Selection Guide for Plastic Materials

Introduction to Plastic Materials

Plastic is mainly composed of carbon, oxygen, hydrogen, nitrogen and other organic or inorganic elements. The finished product is a solid, which is a molten liquid in the manufacturing process. Therefore, it can be melted by heating, flow by pressurizing, and solidified by cooling to form various shapes. This huge and changing multi end material group becomes plastic. The selection of plastic materials is to select a suitable variety among many resin varieties.

Classification of thermoplastics

Classification of thermoplastics

High strength plastic materials and special injection molding materials are usually necessary materials for various injection molding products for communication, automobile, military, national defense, aerospace and medical applications. The strength, toughness, high temperature resistance and durability provided by these special materials are unmatched by standard injection molding plastics. Please refer to the link: High Strength Plastic for how to select high-strength plastic materials and special injection molding materials

Selection Guide for Plastic Materials

Collect and analyze customer product design requirements:

• User requirements, such as application scenario, service environment and service life
• CE/UL/CCC/RoHS certification requirements
• Appearance requirements, such as transparency, raw material color, surface treatment, etc
• Structural requirements, such as bearing capacity, impact, drop, vibration, etc;
• Dimensional accuracy requirements for plastic products (see the table below)
• Cost requirements

Translate the collected design requirements into general material requirements

• Material property requirements:
  • Phyiscal properties, such as shrinkage, relative density, water absorption, melt index, moisture absorption balance, etc
  • Mechanical properties, such as tensile strength, yield strength, impact strength, bending strength, etc
  • Electrical properties, such as dielectric constant, dissipation factor, dielectric strength, resistivity, etc
  • Flame retardancy, such as flame retardancy, oxygen index, burning wire flammability index, etc,Flame retardant grade: from HB, V-2, V-1, V-0,5VB to 5VA
  • Thermal properties, such as HDT, RTI, melting point, thermal conductivity, linear thermal expansion coefficient, Vicat softening point, etc
  • Environmental performance, such as chemical resistance, weather resistance, etc
• CE/UL/CCC/RoHS certification requirements
• Availability of raw materials:
  • Price of raw materials
  • Source of raw materials
  • Waste disposal of plastic processing
  • Processing cost

Compare the general requirements of material properties with the physical property table of plastic of specific brand to find the most suitable material