ePTFE Membranes – The Possibilities are Endless

It doesn’t require a scientist or an engineer to take a basic property of a material and extrapolate the possible areas of application.

We have spent the last one year developing ePTFE membranes, as we saw it as a key growth area within the PTFE space. As a technology, it remains obscure. Yet the demand for this product is so vast that it is no wonder that the few companies that have perfected it have been able to command the market (and by extension, the price).

To say that we have perfected ePTFE membranes would still be an overstatement. Being an SME, we have had to focus our R&D in those areas where clients have shown interest, rather than take a broader approach and simultaneously develop multiple variants. However, in our pursuit of client satisfaction, there have been consistent findings that have slowly allowed us to start tapping into the broader demand in the market. In addition to this, what we know about the property of the material gives us insights into other, perhaps less explored areas of application.

To start with, let us lay out the most fundamental property of this material:

ePTFE membranes allow gases and vapours to pass, while restricting liquids

This ability is what lays the foundation for the myriad applications (and potential applications) of ePTFE membranes. When coupled with the other properties of PTFE – such as temperature resistance, chemical inertness and dielectric strength – it is easy to see why the product is so much in demand.

1. ePTFE Membranes in Automotive Vent Applications
   
   Auto is a well traversed industry for ePTFE usage. We started our development of ePTFE membranes when we were asked to replicate an automotive vent as manufactured by Gore. The vent is a small disk of ePTFE membrane, with an adhesive backing. We were able to develop it in both virgin form and with a carbon filling.The purpose of this vent is to sit on a small opening at the back of the headlamp chamber. Any moisture that could potentially fog the headlights and/or condense within the chamber is released via the vent. However, as the vent is only permeable to gases and not liquids, water is no allowed back into the headlamp chamber, keeping it free from moisture.
   
   
2. ePTFE Membranes in PCB applications
   
   The effect of moisture on PCBs is well known. Apart from rust and corrosion, the presence of excess moisture can cause multiple short circuits, destroying the device within which the PCB is operating.ePTFE membranes are ideal in allowing any moisture built up within the PCB assembly to escape. At the same time, in the event of direct exposure to liquids, the ePTFE membrane shields the PCB, keeping it dry.
   The usefulness of this application is seen in nearly every industry where electronics are used. With mobility becoming more important, the chance of exposing a device to moisture becomes nearly unavoidable (think, dropping your smartphone into water). Having the protection of a breathable ePTFE membrane means the device is less likely to fail in such an event.
   
3. ePTFE Membranes in Cable Wrapping
   
   We have covered this in an earlier post. However, it is useful to reiterate that the high dielectric capabilities of ePTFE drive its use as a cable wrapping medium.ePTFE insulator tape can be made with tightly controlled thicknesses of as little as 0.05mm, with a uniform density, and dielectric constant. Wrapping individual conductors in ePTFE can cut interference, noise, cross-talk, and signal attenuation. In some applications, ePTFE tape helps limit phase shift to 4.3° and signal attenuation to 0.05 dB at 110 GHz.
   
4. ePTFE Membranes in Filtration
   
   Multiple applications within filtration exist for the use of ePTFE. Filtration itself requires different levels of porosity and pore size and the membrane needs to be customised accordingly.
   
   One of the most commonly known filters is used in vacuum pumps. It consists of a single ePTFE layer, moulded into a polypropylene housing (see below).
   
5. ePTFE Membranes in Desalination
   
   We believe this may be a huge growth area going forward. Desalination is an expensive process currently. An ePTFE layer could be used to allow for evaporated vapours from a salt water reservoir to pass through it and into an upper chamber. Consequently, it would prevent the condensed liquid from re-entering the salt water reservoir. In this manner, the water is separated from the salt using only solar energy. Spread over a wide enough area, this could effectively trap evaporating sea water to convert to fresh water.

We expect to continue adding to this list as more uses of ePTFE membrane become apparent. One thing we do know is that is a material of the future and that being able to modify and customise its texture and form would be a key proprietary skill going forward.

PTFE Pricing – Is volatility making a comeback?

An introduction to PTFE Pricing

Being a niche industry, PTFE doesn’t exactly get a lot of press even when large shock waves surge through it, disrupting the operations of manufacturers and end-users alike.

In 2010-11, the price of virgin PTFE began climbing, after having dipped consistently over the preceding 5 years. What started out as an understandable correction soon turned into an all-out crisis, as the price nearly quintupled over the next 8-10 months.

