Thermoset vs. Thermoplastic

Key Differences and Choosing the Right Solution

When it comes to plastic materials, thermoset vs. thermoplastic is one of the most important distinctions manufacturers need to understand. While both play essential roles in various applications, their behavior, recyclability, cost-effectiveness, and processing methods differ significantly. 

At Integrated Molding Solutions (IMS), we specialize in helping clients identify the best material for their specific needs, often transitioning projects from thermoset to thermoplastic for improved performance, efficiency, eco-friendliness, and cost savings.

What Is Thermoplastic? 

Thermoplastics can be melted, reshaped, and reused multiple times without altering their chemical structure. When thermoplastics are heated, they transition from solid to liquid and back to solid when cooled, like freezing water into ice. This property makes thermoplastics highly recyclable. They can be ground down, cleaned, and remelted for reuse without losing performance.

Thermoplastics begin as pellets and are processed using injection molding or extrusion, where the material is heated, shaped, and quickly cooled to solidify. Because thermoplastics do not require chemical curing, cycle times are significantly shorter. This efficiency makes thermoplastics ideal for large-scale production.

Examples of thermoplastics include polypropylene (PP), polyethylene (PE), and nylon.

What is Thermoset? 

Thermosets, on the other hand, undergo a chemical curing process during heating that changes their chemical structure permanently. Once cured, thermosets cannot be melted or reshaped. The chemical changes are irreversible, much like baking a cake or frying an egg. While thermosets can withstand high temperatures without breaking down, they are not recyclable like thermoplastics.

Thermosets typically begin as a liquid resin and involve a more complex curing process, where heat triggers a chemical change that sets the material permanently. This step adds time and complexity to the manufacturing process, resulting in longer cycle times and higher costs.

Examples of thermosets include epoxy resins, silicone rubber, and vulcanized rubber.

How Are Thermoplastics and Thermosets Used? 

Thermoplastics and thermosets each serve unique purposes, depending on the specific application requirements. 

Swapping Thermosets for Thermoplastics 

At IMS, we help clients evaluate whether a thermoset material can be replaced with a thermoplastic alternative. For instance, a customer may request a silicone part (thermoset) for its flexibility and heat resistance. By working with clients to understand the necessary properties of the part as well as its application, IMS can recommend a thermoplastic solution like TPU that matches the tensile strength, yield strength, and shore hardness (flexibility and feel) of silicone, while being easier, faster, and more cost-effective to manufacture.

Our expertise lies primarily in thermoplastic injection molding. If you currently use thermoset materials, our team can assess whether a thermoplastic alternative could provide the same performance benefits while streamlining production and reducing costs.

Benefits of Switching to Thermoplastic 

Thermoplastics are faster, less expensive, and more environmentally friendly than thermosets for several reasons. First, material costs are cheaper. Thermoplastics are more widely used and available, leading to a lower per-pound price. Additionally, recycled or reprocessed thermoplastics provide further cost savings. 

Second, thermoplastics only require cooling time, not curing, allowing for faster cycle times and higher throughput. Third, thermoplastics can be reused, reducing waste and overall material costs. While thermosets have advantages in specific applications, their longer production times,  and lack of recyclability often make them a less economical choice for high-volume manufacturing.

IMS Can Help You Choose the Right Material 

Integrated Molding Solutions specializes in helping our clients navigate plastic material choices for the injection molding process to ensure their parts meet performance, cost, and sustainability goals. Our hands-on approach also includes design optimization, ensuring parts are engineered for efficient manufacturing. 

Contact IMS today to learn how our thermoplastic solutions can help you achieve your manufacturing goals.