Polyethylene plastics are some of the most commonly used plastics on the market today. They are found in products you use every day, from water bottles to sandwich bags to garbage cans. Polyethylene plastics can be further broken down into High-Density Plastics (HDPE) or Low-Density Plastics (LDPE).
Polyethylene plastic is created through the polymerization of petroleum. Although HDPE and LDPE are both polyethylene plastics, they have visible differences. This is due to the differences in the manufacturing process. LDPE has an amorphous structure that isn’t organized, while HDPE has either a partially or completely crystalline structure, making it stronger and more durable.
High-Density vs. Low-Density Polyethylene
High-density polyethylene is a petroleum product. This polymer is melted into liquid form for easy molding and shaping. This allows manufacturers to create custom-shaped, durable containers. During manufacturing, HDPE experiences very little polymer branching, keeping the molecular structure very tight. The resulting material is strong and more rigid with the ability to retain its shape under pressure.
HDPE is ideal for projects that require custom printing or coloring. Since it’s both easy to manufacture and incredibly strong, it’s a preferred material for packaging. HDPE can also be made food-safe and it is capable of withstanding caustic chemicals.
LDPE is a lighter and more flexible plastic. LDPE polymer chains experience a considerable amount of branching and spreading. Since the chains are separated or scattered, the plastic has far less structure. The resulting plastic is lighter and more flexible. Its softness, however, means it is prone to damage.
Similarities Between HDPE vs. LDPE
There are numerous similarities between the two polyethylene plastics. Both plastics have a low material weight, are highly recyclable and have a high impact strength, and can be resistant to water vapor, weathering, and even chemicals. The tensile strength of both plastics ranges from 0.02 to 0.40 N/mm2 and are cost-effective to manufacture. Polyethylene is naturally inert, which provides both HDPE and LDPE with excellent mechanical and electrical properties.
Differences between HDPE & LDPE
The different production methods of the two substrates give them very distinct properties. These include:
- Physical Characteristics: HDPE is much sturdier than LDPE. LDPE has a lower melting point and the products are usually more transparent than HDPE products. LDPE is slightly abrasion-resistant but is the more fragile of the two plastics. HDPE is more rigid. This durability makes it more resistant to chemicals. It has a higher melting point, which means it can withstand greater temperatures. Unlike LDPE, it’s much less transparent. HDPE is fully abrasion-resistant.
- Recyclability: Both plastics can be recycled, but have different recycling requirements. LDPE is a recycling number 4 product and is more difficult to recycle due to its softness, increasing the risk of binding or clogging recycling machinery. HDPE is a recycling number 2 product and is easier to process through the recycling equipment.
- Production Methods: HDPE is manufactured by heating petroleum to an extreme temperature. This releases ethylene gas monomers, which combine to form the polymer chains. LDPE is created by compressing the monomer ethylene gas within a tubular reactor, or autoclave, to facilitate linking monomers, creating the polymer chain.
Applications of HDPE vs. LDPE
HDPE and LDPE are often used in the same industries, but for different purposes. These industries include:
- Hydraulics and pneumatics
- Pipe and Piping
HDPE plastics are used in applications such as:
- Food processing
- Chemical and petroleum manufacturing
- Pharmaceutical processing
LDPE plastics are used for applications such as:
- Food processing
- Paper processing
- In the marine market
HDPE Solutions from New Process Fibre
While both HDPE and LDPE thermoplastic have their advantages, HDPE plastic creates more durable products for a wide range of applications. New Process Fibre specializes in complete HDPE stamping and die-cutting services. We are an ISO 9001:2015-certified manufacturer that provides custom thicknesses, widths, and colors to meet your project’s requirements.
Contact us for further information on our HDPE solutions.
Plastic extrusion involves a top-mounted hopper system that feeds thermoplastic resin through an extruder barrel. With the help of heat and pressure, the plastic takes the shape of the mold. Manufacturers can incorporate additives like colorants and UV inhibitors to enhance the appearance or performance of the final product.