Imagine that scenario in any other industry. If the steel price to see a 5x increase in less than a year, what horrors would that unleash into the broader market? That the PTFE industry survived is a testament to the incredible properties of the material, that make it so difficult to substitute using other polymers.

To make matters worse, since the industry is small, there was no one to really make sense of the economic factors driving the price increases.

We stepped in at that time, partly driven by our own need to analyse the situation, but also because the information we collected seemed like it would be useful to other industry players.

Many articles were released between 2011 and 2013 that charted the various drivers of PTFE pricing and made sense of the driver that would play out going forward.

April 2011 – What’s the matter with PTFE prices?

May 2011 – The mysterious relationship between Fluorspar and PTFE prices

August 2011 – Mapping the PTFE Price Increase

December 2011 – PTFE Pricing Again – is there another price hike in the offing?

March 2012 – PTFE Prices – taking a step back to leap forward?

February 2013 – Mapping the PTFE Price Increase – An Update

Over the past few months, there have been murmurs of a return to the high pricing seen in 2011. Resin suppliers have offered ample warning that a price revision was imminent. So far, this has translated into 2 price corrections to the extent of 10-15% and 8-10% in the months of April and May respectively.

We need to compare this with the escalations seen in 2011-12 and understand that the rise is not quite so sharp. Nonetheless, we also need to compare the cost drivers and ensure that the same pattern is not repeating.

Key Drivers of PTFE Price

Unlike other polymers – such as polythene, polypropylene and polycarbonates, PTFE does not result as a by-product of the oil refining process. This comes as a shock to many, who assume that our fates are tied to oil prices and that we should therefore be benchmarking our final rates accordingly.

PTFE is made from the polymerisation of R22 gas – a refrigerant that finds its use mainly in the air conditioning and refrigerator industries. As a result, PTFE prices are driven by the demand and supply of R22.

When prices started increasing in 2011, the key driver was thought to be Fluorspar – a mineral that is critical to the manufacture of R22. In conjunction with this, a spike in demand from the AC and refrigerator markets in China along with a general crackdown on R22 usage (as it is not an environmentally friendly gas) caused prices to shoot up.

Today, the scenario is slightly different.

For one – we’re over halfway through the summer, so we’re not likely to see any shocks due to AC and refrigerator demand. Furthermore, Fluorspar supply has also regularised. A key effect of the price increase in 2011 was that idle Fluorspar mines in South Africa were reopened, offering an easing of supply to the market that was otherwise dominated by China.

If industry insiders are to be believed, the key driver this time around is environmental. China has been actively seeking to clamp down on R22 usage and has, in the process, shut down two PTFE plants that were not adhering to the standards. It is from here than the supply constraint has originated, driving up PTFE raw material prices within China. Obviously, as the China price is usually the floor price for most goods in the world, this has allowed resin manufacturers around the world to increase rates accordingly.

Where the prices go from here depend on three factors:

1. Whether the shut-down plants will be coming back on line after making the necessary changes
   
   It is yet unclear if the plants have been permanently shut down or are only undergoing an overhaul to make them compliant with the environmental codes. If they do come back online within the next 6-8 months, we would see a return to lower prices
2. Whether the move to phase out R22 will go as scheduled
   
   R22 is being phased out not only in China, but all over the world. India has also committed to stop using the gas completely by 2032. If this phase out continues, it could result in a supply surplus to the PTFE industry, driving down prices. However, if the use of R22 in PTFE is itself restricted, then it would require a shift to alternatives of R22, which would be
   
   expensive.Currently, as there is no talk of restricting R22 in PTFE specifically, it is likely that the former would result
3. Price inelasticity of PTFE
   
   In 2011, one thing that was made clear was that even at 5x multiples, there was still demand for PTFE resins. This allowed the resin manufacturers to continue increasing prices well above the rates that would have resulted from purely economic factors.

Ultimately, it was due to competition from China that forced prices back to normal levels.

In the short term, it is likely that resin suppliers will again try and test the market to see what levels they can sustain at. With the threat of China temporality removed, it remains to be seen how far they will push the market.

We only have snippets of information at this point to make sense of the situation. Clearly, with PTFE being used in so many fields, this poses some concern to many industries. We will be keeping our ears to the ground to see if anything else come up.

End Properties and Characteristics of PTFE (Teflon) Tubing

The development of a new process or product is usually accompanied by a steep learning curve.

Some of the findings are obvious, and may even be accessible in the public domain. Others are less easily understood and might be specific to the manufacturer due to the nature of the set-up, the environment and the materials used.

