Method and apparatus for dry forming of a fabric

1. Method for dry forming of a fabric comprising:

forming a first non-woven fabric,

transferring the first non-woven fabric between two forming or conveying wires by a transfer wire,

forming an airlaid, second non-woven fabric at the top side of an upper run on the transfer wire by using at least one forming head,

and leading the second non-woven fabric downwards and along the underside of a lower run of the transfer wire for being laid off on a subsequent conveying wire together with the first non-woven fabric.

2. Method according to claim 1 , further comprising integrating the two non-woven fabrics as they are disposed at the underside of the transfer wire, while passing them between rollers during transfer to the subsequent conveying wire.

3. Method according to claim 1 , characterised in that the first non-woven fabric is made by carding.

4. Method according to claim 3 , further comprising integrating a web formed of plural non-woven fabrics by hydroentanglement.

5. Method according to claim 1 , characterised in that the first non-woven fabric is made with a density which is greater than the density of the second non-woven fabric.

6. Method according to claim 1 , further comprising disposing in the top layer of a non-woven fabric which is in contact with the second non-woven fabric, a thin layer of thermoplastic binder fibres.

7. The method of claim 5 , wherein the density of the first non-woven fabric is between 0.1 and 0.5 g/m 3 and the density of the second non-woven fabric is between 0.01 and 0.10 g/m 3 .

8. The method of claim 6 , wherein the thin layer of thermoplastic binder fibres has a basis weight between 2 and 10 g/m 2 .

9. Method for dry forming of a fabric comprising:

forming a first non-woven fabric in a first dry forming unit while depositing fibres on a first former wire over a vacuum box,

transferring the fibre layer from the first former wire to the underside of a lower run on a transfer wirer while forming a vacuum between an upper run and the lower run of the transfer wire,

forming on the top side of the upper run of the transfer wire an airlaid second non-woven fabric by using at least one former head, and sucking said first non-woven fabric against the transfer wire and thereby also against the lower run by suction action through the second non-woven fabric, and transferring the two non-woven fabrics to a subsequent conveying wire.

10. The method of claim 9 , wherein the subsequent conveying wire comprises a further former wire for forming a third non-woven fabric upon the two previously formed non-woven fabrics.

11. The method of claim 10 , wherein the third non-woven fabric is a carded non-woven fabric.

12. Apparatus for dry forming of a fabric which is formed by at least two non-woven fabrics comprising:

a transfer wire disposed after a first former wire used for forming a first non-woven fabric,

at least one former head placed at the top side of an upper run of the transfer wire, and

a vacuum box provided between the upper run and a lower run of the transfer wire.

13. Apparatus according to claim 12 , further comprising a card for forming the first non-woven fabric at each side of the transfer wire and a third non-woven fabric at each side of the transfer wire over the non-woven fabric formed on the transfer wire.

14. Apparatus according to claim 12 , further comprising a former head above the first former wire.