Blow molding products processing plant controls blow molding process

Author: MULAN - Plastic Molding Manufacturer

Blow molding products processing plants have relatively mature experience in blow molding technology. When using batch extrusion blow molding, it is necessary to consider whether the molecular weight distribution of the material used is suitable for this kind of processing. When considering the processing conditions, under the premise of ensuring uniform melting of the melt, the melting temperature should be slightly lower, which can increase the strength of the melt and reduce the phenomenon of drooping. During the operation of blow molding products processing plants, there are mainly 4 common problems that really deserve attention. 1. Formation of the parison From the perspective of product design and economy, the shape and thickness of the parison must be controlled before the blow mold is closed over the entire length of the parison. In this way, the wall thickness distribution of the product can be guaranteed to be even and lightest. Factors that affect the parison include the structure of the die, the molecular parameters of the polymer, and the operating conditions. 2. Inflation of the parison The shape of the blow molding cavity has a significant effect on the wall thickness distribution of the product. Therefore, it is necessary to understand the relationship between parison inflation thinning and cavity shape. When designing the cavity of the blow molding model, it is necessary to refer to the empirical formula of the parison wall thickness variation ratio. 3. The design of the blank cutting port Large hollow products require high strength and rigidity, and good sealing. The seam formed by the cutting mouth is the key part that affects the sealing. If the cutting opening is not designed properly, the thickness of the seam will be too small, and even the cross section will be V-shaped, resulting in low strength and leakage at the seam. 4. Cooling and solidification time of the parison The cooling stage is the longest part of the entire blow molding cycle. In order to improve production efficiency, it is necessary to improve cooling efficiency. High cooling rates can cause freezing stress and defects in the product, so optimization of the cooling device should be considered. When designing the mold, the blow molding product processing plant should strengthen the cooling of the thick-walled part and the area of ​​the cut-off opening. .