Key Applications of Polyethylene
Polyethylene is the most common plastic produced in the world and manufactured in three different forms - HDPE, LDPE, LLDPE. So, what are the typical applications where you will find PE?
From electrical insulation, household containers, packaging and films to buckets and bottles, each form of polyethylene has a wide range of applications as discussed below.
There is no doubt that the excellent combination of properties makes polyethylene an ideal material in diverse applications across industries. Further, it can be engineered according to the end use requirements.
Among more than 6800 Polyethylene grades available today in the market, you can find PE uses in the following applications.
Packaging bottles & films - HDPE is widely used to manufacture crates, trays, bottles caps, drums, etc. While LDPE is majorly used in films, plastic bags, trash bags, and other food packaging material.
Medical and healthcare - Used to create medical products such as patches, personal protective equipment, packaging films, containers, lidstock, and bag headers, etc.
Pipes, Hoses & Fittings - PE parts are used in gas pipes, water pipes, sewer pipes, hoses, etc. thus offering excellent resistance to chemicals and hydrolysis.
Household products/ Consumer Goods - Garbage containers, kitchenware, housewares, ice boxes, bowls, buckets, ketchup bottles, etc.
Agriculture - PE films are used widely for greenhouse, walk-in tunnel and low tunnel covers, and mulching.
Wiring & Cable - Crosslinked polyethylene or polyethylene copolymer resins are useful for wire and cable insulation and jacketing.
HDPE
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Injection Molding
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Melt temperature: 200-300°C
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Mold temperature: 10-80°C
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Drying is not necessary if stored properly
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High mold temperature will improve brilliance and appearance of the part
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Mold shrinkage lies between 1.5 and 3%, depending on processing conditions, rheology of the polymer and thickness of the final piece
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Extrusion
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Melt temperature: 200-300°C
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Compression Ratio: 3:1
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Cylinder Temperatures: 180-205°C
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Pre-Drying: No, 3 hours at 105-110 C (221-230°F) for regrind
LDPE
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Injection Molding
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Melt temperature: 160-260°C
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Post mold shrinkage lies between 1.5 and 3.5%
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Material Injection Pressure: Up to 150 MPa
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Extrusion
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Melt temperature: 180-240°C
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Higher melt temperatures are needed for extrusion-coating (280-310°C)
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A three zone screw with an L/D ratio of around 25 is recommended
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Melt temperature: 160-260°C
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Post mold shrinkage lies between 1.5 and 3.5%