Solving the challenges in PVC free-foaming board production: Anhui Jiewei, a manufacturer of PVC free-foaming board molds and flat-die extrusion systems.

　　Solving the challenges in PVC free-foaming board production: Anhui Jiewei, a manufacturer of molds for PVC free-foaming boards, is a producer of flat-die extrusion systems. We specialize in manufacturing a wide range of single- or multi-layer co-extrusion dies for plastic sheets, boards, films, and coated products, as well as distributors, melt-metering pumps, screen changers, mirror-finish rollers, and other ancillary equipment to complement various finished-product processing lines: I 87⑤ /5O5⑤/7#PVC free-foaming board mold#62.

　　1. PVC free-foaming board (also known as Chevreau board) is made from polyvinyl chloride as the base material and formed through extrusion foaming, resulting in a uniform honeycomb structure inside and a naturally textured, matte surface. It boasts advantages such as lightweight yet high strength, complete water resistance and corrosion protection, self-extinguishing upon removal from flame, and being formaldehyde-free. It also exhibits excellent machinability: it can be sawn, planed, nailed, drilled, and carved, as well as thermoformed, welded, and UV-printed. Its surface has strong adhesion, making it suitable for screen printing and mounting artwork. Thanks to its outstanding weather resistance and dimensional stability, this board is widely used in advertising production, architectural decoration, furniture and cabinetry, vehicle and vessel interior panels, and chemical corrosion protection—particularly in applications with stringent requirements for water resistance, environmental friendliness, and secondary processing.

　　

　　PVC Free-Foaming Board

　　Second, production centers on a conical twin-screw extrusion process, involving high-temperature mixing and plasticization, cold mixing, extrusion, foaming, and cooling and shaping. The main processing challenges lie in PVC’s strong thermosensitivity and narrow processing temperature window, requiring a careful balance between foaming temperature and the risk of thermal degradation; melt strength must be sufficient to encapsulate the bubbles and prevent density inconsistencies; and when producing sheets of varying thicknesses, wide-flow channels are prone to defects. To address these issues, a specialized hanger-type flow-channel die is employed, featuring an adjustable upper die lip, a replaceable lower die lip, and a vertical throttling-bar adjustment mechanism, thereby ensuring dimensional accuracy and superior surface quality of the finished sheets.

　　

　　PVC Free-Foaming Board Mold

　　Third, the mold is hailed as the “heart” of PVC free-foaming board production, and Anhui Jiewei’s ingenious structural design lies at the core of overcoming the numerous technical challenges inherent in the foaming process of thermosensitive plastics. First, the specially designed hanger-type flow channel ensures, through geometric deformation, that the melt flows an equal distance from the central inlet to both side die lips and experiences perfectly uniform pressure distribution, thereby eliminating the common defect of a thicker center and thinner edges in wide-format boards and achieving more uniform transverse thickness. At the same time, the streamlined flow channel leaves no dead zones, effectively removing the risk of thermal degradation caused by prolonged residence of the PVC and addressing the critical issue of easy ablation in thermosensitive materials. Second, the vertical throttling-bar adjustment mechanism serves as a fine-control tool: by installing throttling bars across the width of the die head, local melt-flow resistance can be increased or decreased, allowing precise correction of the melt velocity profile at the die lip exit. This effectively mitigates the “M-shaped” or “W-shaped” flow defects that often occur during wide-format production, ensuring flat, wrinkle-free boards—particularly crucial when producing boards 2 to 20 mm thick, where this device is an indispensable key component. In addition, the combined design of an adjustable upper die lip and a replaceable lower die lip endows the production line with exceptional process flexibility: the upper die lip can be finely adjusted in real time to correct localized thickness tolerances, guaranteeing board dimensional accuracy; meanwhile, the lower die lip can be quickly swapped according to product thickness, easily accommodating the broad range from thin to thick boards (2–20 mm). As a result, the same production line can efficiently manufacture both thin and thick boards while consistently meeting stringent precision requirements for all specifications. It is precisely the synergistic interaction of these three core structural features that enables the mold to fully unlock the potential of the raw-material formulation and extrusion process, transforming them into high-quality boards and establishing the mold as the core technological equipment that ensures precision, efficiency, and stability in foam-board production.

 

　　PVC Free-Foaming Board

　　Summary: PVC free-foaming boards are based on polyvinyl chloride and find wide application. The production process centers on conical twin-screw extrusion, with key challenges including the material’s high thermal sensitivity. The die is the “heart” of the production line; Anhui Jiewei’s three innovative structural features—the specialized hanger-type flow channel, vertical throttling-bar adjustment, and adjustable upper die lip combined with a replaceable lower die lip—work in concert to ensure board dimensional accuracy, processing efficiency, and operational stability.