Our recent installation of a continuous line PTFE Paste Extruder has thrown up many such findings. At each stage, we have needed to evaluate whether the finding impacts the properties of the final product. Given the fact that globally, very few companies manufacture PTFE tubes, our access to external information is limited. Thus, trial and error has been the key to fine tuning the extrusion process and derive a product of consistently good quality.

Our journey in developing the product confirms that much of what is learnt needs to be kept proprietary, as it is part of a rich process technology not easily obtained. However, in doing so, we have also studied the final characteristics of PTFE tube and tried to make sense of what properties go in to define a tube of good quality.

Properties of PTFE Tube

When clients approach us with enquiries for PTFE Tubing, they are primarily concerned with 3 factors. Each of these factors plays back into how the PTFE tube is processed and has relevance to the end-application in questions

1. Dimensional stability
   The outer and inner diameters of the tube (OD and ID) are of utmost importance. In almost all cases, the tube will be used in an assembly, where fittings have been designed to accommodate the tube in question. Although minor variations in dimension may be accommodated, the tube needs to adhere to the fitments used with it.
   We have observed that when high quality resins are used, the dimensional stability during extrusion is highly predictable and easily maintained within a tolerance of 50 microns (0.05mm). Certain Chinese resins, when extruded, do not maintain this integrity. So, a tube with a required OD of 6mm may sometimes measure at 5.9mm and at other times measure to 6.2mm, despite all other parameters remaining unchanged.
2. Burst Pressure
   In applications involving high pressures, it is important that the tube does not yield during service.
   An easy formula to calculate the burst pressure is as follows:
   
   There are two critical parameters here that define the effectiveness of the formula.
   The first is the tensile strength – which is denoted by “T”. In most cases, we are told to take a tensile strength of 25Mpa for this value. Our own testing indicates a tensile strength of 28-31Mpa on our tubes, meaning that the value of 25Mpa is safe to use. However, tube that is not properly processed can often have a tensile strength of less than 20Mpa. This means that while a manufacturer may use the value of 25Mpa for calculation, the actual burst pressure is at least 20% lower.
   The other factor – that does not even feature in this formula is the concentricity of the tube. PTFE tube that is non-concentric will show a higher wall thickness on one side as compare to the other side. It will not have the same burst pressure of good quality tubes, even though the ID and OD may be the same. This issue also results in problems when we try and braid the PTFE Tube using stainless steel. The unevenness in wall thickness causes one side of the tube to collapse during braiding due to the pressure applied by the stainless steel.
   
   As a rule, we try and maintain a concentricity exceeding 95%.
   Calculating concentricity is quite simple. It is the ratio of the minimum wall thickness to the maximum wall thickness of the PTFE Tube. So a 6mm x 4mm PTFE tube, which has a wall thickness of 1mm, would need to have a tolerance of +/-0.025 to attain such a degree of concentricity.
   We have observed many tubes where the concentricity varies by up to 0.1mm on the wall thickness (implying a concentricity of only 81% on a 6mm x 4mm tube). While some applications may be fine with this level, it is up to the manufacturer to inform the client regarding the same, as the client may not always be aware of how critical this parameter is in the final application.
   Both concentricity and tensile strength are end properties derived from how the tube is processed during extrusion. Factors such as blending, extrusion pressure and sintering all lend themselves to arriving at a tensile strength acceptable by global standards. Similarly, extrusion speed, alignment and the blending process all play a part in ensuring concentricity exceeds 95%.
3. Visual
   Good quality PTFE tube will have a smooth even surface without any pitting, waviness or discolouration. Visually, concentricity also plays a part, as a tube that is significantly off-centre will usually raise concerns from the client.
   We have already looked at how concentricity is influenced by the extrusion process. Similarly, factors such as quantity of extrusion aid, extrusion speed and pressure, finish on the die and sintering temperatures all weight in on how the tube appears.
   Invariably, visual factors such as pitting, waviness and discolouration will give clues as to the fundamental properties such as tensile strength, elongation and dielectric strength. Hence, these need to be evaluated no just from a cosmetic point of view, but also in terms of what characteristics of the final product are being diminished due to the appearance of visual indicators.

It should be noted that the above characteristics cover only the very basic aspects of PTFE tubing. Products such as anti-static tubing, ePTFE tubing and convoluted tubing will each bring a new set of challenges that will need to be studied from first principles.

For the time being, we are satisfied to have attained global quality standards on characteristics that drive a majority of the demand for PTFE tubes.

