Sustainable Development of Blow Molded Products

Author: MULAN -Plastic Molding Manufacturer

Blow molding products will have the following development trends in terms of materials, machinery, auxiliary equipment, control systems, software, etc., following the market's demand for blow molding products. (1) Raw materials In order to meet the function and function (medicine, food packaging) requirements of blow molding products, the raw materials of blow molding products will be more abundant and the processing performance will be better. For example, PEN materials not only have high strength, good heat resistance, strong gas insulation, transparency, and resistance to ultraviolet radiation, but are also suitable for blowing various plastic bottles, and have high filling temperature and excellent insulation performance against carbon dioxide gas and oxygen. And chemical resistance. (2) Blow molding products, packaging containers, and industrial products will have a greater increase, and injection blow molding and multi-layer blow molding will develop rapidly. (3) Fine and efficient blow molding machinery and equipment blow molding machinery; auxiliary production (operation) automation of equipment. Fine and efficient”It not only refers to the high speed and high pressure of mechanical equipment in the production and molding process, but also requires the products produced to achieve high stability in terms of appearance size fluctuations and piece weight fluctuations, that is to say, the production of blow molding The size and shape of each part of the product have high geometric precision, small deformation and shrinkage, and the appearance, internal quality and production efficiency of blow molded products must reach a higher level. Auxiliary operations include deflashing, cutting, weighing, drilling, leak detection, etc., and its process automation is one of the development trends. (4) The research on the blow molding mechanism of blow molding products is more in-depth. The reasonable construction of the mathematical model of blow molding simulation and the fast and accurate numerical algorithm are the key to the simulation. The blow molding simulation will play a role in product quality prediction and control. increasingly important effect. The molding parameters of each stage are analyzed from the process of blow molding products. The process of blow molding products can be divided into four stages: (1) The formation stage of the parison The conveying, melting, mixing, and pumping of the polymer in the extruder form the formation stage of the parison; at this stage, the main process parameters that affect the distribution of wall thickness are: ① Molecular weight distribution and average molecular weight of the material; ②The temperature control system and screw speed of the blow molding machine, where the temperature control system includes the temperature of the hopper, the temperature of the barrel zone 1, zone 2, zone 3, and zone 4, the temperature of the flange, and the storage die; (2) The parison blanking stage The parison is extruded from the gap between the die lip and the core for the blanking stage. At this moment, the two phenomena of parison release expansion and parison sagging affect parison molding. The main process parameters that affect the distribution of wall thickness are the die head diameter and wall thickness control system of the blow molding machine. The control system includes an axial wall thickness control system and a circumferential wall thickness control system to adjust the gap between the die lip and the core. (3) In the parison pre-blowing stage, in order to prevent the contact and adhesion of the inner and outer surfaces of the parison, and improve the uniformity of the wall thickness of the blown product, the parison must be pre-inflated. In the pre-blowing stage of the parison, air is injected into the parison from the bottom of the parison to protect the parison and reduce its overhang. At this stage, the main process parameters that affect the distribution of wall thickness are: pre-blowing pressure, pre-blowing time.(4) In the stage of high-pressure blowing of the parison, the parison is inflated under high pressure to make it close to the mold cavity, and the plastic molding stage of the product is completed. At this stage, what affects the product molding is the deformation of the parison by high pressure inflation, and the deformation of the parison and the mold cavity. The main process parameters that affect the distribution of wall thickness are: material shrinkage rate; blowing pressure, time; mold material, structure, mold exhaust system and mold cooling system, such as cooling water channel distribution, cooling water inlet temperature, etc. Although there are many factors that affect the quality of blow molding products, after the production conditions and requirements of blow molding products are determined, adjusting the blow molding process parameters can effectively improve product quality. Optimized process parameters can improve production efficiency, reduce raw material consumption, and optimize the overall performance of the product.