UHMW (Ultra High Molecular Weight Polyethylene) and PTFE Sheet(PolyTetraFlouroEthylene) are very similar materials, and yet very different at the same time. They both possess certain characteristics that make them similar to each other. For instance, they both have a very low co-efficient of friction, which means they are great for sliding applications and are easy to machine.
Both of these materials are very resistant to chemicals such as chlorine and some acids and have great wear resistance. They have low to no water absorption. They also are FDA approved for handling food. PTFE and UHMW Polyethylene are both nearly impossible to bond (without treatment) and are susceptible to sagging under tensile load which is called ‘creep’. These both have very low coefficient of friction and work well for wear strips, slide pads and truck liners to make it easy to empty. These two materials are different in many ways also, and choosing between the two materials for a specific job is critical.
Below are a few examples of how these two materials are different.
1. UHMW is a polyolefin and PTFE is a fluoropolymer. Polyolefins are double bonded carbon while Fluoropolymers are carbon and fluorine bonded. UHMW is a monomer which is consisted of one atom that will bond with another to form a polymer. PTFE is a polymer which is made up of a repeating chain of monomers.
2. PTFE has a higher temperature range than UHMW. The PTFE has a continuous use temperature of 500 degrees F. UHMW is much lower with a continuous use temperature of 200 degrees F and a melting point of 271 degrees F. The UHMW starts to become become soft at higher temperatures while the PTFE is much more resistant and with a melting point of 621 degrees F.
3. UHMW has higher abrasion resistance than PTFE. Both have great impact and wear resistance but because of UHMW having a molecular weight between 2-6 million making it the best wear resistance material in the plastic family, it makes it ideal to take wear and impact over a wider range and longer period of time without losing its properties.
4. UHMW has a much lower density than PTFE. This makes UHMW able to float in water while Fluoropolymers are significantly heavier (almost twice the density of UHMW) and would sink.
5. PTFE has excellent electrical and thermal properties. The virgin grade of PTFE is a better insulator and exhibits better electrical properties which can be used in radio frequencies, cables and circuit boards while UHMW cannot.
6. UHMW is much less expensive than the Fluoropolymers. Especially recently, PTFE has become harder to come by, and during the last 18 months there has been a global shortage of a key raw material called fluorspar that is used to make all Fluoropolymer materials. The ability to take lots of wear and tear and requiring low long term maintenance makes UHMW more cost effective.
7. The standard color of PTFE is Natural, which is a dense white. The UHMW comes in Natural (a deep milky white) or Black. The UHMW can be produced in many colors, and minimums are rather low. To obtain PTFE in colors is much more difficult, and would also have large minimum orders.
Click here for data sheet comparisons for each material…
Both the UHMW and the PTFE are available as sheet, sheets, sheeting, slab, bar, strip, panels, film, round rod, rods and block. Contact us for assistance with these or other shapes.
PTFE Sheeting Properties
Specific Gravity D792 2.14 – 2.24
Tensile Strength Yield D638 2,500 – 6,000
Tensile Modulus D638 80,000
Izod Impact – Notched D256 3.0
Hardness – Rockwell D785 D50 – D65
Deflection Temp @ 264psi D648 150
Deflection Temp @ 66 psi D648 250
Co. Thermal Expansion D696 5.5X10-5
UHMW Sheeting Properties
Specific Gravity D792 .93 – .94
Tensile Strength Yield D638 6,800
Coefficient of Friction – Static D1894 .25
Izod Impact – Notched D256 No Break
Hardness – Rockwell D785 R64
Vicat Softening Temp D1525 260
Deflection Temp @ 66 psi D648 174
Co. Thermal Expansion D696 11.0X10-5
These are just some examples of plastic materials being similar, and yet having very different properties. The PTFE Sheet and UHMW Sheet may appear very similar in color and can be used for some of the same applications, but when needed for a specific use or property needed, one might be dramatically better than the other. As the old saying goes, “You should never judge a book by its cover” and the same is true with plastic. Review the properties and test prior to choosing a final material for your application.