PEEK filled PTFE – A Useful Blend

The blending of polymers with additives is a common practice. There are very few materials that are used purely in their virgin form and PTFE is no exception here. Adding materials such a bronze, carbon and glass (to name but a few) have allowed us to augment the properties of PTFE to suit specific applications. In each case, we sacrifice some element of the original property of the PTFE, but enhance another. To take the case of bronze – the addition significantly increases the coefficient of friction of the PTFE and eliminates all electrical insulation properties. However, this is offset by a large and highly sought after increase in wear and hardness. Hence bronze filled PTFE is a preferred compound for a number of automotive and industrial applications.

In exploring what different additives do to the final properties of PTFE, we have found literature relating to materials such as those above, as well as less used additives such as molybdenum-di-sulphide, ekonol, stainless steel and graphite.

With the addition of PEEK, however, we find few sources with which to refer to on properties. While we do receive many requests for PEEK filled PTFE, the actual test data to support the compound is not easily obtained.

A 2006 paper titled: “A low friction and ultra-low wear rate PEEK/PTFE composite”, by David L. Burris, W. Gregory Sawyer, is all we have to refer to in this respect, but we will see that there are sufficient insights to help any OEM designer to assess the exact composition needed.

PTFE with PEEK fillers

We have come across a few applications where PEEK filled PTFE is the requested material. In most cases, what we receive is only a sample from the client. The light brown colour combined with the fact that the material “feels like”PTFE, is usually all we have to go with. Usually, the compound is used in sealing applications where high RPMs are involved.

Blending PEEK and PTFE

Unlike most other additives, PEEK blends with PTFE quite effortlessly. The lower particle size of PEEK (about 5microns against 25microns for PTFE) means that the grains of loose PEEK powder flow easily in between the PTFE grains and allow for a reasonably good blend. Further mixing is needed to ensure that the blend is uniform, but in our experience, it was less of a challenge to blend PEEK with PTFE than to blend pigments with PTFE.

Processing the material requires some minor fine tuning in the sintering cycle. However, when done properly, the resulting product is a very light brown that machines easily and offers some interesting properties.

Properties of PEEK filled PTFE

The paper by David L. Burris, W. Gregory Sawyer only looks into the wear and coefficient of friction of the blends of PEEK with PTFE. The paper looks at ratios (by weight) of 5%, 10%, 20%, 30%, 40%, 50% and 70%. The results obtained can be seen on the graphs below.

Coefficient of friction

Coefficient of Friction – PEEK filled PTFE

PTFE has a lower coefficient of friction than PEEK, so it would be reasonable to assume that the value keeps increasing with the addition of more PEEK. However, it is surprising to note that the coefficient is lowest at 50% of PEEK – at about 0.12.

It is important to mention than even at its lowest, the coefficient of friction is still much higher than for pure virgin PTFE(between 0.03-0.05). However, from a design standpoint, it is useful to know that adding a very small amount of PEEK is not the key to keeping the overall coefficient of friction as low as possible.

Wear resistance

Wear Resistance – PEEK filled PTFE

Again, given that virgin PEEK has better wear resistance when compared with virgin PTFE, we would assume that adding more PEEK keep improving this property. However, we again see that the best performing blend is PTFE+32% PEEK.

Conclusion

The above findings are useful from the point of view of grade selection. If an OEM wishes to design a seal using a combination that minimises the coefficient of friction and wear rates, they would be better off using a filler percentage close to 40%.

Charting ePTFE (expanded PTFE) Specifications as per Global Standards

One of the toughest things about being the first in a given field is that there is so little data available for testing against.

As the only Indian company manufacturing ePTFE (expanded PTFE) gasket tapes, we are constantly met with questions regarding how the properties of our material hold up against those of competing brands operating in Europe and the USA. However, since the material is so new, there do not exist any established testing standards locally for us to check the product.

Basic Initial Data

To counter this, we initially took up the task of importing tapes from other manufacturers and testing the tensile properties and specific gravity against the same. Initially, we were trying to answer only 2 questions:

1. How soft should our tape be?
   Since the extent to which we expand the PTFE can be adjusted, it directly impacts the specific gravity of the end product. For a like-to-like comparison, we were hoping to match this with global brands. We eventually found that the standard density of ePTFE Gasket Tapes is 0.6-0.65g/cm3
   It should also be mentioned that some clients have specifically come to us asking whether they can get the tapes even softer, as their application is such that not much force can be applied to the tape. We have obliged – getting the density down to as little as 0.3g/cm3 in some cases.

