When plastic hoses are used at low temperatures, most of them should have long-term flexibility. For ordinary plastic hoses, we can choose DOP as the main plasticizer and DOA as the supplement. The effect of the combination is good. Under low temperature conditions, the working performance is ideal. Because of the good compatibility and plasticizing speed of DOP and PVC, PVC can maintain good viscous stability, and its low volatility, water resistance and soft properties at low temperature are better; while the solidification point of DOA is – 60 C, plasticizing temperature is 121 – 25 C, using it to improve the working performance of plastic hose at low temperature can achieve comparison. Ideal effect.
The plastic hose is easier to form than the plastic hard pipe. It does not need cutting device and cooling setting device. Therefore, the mixing process is very important in the forming process. Because this will not only affect the plasticizing effect, but also affect the low temperature toughness.
The mixing process is as follows: first, PVC, stabilizer, lubricant, plasticizer and filler are put into the high-speed mixer. The mixing temperature is 60-70 C. After mixing for 5-7 minutes, they are put into the low-speed mixer for cold stirring for about 2 minutes. Then appropriate amount of CPE or NBR is added, and the material can be discharged after continuous stirring for 3 minutes.
When we extrude plastic hoses, we must pay attention to that whether CPE or NBR modifiers, we can not add them together with other plasticizers and other plasticizers. If they are added early, the oil absorption of CPE or NBR will be larger and faster than that of PVC resin, and plasticizers will be absorbed quickly, which will make PVC resin unable to absorb. Absorption of plasticizers is the key to our extrusion of plastic hoses.