Are you clueless on PVC Strip and unsure on how the technical specifications will affect your application? We simplify the specs and help you discover your ideal curtain…
PVC strip has a large temperature range for such a flexible product. The temperature range is simply the range at which the PVC strip will maintain its structure. At temperatures lower than specified the molecules will react together becoming hard, brittle and the clarity will alter. At the higher end of the spectrum, the material will deform, lose its shape, and basically melt. Here’s our guide to the minimum and maximum usage temperatures on quality PVC strip:
Standard Grade PVC: -15°C – +50°C
Low Temperature / Polar Grade PVC: +30°C – -40°C
We are often asked, “is flexible PVC strip chemical resistant?” The answer is a resounding yes! PVC strip has good mechanical properties and excellent chemical resistance, as with other general-purpose plastics. It’s particularly good with organic solvents, salts, acids, and alkalis. This is why it’s used to make chemical storage tanks, plastic valves and flanges, drainage, and water pipes. However, if you want to understand how it behaves in relation to a specific chemical within a given environment then it needs to be independently tested.
We can send you samples to test in your actual environment or for more technical results we can send our materials to independent Laboratories on your behalf. Bear in mind independently testing is costly and the customer bears the cost for any external test requirements but it will ensure that you’ve got bespoke, application-specific test results for your unique environment.
So, you have a flexible PVC strip technical specification in front of you, you know that you need a strong material but you have no idea what that means or what to look for in quality grade PVC. Here we break it down into simple terms and explain the basics of tensile strength.
The tensile strength of a material is measured in N/mm². This is the maximum force the PVC strip can be subjected to before it breaks. Good quality PVC strip should achieve results between 10 and 18 (the stronger the PVC the higher the number).
- Standard grades should be around 16-17;
- Low-temperature grades should be around 12-13;
- Super polar grades should be around 10;
Low-temperature grades include added softeners in the PVC compound mix to avoid the material becoming brittle at freezing temperatures, hence the lower figures.
To simplify what is actually quite a complex test, the Vicat softening temperature or heat distortion temperature is basically how far a needle can penetrate into flexible PVC strip, to a specific depth at given temperature variables. The higher the temperature the easier it is for the needle to penetrate the PVC strip.
PVC strip is at a disadvantage when it comes to having a low heat distortion level if you compare it to other plastics, however, this is due to its high levels of flexibility and requirements to be a soft, moveable material.
Ideally, you want this score to be between 45-50, the higher the score the more rigid the material will be.
PVC strip is an inherently fire resistant plastic as it contains a high percentage of chlorine. Make no mistake, all PVC will burn (as do almost all materials) but when burned, hydrogen chloride gas is released which slows down the continuous combustion reaction and when the naked flame is removed it will self-extinguish – the material basically chokes itself. Additionally, the odour released is unpleasant allowing early detection of a fire.
There are many ways of evaluating flexible PVC strip, all PVC strip should be as minimum classified as “self-extinguishing” but the oxygen index is a good line in the sand – the higher the value the better. Materials that achieve OI ratings of 26+ are as near to a true fire retardant PVC material as you’re going to get in the PVC world.
If would like to view our independent testing video showing the behaviour of standard grade and OI27 PVC strip where you can see which PVC takes the flame and burns quicker for yourselves – then please just ask and we can send it over to you via email.