Extrusion works with a variety of thermoplastic materials, including:
- Teflon PTFE
- Nylon (6, 6/6, MDS)
- Polypropylene (PP)
- Low-density polyethylene (LDPE)
- High-density polyethylene (HDPE)
- High-impact polystyrene (HIPS)
- Flexible polyvinyl chloride (PVC)
- Acrylonitrile butadiene styrene (ABS)
- Thermoplastic elastomers (Santoprene®)
- Polyethylene terephthalate glycol (PETG or Codar®)
There are five main types of plastic extrusion methods that use different types of extrusion dies. We will describe the benefits and applications of each type of extrusion to help you determine the ideal method for your application.
Sheet extrusion works by extruding a molten plastic material in powder, flake, granule, or pellet form through a die into a flat shape. Rollers cool the sheets, which can be between 0.2 and 15 mm. Thin sheets are ideal for consumer products, while thicker sheets are best for industrial or commercial applications. The following are examples of applications for these extruded flat sheets:
- And more
Thermoplastic Extrusion Services from New Process Fibre
Thermoplastic extrusion is one of the most versatile manufacturing methods. It can produce hollow tubes, sheets of varying thickness, plastic parts with unique properties, plastic wire insulation, and uniform films for packaging.
At New Process Fibre, our specialization in non-metallic products allows us to deliver high-quality thermoplastic extrusion services. We collaborate with our clients from start to finish, ensuring our products meet their goals and expectations. Contact us today to place an order or to speak with a representative about our extrusion capabilities.
As a common alternative to metal washers, plastic washers for screws provide watertight seals, minimize vibrations, and offer unique benefits over their metal counterparts. These opaque or clear plastic washers are available in a wide range of material options to suit nearly every application. Here, we’ll discuss when to use plastic washers, including the common materials to consider when selecting a washer for your specific application.
Like metal washers, plastic washers are disks with a hole in the center and function primarily to distribute a fastener’s load. Because of their nonmetal composition, plastic washers do not cause sparks, creating a safer and more reliable work environment. Plastic washers also streamline production by decreasing maintenance downtime.
For these reasons, plastic washers are an attractive, cost-effective option for many applications. Other benefits of plastic washers include:
- Vibration and shock resistance
- High-temperature resistance
- Weather resistance
- Water and moisture resistance
Plastic Washer Material
Plastic washers come in a variety of material options. The best one depends on the unique needs of your application. Here are the most common plastic washer materials:
- Nylon: Nylon is a highly versatile synthetic material that comes in several types and offers flexibility, abrasion resistance, chemical resistance, and machinability. This material is preferable for electrical and chemical applications due to its excellent absorption and insulation properties. Nylon washers are also a durable, lightweight alternative to metal washers in weight-sensitive applications.
- Teflon™: Also known as PTFE, Teflon™is known for its extremely low coefficient of friction and resistance to water and oil. Compared to other washer materials, Teflon™ offers exceptionally high chemical and thermal resistance properties. These low-friction washers are ideal for HVAC, automotive, and plumbing applications.
- Delrin®: Delrin® is a patented homopolymer with a stable crystalline structure that offers dimensional stability, stiffness, and durability in heavy-duty applications. The material also provides impact and temperature resistance from -50 °C to 90 °C, making Delrin® washers ideal for applications ranging from consumer goods to military equipment.
- Polyethylene (PE): We offer both low-density polyethylene (LDPE) and high-density polyethylene (HDPE) washers. The flexibility of LDPE washers is ideal for water-resistant applications in drains, water systems, and fluid feeds. HDPE washers are stronger and less flexible, so they are better suited to mechanical and industrial applications that value crush and abrasion resistance.
Plastic Washer Applications
Plastic is an exceptionally versatile and low-cost material for washers. The following applications rely on plastic washers:
- Power tools
- Farm and Garden
- Aerospace and Military
- Sporting Goods / Fitness Equipment
- Consumer and Kitchen Appliances
Plastic Washers From New Process Fibre
Plastic washers are a reliable alternative to metal washers for distributing fastener loads. Four of the most common materials include PE, Delrin®, Teflon™, and Nylon, each of which offers unique advantages.
To select the best plastic washers for your application, consult with an industry professional. Since 1927, New Process Fibre has been a leader in custom nonmetallic solutions. Contact us to learn more about our plastic washers for OEM equipment across diverse industries.