Can the same formulation be used for both single-screw and twin-screw extrusion when producing rigid PVC window profiles?

Can the same formulation be used for both single-screw and twin-screw extrusion when producing rigid PVC window profiles?

Generally, it is not possible. 
When producing hard PVC window profiles using different processing methods, appropriate adjustments should be made to the formula based on the characteristics of the molding process. 
When producing hard PVC window profiles using a single screw extruder, since the heating process of the material in the extruder is relatively long, the dosage of stabilizer (trisodium) generally needs to be increased, and calcium soap type heat stabilizers should be used in combination to prevent the plasticization speed from slowing down. At the same time, the dosage of lubricant should not be too large, otherwise it will affect the material's transportation. 
When using a twin-screw extruder, the heating process of the material in the extruder is relatively short. The dosage of the heat stabilizer can generally be appropriately reduced. However, since a higher molding temperature is usually adopted, in order to prevent the material from adhering to the equipment, the dosage of the lubricant usually needs to be appropriately increased. It is advisable to use polyethylene wax for lubrication rather than paraffin wax, as paraffin wax has a low viscosity and may affect the lubrication effect at the die mouth.
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