Thermosets compared to thermoplastics.
Thermoset or thermoplastic?
When talking about advanced composite materials, thermoset-based composites are more established and have been used for over 40 years in high-performance environments, including aerospace and Formula 1 motorsport. So, how do thermoplastics differ, and what advantages do they offer over their more established thermoset counterparts?
Fundamentally, polymer science is what distinguishes thermoplastics from thermoset composite materials. Thermoplastics soften when heated and can be remelted and reformed. Thermosets undergo a chemical reaction when placed under heat (also known as “curing”), which is irreversible.
A wide range of thermoplastic resins.
At Oribi, we use a wide range of engineered thermoplastic resins, in partnership with our key supply partners, such as Celanese, Toray, Solvay, Victrex, Hexcel and others. We select from this family of thermoplastic polymers based on the specific end use requirements. Our process is capable of processing an enormous range these melt-processable polymers, from very high temperature PEEK and PEKK polymers, down to low temperature polyolefins, such as PP and PE.
The benefits of thermoplastic composites.
Rather than using two-part epoxies or heat/cure epoxies, a thermoplastic composite utilizes plastics as the matrix binder that holds the fibers together during processing. There are many kinds of plastics that are compatible within our manufacturing process; and each of them have common properties - toughness, impact resistant, and durability, and ability to be processed rapidly into structural components.
LOW VOID CONTENT
Because a thermoplastic material requires an enormous amount of heat and pressure to be formed properly, the material is compressed and formed under very precise operating conditions, leaving very low void content within the finished part. Air voids are considered flaws within a composite part and are generally deemed undesirable. A well-formed thermoplastic composite part can have less than 1%, making it perform better in every way.
HIGH VOLUME MANUFACTURING
Thermoplastics are processed by heating and melting and are rapidly formed into final part dimensions in seconds. By exhibiting significantly shorter cycle times than thermoset systems, thermoplastic composites are the ideal material for high volume manufacture of high precision, repeatable composite parts, making the technology much more commercially attractive for all markets.
During the processing of a thermoplastic composite there are NO toxic smells, fumes, or harmful discharges. This makes it safer and more worker friendly to manufacture. In addition, the cycle-times of thermoplastic parts are regulated by how fast heat can get in, and out, of each part instead of having to manage a chemical reaction.
PART CONSOLIDATION AND DESIGN FREEDOM
Thermoplastic composites can be further enhanced through Over Molding (or injection molding) of short fiber reinforced or neat thermoplastic resin. The polymer chemistry enables a superior cohesive bond between the two material substrates, thereby enabling further design freedom for cosmetic or functional elements into your part, while also reducing final part count and requirements for final part assembly.
Using thermoplastic composites, you can achieve significant improvements in strength-to-weight ratio when compared to other materials, such as metals or non-reinforced plastics. The strength and resiliency of thermoplastics also typically make them ideal as a matrix material in a composite material because they retain strength characteristics while holding the fibers tightly together in the finished structural component.
Thermoplastics are common in our everyday life - they are tough, strong, and typically economical to purchase, and used in everything from water bottles to aircraft structures. More importantly, thermoplastics are eco-friendly as they are recyclable and do not out-gas harmful toxins during production. Not only can you build thermoplastic composite parts using recycled plastic material, but the final part can even be recycled to make other products.