Pre Co-extrusion Tooling

Key Processes and Technologies of Pre Co-extrusion Tooling

1. Pre Co-extrusion Tooling is a core precision mold for the integrated molding of PVC door and window profile sealing strips. Unlike post-co-extrusion processes, its biggest advantage is its superior adhesion. Through simultaneous melting and molding at the front of the die head, the soft PVC sealing strip is deeply integrated with the profile body, resulting in seamless molding without delamination or detachment. The finished product’s sealing performance, weather resistance, and structural stability are far superior to products using manual pasting or post-pressing. This is the preferred process for producing high-quality door and window profiles.

2. Stable raw material pretreatment is fundamental to ensuring bonding quality. The soft PVC granules used in Pre Co-extrusion Tooling must be dried at a constant temperature of 80℃ for at least 3 hours before production to thoroughly remove residual moisture. This effectively avoids quality problems such as delamination, cracking, and weak adhesion after molding, maximizing the fusion and bonding effect of the two materials and ensuring that the finished product will not detach or crack during long-term use.

3. In terms of production equipment compatibility, Pre Co-extrusion Tooling equipment boasts strong versatility and low adaptation costs. For standard profile cross-section production, a 35-25 model single-screw co-extruder can meet stable mass production needs, with simple equipment debugging and stable operation. Only for extra-large profile cross-sections, an upgrade to a 45-25 model single-screw co-extruder is required to match the high-flow material extrusion requirements, adapting to the production line equipment configurations of most profile manufacturers.

4. Pre Co-extrusion Tooling design and shaping calibration, which are also technical pain points that most manufacturers in the industry struggle to overcome. Firstly, the dual-flow channel collaborative design requires the die to simultaneously adapt to the melt extrusion of both the main profile material and the soft PVC auxiliary material. The two materials must precisely converge at a 5-degree acute angle at the die opening, and the extrusion flow rates must be completely synchronized. Without mature design experience, uneven material fusion and insufficient bonding strength are highly likely to occur, directly leading to product scrap and a significant decrease in yield. Secondly, the design of the soft rubber strip calibrator is crucial. Vacuum pressure is strictly prohibited in the forming area of ​​soft materials. Vacuum formation will cause mold blockage, strip breakage, and machine shutdown. Therefore, the equipment must be equipped with an adjustable localized water spray cooling system to ensure continuous and stable forming of the soft rubber strips through precise water volume control.

5. Simultaneously, the Pre Co-extrusion Tooling in equipment debugging, temperature control, and speed matching. Insufficient experience can easily lead to product dimensional deviations, adhesion defects, and other problems, making it difficult to guarantee mass production stability.

6. Our company has been deeply involved in the R&D and process experimentation of Pre Co-extrusion Tooling since 2002. After 24 years of technological accumulation, we have accumulated numerous successful implementation cases of special cross-sections and highly complex pre-co-extrusion dies. Our team has systematically summarized years of practical experience into a mature design and production process system, which can effectively solve various difficult problems in the industry, such as poor adhesion, mold blockage, and unstable mass production. Customers can consult us at any time if they encounter any technical problems during the production process. Our professional engineers will provide one-on-one precise technical guidance and after-sales support services.