Polytetrafluoroethylene Fabrics, commonly known as PTFE Fabrics, are loved for their electrical properties, excellent release surfaces, and their chemical and temperature resistance. They are available in a variety of forms, with the common forms being ivory white and opaque plastic fluoropolymer.
PTFE fabrics are primarily made from the polymerization of free radicals of various tetrafluoroethylene molecules. Their application is wide and varied, and you will find them in industries such as food and drink, aerospace, telecoms, and the pharmaceutical industries, among others. But what makes them durable and accords them the versatility to be used in a variety of industries? In this piece, we will be exploring the properties of PTFE fabrics, their benefits, and some of their interesting uses.
The main properties of PTFE Fabrics
- Durability: To understand the durability of PTFE fabrics, it is vital to delve into their properties and pick out the specific components that allow them to behave the way they do. To begin with, the melting point of PTFE is around 327.0°C.
- Chemically inert: However, pure PTFE fabrics are almost totally chemically inert, insoluble in most chemicals and solvents, and they are thermally stable in most conditions. This explains why they are the tape of choice for applications that feature very high-temperature environments.
- High flexural strength: PTFE fabrics also have every high flexural strength. This is very impressive even in conditions of high electrical resistance, and low temperatures. The tapes will also not disappoint in terms of dielectric strength and due to their electronegativity, they enjoy very high resistance to water. Additionally, they have a low coefficient of friction, and a very high density of 2200kg/m3.
- There are not factors to consider: PTFE is such a stable substance that you don’t have to consider most of the factors you would normally consider when working with other tapes. When using Teflon tape, perhaps the only factor you need to consider is the fact that it doesn’t have good resistance to high-energy radiation. This is one of the few known factors that have the ability to breakdown PTFE molecules.
- Signs of creeping: Though PTFE sometimes shows signs of creeping, PFA is known to be creep resistant and it is highly recommended for melt-processing, compression moulding, extrusion, blow moulding, and transfer moulding. TFM, on the other hand, is just a modifier of PTFE. It is used to make PTFE tapes denser, and stiffer hence, increasing creep resistance to levels similar to PFA.
With these enviable features and properties, it is easy to understand why PTFE fabric tapes have lots of versatile applications. This is not to say that they are the holy grail of the tape industry, but their strength, durability, and versatility have made them the go-to tapes in a variety of applications.
PTFE Fabric Options
Standard grade PTFE fabrics are available in a variety of options. This is a subtle demonstration of their versatility in terms of application, which we have already mentioned. Some of the common applications of these standard grade PTFE fabrics include:
- Baking and food processing industries
- Heat shrink tunnel curtains
- Liners for chemical tanks
- Composite curing/molding
- Gaskets
- Release surfaces on packaging machines or heat sealing machines
Apart from standard grade PTFE fabrics, there is also the Premium Grade PTFE Fabric. This grade is hailed for their optimum release and the durability they display under harsh conditions. Some of the notable applications for this grade include laminating separator sheets, making liners for cooking and baking pans, and any other application, which may require fabric weave impression.
Though the standard grade PTFE fabrics are just as good, there are certain subtle benefits you will get by using premium PTFE fabrics. For instance, premium-grade PTFE fabrics have the highest PTFE-to-substrate ratio. Also, they are designed for use in environments with extreme conditions where superior releases and prolonged life may be critical. Finally, their chemical resistance and electrical strength are simply comparable to none.
The other grades and their respective applications are as follows:
Mechanical grade PTFE fabric – these feature a specially treated glass thread usually necessary for a variety of mechanical low-load applications.
Anti-static grade PTFE fabrics – these come with an anti-static surface that contains electrically conductive substances.
Crease and tear-resistant grade PTFE fabric – just as the name suggests, this grade of PTFE fabrics can withstand the forces of tear and creases. As such, they will not bend, tear or fold when subject to heavy usage.
Porous grade PTFE fabrics – the porosity of this category is up to ¼ inches mesh. They are primarily used in applications involving the release of hot gases and air.
Shortcomings of PTFE fabrics
Before you think that PTFE fabric tapes are perfect with no flaws at all, you should know that they also have some shortcomings, which you should know about when considering buying them. For example, under very high temperatures, they can release mildly toxic fumes, which may cause respiratory problems following long hours of exposure. Additionally, its abrasion resistance may not be desirable in a number of applications, just as it is always the case with other tapes.
Though PTFE is a wondrous material with an impressive range of versatile applications, it cannot be used for everything. Depending on why you need the fabrics, some of the potential challenges you are likely to face include:
- They are very expensive – with the strength, durability, and versatility in applications, these are not among the cheapest polymers you will find in the market.
- It is possible for PTFE fabrics to change their shape when subjected to lots of pressure.
- They can’t withstand temperatures above 326.0°C.
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