The temperature of the plastic extruder has a significant effect on the effect of the plasticizer.
When the extruder temperature is low:
1. The plasticizer may not be fully diffused and evenly distributed in the plastic matrix, resulting in poor local plasticizing effect, affecting the overall flexibility and processing properties of the plastic.
2. The melt viscosity of plastics is high, even if there is a plasticizer, it is difficult to achieve the ideal fluidity, increasing the difficulty of extrusion and energy consumption.
As the extruder temperature rises:
1. The diffusion rate of the plasticizer is accelerated, and it can be more evenly dispersed in the plastic, giving full play to its role of reducing melt viscosity and increasing flexibility.
2. Help to improve the compatibility between plastics and plasticizers, so that the plasticizing effect is more significant.
However, if the extruder temperature is too high:
1. It may lead to volatilization loss of plasticizer, reduce its effective content, and affect the plasticizing effect.
2. It may also cause thermal degradation of plastics and affect product quality.
For example, in the production of PVC pipes, if the extruder temperature setting is unreasonable, too low will make the pipe surface rough, hardness and not easy to bend; Too high may lead to bubbles and discoloration of the pipe, while the plasticizer volatilizes too much, which reduces the flexibility of the pipe.
Therefore, in the plastic extrusion process, it is necessary to accurately control the temperature of the extruder according to the type of plastic, the characteristics of the plasticizer and the product requirements in order to obtain the best plasticizing effect and product quality.
And there are obvious differences in the temperature requirements of different types of plasticizers for plastic extruders:
For phthalate plasticizers, such as dioctyl phthalate (DOP) :
This type of plasticizer has good compatibility and usually works better at relatively low extrusion temperatures. In general, the extruder temperature can be set in a medium range.
Aliphatic dibasic acid ester plasticizers, such as dioctyl adipate (DOA) :
Their volatility is relatively high, so the extrusion temperature should not be too high to reduce the volatilization loss of the plasticizer. However, the temperature should not be too low, otherwise it may affect the plasticizing effect and product performance.
Phosphate plasticizers, such as tritylene phosphate (TCP) :
Due to its good thermal stability, the extrusion temperature range is relatively wide, but in order to ensure good plasticizing effect and product quality, it is still necessary to make reasonable adjustments according to the specific plastic formula and product requirements.
Polyester plasticizer:
This type of plasticizer has a large molecular weight, a relatively slow diffusion rate, and usually requires a high extrusion temperature to promote its uniform dispersion and plasticization in plastics.
For example, in the production of soft PVC products, if DOP is used as a plasticizer, the temperature of the extruder can be set between 160-180 °C; When using polyester plasticizers, the extruder temperature may need to be increased to about 180-200 °C to achieve the ideal plasticizing effect and product performance.
It should be noted that to determine the optimal temperature of the extruder in actual production, it is also necessary to consider various factors such as the type of plastic, other components in the formula, product requirements and equipment characteristics.
