	US 11,904,582 B2
	Use of layer structures in wind power plants
Dirk Passmann, Oberhausen (DE); Klaus Franken, Bergisch-Gladbach (DE); and Stefan Lindner, Cologne (DE)
Assigned to Covestro Deutschland AG, Leverkusen (DE)
Filed by Covestro Deutschland AG, Leverkusen (DE)
Filed on Oct. 31, 2017, as Appl. No. 15/799,511.
Application 15/799,511 is a continuation of application No. 13/514,523, granted, now 10,293,586, previously published as PCT/EP2010/068992, filed on Dec. 6, 2010.
Claims priority of application No. 102009058101.4 (DE), filed on Dec. 12, 2009.
Prior Publication US 2018/0050526 A1, Feb. 22, 2018
Int. Cl. B29D 99/00 (2010.01); B32B 27/40 (2006.01); B29L 31/08 (2006.01)

CPC B32B 27/40 (2013.01) [B29D 99/0028 (2013.01); B29K 2875/00 (2013.01); B29L 2031/085 (2013.01); Y02E 10/72 (2013.01); Y02P 70/50 (2015.11)]

15 Claims

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.