amount ofbranching in the chain (on about 2% of the carbon molecule).
It is translucent to opaque, strong, tough & enough to be virtuallyunbreakableand at the same time quite flexible.
CHEMICAL PROPERTIES
Chemically LDPE is uncreative at room temperature, slowly attackedby strong oxidizing agents and some solvents will cause softening orswelling.
It may be used at temperatures up to 95 Celsius for short periodsand at 80 Celsius continuously.
8/13/2019 LDPE Bags - Pharma Grade
11/21
Surface Property Modifiers
Sleep & Blocking AgentPrevent film & sheet sticky
Anti Static AgentPrevent static charges on surface
Anti Fogging AgentDisperse moisture droplets on film
8/13/2019 LDPE Bags - Pharma Grade
12/21
Aesthetic property
Dyes and pigments - impart color
Odorants - add fragrance
Deodorants - prevent development of odor
8/13/2019 LDPE Bags - Pharma Grade
13/21
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.
8/13/2019 LDPE Bags - Pharma Grade
14/21
Plastic Polymer Additives
Process stabilizers (heat stabilizers)
Environmental stabilizers (anti-oxidants, UV
stabilizers)
Surface modifiers (anti-static, anti-blocking)
8/13/2019 LDPE Bags - Pharma Grade
15/21
Applications of LDPE
Agriculturefor protection of delicate crops fromextreme 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.
8/13/2019 LDPE Bags - Pharma Grade
16/21
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 howthe material will react to forces being applied in
tension. As the material is being pulled, one can find
its strength and stretch.
http://www.instron.in/wa/resourcecenter/glossaryterm.aspx?ID=164http://www.instron.in/wa/resourcecenter/glossaryterm.aspx?ID=1648/13/2019 LDPE Bags - Pharma Grade
17/21
Tear Strength Test (Tear Testers)
Tear testing is a measurement of the resistance of sheet typematerials to tearing. A common approach is to apply a tension loadto a sample that has been prepared with a cut to begin thecontrolled tear.
Dart Impact Test
Falling dart impact is a traditional method for evaluating the impactstrength or toughness of a plastic film. This test uses a single dartconfiguration and a single drop height, while change the weight ofthe dart. Test results can be used either as a quality controlevaluation or for end use comparisons.
8/13/2019 LDPE Bags - Pharma Grade
18/21
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.
8/13/2019 LDPE Bags - Pharma Grade
19/21
Recycling Code
8/13/2019 LDPE Bags - Pharma Grade
20/21
Comparison
16%
76%
0%11%
Film Applications
HDPE
LDPE/LLDPE
PP
PVC
As per the Saltors Advanced Chemistry 2000
8/13/2019 LDPE Bags - Pharma Grade
21/21
Thank You