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

Claim 13:
14. A process for producing the oriented strand board of claim 1, the process comprising:
producing a scattered particle mat by;
producing a first surface layer mat having wood material consisting of recycled wood flakes, strands, and a binder by oriented scattering of a flake mixture consisting of recycled wood flakes and strands that have been provided with binder, wherein the proportion by weight of the strands predominates over the proportion by weight of the recycled wood flakes in the first surface layer mat,
scattering three core layer mats arranged one on top of another, the three core layer mats comprising or being formed from a mixture of flakes which have been obtained by flaking of recycled wood (RW) and strands which have been obtained by flaking of virgin fiber wood, wherein the flakes and the strands have been bonded together by a binder and have been provided with the binder to the first surface layer mat,
producing a second surface layer mat having wood material consisting of recycled wood flakes and strands that have been provided with binder on the three core layer mats by oriented scattering of a flake mixture consisting of recycled wood flakes and strands that have been provided with a binder, wherein the proportion by weight of the strands predominates over the proportion by weight of the recycled wood flakes in the second surface layer mat; and
pressing the scattered particle mat, for hardening and solidification of the binder, at an elevated temperature relative to standard conditions;
wherein the strands present in the first surface layer mat and/or in the second surface layer mat are from virgin fiber wood,
wherein the proportion of recycled wood flakes in the surf ace layer mats is less than the proportion of recycled wood flakes in the core layers,
the three core layers comprising an inner core layer mat enclosed by one outer core layer mat on each side,
wherein a proportion by weight of the recycled wood flakes in the inner core layer mat is greater than in the outer core layer mats, and
a proportion by weight of the strands having a smaller mean length (number-average) compared to the strands in the first and second surface layer mats is less in the inner core layer mat than in the outer core layer mats.