Preform moisture absorption during storage (re-drying required)

In the stretch '2079851475616104457 production process, the product exhibits the quality defect of "Preform moisture absorption during storage (re-drying required)". The specific manifestation is that the preform absorbs moisture during storage, resulting in poor '2079851475616104457. 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 "Preform moisture absorption during storage (re-drying required)" 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. High humidity in the PET preform storage environment. 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. Storage time too long. 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 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 "Preform moisture absorption during storage (re-drying required)" 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 "Preform moisture absorption during storage (re-drying required)" problem.

1. Store preforms in a dry environment. Raw '2079851475616104451 should select a matching drying equipment type according to the resin type and water absorption characteristics, and reasonably set the drying temperature, drying time, and dew point indicators. The dried raw material should be put into production use as soon as possible; if temporary storage is required, it should be stored in a sealed container in a dry environment (dew point below -30°C). Regularly test the drying effect to ensure the moisture content meets the standard. 2. Control the storage time. The key to process parameter control lies in establishing a reliable closed-loop feedback adjustment mechanism. Through online real-time detection and SPC statistical process monitoring, deviation trends are discovered in time, and automatic control systems or manual intervention are used to maintain key parameters within the set window, achieving a fundamental shift from after-the-fact remediation to prior prevention. 3. Re-dry when necessary. Raw '2079851475616104451 should select a matching drying equipment type according to the resin type and water absorption characteristics, and reasonably set the drying temperature, drying time, and dew point indicators. The dried raw material should be put into production use as soon as possible; if temporary storage is required, it should be stored in a sealed container in a dry environment (dew point below -30°C). Regularly test the drying effect to ensure the moisture content meets the standard. 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 "Preform moisture absorption during storage (re-drying required)" problem can be attributed to the combined action of multiple factors such as High humidity in the PET preform storage environment, Storage time too long. Solving this problem requires starting from aspects such as Store preforms in a dry environment, Control the storage time 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.