Insulation board made of a mixture of wood base material and binding fibers

1. An insulation material board composed of a wood fiber material/binder fiber mixture with a bulk density of at least 20 kg/m 3 , comprising an additive having thermosetting and thermoplastic portions in granular form, wherein the thermosetting portion forms a core and the thermoplastic portion forms a thermally activatable coating that at least partially encloses the core.

2. The insulation material board according to claim 1 , wherein the core is formed from perlite or thermosetting plastic material.

3. The insulation material board according to claim 1 , wherein the core takes the form of granulate or fiber material.

4. The insulation material board according to claim 1 , wherein the additive has a grain size of 0.3 to 2.5 mm.

5. The insulation material board according to claim 1 , wherein a proportion of the additive in relation to an overall mass of the insulation material board is at least 20%.

6. The insulation material board according claim 1 , wherein the additive is distributed homogeneously within the wood fiber material/binder fiber mixture.

7. The insulation material board according claim 1 , wherein the additive is hydrophobic.

8. The insulation material board according to claim 1 , comprising binder fibers, wherein a proportion of the binder fibers is between 10 and 20 percent by weight of the overall mass.

9. Additive for improving the compressive strength and improving the structure of insulation material boards composed of a wood fiber material/binder fiber mixture, comprising an additive having thermosetting plastic and thermoplastic portions in granular form, wherein in granules of the additive the thermo setting plastic portion forms a core and the thermoplastic portion forms a thermally activatable coating that at least partially encloses the core.

10. The additive according to claim 9 , wherein the thermally activatable coating is a thermoplastic or bitumen.

11. The additive according to claim 9 , wherein the thermally activatable coating completely surrounds the core.

12. The additive according to claim 9 , wherein the core comprises a granulate or a fiber.

13. The additive according to claim 9 , wherein the thermosetting plastic portion comprises polyester or polyurethane.

14. The additive according to claim 9 , wherein the additive is hydrophobic.

15. Method for producing an insulation material board composed of a wood fiber material/binder fiber mixture with a bulk density of at least 20 kg/m 3 , comprising:

mixing the wood fiber material/binder fiber mixture in an aerodynamic fleece forming machine to form a first fleece;

admixing to the first fleece an additive composed of thermosetting and thermoplastic portions in granular form, wherein the thermosetting portion forms a core and the thermoplastic portion forms a thermally activatable coating that at least partially encloses the core; and

thermally activating the thermally activatable coating to cross-link the additive with the wood fiber material/binder fiber mixture to form the insulation material board.

16. The method according to claim 15 , wherein the thermally activatable coating is activated in a hot-air stream.

17. The method according to claim 15 , wherein admixing of the additive and a spatial orientation of the fiber matrix take place in a separate fleece forming machine.

18. The method according to claim 15 , wherein the additive is distributed homogeneously within the wood fiber material/binder fiber mixture.

19. The insulation material board according to claim 1 , wherein the thermally activatable coating completely surrounds the core.

20. The additive according to claim 9 , wherein a grain size of the additive is in a range of 0.3 mm to 2.5 mm.

21. The insulation material board according to claim 1 , wherein the binder fiber comprises thermoplastic binder fibers.

22. The method according to claim 15 , wherein the first fleece is a dry mixture of the wood fibers and the binder fibers.