Uneven preform heating

In the stretch '2079851475616104457 production process, the product exhibits the quality defect of "Uneven preform heating". The specific manifestation is that the temperature distribution of the preform in the circumferential or axial direction is uneven. This defect is relatively common when processing materials such as PET, PP, PC, and its occurrence conditions are usually related to the unreasonable settings of stretching temperature, stretch ratio, blowing pressure, and preform heating uniformity. When the "Uneven preform heating" situation is severe, it will cause a series of chain quality defects in the product in terms of appearance, dimensional accuracy, mechanical properties, etc., which not only reduces the functionality and safety of the product 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 stretch '2079851475616104457 machine, heating oven, stretch rod, and blow mold, and stretching temperature, stretch ratio, blowing pressure, and preform heating uniformity.

1. Inconsistent lamp tube power in the heating oven. This factor causing the problem reflects that certain process conditions or material characteristics in stretch blow '2079851475616104453ing have not met the optimal molding requirements. Such problems are often cumulative and hidden, and should be investigated and verified as key focus items during process debugging and finalization to ensure that hidden dangers are eliminated at the source. 2. Uneven preform rotation speed. The speed parameter affects the flow state and time allocation of the melt during the forming process. A speed that is too slow causes premature cooling and insufficient filling; a speed that is too fast causes melt fracture, air entrapment, and shear overheating. The optimization of the speed curve should make the melt flow smoothly and orderly in the cavity. 3. Improper oven temperature zone settings. This factor causing the problem reflects that certain process conditions or material characteristics in stretch blow '2079851475616104453ing have not met the optimal molding requirements. Such problems are often cumulative and hidden, and should be investigated and verified as key focus items during process debugging and finalization to ensure that hidden dangers are eliminated at the source. In terms of equipment maintenance, the regular overhaul and precision confirmation of the stretch '2079851475616104457 machine, heating oven, stretch rod, and blow mold 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 preform heating" problem.

1. Inspect and replace the lamp tubes. Inspection work should establish a standardized inspection checklist, clarifying inspection items, technical standards, inspection frequency, and responsible persons. Key equipment components should be regularly disassembled to check the status of hidden parts, and judgments should not be made solely based on operating appearance. Inspection results should be recorded in detail and a trend analysis mechanism should be established to predict potential failures. 2. Ensure uniform preform rotation. 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, closely monitor changes in key quality indicators, promptly record and feedback the adjustment effect, and form reusable process experience. 3. Optimize the oven temperature zones. Optimization work must be based on an accurate diagnosis of the root cause of the problem, and blind attempts must be avoided. It is recommended to first determine the key influencing factors and their interactions through the process DOE test method or historical production data analysis, and then carry out parameter optimization and structural improvement in a targeted manner to achieve twice the result with half the effort. In terms of material management, incoming inspection of raw materials upon arrival and in-process inspection of work-in-progress should be strengthened, and the key performance indicators of PET, PP, PC should be strictly controlled to ensure the stability of molding quality from the source.

In summary, the causes of the "Uneven preform heating" problem can be attributed to the combined action of multiple factors such as Inconsistent lamp tube power in the heating oven, Uneven preform rotation speed. Solving this problem requires starting from aspects such as Inspect and replace the lamp tubes, Ensure uniform preform rotation 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 preform heating uniformity and biaxial stretch orientation control.