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The Annealing Process of Plastics

The annealing process is performed on plastics to remove stress that could potentially result in cracking, wearing, poor chemical resistance, or degradation of the performance of the material. Stress can be caused by any process that intrudes heat to a plastic.

Since plastics are poor conductors, rapidly heating and then cooling the material is stress-inducing. Mechanical processes like molding, casting, extrusion, cutting, drilling, and more can cause stress to plastics. Using annealing on machined plastic helps to ensure dimensional stability over time.


The Plastic Annealing Process at Upland Fab 

The annealing plastic process involves heating a part up to half of the melt temperature for a period of time and then cooling the part back down to allow the part to relax. The process at Upland Fab ensures longevity and quality in our plastic parts. Our process involves:


Determine the Proper Temperature and Time 

Depending on the type of plastic, the temperature and time spent in the annealing process differs. Different plastic materials experience softening at different temperatures, so it’s important to customize the process. The parts are analyzed beforehand to determine the best process for the specific material.


Design the Annealing Process Tailored to the Specific Plastic Part

In addition to the temperature and cycle time, we also determine when annealing should occur. Depending on the application, the process can happen before or after machining and finishing. The racking system for the plastic part is also customized to meet the application needs.


Perform the Specific Annealing Cycle

Once the right process is determined, the material is heated slowly to the temperature just below the specific plastic’s softening point. Once the specified temperature is reached, it is held for a specified amount of time depending on material and thickness, the temperature is then lowered slowly over time until the part reaches room temperature.


The Benefits of Annealing Plastic

The plastic annealing process offers many advantages, both in the short-term and the long-term. These benefits include:


  • Increased dimensional stability
  • Improved integrity
  • Reduced shrinkage and expansion
  • Improved chemical resistance
  • Tighter tolerance capability
  • Improved wear resistance


Discover More About Upland Fab's Plastics and Composites Machining

We specialize in machining complex plastic and composite parts.  Our plastics are used for a variety of industries, from aerospace to electronics to commercial applications.  Our engineers are experts in plastics and will work with you to create the highest quality parts that meet your exact needs.

If you have questions about your project's unique needs or specifications, please contact us to get in touch with one of our engineers today!


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