2. How strong should our tape be?
   ePTFE tape looks great coming out of the machine. It is pure white, soft to touch and very smooth. However, two tapes that look exactly the same, could give completely contrasting values when tested for tensile strength. We found that global brands offered tensile strengths in the range of 5Mpa to 10Mpa.
   Once we standardised our production process, our own tapes showed a tensile strength of 12Mpa, so we were satisfied with the result.

Looking for global standards

Although we were happy with the properties of our material, there were still gaps in our understanding. Most notably, what were the other properties we should be testing? And rather than compare between brands, should there not be a global standard that specified the values we needed to obtain?

Again, going through competitor data provided very little information on this front. Expanded PTFE is a very niche market and from our own experience of getting the product right, we know that not much information can be divulged with regards to the behaviour of the material.

We looked around for global standards and realised that although there are many ASTM standards for regular PTFE, for ePTFE there were none. A few competitors had put up data on compressibility (ASTM F 36) and creep relaxation (ASTM F 38), but these were only comparing values to “leading brands” and not referring to any standard for the values. Others simply quoted the values, but did not elaborate the specifications against which these values would hold up.

We also went through the certifications that competitor brands were providing. These included:

1. DVGW VP 403 – The German standard for checking ePTFE Tapes
2. TUV MUC-KSP-A066 – The TUV Standard for ePTFE
3. BAM – For use in Oxygen rich environments

We contacted each of these organisations and were given estimates on how much the testing would cost. However, at no point are any values discussed. These remain guarded by the certification bodies. Our worry was that if we sent our material to these bodies without adequately testing them ourselves first – there was a risk that we may have overlooked a certain property and due to this, the product may not pass, resulting in an expensive mistake.

Eventually, we came upon the one standard that dealt specifically with ePTFE Tapes and was willing to offer values for us to compare against – the AMS 3255A.

The AMS is globally recognised as a leading authority for aerospace related materials. As such, we felt confident that their values would be stringent and thereby an effective standard to hold ourselves to.

The AMS 3255A prescribes many types of ePTFE Tape. Our basic tape falls under Class 2, Type 1, which requires the following properties to be met:

Property	Value/Result	Unit
Specific Gravity	0.4-1.2
Tensile Strength	3.44	Mpa
Tensile Strength (Fluid/Thermal Stability)	8.27	Mpa
Low Temperature Flexibility	No evidence of cracking
Liquid Sealability	No fluid leakage or loss of pressurization
Reparability	No fluid leakage or loss of pressurization

Armed with the above data and the testing procedures prescribed by the AMS 3255A, we were able to test our material in-house to confirm that the properties we were observing were as per the requirements of the standards.

In addition to this, we were also able to test the material with local certification bodies, to confirm the properties.

To the best of our knowledge, the AMS 3255A remains the only globally recognised standard to offer any values and/or testing procedures to verify the properties of ePTFE Gasket Tapes.

Expanded PTFE (ePTFE) Tapes – Properties and Installation Techniques

ePTFE Tapes are an ideal form-in-place gasket material made from 100% pure virgin PTFE that has been expanded to achieve a foamy structure.

While we have covered the applications of this earlier and also touched upon some of the variants, we would like to re-explore some of the finer aspects of the material as well as look at the installation in more detail.

ePTFE Structure

A number of variables contribute to what we would define as a suitable final product. While the nuances of the production technique are proprietary information, what we can reveal is that the end product, while seemingly uniform, can be anything but.

1. Specific Gravity
   In achieving a final product that matches the properties of other ePTFE Gasket Tapes in the market, one of the key properties explored was the density of the material. By varying the process, this parameter can be altered to produce different results. While most commercially available ePTFE Tapes have a specific gravity of 0.6-0.7, we were able to bring this down to 0.3, making the material much softer and more malleable.
   This reduction in density is not always preferred. In applications where the ePTFE is sandwiched between steel elements, you would prefer a higher specific gravity. However, in delicate applications, such as electronics and medicine, we may need to use a gasket or sealing element upon which large pressures cannot be applied as the equipment themselves are fragile. In such cases, a low density tape would be ideal as it would take the shape required with minimal pressure
2. Thickness
   Standard ePTFE tapes come in thicknesses starting from 1.5mm. However, certain applications such as cable wrapping and filtration require tapes as low as 0.1mm in thickness. While achieving was not easy, it did allow us to explore the properties of tapes under 1mm in thickness and gauge what made them so different.
   ePTFE Tapes fall somewhere between sintered PTFE tapes (made from skiving a fully sintered PTFE billet) and thread sealant tape (made from calendaring unsintered PTFE strips). As such, they imbibe the electrical properties of skived tapes, while retaining the malleable structure of thread sealant tape. Furthermore, the foamy structure allows for better thermal insulation as compared to both the other variants
3. Fillers
   Fillers are commonly used in PTFE to attain variations in final properties. We have experimented with fillers of PEEK and Carbon to reveal variations that significantly improve what the ePTFE tapes are capable of. Carbon allows us to make anti-static tapes, which are used extensively in the manufacture of co-axial cables. PEEK, meanwhile allows for vastly improved wear properties, while not violating any dielectric parameters or FDA parameters.
   In addition to this, we will be looking at fillers of glass and graphite. Each will bring its own unique alterations to the material.