Choosing a PTFE – TFE Sheet Supplier can be difficult, confusing and potentially costly. There are many industries and applications where PTFE – TFE Sheet materials are used, and many providers that want to fill this need. However, it can be difficult to find a supplier that meets all of your business’ PTFE – TFE Sheet needs. To help you choose the supplier that is right for your business, we have compiled this list of 7 things you must know when picking PTFE – TFE Sheet Suppliers.
1. PTFE – TFE is available in many shapes and sizes
Polytetraflouroethylene (PTFE) can be ordered in many different forms, including rods, sheets, blocks, strips, slabs and tubes. As your business grows, you may need access to one or more additional configurations – or perhaps your business is already using multiple configurations. Choose the proper PTFE Sheet Supplier that can meet not only your current needs, but future needs as well. You can view further information about the shapes and sizes as well as and resin properties on our PTFE – TFE information page here.
2. There are a variety of PTFE – TFE Sheet thicknesses to choose from
It is important to have access to multiple sheet thicknesses, and convenient and cost effective to access them all from one Sheet Supplier. That’s why Industrial Plastic Supply offers sheet thicknesses ranging from .005″ to 3.0″, and rod diameters from .125″ to 6.0″. Film is also available. As with in stock availability, your PTFE Sheet Supplier should also be able to meet all of your Sheet thickness needs. Standard sheet sizes are 48” X 48”, and films generally are stocked in 12” wide rolls.
3. Not all PTFE materials are created equal
Some PTFE – TFE Sheet Suppliers order materials from ‘who ever they can get it from’ on an as-needed basis. This brings the question of quality and consistency to mind. There are many manufacturers, including some from China and Russia with questionable quality ratings and machinability. Before committing to a quality PTFE Sheet Supplier, make sure that the supplier is using a reputable manufacturer, and that the quality of material meets your needs. Getting stuck with a poor quality, difficult or impossible to machine block of PTFE can be time consuming and costly.
4. Minimum material order amounts matter
Large Sheet Suppliers and other plastic suppliers often have high minimum order requirements. This makes sense for high volume applications, but for small businesses, or any business in the clutch, it may be necessary to request a smaller total order. Rather than work with multiple PTFE or Plastic Sheet Suppliers based on order size, choose a supplier that can service any order whether large or small. Industrial Plastic Supply has a low minimum material order of $20.
5. Many suppliers do not keep inventory in stock
Just like Grandpa used to say, “You can’t sell from an empty cart”.
Buying your materials from a plastic ‘broker’, means you may have to wait while they try to find the materials to fulfill your requirements. It may also mean that you get the quality of material that they can find quickly. While this may be acceptable for materials that are rarely ordered, your PTFE Sheet Supplier should have your business’ most commonly used materials on hand. This avoids delays and ensures the quickest possible turnaround times on your important orders, and materials from stock means a quality product for your parts.
6. Industry knowledge is critical
You want a Sheet Supplier that not only can deliver your materials, but answer any questions you may have, including the tough ones – whenever they arise. Finding a quality PTFE Sheet Supplier with expert knowledge and great availability will save your business headaches in the long run. Industrial Plastic Supply’s highly trained staff has an average of nineteen and a half years of experience in the plastic industry, and are only a phone call or e-mail away.
7. Choose a supplier with focus
A focus on industrial grade plastic supplies ensures that a supplier is specialized and knowledgeable enough to be your PTFE Sheet Supplier. By focusing on plastics, such a supplier will be dedicated to your mechanical plastic Sheets, Rods, Tube and other shape needs, no matter the application, and no matter how your business changes. Your important orders will be processed timely and efficiently. Since 1975, Industrial Plastic Supply has focused on the mechanical and machinable plastics market, and nothing else. For more information on PTFE Sheets or other plastic materials, contact Industrial Plastic Supply, 866-832-9315. We will work to earn your business.Also, compare PTFE with UHMW or read our post UHMW Sheet versus PTFE Sheets; or read our post How to use PTFE Rod for ideas.