The production process of PVC pipe mainly includes raw material preparation, extrusion molding, cooling, sizing treatment, cutting and quality inspection.
How to produce PVC pipes?
1. Raw material preparation (By high speed hot and cold PVC mixer machine): First, PVC resin particles and other additives ( such as stabilizer, plasticizer, filler, etc.) according to a certain proportion of mixed heating, melt it into a thick melt material.
2. Extrusion molding: the molten PVC material is extruded through an PVC pipe extruder. The PVC pipe extruder is composed of feeding device, screw, die head and extrusion mechanism, etc. After the rotation of the screw, will melt PVC material from the feed port into the screw chamber, with the rotation of the screw gradually extruded out, and through the extrusion mechanism in the die head to form a tube.
3. Cooling: the PVC pipe after extrusion needs to be cooled, usually use the water cooling method, by passing cold water through the inside of the pipe wall, to reduce the temperature of the pipe wall, to harden it.
4. Sizing treatment: cooled PVC pipe needs to be sizing treatment, through the mold, makes the shape of the pipe wall to be pressed to a certain extent, makes the pipe diameter reach the specified size. At the same time, cooling device can also continue to cool the PVC pipe, to ensure the stability of its size.
5. Cutting: Cut the PVC pipe through the cutting equipment, to form the desired length. The cutting equipment is usually done in the form of sawing or cutting blades.
6. Quality inspection: Finally, through the inspection process of PVC pipe quality inspection, mainly check the appearance of PVC pipe, size, mechanical properties and other indicators, to ensure that the quality meets the standard requirements.
This series of production process ensures that the final production of PVC pipe has excellent performance and stability can meet a variety of use needs.
PVC pipe production line
Process conditions and control of PVC pipe production line
In the production process, because PVC is a heat-sensitive material, even if the heat stabilizer is added, it can only increase the decomposition temperature, extend the stability time and it is impossible not to decompose, which requires that the molding temperature of PVC should be strictly controlled. Especially RPVC, because its processing temperature is very close to the decomposition temperature, often because of improper temperature control caused by decomposition phenomenon. Therefore, the extrusion temperature should be determined according to the formula, extruder characteristics, head structure, screw speed, temperature measuring point position, temperature measuring instrument error and temperature measuring point depth and other factors.
1. the temperature control
Temperature control is an important control factor in extrusion operation. The temperature of the control factors required for extrusion molding is barrel temperature, machine diameter temperature, and die temperature. The temperature is too low, the plasticization is poor, the appearance of the pipe is lustrous, the mechanical properties are poor, and the product quality can not meet the requirements: the temperature is too high, the material will decompose, and the phenomenon of product discoloration appears.
2. screw speed
The screw speed increases, the amount of extrusion increases, so that the output can be improved, but it is easy to produce poor plasticization phenomenon, resulting in the inner wall of the pipe rough, strength decline, then the head pressure should be adjusted to make the output and quality reach the best. The temperature control of the screw affects the material conveying rate, the plasticization and melting quality of the material. The extrusion pipe needs to pass cooling water, reduce the temperature of the screw, which is conducive to improving the quality of plasticization, and the temperature of the screw through cooling water is about 50 to 70.
3. traction speed
The adjustment of traction speed in the extrusion operation is very important, the material is melted and plasticized by extrusion, and it is pulled after continuous extrusion from the head, so as to enter the styling device, cooling device, traction device, etc., and the traction speed should match the extrusion speed. Generally in normal production, the traction speed should be about 1% to 10% faster than the extrusion speed of the pipe.
4. compressed air and pressure
Compressed air is able to blow up the pipe and make the pipe maintain a certain roundness. The required pressure should be of an appropriate size. The pressure is too small, the pipe is not round, the pressure is too large, the mandrel is cooled, the inner wall of the pipe is cracked, it is not smooth, and the quality of the pipe is decreased. At the same time, the pressure is required to be stable, such as the pressure is suddenly large and small, the pipe is easy to produce bamboo joints.
5. sizing device, cooling device temperature
Extrusion of different plastic products, using different sizing methods and cooling methods, the cooling medium can be air, water or other liquids, the need to control the temperature, the temperature is mainly related to production efficiency, product internal stress.
PVC pipe production line
Newrgy PVC pipe production lines for water supply, drainage and electrical conduit applications. Compare extruder configurations and send your pipe diameter, wall thickness and target output for a quotation.