PU pads (polyurethane pads) are functional gaskets made from polyurethane materials, widely used in industrial, medical, and household applications. Their preparation mainly involves key steps such as raw material selection, mixing and reaction, molding and processing, and post-treatment.
First, the preparation of PU pads requires the selection of high-quality raw materials, including polyols (such as polyether polyols or polyester polyols), isocyanates (such as TDI or MDI), catalysts, foaming agents, and additives (such as flame retardants and antioxidants). The selection of raw materials directly affects the physical properties of the PU pad, such as hardness, elasticity, and durability.
Second, mixing and reaction are the core steps in PU pad molding. Polyols and isocyanates are mixed in a specific ratio, and a catalyst is added to control the reaction rate. The introduction of a foaming agent (such as a physical or chemical foaming agent) causes the mixture to generate bubbles during the reaction, forming a porous structure, thereby giving the PU pad excellent cushioning properties. The reaction is usually carried out at room temperature or under heating conditions to ensure that the polyurethane prepolymer is fully cross-linked, forming a stable polymer network.
In terms of molding processes, PU mats can be produced using casting, molding, or extrusion. Casting is suitable for small-batch customization, where the mixed raw materials are injected into a mold, foamed, cured, and then demolded. Molding is suitable for large-scale production, using high temperature and pressure to rapidly shape the raw materials in a mold. Extrusion is suitable for continuous production of sheet or tubular PU mats.
Finally, post-processing includes trimming, surface treatment, and performance testing. Trimming removes burrs, and surface treatments (such as coatings or printing) can enhance abrasion resistance or aesthetics. Finished products need to be tested for hardness, tensile strength, resilience, and other indicators to ensure they meet application requirements.
Due to their excellent elasticity, impact resistance, and chemical stability, PU mats have wide applications in mechanical shock absorption, medical mattresses, and anti-slip mats. In the future, with the development of environmentally friendly raw materials (such as bio-based polyols) and low-VOC processes, the manufacturing technology of PU mats will become more efficient and sustainable.
