The greatest thing about TPV (thermoplastic vulcanizate) is that it combines the qualities of thermoplastics and those of EPDM thermoset rubber to create the perfect polymer. One of the most common processes that are used in fabricating parts that come from TPVs is extrusion. Here are a few of the most important tips that can help you have a simple time with the entire extrusion process to create superior quality polymers.
Pick the right size and shape of the extruder
The first and most important tip to follow is to ensure you have selected the right shape and size of the extruder. If you want to create an item that has a small cross-sectional profile, choose an extruder with a small barrel. On the other hand, if you're going to create something that has a larger cross-sectional barrel, pick a larger barrel for your extruder. Another size aspect that you need to consider is the length to diameter ratio.
Think about the materials to use for pre-drying
Next, you need to think about the fact that TPV often needs to be pre-dried before you can start the extrusion process. The problem with pre-drying is that when poorly handled, it will add bubbles to the final product, which will interfere with the quality. To prevent this from happening, think about getting a vented extruder that will have a two-stage screw. This will give the room needed for extra air and, therefore, it will eliminate the need to pre-dry the product. You could also consider replacing the twin screw extruder with a metal gear pump.
Make sure the die plate is balanced
TPV flows through the conduit and onto the die to create the shape that you want. This may sound quite straightforward. However, when the TPV flows too fast or in an irregular manner, the resulting product will not have a regular shape. You need to ensure that the die stays in place throughout the process, and if any adjustments need to be made, handle them before the setting part of the process starts.
It is also important to look at the material and shape which you are trying to create before deciding whether you want to use plastic dies or metallic ones. If you are going to use metallic dies, make them a little rough so that the mould can come over quickly. When these guidelines are followed, the resulting items will be superior in quality.
For more information about TPV Santoprene extrusion, contact a professional near you.