Thermoplastics are a class of polymer that encompasses a wide range of materials, each with its own unique mechanical and chemical properties, making it ideal for a variety of applications across multiple industries that require high-performance components, including electronics, aerospace, and transportation. However, the nuances of the thermoplastic composition, as well as the high demands placed on them in critical applications, present an array of challenges when it comes to manufacturing and processing thermoplastics.
Because high-performance thermoplastics often need to meet strict requirements and hold up under intense conditions, expert knowledge and experience are critical when working with thermoplastics in order to safeguard against component failure, manufacturing inefficiencies, and potential economic loss.
Processing Thermoplastics: Some Challenges and Considerations
The Importance of Material Selection when Processing Thermoplastics
Choosing the right thermoplastic material for a specific application can be challenging. Each thermoplastic has its own unique molecular structure and not every thermoplastic is right for every situation.
Properties such as glass transition temperature, tensile strength at yield, and thermal conductivity can vary drastically from material to material and will have a significant impact on how well the thermoplastic performs under a specified set of conditions. Key factors to keep in mind when evaluating different thermoplastic materials include:
- Thermal properties – Thermal properties are one of the most important characteristics when it comes to determining the suitability of a thermoplastic for critical applications. Thermal properties include everything from heat deflection temperature to the glass transition temperature, but the key determinant is a thermoplastic’s melting point. The degree of variance in melting points among thermoplastics is vast and can range anywhere from 50℃ for some low-density polyethylenes to 300℃ for high-performance engineering plastics like PEEK. The melting point not only dictates the temperatures required in the manufacturing process but also indicates how certain materials perform when subjected to high levels of heat in the end-use product.
- Chemical properties – Many applications require exposing thermoplastic components to various chemicals such as acids, bases, solvents, and oils. Another key characteristic of a thermoplastic material is its ability to resist attack from these chemicals. If the wrong material is chosen, it could cause the component to degrade or become brittle, thereby compromising the application and leading to performance issues or possible part failure.
- Mechanical properties and strength – Mechanical properties of thermoplastics play a major role in the performance of end-use products as these properties determine the behavior of the material when force is applied. It’s essential to understand the ways in which thermoplastics differ in strength, stiffness, ductility, and impact resistance in order to make the best selection of materials for your specific application.
Challenges in Processing Thermoplastics
With narrow processing windows, manufacturing thermoplastic components requires strict control of temperature, pressure, and cooling rate to avoid defects and product failure. Several thermoplastics also possess nuanced characteristics and behaviors that require additional handling procedures and highly specialized equipment to be properly processed.
Many thermoplastics, such as polycarbonate, acrylic, and nylon, are moisture sensitive and must be dried before undergoing a process like injection molding. Failure to remove the moisture that these polymers have attracted and retained over time could result in material degradation during manufacturing and eventual negative impacts on end-use product performance and viability.
There are also several materials, like PEEK and PPS that require extremely high temperatures in order to be melted down and molded into the desired component shape. These materials not only require highly specialized equipment that can reach these temperatures but they must be handled with extreme care to avoid cracking and shrinkage. Expertise is required to handle materials properly and avoid additional costs and major product defects.
Ensinger is a Plastics Partner With Expertise in Thermoplastics
Ensinger has decades of experience in meeting customers’ manufacturing needs through injection molding services for high-performance thermoplastics across a wide range of industries. We use our years of expertise to understand your unique challenges, meet compliance standards, and make material recommendations based on practical testing.
Connect with Ensinger Precision Components today to learn more about how we can handle your thermoplastic processing needs so you can focus on growing your business.