Material Description

Polyurethane (PU) is a versatile polymer known for its exceptional material properties, making it suitable for a wide range of applications. PU is a synthetic material composed of organic units joined by urethane links, which impart it with its distinctive characteristics. Its outstanding mechanical properties include high flexibility, toughness, and abrasion resistance, making it ideal for applications such as automotive parts, footwear, and coatings. PU also exhibits excellent chemical resistance, with a strong resistance to oils, solvents, and hydrolysis, enhancing its durability. Moreover, its low thermal conductivity and good insulating properties make it a valuable material in the construction industry for insulation and sealing purposes. Polyurethane foams, used in mattresses and cushions, offer superior comfort and energy absorption. PU materials can be tailored to specific needs, with a wide range of hardness levels and formulations available. Its ability to be molded and shaped easily further adds to its utility, as it can be cast, extruded, or molded into various complex forms. These diverse attributes position polyurethane as a key material across multiple industries, thanks to its adaptability, durability, and exceptional mechanical and chemical properties.

Tensile Yield
Modulus (MPa)
Point (°C)
Coefficient of
(x 10^-6 /°C)
Absorption (%)
1000 - 120020 - 600.5 - 10.055-800.01 - 0.031.7 - 2.2100 - 2000.01 - 0.5

Design Recommendation

When designing for Polyurethane (PU) in injection molding applications, it is essential to consider the material’s unique properties. PU is known for its versatility and can be formulated to have a wide range of hardness and flexibility. Therefore, it is crucial to select the appropriate PU formulation that matches the specific requirements of the end product. Moreover, in the design of the mold, paying close attention to the gate and runner system is vital, as PU has a lower melt viscosity compared to some other thermoplastics, which can lead to material leakage if not properly controlled. Additionally, PU has a tendency to foam during injection, so proper venting in the mold is necessary to avoid air entrapment and defects in the final product. Finally, ensuring consistent temperature control in the mold is critical to prevent uneven cooling and warping, as PU is sensitive to variations in temperature. In summary, understanding PU’s formulation options, optimizing the gate and runner design, providing proper venting, and maintaining temperature control are crucial design recommendations for successful injection molding with Polyurethane.

Cost Saving Tip

Cost-saving in polyurethane (PU) injection molding processes can be achieved through several technical strategies. Firstly, optimizing the mold design is crucial, as it directly impacts material consumption and cycle time. Employing features like uniform wall thickness, efficient gating, and appropriate cooling channels can significantly reduce material waste and shorten cycle times. Furthermore, selecting the right PU material with an optimal hardness and viscosity for the specific application can enhance efficiency and reduce production costs. Implementing a scientific approach to process parameters, such as temperature, pressure, and injection speed, can also minimize PU waste and improve part quality. In addition, utilizing regrind or recycled PU material, when feasible, can further cut down on material costs. By incorporating these technical cost-saving measures, manufacturers can achieve improved resource utilization and higher overall efficiency in PU injection molding processes.