Method for manufacturing a polypropylene composition with controlled fluidity
The method for manufacturing a composition consists in bringing into contact a product containing mostly polypropylene having a controlled fluidity less than 10 g/10 min with highly fluid polypropylene and a polymer grafted with maleic anhydride.
1. Method for manufacturing a composition, comprising bringing into contact the following three components:
a product containing mostly polypropylene having a controlled fluidity according to standard ISO 1133 (230° C., 2.16 kg) less than 10 g/10 min, present in an amount from 82% to 88% inclusive, by total weight of the composition,
polypropylene having a controlled fluidity according to standard ISO 1133 (230° C., 2.16 kg) greater than 400 g/10 min, present in an amount from 7% to 13% inclusive, by total weight of the composition, and
a polymer grafted with maleic anhydride, present in an amount from 2% to 8% inclusive, by total weight of the composition.
2. Method according to claim 1 , said method further comprising two steps, performed in this order:
bringing into contact the product containing mostly polypropylene and the polypropylene having a controlled fluidity according to standard ISO 1133 (230° C., 2.16 kg) greater than 400 g/10 min, and
adding the polymer grafted with maleic anhydride.
3. Method according to claim 1 , wherein the product containing mostly polypropylene and the polypropylene having a controlled fluidity according to standard ISO 1133 (230° C., 2.16 kg) greater than 400 g/10 min are brought into contact so as to obtain a first mixture and the polymer grafted with maleic anhydride is added in a second stage to this first mixture.
4. Method according to claim 1 , wherein the polymer grafted with maleic anhydride is Styrene Ethylene Butadiene Styrene (SEBS).
5. Method according to claim 1 , wherein the components are brought into contact in an extruder.
6. Method according to claim 1 , wherein the components are brought into contact in a plasticating screw.
7. Method according to claim 1 , wherein the product containing mostly polypropylene contains between 5% and 10% inclusive of polyethylene, by total weight of said product.
8. Method according to claim 1 , wherein the product containing mostly polypropylene is obtained at least partly from recycling.