Blow Molding Machine Blow molding machine basics science
Blow molding machine basics science
Blow molding (blow molding) also known as hollow blow molding, a rapid development of plastic processing methods. The thermoplastic resin is extruded or injection molded into a tubular plastic parison which is heated (or heated to a softened state), placed in a split mold, and immediately after the mold is closed, compressed air is introduced into the parison, Swell and close to the mold wall, the cooling stripping, that is, a variety of hollow products. Blown film manufacturing process in principle and hollow products blow molding is very similar, but it does not use the mold, from the plastic processing technology classification point of view, blow molding film molding process is usually included in the extrusion. Blowing process during the Second World War began to produce low-density polyethylene vials. The late 50s, with the birth of high-density polyethylene and blow molding machine development, blow molding technology has been widely used. Hollow container volume up to thousands of liters, and some production has been used in computer control. Applicable to blow molding of plastic polyethylene, polyvinyl chloride, polypropylene, polyester, etc., the hollow containers are widely used as industrial packaging containers. Blow Molding Machine Classification
Blow molding machine can be divided into extrusion blow molding machine, injection blow molding machine and special structure blow molding machine three categories. The stretch blow molding machine can be attributed to each of the above categories. Extrusion blow molding machine is a combination of extruder and blow molding machine and mold clamping mechanism, composed of extruder and parison die, inflatable device, mold clamping mechanism, parison thickness control system and transmission mechanism. The parison die is one of the important components that determine the quality of the blow molded product, usually with a side feed die and a central feed die. Large products blow molding more use of storage tank type blank die. Storage tank volume of the smallest 1kg, up to 240kg. The parison thickness control device is used to control the parison wall thickness, the control point up to 128 points, usually 20 to 30 points. Extrusion blow molding machine can produce volume range of 2.5ml ~ 104l of hollow products. Blow molding machine control system
Automatic air ring is an online real-time control system, the system is controlled by the object is distributed in the wind ring on a number of motors. The cooling air sent by the fan is distributed to each air duct by the air-ring wind chamber, and the valve is driven by the motor to open and close the movement to adjust the size of the tuyere and the air volume, change the cooling effect of the film discharge, So as to control the thickness of the film, from the control process, the film thickness changes and the motor control can not find a clear relationship between the different thickness of the film and the valve at different locations and changes in the thickness of the control of the non-linear changes in the law, each adjustment of a valve The relationship between the adjacent points is very large, and the adjustment has lag, so that between different moments and each other, for this highly nonlinear, strong coupling, time-varying and control uncertainty system, the exact mathematical model is almost impossible Even if the mathematical model can be established, it is also very complicated and difficult to solve, so that there is no practical value, and the traditional control has better control effect on the control model, and the control effect is very poor for the nonlinearity, uncertainty and complex feedback Even powerless. In view of this we have chosen the fuzzy control algorithm. While changing the fuzzy quantization factor to better adapt to changes in system parameters.