It’s hard to imagine a world without plastics. The versatile material has different uses in numerous industries. However, to make a precise product from it, it has to go through a heat treating process (also known as Annealing or Normalizing). In this article, we’ll explain what heat treatment is, what it consists of and in which fields we use it.
What is Heat Treatment of Plastics?
Heat treating is a series of controlled heating and cooling processes used to alter the physical or chemical properties of various materials.
Heat treating plastics is a procedure to bond the particles, to polish it and to avoid cracking during the production process. After polymers go through heat treating, their mechanical and thermal properties improve. Moreover, the method removes internal stresses of the material.
Types of Heat Treatment
As mentioned, heat treating has two main types.
1. Normalizing
Normalizing gives plastic material a higher resistance to internal stresses and makes a uniform structure. The material must heat to a specific temperature to change its properties. After heating, the polymer is cooled down at a controlled rate.
Industries use normalizing to get a calculable microstructure. Once this stage ends, it enhances the plastic’s mechanical features. In other words, the polymer can resist stronger impacts. Still, the plastic shrinks during the process for up to 4%.
2. Annealing
Annealing is the second type of heat treatment procedure. It is mostly used to change the properties of metals. Nonetheless, glass and plastic can also go through the annealing process to improve its physical and chemical properties.
Once the annealing process is done the polymer and or other synthetic materials are more malleable and has an improved ductility and wear resistance. It is required in all types of plastic molding. You also get a predictable microstructure with annealing as with normalizing.
Plastic annealing is recommended if:
- The end-use circumstances require stress relief that has to have properties impossible to achieve through materials or the product design
- You have to remove stress after machining
- The material would crack in the post-polishing process due to surface stresses.
Why Do You Need to Heat Treat Plastics?
Heat treating plastics is a cheap way to produce resistant plastics. Certain processes can prolong the plastics’ lifespan, as well as relieve internal stresses caused by manufacturing methods.
Ovens should heat the polymers to a specific degree to introduce new properties. The heat softens the ingredients so you can shape or cut them more easily. What’s more, it improves the material’s strength and prepares it for further heat treatments if needed.
Need a Heat-Treating Oven?
You can find plastics in different industries, ranging from technology and healthcare to industrial manufacturing of consumer goods. Heat treatment of plastics is necessary for most industries that work with polymers and similar synthetic materials.
Despatch manufactures plastic tempering and plastic annealing ovens in both batch and conveyor style. If you need more information about any of our ovens, from oven design, sales to installation and maintenance services, please contact us.
