Patent ID: 11904582
Assignee: COVESTRO DEUTSCHLAND AG
Field: Other special machines (Mechanical engineering)
Classification: CPC B  Y | IPC B

Claim 0:
1. A vacuum-assisted resin transfer moulding process for the production of layer structures for rotor blades in wind power plants, the process comprising:
a. providing a mould;
b. placing dry fibre mats in the mould according to a precise production plan;
c. hermetically sealing the mould as a whole;
d. removing the air from the mould to thereby produce an evacuated layer structure; and
e. injecting into the evacuated layer structure a liquid polyurethane reaction mixture comprising:
(1) a polyether polyol having a viscosity of ≤800 mPas at 25° C.
(2) a di- and/or poly-isocyanate having a viscosity of ≤.250 mPas at 25° C., and
(3) a catalyst,

wherein the liquid polyurethane reaction mixture has a viscosity, measured 30 minutes after mixing (1) with (2), of ≤5000 mPas at 25° C.; and
wherein the dry fibre mats consist of polymer fibre mats, glass fibre mats, aramid fibre mats, carbon fibre mats, or a mixture thereof.