Product surface roughness (poor gloss)

During the extrusion '2079851475616104457 production process, the product exhibits the quality defect of "Product surface roughness (poor gloss)". Specifically manifested as the outer surface of the product not being smooth, with low gloss. This defect is relatively common when processing materials such as HDPE, PP, PVC, and PC, and its occurrence conditions are usually related to unreasonable settings of melt temperature, extrusion speed, blowing air pressure, and mold temperature. When the Product surface roughness (poor gloss) situation is severe, it will cause a series of chain-reaction quality defects in the product in terms of appearance, dimensional accuracy, mechanical properties, etc., which not only reduces the usability and safety of the product, but also directly increases the scrap rate and production cost. Therefore, this problem requires systematic diagnosis and optimization from multiple dimensions, including material selection, the condition of the extruder, die head, die, mold clamping mechanism, and blowing system, as well as melt temperature, extrusion speed, blowing air pressure, and mold temperature.

1. Rough mold cavity surface. The mold is the core tool that imparts shape and surface quality to the product. Unreasonable mold design, such as improper runner/gate dimensions, insufficient venting, inadequate draft angle, etc., will directly cause molding defects. The machining accuracy, surface treatment quality, and daily maintenance condition of the mold also directly affect product quality. 2. Insufficient blowing air pressure. Pressure directly determines the filling ability of the melt and the mold-contacting effect during the '2079851475616104453. Insufficient pressure results in incomplete filling and poor replication accuracy; excessive pressure may cause secondary defects such as flash and excessive internal stress. The setting of pressure should comprehensively consider factors such as material viscosity, product dimensions, and mold structure. 3. Melt temperature too low. Temperature is the core factor affecting melt fluidity and viscosity. Setting the temperature too high will cause the melt viscosity to decrease, insufficient melt strength, and even thermal degradation; if the temperature is too low, the melt fluidity is poor and plasticization is insufficient, making it impossible to fill or mold smoothly. A reasonable temperature window should be optimally determined within the recommended range according to the melting characteristics and thermal stability of the material. In terms of equipment maintenance, inadequate regular overhaul and accuracy confirmation of the extruder, die head, die, mold clamping mechanism, and blowing system cause the actual operating parameters of the equipment to deviate from the process requirements, which can also become a potential inducement of the Product surface roughness (poor gloss) problem.

1. Polish the mold cavity. The polishing operation should proceed step by step from coarse to fine; each time a finer abrasive is used, the polishing direction should be changed to eliminate the texture marks of the previous step. The final surface roughness should be tested with a roughness meter to confirm that it meets the standard. After polishing is completed, it should be thoroughly cleaned to remove residues of abrasives and grinding agents to prevent them from entering the melt and contaminating the product. 2. Increase the blowing air pressure. 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 multiple parameters changing simultaneously making the cause of the problem untraceable. The adjustment magnitude 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. 3. Appropriately increase the melt 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 multiple parameters changing simultaneously making the cause of the problem untraceable. The adjustment magnitude 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. In terms of material management, incoming inspection of raw materials and in-process inspection of work-in-progress should be strengthened, and the key performance indicators of HDPE, PP, PVC, and PC should be strictly controlled to ensure the stability of molding quality from the source.

In summary, the causes of the "Product surface roughness (poor gloss)" problem can be attributed to the combined action of multiple factors such as rough mold cavity surface and insufficient blowing air pressure. Solving this problem requires starting from aspects such as polish the mold cavity and increase the blowing air pressure, and adopting 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 control and parison temperature uniformity.