In the production process of wooden door rubber processing centers, flash caused by mold wear directly impacts the appearance quality, sealing performance, and service life of sealing strips. Flash, a product of rubber overflow caused by increased gaps or surface roughness on the mold parting surface, is closely related to the degree of mold wear, the flowability of the rubber material, and processing parameters. A systematic solution to this problem requires mold maintenance, process optimization, and material selection.
Mold wear is a direct cause of flash. With increased use, repeated compression can cause scratches, dents, or increased gaps on the mold parting surface, leading to rubber leakage under high pressure and flash. Wooden door rubber processing centers should establish a regular mold inspection system, using high-precision coordinate measuring machines or optical projectors to check the parting surface gap. If the gap exceeds twice the design standard, the machine should be shut down for repair. For localized wear, electrospark deposition repair technology can be used to restore surface accuracy. For larger areas of wear, the mold core or cavity plate must be replaced. Furthermore, the choice of mold material is crucial. Using high-hardness, wear-resistant alloy steel (such as HRC58-62) can significantly extend mold life.
The flowability of the rubber material is another key factor affecting flash formation. Mooney viscosity is a core indicator of rubber compound flowability. A value that is too low will cause the compound to flow too quickly within the mold cavity, increasing the risk of flash; a value that is too high may lead to insufficient filling and cause gaps. Wooden door rubber processing centers should determine the optimal Mooney viscosity range through experimentation and achieve precise control by adjusting the ratio of plasticizers and fillers in the formula. For example, adding nano-calcium carbonate can improve the compound's thixotropy and reduce flow resistance, while the introduction of silane coupling agents can improve filler dispersion and reduce flash caused by localized viscosity variations.
Optimizing processing parameters is key to resolving flash issues. Curing pressure, temperature, and time are key variables affecting rubber compound flow and curing. Insufficient curing pressure prevents the compound from fully filling the mold cavity, easily forming flash at the parting surface. Excessive pressure can cause mold deformation and increase wear. Wooden door rubber processing centers must set a dynamic pressure curve based on the structural characteristics of the sealing strip. High pressure and rapid filling are employed during the initial mold closing phase, followed by gradual pressure reduction during the mid-vulcanization phase to minimize flash. Furthermore, vulcanization temperature control must balance the fluidity and cross-linking efficiency of the rubber compound to avoid premature vulcanization due to excessively high temperatures or prolonged flow time due to excessively low temperatures.
Mold structural design has a fundamental impact on flash control. During mold design, wooden door rubber processing centers should adhere to the principle of "prevention first." Flash generation can be reduced by minimizing the pressure-bearing area of the parting surface, optimizing the layout of the residual rubber groove, and providing flash removal edges. For example, a flashless mold structure with flash removal edges of 0.05-0.15mm width on both sides of the cavity can directly cut off flash during vulcanization. Furthermore, the mold venting system must be designed to match the fluidity of the rubber compound to prevent abnormal cavity pressure caused by gas entrapment.
The introduction of automated trimming technology can significantly improve flash control efficiency. For existing flash, the Wooden Door Rubber Processing Center can use a low-temperature embrittlement trimming method. Liquid nitrogen or dry ice is used to cool the seal strip to below its brittle temperature, followed by high-speed shot blasting or drum impact removal. This method is suitable for treating micro-flash below 0.02mm without damaging the seal strip's structure. For complex curved surfaces or irregular cross-sections, a CNC five-axis trimming machine combined with a vision positioning system can achieve a machining accuracy of ±0.03mm.
In the long term, the Wooden Door Rubber Processing Center needs to establish a comprehensive "prevention-monitoring-repair" lifecycle management system. By optimizing the rubber flow path using mold flow simulation software and dynamically adjusting process parameters using an intelligent vulcanization control system, flash can be reduced at the source. Furthermore, a mold wear PDCA cycle system should be established to regularly analyze the causes of flash and optimize process solutions, ultimately achieving optimal quality and cost.
