One

PVC co-extruded foam board is a new type of composite sheet material made from polyvinyl chloride (PVC) through a co-extrusion foaming process, resulting in a distinctive “dense surface layer + microporous core layer” structure. The closed-cell foam core achieves a density of 0.5–0.8 g/cm³, making it lightweight yet strong, effectively reducing building dead load while offering excellent thermal insulation, soundproofing, fire resistance, waterproofing, and corrosion resistance. It is self-extinguishing (flame retardant) and ideal for applications such as exterior walls, roofs, and partitions, significantly enhancing indoor comfort and building safety.

The material is highly workable—it can be sawn, nailed, drilled, and bonded—and its smooth surface supports lamination, printing, and embossing for versatile design options. Widely used in architectural exterior cladding, interior partitions, ceilings, bathroom furniture, advertising signs, display boards, cold storage insulation, industrial anti-corrosion liners, and packaging, PVC co-extruded foam board stands as an ideal engineering material in the ongoing trend of “replacing wood and steel with plastic.”

Two

The production of PVC co-extruded foam board involves two extruders working in tandem: the main extruder plasticizes the core-layer foaming melt, while the co-extruder supplies the surface-layer rigid melt. After pressure balancing in a distributor, the two melts enter the die, where the surface layer encapsulates the core layer to form a “skin-core” structure. Upon exiting the die, the core layer foams while the surface layer solidifies. The board then undergoes vacuum sizing, cooling, and haul-off cutting to become the finished product. Throughout this process, the co-extrusion die from anhui jwell is the key factor determining board quality. By integrating the “dense surface layer + foamed core layer” in a single forming step, PVC co-extrusion foaming technology delivers comprehensive performance far superior to that of single-layer foam boards.

Three

Technical Advantages of Anhui Jiewei's Co-extrusion Molds for PVC Co-extruded Foam Boards

1. Special coat-hanger flow channel design – solving the problem of thermal degradation of heat-sensitive materials

PVC is a typical heat-sensitive material, prone to decomposition and burning during high-temperature extrusion, which can result in surface defects such as specks, burnt material, or flow marks. High-quality co-extrusion dies employ a special coat-hanger flow channel design that optimizes the melt flow path, ensuring uniform distribution and smooth passage of the material within the die. This significantly reduces residence time and the risk of localized overheating, effectively preventing material degradation from the source, thereby ensuring surface smoothness and internal quality of the board.

2. Co-extrusion distributor – ensuring uniform merging of multi-layer melts

The key to the co-extrusion process lies in precisely merging melts from different extruders within the die to form a stable composite structure. The PVC-specific co-extrusion distributor uses precision flow channel design and pressure balancing to ensure that the core-layer foaming material and the surface-layer rigid material meet at the merging point with consistent flow velocity and balanced pressure. This fundamentally eliminates defects such as delamination or poor bonding, serving as the technical prerequisite for large-scale production of high-quality co-extruded foam boards.

3. Push-pull flexible fine-tuning mechanism – precise thickness control

Thickness accuracy is a core indicator of board quality. Traditional dies rely on choke bars or rigid adjustments, which are cumbersome to operate and slow to respond. The co-extrusion foam board die features a design without choke bars or movable die lips, and is equipped with a push-pull flexible fine-tuning mechanism at the die exit. This allows operators to continuously and sensitively adjust the die lip gap, enabling micron-level thickness correction across different transverse zones. This design not only eliminates the common “thick in the middle, thin on the sides” defect, but also flexibly accommodates the production of multiple specifications within a thickness range of 5 mm to 18 mm.

4. Independent die lip temperature control – optimizing skin layer formation

Temperature control in the die lip area directly affects the surface skin quality and internal stress distribution of the board. High-quality dies are equipped with an independent oil temperature control system that maintains a constant die lip temperature. This ensures a dense and smooth skin layer while effectively reducing internal stress within the board, preventing warpage and deformation, and ensuring dimensional stability and reliable performance during subsequent processing and use.

In Summary: PVC co-extruded foam board is lightweight, high-strength, heat-insulating, and fire-retardant, making it widely used in construction, advertising, and other fields. Its production relies on the co-extrusion process, and Anhui Jwell’s PVC co-extruded foam board die plays a key role in ensuring stable quality: the special coat-hanger flow channel prevents material degradation; the co-extrusion distributor ensures proper layer bonding; the flexible fine-tuning mechanism controls thickness with precision; and the independent temperature control optimizes the skin layer—together delivering high-quality boards.