Product failure in stress cracking test

In the injection '2079851475616104457 production process, the product exhibits the quality defect of "Product failure in stress cracking test".The specific manifestation is The product undergoes stress cracking after contact with surfactants.This defect is more common when processing materials such as PET, PP, HDPE and PS, and its occurrence is usually related to unreasonable settings of injection pressure, parison temperature, blowing pressure and mold temperature.When the Product failure in stress cracking test situation is severe, it will cause a series of chain quality defects in the product's appearance, dimensional accuracy, mechanical properties and other aspects, 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, the status of the injection '2079851475616104457 machine, core rod, parison mold, blow mold and transfer mechanism, and injection pressure, parison temperature, blowing pressure and mold temperature.

1. Large residual stress in the parison.This factor causing the problem reflects that certain process conditions or material properties in injection '2079851475616104457 do not meet the optimal forming requirements.Such problems are often cumulative and concealed, and should be investigated and verified as key focus items during process debugging and finalization to ensure hidden dangers are eliminated at the source. 2. Poor environmental stress cracking resistance of the resin.Material selection and handling are the foundation of forming quality.The intrinsic properties of the resin such as molecular weight, molecular weight distribution and melt index determine its processing window and final performance.Factors such as excessive moisture content of raw materials, mixed impurities and improper regrind ratios will all cause various defects during processing. In addition, the insufficient overall coordination of parison wall thickness uniformity and transfer temperature control 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 Product failure in stress cracking test through chain effects. In terms of equipment maintenance, the regular overhaul and accuracy confirmation of the injection '2079851475616104457 machine, core rod, parison mold, blow mold and transfer mechanism are not in place, causing the actual operating parameters of the equipment to deviate from process requirements, which will also become a potential inducement of the Product failure in stress cracking test problem.

1. Reduce residual stress.Adjustments should follow the principle of gradual progress; each adjustment should not be too large, and a decrement of 5%~15% of the current value is recommended.After each adjustment, stably observe the product quality changes for at least 5~10 mold cycles, and continue adjusting only after confirming the improvement direction is correct; never make excessive one-step adjustments. 2. Select a resin grade with good ESCR performance.Before introducing new tools, new materials or new methods, sufficient applicability evaluation and small-batch verification should be carried out.It is recommended to first conduct offline tests or simulation analyses outside production conditions, and introduce them into the formal production line only after confirming effectiveness and safety.Keep proper change management records to facilitate subsequent traceability and experience accumulation. It is recommended to formulate a preventive checklist for the Product failure in stress cracking test problem, incorporate parison wall thickness uniformity and transfer temperature control into the daily inspection scope, and conduct online monitoring of key parameters through the SPC statistical process control method to achieve early warning and rapid response to problems. In terms of material management, incoming inspection of raw materials and in-process testing of work-in-progress should be strengthened, and key performance indicators of PET, PP, HDPE and PS should be strictly controlled to ensure the stability of forming quality from the source.

In summary, the causes of the "Product failure in stress cracking test" problem can be attributed to the combined action of multiple factors such as Large residual stress in the parison, Poor environmental stress cracking resistance of the resin.To solve this problem, it is necessary to start from aspects such as Reduce residual stress, Select a resin grade with good ESCR performance and take 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.