EANS UPVC window sill production line uses a continuous extrusion process to convert UPVC compounds into accurately formed window sill profiles. The complete process typically includes material mixing, controlled feeding, extrusion and plasticization, die forming, vacuum calibration and cooling, surface finishing, haul-off, cutting, and stacking.

• 1. Raw Material Mixing & Blending: UPVC resin, calcium carbonate, stabilizers, processing aids such as ACR/CPE, and titanium dioxide are blended according to the required formulation for PVC window sill profiles. Hot mixing typically reaches 115–120°C, followed by cold mixing to approximately 40–45°C for stable material preparation.

• 2. Feeding & UPVC Extrusion Plasticization: The prepared PVC window sill compound is continuously fed into the conical twin-screw extruder of the UPVC Window Sill Making Machine. Controlled heating, conveying, and shearing plasticize the material into a uniform melt, with processing temperatures typically around 170–190°C. Vacuum degassing helps remove residual moisture and volatile gases.

• 3. Window Sill Profile Die Forming: The UPVC window sill melt is pushed through a window sill profile extrusion die designed according to the required cross-section. The die can be matched to different UPVC window sill profiles, including variations in width, thickness, hollow structure, and reinforcing ribs.

• 4. Vacuum Calibration & Cooling: The hot extruded PVC window sill enters the vacuum calibration and cooling system, where controlled vacuum pressure maintains the required profile dimensions and cross-sectional shape. Circulating cooling water, typically around 15–20°C, gradually cools and solidifies the PVC window sill profile.

• 5. Surface Laminating & Continuous Haul-Off: After calibration and cooling, an optional surface laminating unit can apply protective film to the UPVC window sill profile. The haul-off system continuously pulls the PVC window sill board at a controlled speed of approximately 0.8–2.5 m/min, supporting stable PVC window sill extrusion.

• 6. Automatic Cutting & Stacking: The continuous PVC window sill profile is cut into the required lengths by an automatic or servo tracking cutting system. Finished UPVC window sill profiles are then transferred to the stacking table for inspection, counting, and packaging.

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• Optional Surface Decoration: For marble-effect, wood-grain, or other decorative finishes, the UPVC Window Sill Production Line can be equipped with an online heat transfer or lamination system according to the required surface design and production configuration.