The performance core of PVC corner protectors and conduit depends on the material formula and production process. High quality products need to balance practicality and environmental protection, strictly follow industry standards, and avoid problems such as aging and brittleness caused by inferior raw materials. The material formula and production process of the two have both similarities and differentiated designs.
The core material is made of polyvinyl chloride (PVC) resin as the base material, combined with various auxiliary materials to optimize performance: stabilizers are used to prevent PVC material from high-temperature decomposition and low-temperature brittleness, prolong service life, and are divided into lead salt stabilizers (low cost, gradually phased out) and environmentally friendly calcium zinc stabilizers (lead-free and mercury free, in line with modern environmental requirements); Toughening agents are used to enhance product toughness, avoid stress fracture, corner protectors focus on impact resistance, and threading tubes focus on compression and bending resistance; Fillers (such as calcium carbonate) are used to optimize the molding effect of products, control costs, and strictly control the addition ratio to avoid affecting product strength. In addition, flame retardants (such as magnesium hydroxide and aluminum hydroxide) will be added to the flame-retardant version of the conduit, color masterbatch will be added to the decorative version of the corner protector, and the mesh cloth composite corner protector will be combined with glass fiber mesh cloth to enhance the bonding strength.
The production process is centered around extrusion molding, which can be roughly divided into four steps: raw material mixing, extrusion molding, cooling and shaping, and cutting and inspection. The first step is raw material mixing, where PVC resin is mixed with various auxiliary materials in proportion and stirred evenly to ensure uniform performance; The second step is extrusion molding, which involves feeding the mixed raw materials into an extruder and extruding them from the corresponding mold through heating, melting, and screw extrusion (the corner guard has a irregular cross-section, and the threading tube has a circular cross-section); The third step is to cool and shape the product by using a cold water tank or air cooling method to ensure dimensional accuracy; The fourth step of cutting inspection is to cut according to the standard length, test the product size, strength, appearance, etc., and reject unqualified products.
Differentiated process: After extrusion molding, the mesh fabric composite corner protector will add a mesh fabric bonding process to ensure a tight connection between the mesh fabric and the PVC body; The corrugated conduit needs to use a dedicated corrugated mold, and the spacing and thickness of the corrugations should be controlled during the extrusion process to ensure flexibility and impact resistance; Flame retardant and corrosion-resistant products will precisely control the proportion of specialized auxiliary materials during the raw material mixing stage, and subsequently add performance testing processes to ensure compliance with corresponding functional standards.