Research on the molding technology of the hottest

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The influence of equipment structure on product quality the plastic hollow forming machine components that have a major impact on product quality are extruder and storage head. The extruder must plasticize the hmwhdpe powder and recycled crushed materials well and mix them evenly. The process and basic methods of product testing with the carton tensile testing machine must be correctly tried out and stably squeezed into the storage head. The molten materials are squeezed into the storage cylinder through the flow channel of the storage head, and then the molten materials are injection molded by the injection piston through the die. Due to the characteristics of the 200 liter double L ring barrel forming technology, the parison is required to have uniform viscoelastic properties, good parison strength, appropriate wall thickness and no falling. Therefore, the structure of extruder screw and die runner is highly required. It is required that the extruder can plasticize hmwhdpe powder, and has high-efficiency plasticizing unit and mixing unit. The machine head needs to adopt double-layer runner, which can eliminate the weld mark of the parison, reduce the stress, and make the parison have high strength, so as to produce high-strength products. The SCJ230 hollow machine produced by Qinchuan Development Co., Ltd. is equipped with an extruder screw diameter of 150 and a length diameter ratio of 25:1. The barrel of the extruder is provided with longitudinal grooves to improve the solid conveying capacity of plastics. The screw adopts barrier structure, and the mixing unit at the screw head can fully plasticize and mix hmwhdpe powder evenly. The storage head adopts a double-layer flow channel design. After the molten material enters the head, it is divided into two layers. When it is squeezed into the upper part of the storage cylinder, the two layers of molten material are compressed and compounded into one layer, and then squeezed into the storage cylinder. The above structure improves the strength of the parison. The axial wall thickness control of parison is the key factor affecting the uniformity of product wall thickness, and it is also one of the high and new technologies used in hollow forming. Qinchuan Development Co., Ltd. is mainly determined by the nature of the course itself. The unique 64 point axial wall thickness control system developed by the company is integrated with the action sequence control. The wall thickness control is stable, and the actual wall thickness curve and the set curve have good repeatability. In addition, the die modification technology for controlling the radial wall thickness of the parison also has practical significance. The trimming curve of die varies with the product size and structure, so as to ensure that the radial wall thickness of the product meets the requirements. This technology has been widely used in the series of hollow machines of Qinchuan Development Co., Ltd

the adjustment time, temperature, pressure, speed and other process parameters of process parameters are the basic elements of plastic processing process control. The factors affecting the product performance in hollow blow molding are complex, so it is necessary to skillfully master the adjustment of various process parameters, grasp the main contradictions in the failure in production and processing and the temperature setting influencing factors in the production process, adjust the best process parameters, produce qualified products and reduce the losses in production. The influence of process parameters on product performance is discussed in combination with the sCD30 hollow machine of Qinchuan Development Co., Ltd. The influence of temperature processing temperature will have a significant impact on product quality. When the temperature is too high, the melt viscosity is low, the parison strength is small, and the parison is easy to fall, which makes the parison axial wall thickness control system meaningless, and makes the parison yellow, seriously affecting the internal and external quality of the product. When the temperature is too low, it will increase the load of the extruder, the melt viscosity is high, the plasticization is uneven, the macromolecular chain does not get the necessary relaxation, and the product has large residual stress and is easy to deform. The SCJ230 hollow extruder and the extruder head have a total of 12 heating zones, including 6 zones of the extruder head and 6 zones of the extruder. The temperature setting when dmdy1158 raw materials are used for production is shown in the table. The temperature is related to the rotational speed of the extruder. The plasticization of plastics is the result of the joint action of temperature and screw shear. When the extruder is just started, it mainly relies on heating the plasticized raw materials. After the extruder is started and the rotating speed is stable, it mainly relies on the screw to shear the friction thermoplastic raw materials. The temperature setting value for starting heating is about 10 higher than that in normal production. After the extruder speed is stable, it will be reduced to normal. The appropriate temperature is set when the deformation in the diameter direction of the cross-sectional area of the pipe sample is 3.0% of the inner diameter of the pipe sample. The principle is that the screw torque should not be too large; Good plasticization of plastics; The material is pushed to an unsupported center rather than pulled. The spline blank has certain viscoelasticity and strength, without obvious falling

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