1. POLYETHYLENE SUBMITTED BY SRAVYA DANDAMUDI-B130832CH
SREE SANJANA-B130185CH
SRUTHY S KUMAR-B130390CH

2. INTRODUCTION
Fiber made from polymer or copolymers of olefin hydrocarbon such as ethylene, propylene etc is called polyolefin fiber. Polyethylene and polypropylene are the important fibers in this group of fibers.
Polyethylene has the simplest basic structure of any polymer It is a polymer of ethylene produced by addition polymerization.
The different types of polyethylene are:
HDPE - High Density Polyethylene
LDPE - Low Density Polyethylene

3. PROPERTIES Molecular Formula: Molecular Weight: 1,500-100,000
Melting Point: K
Density: by high pressure process; 0.96 by low pressure process.
Grades: 1.5mm to 3mm pellets, flake or powdered solid sold to extruders.

4. ELECTRICAL PROPERTIES
THERMAL PROPERTIES
Polyethylene is tough at room temperature and becomes brittle on cooling.
CHEMICAL PROPERTIES
Polyethylene is resistant to non-oxidizing acids, alkalis and many aqueous solutions.
ELECTRICAL PROPERTIES
The insulating properties of polyethylene evaluate favorably with any other dielectric material. It is a non-polar material property such as power factor and dielectric constant are independent of temp and frequency.

5. METHODS OF PRODUCTION HIGH PRESSURE (1,000-2,500 atms)
This was the original process developed by ICI in the UK using peroxide
catalyst at K and producing low density random oriented, low
melting point polymer
INTERMEDIATE PRESSURE ( atms)
This uses MoO3 or Cr2O3 on alumina as catalyst, produces high density
density polymer with accompanying increases in rigidity, crystallinity,
tensile strength and softening point.
LOW PRESSURE (6-10 atms)
It uses a catalyst consisting of aluminium triethyl activated with heavy
metal derivatives such as TiCl4.

6. LOW PRESSURE ZIEGLER PROCESS
PROCESS DESCRIPTION
Very high purity ethylene is prepared by desulfurizing and removing light ends.
It is further treated to remove traces of oxygen or its compounds which
deactivate the catalyst consisting of aluminium triethyl combined with TiCl4
to produce a finely divided precipitate in C5-C7 saturated paraffin diluents.
The purified ethylene is pumped to a reactor where it is continuously mixed with the catalyst diluent stream. The effluent goes to a series of flash drums to
remove the solvent from the catalyst. Water is added at this point to destroy
residual catalyst which is highly flammable in the dry condition.
The flashed solvent is dried, redistilled, and recycled to the catalyst
make-up unit. Polyethylene slurry is centrifuged to dewater.
Polyethylene solids are dried, extruded and finished to required form (pellets,
flakes or powder).

7. Low Pressure Ziegler Process

8. LOW DENSITY POLYETHYLENE
Polyethylene with low molecular weight
LDPE has density range of 0.910–0.940 g/cc.
It has a high degree of short and long chain branching, which results in loose packing of the chains.
Produced using a high pressure process via radical polymerization.
Major applications for LDPE film include heavy-duty sacks, carrier bags and for general packaging.

9. HIGH DENSITY POLYETHYLENE
Polyethylene with high molecular weight
LDPE has density greater or equal to g/cc.
HDPE has a low degree of branching and thus low intermolecular forces and tensile strength.
Synthesized by co-ordination polymerization.
High Density polyethylene film is used for carrier bags. Filament for ropes, fishing nets and fabrics are an important outlet for the high-density polyethylene.

10. ECONOMICS OF POLYETHYLENE

11. THANK YOU