Poor demolding (sticking to the core rod)

During the injection '2079851475616104457 production process, the product exhibits the quality defect of "Poor demolding (sticking to the core rod)". Specifically manifested as the product adhering to the core rod and being unable to demold. 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 Poor demolding (sticking to the core rod) 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. Core rod temperature too high. Temperature is the core factor affecting melt fluidity and viscosity. Setting the temperature too high will cause the melt viscosity to decrease, insufficient melt strength, and even thermal degradation; if the temperature is too low, the melt fluidity is poor and plasticization is insufficient, making it impossible to fill or mold smoothly. A reasonable temperature window should be optimally determined within the recommended range according to the melting characteristics and thermal stability of the material. 2. Small product shrinkage rate. The cooling shrinkage behavior of the product is closely related to the resin type, crystallinity, wall thickness distribution, and cooling conditions. Insufficient or excessive shrinkage, and inconsistent shrinkage in all directions, will both cause dimensional deviations and internal stress. Reserving a reasonable shrinkage allowance and ensuring uniform shrinkage in all directions is the core of dimensional accuracy control. 3. Insufficient ejection force of the stripper plate. 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 Poor demolding (sticking to the core rod) problem.

1. Strengthen core rod cooling. 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. Select a resin with a moderate shrinkage rate. Before introducing new tools, new materials, or new methods, a full applicability assessment and small-batch verification should be carried out. It is recommended to first conduct offline tests or simulation analysis outside of production conditions, and introduce them into the formal production line only after confirming effectiveness and safety. Keep change management records to facilitate subsequent traceability and experience accumulation. 3. Increase the demolding ejection force. When implementing adjustments, it is recommended to adopt the single-factor variable method, adjusting only one parameter at a time and fully evaluating the effect, to avoid multiple parameters changing simultaneously making the cause of the problem untraceable. The adjustment magnitude should be small rather than large; each adjustment is recommended to be controlled within 5%~10% of the original value, and after adjustment, run stably for at least 3~5 mold cycles to observe the effect. 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 "Poor demolding (sticking to the core rod)" problem can be attributed to the combined action of multiple factors such as core rod temperature too high and small product shrinkage rate. Solving this problem requires starting from aspects such as strengthen core rod cooling and select a resin with a moderate shrinkage rate, 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.