PVC drainage pipes are one of the most widely used pipes. They are used frequently whether in construction or decoration. Therefore, the quality requirements are very strict. In order to ensure quality, the following matters must be paid attention to during the production process:
1. Traction speed
In the extrusion operation, the adjustment of the traction speed is very important. The material is melted and plasticized by extrusion, and then traction after continuous extrusion from the machine head, and then enters the shaping device, cooling device, traction device, etc. The traction speed should be consistent with the extrusion speed. match. Generally, during normal production, the pulling speed should be about 1% to 10% faster than the pipe extrusion speed.
2. Temperature control
Temperature control is a very important control factor in extrusion operations. The temperature control factors required for extrusion molding are barrel temperature, machine diameter temperature, die temperature, etc. If the temperature is too low, it will lead to poor plasticization, dull appearance of the pipe, poor mechanical properties, and product quality that does not meet the requirements; temperature If it is too high, the material will decompose and cause discoloration of the product.
3. Temperature of sizing device and cooling device
When extruding different PVC drainage pipes, the sizing and cooling methods used are different. The cooling medium can be air, water or other liquids, and the temperature needs to be controlled. The temperature is mainly related to production efficiency, internal stress of the product, etc.
4. Screw speed
As the screw speed increases, the extrusion volume increases, which can increase the output, but it is easy to cause poor plasticization, causing the inner wall of the pipe to be rough and the strength to decrease. At this time, the machine head pressure should be adjusted to achieve better output and quality. The temperature control of the screw will affect the material conveying rate, plasticizing and melting quality of the material, etc. Extruding pipes requires cooling water to lower the screw temperature, which is beneficial to improving the plasticizing quality. The temperature of the screw cooling water is around 50~70°C.
5. Compressed air and pressure
Compressed air can inflate the pipe to maintain a certain roundness. The required pressure should be appropriate. If the pressure is too small, the pipe will not be round, if the pressure is too high, the mandrel will be cooled, cracks will appear on the inner wall of the pipe, it will not be smooth, and the quality of the pipe will decline. At the same time, the pressure needs to be stable. If the pressure suddenly increases and sometimes decreases, the pipe will easily develop bamboo knots.
The above is a sharing of precautions for the production of PVC drainage pipes. If you want to know more relevant knowledge, you can continue to pay attention to our site.
