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The main component of PVC plastic sealing strip is polyvinyl chloride, and other components such as plasticizers are added to enhance its heat resistance, toughness and ductility. PVC sealing strip is easy to form, recyclable and reusable.
Production Process:
Production process Raw material + auxiliary preparation → mixing → conveying and feeding → forced feeding → screw extruder → extrusion die → setting
Identification method:
Symptoms of traditional inferior PVC sealing strips:
1. The phenomenon of oil seepage and precipitation on the surface occurs. Those waste oil are not compatible with PVC at all. Grease is easy to appear on the surface of the sealing strip, and yellow marks are also stained on the surface of the light-colored wooden door file and door leaf, resulting in product pollution, and even no Environmental protection There are many volatile substances that pollute the air.
2. When the so-called plasticizer volatilizes or oozes out, the sealing strip will lose its original softness, become very rigid, and will soon shrink with aging, length shrinkage, and broken section shrinkage, so that part of the wooden door is closed. There are large gaps, and the airtightness becomes very poor (water leakage, dust leakage), until the sealing and sound insulation effect is lost, which increases the cost of air conditioning and heating. Without the buffering effect, the life of the wooden door will be greatly reduced.
3. Use your nose to smell whether there is any peculiar smell. The general PVC sealing strip will have a very pungent smell. The normal silicone rubber sealing strip will only have a little mellow smell, and the smell is very small and can hardly be smelled.
4. At the same time, place the PVC sealing strip and the silicone rubber sealing strip at a high temperature for a period of time (place on the roof or in a sunny place), the PVC sealing strip will become very soft in a short time, and the grease on the surface of the sealing strip will be precipitated and contaminated Dust, and yellowing (it is easy to absorb soil with oil) seepage oil, get dirty hands; the physical properties of silicone rubber sealing strips have no change, and the sealing ring of pressure cooker for households is made of silicone rubber, which uses the high temperature resistance and heat resistance of silicone rubber. Non-toxic and environmentally friendly performance, the physical properties of silicone rubber have no obvious change under the working environment of 200 ℃.
5. At the same time, put the PVC sealing strip and the silicone rubber sealing strip in the freezer of the refrigerator for a few hours, the PVC sealing strip will become very stiff and easy to break, and the physical properties of the silicone rubber sealing strip will not change. The physical properties of silicone rubber have no obvious change at -50℃.
6. Some cheaper sealing strips will have a lot of fillers, so the surface will not be very bright, the color will be dull, the cut section of the sealing strip will be rough, the hand feel is stiff, stretched almost inelastic, the silicone rubber sealing strip has bright color and feel Soft, very elastic when stretched, cut off the sealing strip, and the section becomes delicate and shiny.
7. Burning, the PVC sealing strip will foam, shrink, and emit black pungent smoke. The burning is not sufficient, leaving hard plastic residues.
8. Look at the specific gravity, how many meters can be produced per kilogram. Vendors of PVC sealing strips make great efforts in the use of fillers, some in pursuit of greater output, (to save a little electricity) use talc, heavy calcium and other things as fillers, which greatly increases the proportion of sealing strip products, ( Most of our users buy by kilograms and use them by length), which invisibly increases the cost and seriously reduces the quality. Add heavy calcium PVC sealing strip, you stretch back and forth by hand several times, a small amount of white powder will appear on the surface. The density of PVC sealing strip should be 1.4-1.6,. Silicone rubber seals use nano-silica as filling and reinforcement, with light texture and density between 1.1-1.25, so the yield is 20% higher than that of PVC seals. The silicone rubber sealing strip burns almost smokeless, tasteless, fully burned, and turns white powder after burning the substance.