A method for manufacturing a plastic composition, comprising: mixing - thermoplastic polymer material particles and - thermoset composition particles comprising cured thermoset polymer reinforced with fibres, the mixing comprising - rising the temperature of the composition and at least partly melting the surface of thermoplastic polymer material particles, and - simultaneously mixing the particles allowing thermoset composition particles adhere to the thermoplastic polymer material particles, and - cooling the composition, wherein the mixing comprises: - mixing in a high intensity mixer as a batch process, - adding a batch of the thermoplastic polymer material particles and a batch of the thermoset composition particles in the high intensity mixer, the mixer comprising • a vessel establishing an interior space environmentally separable from an exterior space outside of said vessel, • an agitation system comprising mixing and shear heating means arranged in said interior space, and • drive means adapted to rotate said mixing means, - agitating the particles by the mixing and shear heating means, resulting - rising the temperature of the composition above the glass transition temperature (Tg) of the thermoset composition particles and thereby - allowing the thermoset composition particles to soften and get downsized into fines by mechanical forces in said vessel, - allowing the surface of thermoplastic polymer material particles melting at least partly, - allowing thermoset composition particles adhere to the thermoplastic polymer material particles, thus forming agglomerates comprising the thermoplastic polymer material and the thermoset composition and optional fillers and additives, and - cooling the agglomerates by lowering the energy of the agitation. - thermoplastic polymer material particles and - thermoset composition particles comprising cured thermoset polymer reinforced with fibres, the mixing comprising - rising the temperature of the composition and at least partly melting the surface of thermoplastic polymer material particles, and - simultaneously mixing the particles allowing thermoset composition particles adhere to the thermoplastic polymer material particles, and - cooling the composition, wherein the mixing comprises: - mixing in a high intensity mixer as a batch process, - adding a batch of the thermoplastic polymer material particles and a batch of the thermoset composition particles in the high intensity mixer, the mixer comprising • a vessel establishing an interior space environmentally separable from an exterior space outside of said vessel, • an agitation system comprising mixing and shear heating means arranged in said interior space, and • drive means adapted to rotate said mixing means, • a vessel establishing an interior space environmentally separable from an exterior space outside of said vessel, • an agitation system comprising mixing and shear heating means arranged in said interior space, and • drive means adapted to rotate said mixing means, - agitating the particles by the mixing and shear heating means, resulting - rising the temperature of the composition above the glass transition temperature (Tg) of the thermoset composition particles and thereby - allowing the thermoset composition particles to soften and get downsized into fines by mechanical forces in said vessel, - allowing the surface of thermoplastic polymer material particles melting at least partly, - allowing thermoset composition particles adhere to the thermoplastic polymer material particles, thus forming agglomerates comprising the thermoplastic polymer material and the thermoset composition and optional fillers and additives, and - cooling the agglomerates by lowering the energy of the agitation.