The hardest a part of being a pioneer in any discipline is that there's normally no one to show to for technical assist. When Poly Fluoro installed its ePTFE (expanded PTFE) gasket tape line in 2016, we by no means expected how peculiar and intricate the manufacturing process would be. Though there are a handful of manufacturers the world over, we knew we were the first company in India to start out making this product. Furthermore, as all different manufacturers would be our competitors, we realised that we only had a number of consultants, our equipment manufacturers and our raw materials suppliers to turn to for assistance on processing strategies.

However, despite support from these areas, the truth that PTFE behaves differently to other supplies based on the environment meant that numerous learning needed to be completed in-house. As we went deeper into the method, we realised that there are many different parameters that need to be measured and monitored in order to achieve the ultimate properties required. Right here we touch upon these parameters. We can't go into too much detail, as lots of our findings remain proprietary. However, we might like to give a gist of the complexity involved and the engineering that goes into the event and manufacture of such a product.

1. Resin - the resin grade is vital. ePTFE entails extrusion, followed by stretching. The resin needs to be a positive powder, able to taking a good extrusion load. There are particular properties of the resin - equivalent to extrusion pressure and particle measurement - that need to fall inside a specified range. Else, the powder will not work.

2. Blending - the resin is blended with an extrusion aid (normally, naphtha), which can enable it to be extruded. Once the blending course of is done, the resin may be extruded into the required profile (both rectangular, circular or even irregular). The blend time and the quantum of extrusion assist are critical. Too much or too little extrusion assist can imply a very tender or very exhausting extrudate respectively. It is essential to get this right.

3. Extrusion - extrusion is done at a gentle price at a strain that will guarantee the fabric is suitable for stretching. It is essential that the extrusion stress sits inside an acceptable vary. If the strain is simply too low, it would imply a weak extrudate, which may break during stretching. A excessive pressure is nice, but too excessive would possibly imply that the extrudate is just too arduous to stretch.

4. Drying - the drying course of is needed as a way to remove the naphtha from the material. The one purpose of the naphtha is to help extrusion, so once that it done, it need not be current in the fabric. Furthermore, as the material would quickly be heated to a high temperature, it is crucial that all traces of the naphtha are eliminated for the aim of security.

5. Stretching - the stretching process includes three sub-parameters, all of which combine to ensure the ultimate product is as required.

a. Temperature - the temperature needs to be set to make sure the material is heated, however not over-heated. Over-heating would mean that the PTFE gets sintered, which we don't want. ePTFE is a semi-sintered material, so the heat should be just sufficient to make sure that the ePTFE stays mushy.

b. Stretch ratio - the rate at which the profile is stretched will define the density of the final product. Lower densities would name for a higher-stretch charge. Nonetheless, care needs to be taken at the extrusion stage to make sure that materials is able to taking larger stretch rates. Sometimes, China Customized PTFE tape would have a particular gravity of between 0.55 and 0.75. However, in the event that the product wants a decrease density, a much increased stretch would must be given.

c. Speed - the pace of the system feeds back to the temperature. A slow velocity may be needed for increased cross-section profiles, however this would additionally imply the fabric spends extra time in the heat and might get over-cured. On the whole, speed needs to be adjusted after setting the remainder of the parameters, such that the ultimate product achieves the best properties

6. Ultimate curing - even after the stretching process, ePTFE Tapes have a habit of ‘breathing in’. Expanded PTFE tapes - particularly these which have been stretched at excessive charges - will attempt to pull back into themselves. That is primarily an element when the fabric continues to be cooling and results in both a shortening of size and an increase in density. Subsequently, special spooling strategies need to be integrated in order to make sure that the material holds its properties. Sometimes, as soon as the fabric has cooled down sufficiently, it will stabilise.

There are different nuances, apart from the ones talked about above. While the particular technical parameters are kept deliberately vague, we hope that this serves as an example the complexities involved within the manufacture of ePTFE (expanded PTFE) gasket tapes.