Uneven plasticization in the extruder?
Thread Content
I am currently using two types of material in combination for extrusion, but after extrusion the two materials do not mix evenly and are distributed unevenly. How can I solve this?
Check the mixing condition in the upper processing stage and consult the plasticization temperatures of the two materials. The situation you described seems to be caused by uneven mixing; since the two materials can be used together, their plasticization temperatures should not differ significantly.
Is it a compatibility issue? Try adding some compatibilizers.
The melt densities of the two materials are different, making it difficult to blend them after melting. It is possible to consider adding compatibilizers, or to use materials with similar properties for blending, such as blending PET and PBT.
First blend and pelletize, then extrude; this may be because the compatibility between the two materials is poor, or it may be difficult to align their processing ranges
First, check the compatibility of the two substances; if their compatibility is poor, it is necessary to consider adding a phase solvent and then increasing the plasticization temperature.
1. Analyze the material to determine whether its properties are prone to confusion. 2. Examine the processing conditions, including the screw and plasticization temperature
If the original poster can explain which two materials are being mixed, everyone will have a clearer understanding of the reason
According to what the poster said, one reason is that the plasticization temperature is not sufficient； Second, the two materials have poor compatibility. One solution is to appropriately increase the temperature in each area ； Second, select a suitable compatibilizer.
Everyone was very enthusiastic and deeply touched. I’ll make sure to reply actively from now on too! Everyone has taken into account the compatibility issues between the two materials as well as the plasticization temperature issue. Another suggestion: The length of the screw might be something to consider; if it’s not long enough, uneven mixing can occur even if the plasticization temperature is appropriate.
Increasing the shear force of the equipment to improve mixing efficiency, combined with the effect of compatibilizers, should suffice; however, it also depends on the specific materials used
I mainly want to mix the rubber powder obtained by grinding used tires with SBR and then extrude it, but the results of extrusion are not satisfactory – holes appear along the edges of the tubes. I’m not sure what can be added to improve the outcome