While overmolding is a versatile manufacturing process, it is important to consider and understand the requirements needed for every part created. Overmolding material compatibility is the most important consideration because if the materials used are not chemically and thermally compatible, the product may be deformed and have poor performance.
Materials for Overmolding
Overmolding allows manufacturers to create strong, durable, and consistent parts by combining multiple materials. There are many combinations of materials that can be used to create any one part. Luckily, there are many resins common in the industry that each have their own advantages.
High Density Polyethylene (HDPE)
HDPE is one of the most versatile and popular plastics used in the industry. Its properties are great for large parts that require outstanding physical performance like corrosion-resistant piping, plastic lumber, and many other products. HDPE has many other benefits that make it an ideal material including:
- Excellent strength but very lightweight
- Impact and weather-resistant to keep product quality intact in harsh environments
- Very malleable and can be easily molded into any shape
- Great for replacing heavy materials and sustainability value.
Acrylonitrile Butadiene Styrene (ABS)
ABS is an industry chosen material in overmolding processes to reach specific requirements in applications such as consumer electronics or automotive parts. ABS is cost-effective in production and provides many value-added benefits like:
- Low melting point which makes it easy to use in processes like injection molding or 3-D printing
- Low heat and electricity conductivity for products needing electrical insulation protection
- Highly recyclable
- Glossy, smooth, surface finish that can also be compatible with a variety of glues or paints
- Takes color easily in order to meet specific project specifications
- Very resistant to chemical erosion and physical impacts to withstand both environmental demands and heavy use.
- Easily moldable with great tensile strength
Polymethyl Methacrylate Acrylic (PMMA)
PMMA is an economical material used for applications requiring excellent optical, light, transmittance, and weatherability. Common products include lighting and optical applications. PMMA is sometimes referred to as acrylic glass as it is a lightweight, shatter-resistant alternative to glass. Advantages include:
- Resistance to UV radiation and weathering
- High refractive index and clarity
- Great light transmissibility (white light transmittance can be as high as 95%)
- Has the greatest surface hardness of any plastic, making it scratch resistant
- Dyes can be added to get a certain color
- Chemical resistance
Thinking about the requirements of your part while trying to keep in mind the individual characteristics of each material can make the overmolding process overwhelming. Especially, with a new product design process.
Our experts at PMC are extremely knowledgeable in working with resins and have 45 years of experience in overmolding all types of projects. We work with our customers to make sure the overmolding material compatibility will yield the highest quality product for their applications.