Patent ID: 11969971
Assignee: KRONOSPAN LUXEMBOURG S.A.
Field: Surface technology, coating (Chemistry)
Classification: CPC B | IPC B

Claim 0:
1. An oriented strand board comprising:
an upper surface layer having wood material consisting of a mixture of recycled wood flakes and oriented strands bonded together by a binder, wherein the proportion by weight of the oriented strands predominates over the proportion by weight of the recycled wood flakes in the upper surface layer,
three core layers comprising or being formed from a mixture of recycled wood flakes with strands from virgin fiber wood bonded together by a binder,
a lower surface layer having wood material consisting of a mixture of recycled wood flakes and oriented strands bonded together by a binder, wherein the proportion by weight of the oriented strands predominates over the proportion by weight of the recycled wood flakes in the lower surface layer,
wherein the three core layers are arranged between the upper surface layer and the lower surface layer;
wherein the strands present in the upper surface layer and/or in the lower surface layer are from virgin fiber wood,
wherein the proportion of recycled wood flakes in the surface layers is less than the proportion of recycled wood flakes in the core layers,
wherein the three core layers comprise an inner core layer enclosed by two outer core layers,
wherein a proportion by weight of the recycled wood flakes in the inner core layer is greater than in the outer core layers, and
wherein a proportion by weight of the strands having a smaller mean length (number-average) compared to the strands in the upper and lower surface layers is less in the inner core layer than in the outer core layers,
wherein a proportion by weight of the recycled wood flakes obtained in the inner core layer, based on the sum of all strands and flakes in the inner core layer, is 50 to 90% by weight, and
wherein a proportion by weight of the recycled wood flakes in the outer core layers, based on all the flakes in the outer core layers, is 20 to 80% by weight.