Uneven Parison Length

In the extrusion '2079851475616104457 production process, the product shows the quality defect of "uneven parison length". The specific manifestation is obvious parison length fluctuation within the same mold cycle or between different mold cycles. This defect is relatively common when processing materials such as HDPE, PP, PVC, PC, and its occurrence conditions are usually related to unreasonable settings of melt temperature, extrusion speed, blowing pressure, and mold temperature. When the uneven parison length is severe, it will cause a series of chain quality defects in appearance, dimensional accuracy, mechanical properties and other aspects of the product, which not only reduces the product's functionality and safety in use, but also directly increases the scrap rate and production cost. Therefore, this problem requires systematic diagnosis and optimization from multiple dimensions such as material selection, extruder, die head, die, mold clamping mechanism, blowing system status, and melt temperature, extrusion speed, blowing pressure, mold temperature.

1. Unstable extruder feeding. This factor leading to the problem reflects that certain process conditions or material properties in extrusion blow '2079851475616104453ing have not met the optimal molding requirements. This type of problem is often cumulative and concealed, and should be investigated and verified as a key focus item during process debugging and finalization to ensure that hidden dangers are eliminated from the source. 2. Screw speed fluctuation. Uniformity runs through all links of the '2079851475616104453. Uneven temperature, uneven pressure distribution, uneven cooling, uneven material mixing, etc. will all lead to discreteness of product quality. Ensuring the uniform distribution of various physical quantities is a prerequisite for obtaining products with good consistency and stable quality. In addition, insufficient overall coordination of parison wall thickness control and parison temperature uniformity is also a factor that cannot be ignored; there are complex interactions and coupling relationships among the process parameters, and the deviation of any parameter may aggravate the degree of uneven parison length through chain effects. In terms of equipment maintenance, the regular overhaul and accuracy confirmation of the extruder, die head, die, mold clamping mechanism and blowing system are not in place, causing the actual operating parameters of the equipment to deviate from the process requirements, which will also become a potential inducement of the uneven parison length problem.

1. Stabilize the feeding system. Before implementing this measure, its feasibility and expected effect should be fully evaluated, the details of the plan should be communicated and confirmed with relevant technical personnel, the changes of key quality indicators should be closely monitored during implementation, and the adjustment effects should be recorded and fed back in time to form reusable process experience. 2. Calibrate the screw speed controller. A standardized inspection checklist should be established for inspection work, clarifying inspection items, technical standards, inspection frequency and responsible persons. Key equipment components should be regularly disassembled to inspect the status of hidden parts, and judgment should not be based solely on operating appearance. Inspection results should be recorded in detail and a trend analysis mechanism should be established to predict potential failures. 3. Check the stability of the drive motor. A standardized inspection checklist should be established for inspection work, clarifying inspection items, technical standards, inspection frequency and responsible persons. Key equipment components should be regularly disassembled to inspect the status of hidden parts, and judgment should not be based solely on operating appearance. Inspection results should be recorded in detail and a trend analysis mechanism should be established to predict potential failures. In terms of material management, the incoming inspection of raw materials and in-process inspection of work in progress should be strengthened, and the key performance indicators of HDPE, PP, PVC, PC should be strictly controlled to ensure the stability of molding quality from the source.

In summary, the causes of the "uneven parison length" problem can be attributed to the combined effect of multiple factors such as unstable extruder feeding and screw speed fluctuation. Solving this problem requires starting from aspects such as stabilizing the feeding system and calibrating the screw speed controller, and adopting systematic governance measures. In actual production, it is recommended to establish a prevention and rapid response mechanism for this problem, and achieve stable production and continuous improvement through parison wall thickness control and parison temperature uniformity.