In the molding process of preform molds, every step is crucial, from the transportation, melting, mixing, and pumping of polymers in the extruder, to the formation, feeding, pre blowing, and high-pressure inflation of the preform, all of which are influenced by various factors. Today, we will delve into these influencing factors and appropriately mention the role of joint research molds in improving molding quality.
1, Embryo formation stage
In the formation stage of the embryo, the polymer is transported, melted, mixed, and pumped out by an extruder to finally form the embryo. At this stage, the key factors affecting the distribution of wall thickness include:
The molecular weight distribution and average molecular weight of materials: The molecular weight distribution and average molecular weight of materials directly affect their flowability and formability.
The temperature control system of blow molding machine: The temperature control system is crucial for the quality of the formed embryo, including the temperature of the hopper, the temperature of each area of the material cylinder, the temperature of the flange, and the temperature of each area of the storage mold head. The joint research mold ensures the optimal state of the polymer during the molding process through a precise temperature control system.
Screw speed: Adjusting the screw speed can affect the conveying speed and melting effect of the polymer, thereby affecting the quality of the molded embryo.
2, Cutting stage
The stage where the embryo is extruded from the gap between the mold lip and the mold core is called the cutting stage. At this point, common phenomena include embryo dilation and embryo elongation. The factors that affect these two phenomena are:
The diameter of the blow molding machine die: The size of the die diameter directly affects the extrusion speed and forming quality of the embryo.
Wall thickness control system: including axial wall thickness control system and circumferential wall thickness control system, used to adjust the gap between the mold lip and the mold core, thereby controlling the wall thickness distribution of the mold embryo. The advanced wall thickness control system of the joint research mold can ensure uniform wall thickness distribution of the embryo and improve product quality.
3, Embryo pre blowing stage
In the pre blowing stage of the embryo, in order to avoid contact and adhesion on the inner surface of the embryo and improve the uniformity of the product wall thickness, it is necessary to perform pre blowing on the embryo. The factors that affect the wall thickness distribution during this stage are:
Pre blowing pressure: The magnitude of pre blowing pressure directly affects the degree of pre blowing and sagging of the embryo.
Pre blowing time: The length of pre blowing time also has a significant impact on the quality of the formed embryo.
4, Embryo high-pressure blowing stage
In the high-pressure blowing stage of the embryo, the embryo is inflated with high pressure to tightly adhere to the mold cavity, achieving plastic forming of the product. The key factors affecting product quality in this stage include:
The shrinkage rate of materials: Different materials have different shrinkage rates, which have a significant impact on the forming quality of products.
Blowing pressure and time: The choice of blowing pressure and time directly affects the degree of inflation and deformation of the embryo.
The material and structure of the mold: The material and structure of the mold have a direct impact on the molding quality of the product. The joint research mold adopts high-quality materials and advanced design to ensure the durability and molding accuracy of the mold.
Mold exhaust system: A good exhaust system can ensure smooth exhaust of the mold during the molding process, avoiding defects such as bubbles.
Mold cooling system, such as the distribution of cooling water channels and the inlet temperature of cooling water, has a significant impact on the molding quality and production efficiency of products. The cooling system design of the joint research mold is reasonable, ensuring that the product receives uniform and effective cooling during the molding process.
Although there are many factors affecting the quality of blow molded products, when the production conditions and product requirements are determined, adjusting the blow molding process factors can effectively improve the quality of products. With its professional experience and technical strength in mold design and manufacturing, Heyan Mold provides customers with high-quality mold products and solutions, helping enterprises improve production efficiency, reduce raw material consumption, and optimize the comprehensive performance of products.
