Sticking on the Product Inner Wall

In the rotational molding production process, the product exhibits the quality defect of 「Sticking on the Product Inner Wall」. The specific manifestation is that the product inner wall sticks during demolding. This defect is relatively common when processing powder materials such as LLDPE, HDPE, PVC, and PA, and its occurrence conditions are usually related to unreasonable settings of heating temperature and time, rotation speed ratio, cooling rate, and mold wall thickness. When the Sticking on the Product Inner Wall situation is severe, it will cause a series of chain quality defects in the product in terms of appearance, dimensional accuracy, and mechanical properties, which not only reduces the product's use functionality and safety, but also directly increases the scrap rate and production cost. Therefore, this problem needs to be systematically diagnosed and optimized from multiple dimensions such as material selection, the rotational molding machine, the heating oven, the rotating arm, the cooling station status, and heating temperature and time, rotation speed ratio, cooling rate, and mold wall thickness.

1. Insufficient demolding. This factor leading to the problem reflects that certain process conditions or material properties in rotational '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 from the source. 2. Mold temperature too high. Temperature is the core factor affecting melt fluidity and viscosity. Too high a temperature setting will cause the melt viscosity to decrease, insufficient melt strength, or even thermal degradation; too low a temperature will result in poor melt fluidity and insufficient plasticization, making it unable to fill or mold 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. 3. Undercut in the product structure. Unreasonable structural design or process layout is often the systematic root of the problem. Runner design defects leading to uneven flow, unreasonable cooling water channel layout leading to temperature differences, and insufficient venting structure leading to trapped air are all fundamental problems that need to be solved with emphasis in the design and development stage. In terms of equipment maintenance, the regular overhaul and accuracy confirmation of the rotational molding machine, heating oven, rotating arm, and cooling station 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 Sticking on the Product Inner Wall problem.

1. Demold after full cooling. Before implementing this measure, its feasibility and expected effects should be fully evaluated, and the plan details should be communicated and confirmed with relevant technical personnel. During implementation, key quality indicator changes should be closely monitored, and adjustment effects should be recorded and fed back in time to form reusable process experience. 2. Use release agent. Before introducing new tools, new materials, or new methods, adequate applicability evaluation and small-batch verification should be carried out. It is recommended to first conduct offline tests or simulation analysis outside production conditions, and introduce them into the formal production line only after confirming effectiveness and safety. Make good change management records to facilitate subsequent traceability and experience accumulation. 3. Avoid structural undercuts. Before implementing this measure, its feasibility and expected effects should be fully evaluated, and the plan details should be communicated and confirmed with relevant technical personnel. During implementation, key quality indicator changes should be closely monitored, and adjustment effects should be recorded and fed back in time to form reusable process experience. In terms of material management, incoming inspection of raw materials and in-process inspection of work-in-progress products should be strengthened, and the key performance indicators of powder materials such as LLDPE, HDPE, PVC, and PA should be strictly controlled to ensure the stability of molding quality from the source.

In summary, the causes of the 「Sticking on the Product Inner Wall」 problem can be attributed to the combined effects of multiple factors such as insufficient demolding and mold temperature being too high. To solve this problem, it is necessary to start from aspects such as demolding after full cooling and using release agent and take systematic treatment 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 powder melting uniformity and product wall thickness control.