Method of manufacturing a substrate for a floor panel

1. A method for manufacturing a single- or multi-layered substrate, which is suitable for a floor panel, wherein, for forming a substrate layer, thermoplastic material is strewn onto a transport device, and the strewn thermoplastic material is consolidated under an influence of pressure and/or heat in a press device, wherein the thermoplastic material to be strewn comprises micronized material;

wherein the micronized material comprises 12 phr or less than 12 phr of plasticizer;

wherein the strewn thermoplastic material is foamed and to this aim the thermoplastic material to be strewn comprises the micronized material and a blowing agent;

wherein the thermoplastic material to be strewn is a mixture of at least the micronized material and a dryblend material with the blowing agent;

wherein the dryblend material shows one or more of the following characteristics:

the dryblend material comprises PVC with a K (Fikentscher) value of maximum 60;

the dryblend material comprises a vinyl chloride-vinyl acetate, which has a K (Fikentscher) value of maximum 60 or maximum 58;

the dryblend material comprises E-PVC.

2. The method according to claim 1 , wherein the micronized material is obtained by comminuting granulate or rendering it finer.

3. The method according to claim 1 , wherein an average particle size of the micronized material, expressed as a D50 value or a median of a distribution, is situated between 100 and 750 micrometer.

4. The method according to claim 1 , wherein the micronized material comprises one or more of the following characteristics:

the micronized material comprises PVC,

the micronized material comprises filler in an amount situated between 20 and 70 percent by weight in respect to a total weight of the micronized material, or between 30 and 60 percent by weight; and

the micronized material comprises a vinyl acetate-based copolymer.

5. The method according to claim 1 , wherein a thickness of the substrate layer after consolidating is situated between 0.4 and 0.6 millimeters.

6. The method according to claim 1 , wherein the thermoplastic material to be strewn is heated prior to being strewn or during said strewing.

7. The method according to claim 1 , wherein the thermoplastic material to be strewn is strewn onto a glass fiber layer, or a glass fiber layer is provided on the strewn, however, still not yet consolidated thermoplastic material.

8. The method according to claim 7 , wherein the glass fiber layer is impregnated with the strewn thermoplastic material or at least with a portion of the thermoplastic material with a part of the micronized material during the consolidation.

9. The method according to claim 7 , wherein a weight of the glass fiber layer is at or lower than 50 grams per square meter.

10. The method according to claim 1 , wherein the dryblend material shows one or more of the additional characteristics:

the dryblend material is pre-mixed with the blowing agent;

the dryblend material comprises PVC; and

the dryblend material comprises filler in an amount of less than 20 percent by weight in respect to a total weight of the dryblend material, or less than 15 percent by weight or less than 10 percent by weight.

11. The method according to claim 1 , wherein the weight percentage of the dryblend provided with the blowing agent in respect to a total weight of a blend is situated between 1% and 25% or between 5% and 15%.

12. The method according to claim 1 , wherein the weight percentage of the micronized material in respect to a total weight of a blend is situated between 75% and 99% or between 85% and 95%.

13. The method according to claim 1 , wherein the micronized material itself is free from blowing agent.

14. The method according to claim 1 , wherein the strewn thermoplastic material is foamed while the strewn thermoplastic material is consolidated, in the press device.

15. The method according to claim 1 , wherein the press device is a double-belt press.

16. The method according to claim 1 , wherein the micronized material shows a particle size distribution showing a feature that (D50-D10)/D50 is larger than 50%, wherein D50 is a median and D10 relates to a tenth percentile of the particle size distribution.

17. The method according to claim 2 , wherein an average particle size of the micronized material, expressed as the D50 value or a median of a distribution, is situated between 100 and 750 micrometer.

18. The method according to claim 2 , wherein the micronized material comprises one or more of the following characteristics:

the micronized material comprises PVC,

the micronized material comprises filler in an amount situated between 20 and 70 percent by weight in respect to a total weight of the micronized material, or between 30 and 60 percent by weight; and

the micronized material comprises a vinyl acetate-based copolymer.