Knowing the correct plastic material melt & mould temperatures is essential for all manufacturers. Injection moulding at the incorrect temperatures can have a significant impact on the final product, including the appearance & strength of the product. The table below demonstrates the optimal melt and mould temperature ranges of various plastic materials, to ensure product quality and manufacturing efficiency.

As plastic heats up and melts, thermal expansion causes it to occupy more space. Because of this, application, or lack of atmospheric pressure may suppress, or accelerate the expansion: applying an adjustment to the ultimate melting or moulding temperature in any given scenario.

While understanding a plastic’s melting and moulding temperature is typically straight forward, there are other important factors to consider.

This information should be used as an 'on the spot' reference only. Users should always follow the material suppliers processing data sheets. The data is provided “as is” and without any representation or warranty of any kind, including that it is fit for any purpose or of merchantable quality, or functions as intended or at all. Your use of this data is entirely at your own risk and PlastikCity accepts no liability of any kind.

Another consideration is melting point depression caused by impurities in a particular plastic material. This is easily understood as analogous to roads being “salted” during the winter, with an impurity being added to adjust the melting point of ice.

Amorphous polymers (made from atactic polymer chains) on the other hand have no such structure, which can make their exact melting temperature less predictable, leading to temperature ranges being more suitable for classifying their melting points.

Finally, the molecular structure of a plastic is important to consider. Crystalline polymers (consisting of syndiotactic and isotactic polymer chains) that are highly structured, typically have more specific melting points, which can be reliably targeted to achieve the same effect at a definite temperature.