What is Polyethylene (PE) Plastic?

Polyethylene has asserted itself as one of the world's most popular plastic materials. This light, versatile thermoplastic is used for applications ranging from ketchup bottles to packaging film to automobile fuel tanks. It can also be slit or spun into synthetic fibers, useful for wire and cable insulation.

 

There are several types of PE, each best suited for a different set of applications. This material breakdown will focus on three of the more popular compounds, Low-Density Polyethylene (LDPE), High-Density Polyethylene (HDPE), and Ultrahigh-Molecular-Weight Polyethylene (UHMW). 

 

General Properties of Polyethylene:

• High impact strength
• High ductility
• Good electrical insulator
• Excellent chemical resistance
• Low water absorption

 

As a thermoplastic, polyethylene compounds turn to liquid at their melting point, making them desirable for injection molding. They are able to be heated, cooled, and reheated again without significant degradation.

 

Additionally, PE can become a thermoset plastic when modified, such as cross-linked polyethylene. As we delve deeper into each type of PE, we discover that they exhibit wide variability in their crystalline structures. The less crystalline, or amorphous, a plastic is, the more its tendency to gradually soften. In contrast, crystalline plastics display a sharp transition from solid to liquid. 

 

	Low-Density Polyethylene (LDPE)	High-Density Polyethylene (HDPE)	Ultra-High-Molecular-Weight Polyethylene (UHMW)
Melting Point	110°C	130°C	155°C
Density Range	.915-.925 g/cm3	≥ .941 g/cm3	.930-.935 g/cm3
Resistance	Alcohols and acids	Solvents and alcohols	Almost totally inert
Key Properties	High impact strength at low temperatures	Excellent electrical insulating properties	Exceptional wear and abrasion resistance
Common Applications	Plastic bags, wash bottles, molded laboratory equipment	Plastic containers, sports nets, garbage bins	Food handling materials, bearings, artificial joints
Sheet Grades	LDPE	HDPE	UHMW

 

Low-Density Polyethylene (LDPE)

 

LDPE is a semi-rigid polymer with low crystallinity. It is a flexible material with unique flow applications. LPDE has high ductility and low tensile strength, which is displayed by its propensity to stretch when strained. It is most commonly used for different types of packaging, pipes, and fittings.

 

Applications

• Plastic bags
• Manufacturing containers
• Molded laboratory equipment
• Toys
• Houseware 

 

LDPE Plastic Films: Also known as construction films or by its brand name Visqueen, are used to shield surfaces from dirt, dust, moisture, and more. It can be used as a tarp or liner for a broad range of industrial, construction, and packaging applications. 

Production of polyethylene bags

High-Density Polyethylene (HDPE)

 

HDPE is a robust, moderately stiff plastic with a highly crystalline structure. It is flexible, weather resistant, and displays toughness at very low temperatures. HDPE is commonly used in packaging applications, consumer goods, and fibers and textiles. 

 

Applications

• Milk jugs
• Jerry cans
• Mulch
• Garbage bins
• Sports nets

 

HDPE Sheets and Bars

• HDPE: Extremely moisture resistant with good wear and impact resistance. Stronger and more chemical resistant than LDPE plastic. It is easy to weld, often fabricated into water and chemical tanks.
• Marine Grade HDPE: Resistant to rot and rust when exposed to UV, humidity, and salt water. It is also known as Starboard or Seaboard.

 

Ultrahigh-Molecular-Weight Polyethylene (UHMW)

 

UHMW is extremely tough, abrasion-resistant, and low-cost, making it well-suited for manufacturing applications where friction or wear may be a concern. It can be spun into fibers and drawn into a highly crystalline state, which results in a stiffness and tensile strength many times that of steel. UHMW is used in the most corrosive and aggressive environments because it is almost totally inert.

 

This is an extremely heavy polyethylene, with a molecular weight about 10 times higher than HDPE. However, less efficient chain packing in the crystalline structure results in a density lower than HDPE.

 

Applications

• Artificial joints
• Gears and bearings
• Tubes
• Silos
• Bulletproof vests

 

UHMW Polyethylene Plastic Sheets & Bars

 

• UHMW Polyethylene Plastic: Offers excellent impact resistance and a slippery surface that reduces abrasion and wear. It is a strong electrical insulator and resistant to moisture and chemicals
• Recycled UHMW Polyethylene Plastic: Made from regrind or reprocessed UHMWPE, it is an economical and environmentally friendly option. Commonly known by its trade name TIVAR ECO.
• Glass-Filled UHMW Polyethylene Plastic: A glass filler  makes the material stronger and more resistant to abrasion and wear. Commonly known by its trade name TIVAR 88.
• Antistatic UHMW Polyethylene Plastic: An antistatic filler prevents the buildup of static charge and protects sensitive equipment from damage. Commonly known by its trade name TIVAR DrySlide.
• Oil-Filled UHMW Polyethylene Plastic: An oil filler acts as an internal lubricant, making this material more slippery and wear-resistant. Commonly known by its trade name TIVAR Oil Filled.
• Enhanced Temperature UHMW Polyethylene Plastic: Maintains performance properties even at elevated Temperatures. Commonly known by its trade name TIVAR H.O.T.

 

Why is Polyethylene So Popular?

 

PE and its variants are incredibly versatile, making them useful for product design companies, commercial retailers, and industrial manufacturers. It can be used in processes like injection molding, blow molding, extrusion, and various film creation processes. Overall, the properties of PE make it a commodity plastic, ideal for a wide range of applications across industries. 

 

More Applications:

 

• Packaging bottles & films: crates, trays, bottle caps, drums, grocery bags, trash bags, shrink wrap, food packaging
• Pipe, hose, & fittings: gas pipes, water pipes, sewer pipes  
• Consumer goods: squeeze bottles, detergent containers, kitchenware, garbage bins
• Medical & healthcare: PPE, packaging films, lidstock, bag headers
• Agriculture: greenhouse films, tunnel covers, mulching
• Wiring & cable: telecommunication cables, wire insulation, cable jacketing

Polyethylene containers

Can Polyethylene Be Recycled? 

 

Polyethylene is non-biodegradable and is one of the main contributors to plastic pollution. HDPE (#2) products can be reused safely for items including bottles, pens, and trash cans. LDPE (#4) products are often recycled to produce piping, sheeting, films, bags, and liners. UHMW can be effectively recycled for non-food applications, such as chain guides or bumpers.

 

Contact Us

For more information or inquiries about polyethylene products, please contact us at 888-839-0681 or service@fixsupply.com.