Unstable screw retraction of the injection machine

During the injection '2079851475616104457 production process, the product exhibits the quality defect of "Unstable screw retraction of the injection machine". Specifically manifested as fluctuations in the screw retraction speed during plasticizing. This defect is relatively common when processing materials such as PET, PP, HDPE, and PS, and its occurrence conditions are usually related to unreasonable settings of injection pressure, parison temperature, blowing air pressure, and mold temperature. When the Unstable screw retraction of the injection machine situation is severe, it will cause a series of chain-reaction quality defects in the product in terms of appearance, dimensional accuracy, mechanical properties, etc., which not only reduces the usability and safety of the product, but also directly increases the scrap rate and production cost. Therefore, this problem requires systematic diagnosis and optimization from multiple dimensions, including material selection, the condition of the injection '2079851475616104457 machine, core rod, parison mold, blow mold, and transfer mechanism, as well as injection pressure, parison temperature, blowing air pressure, and mold temperature.

1. Unstable back pressure. This factor leading to the problem reflects that certain process conditions or material properties in injection blow '2079851475616104453ing have not met the optimal molding requirements. Such problems often have cumulative and hidden characteristics, and should be investigated and verified as key focus items during process debugging and finalization to ensure that hidden dangers are eliminated from the source. 2. Screw wear. Mechanical wear and loosening during long-term equipment operation will cause clearance changes, accuracy degradation, and unstable operation, thereby triggering various process and quality problems. Establishing a regular inspection and preventive maintenance system for equipment operating conditions, and promptly repairing or replacing worn parts, is a necessary measure to maintain equipment accuracy and process stability. 3. Check ring failure. This factor leading to the problem reflects that certain process conditions or material properties in injection blow '2079851475616104453ing have not met the optimal molding requirements. Such problems often have cumulative and hidden characteristics, and should be investigated and verified as key focus items during process debugging and finalization to ensure that hidden dangers are eliminated from the source. In terms of equipment maintenance, inadequate regular overhaul and accuracy confirmation of the injection '2079851475616104457 machine, core rod, parison mold, blow mold, and transfer mechanism cause the actual operating parameters of the equipment to deviate from the process requirements, which can also become a potential inducement of the Unstable screw retraction of the injection machine problem.

1. Stabilize the back pressure. Before implementing this measure, its feasibility and expected effect should be fully evaluated, and the details of the plan should be communicated and confirmed with relevant technical personnel; during implementation, changes in key quality indicators should be closely monitored, and the adjustment effect should be recorded and fed back in a timely manner to form reusable process experience. 2. Check for screw wear. Inspection work should establish a standardized inspection checklist, clarifying the inspection items, technical standards, inspection frequency, and responsible persons. Key equipment components should be regularly disassembled to inspect the condition 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 established to predict potential failures. 3. Replace the check ring. When replacing parts, spare parts of the same or higher specification from the original manufacturer should be selected to ensure that the installation accuracy and fit tolerances meet the technical requirements of the equipment. After replacement, the relevant parameters need to be recalibrated and a trial run performed to verify the effect; normal production can only be resumed after confirming that the expectations are met. It is recommended to establish a spare parts life cycle management ledger. In terms of material management, incoming inspection of raw materials and in-process inspection of work-in-progress should be strengthened, and the key performance indicators of PET, PP, HDPE, and PS should be strictly controlled to ensure the stability of molding quality from the source.

In summary, the causes of the "Unstable screw retraction of the injection machine" problem can be attributed to the combined action of multiple factors such as unstable back pressure and screw wear. Solving this problem requires starting from aspects such as stabilize the back pressure and check for screw wear, and adopting systematic governance measures. In actual production, it is recommended to establish a prevention and rapid response mechanism for this problem, achieving stable production and continuous improvement through parison wall thickness uniformity and transfer temperature control.