HDPE

HDPE: is defined by a density of greater or equal to 0.941 g/cm3. HDPE has a low degree of branching and thus stronger intermolecular forces and tensile strength. PE-UHMW is not melt processable, because of its extremely high viscosity. It can be processed by ram extrusion and compression molding.

HDPE can be produced by chromium/silica catalysts, Ziegler-Natta catalysts or metallocene catalysts. The lack of branching is ensured by an appropriate choice of catalyst (for example, chromium catalysts or Ziegler-Natta catalysts) and reaction conditions. HDPE is used in products and packaging such as milk jugs, detergent bottles, margarine tubs, garbage containers and water pipes. One third of all toys are manufactured from HDPE.

Key Points: With HDPE properties can be tailored by controlling the molecular weight distribution or by generating very high or very low MW species.

APPLICATIONS OF HDPE

Agriculture 

Drip irrigation drippers, sprinkler parts, agricultural nets, pipes for irrigation.

Automobile 

Fuel tank, petrol and lubricating oil containers, propellers for boats, break handles.

Electrical 

Insulation for electrical and telephone wires

Furniture 

Chairs, chair handles & table

Household 

Buckets, mugs, trays, soap boxes, tubes and pipes, bowls, water tanks, dust bins, suitcases, toys

Industrial 

Chemical storage tanks, gasoline tank impellers, pipes and fittings for chemical and gas transportation

Packaging 

Containers for dairy products, bottle caps, milk crates, containers for pesticides, woven sacks for packaging of grains and powder products.

Strengths:

1. Higher notched impact strength than other PE

2. Higher wear resistance than other PE

3. Higher energy absorption capacity at high stress rates than other PE

4. Higher heat deflection temperature than other PE

5. Higher stress crack resistance than other PE

6. Very low water absorption FDA compliant

7. Good thermal stability

8. Tg is well below room temperature

9. High tensile strength, stiffness, creep resistance, abrasion resistance than LDPE

10. Non-polar in nature

11. Very good chemical resistance

Limitations:

1. Not melt processable

2. Higher Cost than PE

Properties 

1. Very good chemical resistance

2. High tensile strength, stiffness, creep resistance, abrasion resistance than LDPE

3. Tg is well below room temperature

4. Excellent low temperature toughness

5. Good thermal stability

6. Non-polar in nature