Thermoplastic and thermoset composite engineering are two extremely common types of material engineering processes. Although the two processes have similar names, each engineering method yields a product with unique attributes. Therefore, it is vital to understand the difference between the two processes.
What Is Thermoset Composite Engineering?
As the name suggests, “thermoset composite engineering” is an engineering process that is performed using composite materials. The thermoset material used in this process is a polymer. Any thermoset polymer used in this process is alternatively referred to as a “thermosetting resin” or “thermoset plastic.”
These matrix materials are usually in a liquid form at room temperature, or they can be partially cured or “B-staged” to form a flexible partially cured solid. From here, any number of composite manufacturing techniques are used such as resin transfer molding, filament winding or even hand layup to form the composite shape. To cure the composite, heat or a chemical accelerant will be applied. Epoxy, polyester, polyimide and a host of other common matrix materials are thermosetting resins.
Thermoset composites retain their shape after they are cured. However, they can degrade if exposed to excessive temperatures.
Due to the heat-resistant qualities of the material, thermoset composite engineering processes are used when the design team is concerned about heat. For instance, thermosets are often used when creating chemical processing equipment, electronic housing for appliances, and similar items.
There are two primary drawbacks of thermoset composites. First, the material cannot be recycled or otherwise repurposed. Additionally, thermoset composites cannot be remolded after they are cured.
What Is Thermoplastic Composite Engineering?
Thermoplastic composite engineering uses resins that maintain a solid state at room temperature. These thermoplastics become soft and pliable when heat is applied. If engineers continue to apply heat, the thermoplastics will melt into a liquid form.
Modern thermoplastics are easier to engineer into usable products as they do not need to be cured with chemicals. Once melted into a liquid state, thermoplastics can be poured into a mold and then cooled.
Thermoplastics are used in a wide range of applications. They are used to create machine components when heat exposure is not a concern. The most well-known use case of thermoplastics is in manufacturing plastic grocery bags.
Regular thermoplastics can be recycled without negatively impacting the attributes of the material. The material can also be reheated and subsequently reshaped as well.
However, thermoplastics cannot be used in high-heat applications. The material will deform and ultimately melt. Another downside to thermoplastics is that the material is usually more costly than thermosets and the composite processing methods are not as mature as they are for thermosets.
Thermoset composite engineering is the more versatile of the two engineering methods for several reasons, including the thermal stability, chemical resistance, and structural strength of thermoset composites.
The aforementioned attributes make thermoset plastics a prime engineering solution for a multitude of different applications. This material is used to create products such as:
Although thermoplastics are not as robust in terms of durability and heat resistance, these materials are also suitable for many different purposes. The recyclability of thermoplastics is unquestionably the most redeeming quality of this widely-used composite engineering material.
In summation, both materials have their share of strengths and weaknesses. Engineers should select which composite to incorporate into their design based on the unique demands of their intended application.