Wha is the essential for stable plastic injection molding - material temperature?

Metal insert molding parts                    

 

Among the six major resistances that affect plastic flow, "material temperature setting" has the greatest influence. First of all, let us have a basic understanding of the change of material temperature: the melting state of plastic raw materials in the material tube can be imagined as the state where the molecular chains of the plastic become loose. Assuming that the temperature of the material in the material tube is 210 degrees, When the temperature rises to 230 degrees, the molecular chain entanglement becomes more fluffy.

In simple terms, when the temperature rises, the viscosity of the plastic decreases, and when the viscosity decreases, the fluidity increases.
For example, suppose we shoot the ABS material at 210 degrees and 230 degrees respectively, it can be imagined as two horses racing, and the ABS with material temperature of 230 degrees will run faster.

Therefore, moderately increasing the material temperature can improve fluidity and reduce flow resistance. However, when using high material temperature production, the following points should be paid attention to:

1. Types of raw materials

In plastic injection molding, if the raw materials used are "fireproof materials", "materials with poor thermal stability" and "acid materials", when heating the material temperature, if it can be lower, it should not be higher. Due to these three types of raw materials, it is easy to cause risks such as "raw material cracking" or "reduction of physical properties" due to high temperature. In addition, it is also easy to volatilize toxic gases during the processing process, causing harm to the human body.

2. Product color

When the color of the injected product is white, transparent or light, it is easy to cause color difference or slight yellowing of the finished product due to high material temperature.

 

3. Production cycle

In order to ensure the production quality, any raw material should not stay in the material tube for too long. It is recommended that the plastic stay in the material tube for no more than 3 to 5 minutes as a principle.

Finally, I would like to share a suggestion on the temperature setting of the material: when encountering difficulties in mold trial or machine adjustment, please refer to the processing conditions provided by the raw material manufacturer first, and check the temperature of the material tube, and you may be able to find a way to improve the plastic injection.

 

Further understanding for the essential for plastic injection molding stability

This is just a partial overview of plastic injection molding. Are they the right knowldge for you? Not sure how to apply them to your

next project? Just contact our technical experts and we can offer helpful advice about how to get the best results from its processes.