Sizes available

FluoroFoam ePTFE gasket tape is an ideal solution for flange connections, container rims and any other metal to metal application requiring a compressible, chemically resistant seal.

The tape comes with one-side adhesive that aids in installation by allowing an exact placement of the gasket lining.

	Standard Spool Lengths (others on request)
Size (mm)	5m	10m	25m	50m
1.5 x 3
2 x 5
2.5 x 7
3 x 10
4 x 12
5 x 14
6 x 17
7 x 20
5 x 25
5 x 28

Installation guidelines:

Completely clean the sealing area and remove any dirt, corrosion, oil or leftover from old gasket material.

Cut one ending of the sealing tape and remove just a little of the protecting paper. Place the tape at the nearest possible position next to the bolts, starting next to a bolt hole. Fit the gasket around the entire flange circumference and across the endings as shown in figure 1.

Assembled in fragile flanges apply techniques as shown in figure 2. Skive the endings as shown in fig. 3 and overlap according to the recommended overlap length. Cut off the excess, tapering to the end, leaving a total thickness of approx. 120 %.

At least 4 progressive torque sequences with a torque wrench, in a star of 180° (fig. 1), should follow the first torque by hand.

Lastly perform a circular torque to check and ensure a tight and long-lasting seal.

Photos of typical applications:

The ePTFE Tape is allowed to overlap at the ends to ensure complete sealing.
Due to the softness of the tape, this overlap is accommodated during compression causing no variation in thickness

The one-side adhesive backing allows installation even on vertical surfaces, eliminating the need for grooves, clamps or bolting arrangements.

Metal-to-metal flange connections benefit greatly from the use of FluoroFoam ePTFE.
The ePTFE takes the exact shape of the gap between the two metal members ensuring a perfect seal with minimal effort

Form-in-place ePTFE gasket tape can effectively seal flanges on large shell-and-tube exchangers
Available in running lengths – the tape saves big on cost in areas where large, custom made gaskets would be too expensive

The versatility and texture of the material ensures that there is no shape that cannot be attained.
This adds to the effectiveness as well and reduces costs significantly compared with custom made gasket and sealing solutions

Advantages of FluoroFoam ePTFE Gasket Tape:

• Quick and simple installation: adhesive strip makes installation easier while the shape and versatility of the material means minimal cutting and sizing
• Reduced down time: standard sizes are immediately available ex-stock
• Reduced stock: a few spools of different sizes cover most applications within a plant
• No risk: the texture of FluoroFoam ensures the material accommodates the shape of the mating member, so there is no chance of the equipment getting damaged by the ePTFE
• Safe: ePTFE is chemically inert and can therefore be used even in the harshest environments without risk of reacting with the surrounding substances
• No waste: FluoroFoam comes in a spool, so no material gets wasted
• Cost effective – FluoroFoam can be used to replace custom made gaskets that are expensive and made-to-order. This is results in a huge cost saving in larger diameter pipes and vessels. 

Technical Details:

• Temperature range: – 240°C up to +260°C, for short periods up to +310°C
• Chemical resistance: resistant against all chemicals from pH 0-14 – except molten alkali metals and elemental fluorine at high temperature and pressure
• Pressure resistance: vacuum up to 200 bar
• Density: 0,65 g/cm³, +/- 0,1g/cm³ (for rectangular cross sections only)
• Aging resistance: FluoroFoam itself does not age and is UV-resistant. However, the adhesive backing may lose its effectiveness if kept unused for too long
• Colour: white (other pigments available on demand)
• Fillers: FluoroFoam can be offered in virgin and carbon filled variants
• Others: FluoroFoam is physiologically harmless. It has no smell or taste. It is neither contaminating nor toxic. It is made using FDA approved raw materials