Table 1.

Mechanical recycling methods.

Material	Grinding Equipment	Size	Contribution	Ref.
GFR 1 polyester, CFR 2 epoxy and epoxy-based aramid fibers composites	Mini granulator + sieves from 1 to 5.5 mm	4–9 mm length, 8–12 μm diameter. (l/dexp > l/dcrit)	Introduction of mechanically recycled fibers in thermoplastic matrices (ethylene and methacrylic acid/propylene copolymer)	[52]
CFR epoxy	Rotating blade with a sieve/ball mill	1–10 mm 1–10 μm	ABS 3 matrix with recycled CFRP	[53,54]
GFR polyester (SMC 4)	Hammer mill. Sorting by air cascade	2–25 mm	Introduction of recycled fibers for DMC 5	[55]
CFR epoxy with different fiber types (woven, UD 6, ±45°). Several curing stages	Slow speed granulator + sieving	600 μm–11.2 mm	Study of granulator effectiveness	[56]
Commercial rCF (by depolymerization)	-	7 mm length	Enhancement of rCF-matrix adhesion with plasma treatments	[57]
CFR PEEK 7	Electronic equipment + sieving	2–10 mm length, 0.16–2 mm thickness	Electrodynamical fragmentation as an alternative to mechanical shredding	[58]
CFR epoxy	Microfine mill	20–100 μm	Absorption of PMMA 8 particles to improve adhesion with the new matrix	[59]

¹ Glass fiber reinforced; ² Carbon fiber reinforced; ³ Acrylonitrile butadiene styrene; ⁴ Sheet moulding compound; ⁵ Dough moulding compound; ⁶ Uni-directional; ⁷ Polyether ether ketone; ⁸ Poly(methyl methacrylate).