Condensation water marks appearing on the bottle body surface

In the stretch '2079851475616104457 production process, the product exhibits the quality defect of "Condensation water marks appearing on the bottle body surface". The specific manifestation is that water stain marks appear on the bottle body surface. 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 "Condensation water marks appearing on the bottle body surface" 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. Mold temperature below the dew point. Temperature is the core factor affecting melt fluidity and viscosity. A temperature set too high will cause the melt viscosity to decrease, insufficient melt strength, and even thermal degradation; a temperature that is too low results in poor melt fluidity and insufficient plasticization, making it impossible to fill or form smoothly. A reasonable temperature window should be optimized and determined within the recommended range according to the melting characteristics and thermal stability of the material. 2. Cooling water leakage. Cooling conditions determine the setting process of the product and its final internal structure. Uneven cooling causes shrinkage differences and residual stress, leading to warpage and dimensional deviation; insufficient cooling makes the product not rigid enough at demolding; overly rapid cooling generates large internal stress. The cooling system design should ensure uniform and efficient heat dissipation in all parts. In addition, the insufficient overall coordination of preform heating uniformity and biaxial stretch orientation 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 one parameter may aggravate the degree of "Condensation water marks appearing on the bottle body surface" through chain effects. 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 "Condensation water marks appearing on the bottle body surface" problem.

1. Increase the mold temperature. 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 simultaneous changes of multiple parameters making the cause of the problem untraceable. The adjustment amplitude 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. 2. Check the cooling water circuit seals. 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. It is recommended to formulate a preventive checklist for the "Condensation water marks appearing on the bottle body surface" problem, incorporate preform heating uniformity and biaxial stretch orientation 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 the problem. 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 "Condensation water marks appearing on the bottle body surface" problem can be attributed to the combined action of multiple factors such as Mold temperature below the dew point, Cooling water leakage. Solving this problem requires starting from aspects such as Increase the mold temperature, Check the cooling water circuit seals 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.