HDPE
HDPE
HDPE

High-density polyethylene (HDPE)

Is a thermoplastic polymer produced of monomer ethylene. It is sometimes called polythene when used for HDPE pipes. With a high strength-to-density ratio, it is used in producing plastic bottles, corrosion-resistant piping, geo membranes and plastic lumber. It is commonly recycled. color can be white or black mostly in granulated shape , packing mostly is PP bags . for tire and pipe usage the color demand is most of the time black from customers side .

 

 

It is known for its high density ratio. The density of this product can range from 930 to 970 kg/m3. Although the density of it is only marginally higher than that of low-density polyethylene, it has little branching, giving it stronger intermolecular forces and tensile strength than LDPE. The difference in strength effects the difference in density, so it has a higher specific strength. It is also harder and more opaque and can withstand somewhat higher temperatures (120 °C/248 °F for short periods).

HDPE is resistant to many different solvents so it cannot be glued.
The physical properties of this product depends on the molding process that is used to manufacture a specific sample; to some degree a determining factor are the international standardized testing methods employed to identify these properties for a specific process. For example, in rotational molding, to identify the environmental stress crack resistance of a sample, the notched constant tensile load test (NCTL) is put to use
Owing to these desirable properties, pipes constructed out of HDPE are ideally applicable for drinking water, and waste water (storm and sewage).

USES OF HDPE:

  1. Plastic bottles:
    it is great for blow-molding applications, particularly food and beverage containers because it won’t leach into the bottles’ contents. In addition, it is recyclable which makes it a great choice for these highly disposable products.

  2. Toys:
    UV resistant which helps keep the toys resistant to the ray’s damaging and discoloring effects.

  3. Chemical containers:
    With its chemical resistant properties, is great for laundry, shampoo, conditioner, household cleaning products, motor oil, antifreeze and recycling bins. The strength of these bottles is increased when they’ve been colored or pigmented.

  4. Pipe systems:
    pipe grade sheet has a higher molecular weight compared to the standard used in the above examples. This strengthening with its UV-resistance makes it ideal for piping and outdoor applications. Pipe grade sheet has the ability to withstand -220 to 180 degrees Fahrenheit. It’s durable in most chemical interactions which make it useful in a lot of industrial applications.

High Density Polyethylene Molecular Structure

PROPERTIES

Physical properties
Property Test Method Value Unit
Resin Properties

Melt Flow Rate

ASTM D 1238 @ 190 C, 2.16 kg

0.04

g/10 min

Density

ASTM D 1505

0.954

g/cm3

Melting Point

ASTM D 2117

131

C

Vicat Softening Point

ASTM D 1525

124

C

Brittleness Temperature

ASTM D 746

< -60

C

ESCR

ASTM D 1693 @ 50 C

>1000

hrs, F50

(Condition: Compression Molded, 25% Igepal)

Property

Test Method

Value

Unit

Film Properties

Tensile Strength at Yield

ASTM D 882

MD: -*, TD: 250*

kg/cm2

Tensile Strength at Break

ASTM D 882

MD: 620*, TD: 310*

kg/cm2

Tensile Modulus, 2% Secant

ASTM D 882

MD: 8200*, TD: 8000*

kg/cm2

Elongation at Break

ASTM D 882

MD : 240*, TD : 450*

%

Elmendorf Tear Strength

ASTM D 1922

MD : 3*, TD : 80*

g

Dart Impact Strength

ASTM D 1709

139*

g

(*) Properties obtained from film produced on a pilot line
, 12 micron, BUR 5:1, MD = Machine Direction, TD = Transverse Direction
Note: Conversion factor for changing unit from kg/cm2 to MPa is divided by 10.2