Analysis On The Principle And Characteristics Of Plastic Sheet Production Line
Analysis on the Principle and Characteristics of Plastic Sheet Production Line
Plastic Sheet Production Line is mainly used in the production of agricultural water supply and drainage, construction and drainage, cable laying and other aspects of the diameter, wall thickness of plastic PVC pipe, the unit by the cone twin screw extruder, vacuum shaping box, Machine, cutting machine, turning rack and other components. Screw extruder and traction machine with the flow frequency control device, vacuum pumps and traction motors are used high-quality products. Traction has two claws, three claws, four claws, six claws and other traction way.
China's Plastic Sheet Production Line in recent years, the rapid development of PVC pipe annual growth rate of 8%, while the annual demand growth rate of 2%. In the plastic pipe, the amount of PVC pipe has been far ahead, it is widely used in water supply and drainage pipes. As the technology is relatively mature, in recent years, PVC water supply pipe in the product innovation is not much investment in new products is relatively small, the market more than ordinary products, high-tech, high value-added products, similar to generic products, middle and low products accounted for Part of the high-end products less.
At present, the domestic plastic pipe production capacity of 3 million tons, mainly PVC, PE and PP-R pipeline three categories, of which PVC pipe market share is the largest plastic pipe, plastic pipe accounted for nearly 70% of the share. Plastic Sheet Production Line1600 The annual production capacity of more than 2.5 million tons, in 2003 PVC pipe (pipe) annual output of more than 120 million tons. In the plastic pipe, PVC share of 70%, PE accounted for 25%, PP-R accounted for 4%, the other accounted for 1%.
Plastic Sheet Production Line Principle:
In the production process, because PVC pipe is a heat-sensitive material, even if the heat stabilizer can only be added to improve the decomposition temperature, prolong the stability time and can not be decomposed, which requires PVC pipe molding processing temperature should be strictly controlled. Therefore, the extrusion temperature should be based on the formula, the characteristics of the extruder, head structure, screw speed, temperature measurement point position, temperature measurement equipment, temperature and temperature depth and other factors to determine.
Molding rate directly affects the production of pipe production, while the impact of pipe wall thickness, traction rate instability will make PVC pipe diameter suddenly large and small phenomenon. The traction speed should be closely matched with the extrusion rate of the pipe. Normal production, the traction rate should be faster than the extrusion line speed 1% to 10%. The slower the traction rate, the thicker the pipe wall, the faster the traction rate, the thinner the wall, and the vertical shrinkage of the PVC pipe, and the internal stress increases, thus affecting the pipe size, the pass rate and the use effect. Adjust the traction rate in the production The following simple method can be used to place the extruded PVC pipe in the traction track, but the track does not clamp the pipe and observe the difference between the track speed and the PVC pipe. If the traction rate is slower than the extrusion rate, To wall thickness to meet the requirements so far.
Plastic raw material mixing: is the PVC stabilizer, plasticizer, antioxidants and other accessories, according to the proportion of the process has joined the high-speed mixer, the material and mechanical friction from the material to set the temperature to set the process temperature, and then The material will be reduced to 40-50oC by cold mixing; this can be added to the hopper of the extruder.
Plastic Sheet Production Line Extruder part: The machine is equipped with a quantitative feeding device, so that the amount of extrusion and the amount of feed to match to ensure that products stable extrusion. Due to the characteristics of the conical screw, the feeding section has a large diameter, the material heat transfer area and shear rate is relatively large, is conducive to the plastic material, measuring the screw diameter is small, reducing the heat transfer area and the melt Of the shear rate, so that the melt can be squeezed at a lower temperature. Screw in the barrel when the rotation, the PVC mixture plasticized to the nose, so as to achieve compaction, melting, mixing homogenization; and to achieve the purpose of exhaust, dehydration. Feeding device and screw drive device using frequency control, can achieve synchronous speed.
Plastic Injection Molding Process on Plastic Sheet Production Line The injection process is a periodic process from the clamping action. The plastic extruder must complete a series of actions during this periodic process: clamping, opening, injection Block overall movement, packing and ejection products.
In the production process of Plastic Sheet Production Line, according to the needs of the injection molding process, the hydraulic system to the injection molding machine working flow and working pressure should be constantly changing, so the injection system hydraulic system power consumption should also be with the flow And changes in work pressure and constantly changing.