Advantages of natural UHMW
UHMW, also known as UHMW-PE, is an ultra-high-molecular-weight polyethylene. When free of additives, this plastic can be used in a wide range of applications. It has impressive mechanical properties and can tolerate continuous temperatures of up to 80° C (176 °F). Natural UHMW, such as TIVAR® 1000, is food grade approved and can therefore come into direct contact with foodstuffs. It also meets both FDA and 3-A food standards.
Natural UHMW is only made with a high-molecular-weight polyethylene resin. Plastic additives are sometimes added to this resin, thus altering its basic properties. It is important to note that additives have a direct influence on the possible uses of UHMW. Some additives or colour pigments are not compatible with food use and cannot come in direct contact with food.
Use in food environments
Whether used in the production, processing, or packaging of food and beverages, many UHMW are suitable for food applications. When choosing a material, it is important to refer to the manufacturer’s technical data sheet, as each UHMW may have different formulations.
As mentioned above, natural UHMW (TIVAR® 1000) is food grade and can therefore be used in a wide range of applications that come in direct contact with food. Other more specialized UHMW are designed to meet specific needs, such as improving contaminant traceability or reducing contamination risks. These UHMW are also suitable for extreme environments that require high-performance materials. There are currently various UHMW on the market that comply with both FDA and EU standards. When choosing a material, it is important to consider the specific stresses to which it will be exposed, as each type of UHMW has its own unique characteristics and properties.
Withstanding high temperatures: TIVAR® H.O.T. (high operating temperature).png?width=100&name=fire%20(2).png)
This UHMW is specifically formulated to withstand temperatures of up to 135 °C (275 °F) while maintaining its properties and remaining efficient. When used in high-temperature applications, its service life is up to 10 times longer than standard UHMW.
TIVAR® H.O.T. applications:
- Chain guides
- Conveyor components and parts
- Mechanical parts
- Wear strips and plates
- Liners
Reducing contamination: TIVAR® MD
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TIVAR® MD possesses mechanical properties superior to those of natural UHMW and helps reduce contamination through detection thanks to a metal additive that allows it to be located by a standard metal detector. Moreover, its blue colour makes for easy visual identification as it contrasts with food and other foodstuffs
TIVAR® MD applications:
- Mechanical parts
- Chain guides
- Rollers
- Endless screws
- Spouts
Reducing wear and friction: TIVAR® HPV
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TIVAR® HPV comes with a dry lubricant added to its resin, reducing its coefficient of friction by 80% compared to natural UHMW. This highly specialized formulation is ideal for applications subjected to important stresses, friction, abrasion, contact with chemical agents – that cause standard UHMW to deteriorate quickly. It minimizes premature system wear by limiting friction and metal-to-metal contact, among other stressors.
TIVAR® HPV applications:
- Chain guides
- Anti-friction strips
- Wear strips
- Rollers
- Mechanical parts
Other food grade plastics
HDPE (high-density polyethylene)
Often confused with UHMW, HDPE is also part of the polyethylene family. As a food-grade plastic, it is often used in the design of cutting boards for the food processing industry. When it comes to choosing between UHMW and HDPE, resistance to mechanical stress is the deciding factor; UHMW is a more suitable choice for environments with high mechanical constraints.
Would you like to learn more about the differences between UHMW and HDPE?
View our article: What is the difference between UHMW and HDPE?
Nylons
Nylons also possess interesting mechanical properties, specifically in terms of compressive strength. They have a low coefficient of friction and are often used when designing parts that need to withstand high pressure. Although the majority of nylons are not food grade, which prevents them from coming into contact with food, other options are available. For example, NYLON NYCAST® NYLOIL® FG is used in the manufacturing of mechanical parts, conveyor components and liners. Its coefficient of friction is lower than that of standard nylons thanks to a built-in vegetable oil lubricant that helps reduce friction and wear.
