Research on Related Problems of Forming Technology of Plastic Bucket

Impact of Equipment Structure on Product Quality Plastic blow molding machine components that have a major impact on the quality of the product are extruders and stocker heads. Extruder must plasticize HMWHDPE powder and recycled crushed material, mix evenly, and steadily squeeze into the head of the accumulator. Through the flow path of the accumulator head, the melt material is squeezed into the material storage cylinder, and then injected. The piston injects the melt through a die. Due to the characteristics of the 200L double-L barrel molding technology, it is required that the parison has uniform viscoelastic properties, good parison strength, suitable wall thickness, and does not fall. Therefore, the structure of the extruder screw and head flow path is required. Very high. The extruder is required to plasticize HMWHDPE powder and has an efficient plasticizing unit and a mixing unit. The machine head needs to use double flow channels, which can eliminate the welding marks on the parison and reduce the stress, so that the parisons have higher strength and can produce high-strength products. The SCJ230 hollow machine produced by Qinchuan Development Co., Ltd. has an extruder with a screw diameter of 150 and a length-to-diameter ratio of 25:1. The barrel of the extruder has longitudinal grooves to increase the solids conveying capacity of the plastic. The screw adopts a barrier structure and the mixing unit of the screw head can fully plasticize and evenly mix the HMWHDPE powder. The accumulator head adopts a double-layer flow channel design. The molten material enters the head and is divided into two layers. When it is squeezed into the upper end of the storage cylinder, the two layers of melt are compressed and combined into one layer and then squeezed into the storage cylinder. The above structure is improved. The strength of the parison. The control of the axial wall thickness of the parison is a key factor affecting the uniformity of the wall thickness of the product, and is also one of the high technologies used in the hollow molding. Qinchuan Development Co., Ltd. developed a unique style of 64-point axial wall thickness control system and the operation of the order control integration, wall thickness control is stable, the actual wall thickness curve and set the curve repeatability. In addition, the trimming technology of the die head for controlling the radial wall thickness of the parison also has practical significance. Different product size and structure, the trim curve of the die is also different, so as to ensure the radial thickness of the product to meet the requirements. This technology has been widely adopted in the series of hollow machines in Qinchuan Development Co., Ltd.

Process parameters such as adjustment time, temperature, pressure, speed and other process parameters are the basic elements of the plastic processing process control. The factors affecting the product performance in the hollow blow molding process are relatively complex, and it is necessary to proficiently grasp the adjustment of various process parameters, to grasp the main contradictions in the production process, to identify the main contradictions in the temperature setting factors, and to adjust the optimum process. Parameters, produce qualified products, reduce the loss in production. In the following, the SCD30 hollow machine of Qinchuan Development Co., Ltd. is discussed to discuss the influence of the process parameters on the product performance. The effect of temperature has a significant effect on the quality of the product. When the temperature is too high, the melt viscosity is low, the parison strength is small, and the parisons are liable to fall down. As a result, the parison axial wall thickness control system loses its meaning and yellowing of parisons is severely affected, thereby seriously affecting the product's inherent and appearance quality. . When the temperature is too low, the load of the extruder will be increased, the melt viscosity will be large, the plasticization will not be uniform, the macromolecular chains will not be loosened as necessary, and the products will have large residual stress and be easily deformed. There are 12 heating zones in the extruder and head of the SCJ230 hollow machine, including 6 zones in the nose and 6 zones in the extruder. The temperature settings when using DMDY1158 raw materials are shown in the table. The level of temperature is related to the speed of the extruder. The plasticization of the plastic is the result of a combination of temperature and screw shear. When the machine is turned on, it mainly depends on the addition of heat-plasticized raw materials. After the extruder is started, when the rotational speed is stable, the main raw material is the friction-heated raw material of the screw shear. The set value of the temperature at which the heating is started is about 10 times higher than that during normal production. After the extruder rotates at a stable speed, it returns to normal. The proper temperature setting principle is that the screw torque can not be great; the plastic plasticization is good; the blank has a certain viscoelasticity and strength, and there is no obvious drop.