Granted Patent B2

US 8,251,103 · App. 12/915,490 · Granted Aug 28, 2012

Abstract

Claims (43)

1. A papermaking forming fabric, comprising:

a set of top MD yarns;

a set of top CMD yarns interwoven with the top MD yarns to form a top fabric layer;

a set of bottom MD yarns;

a set of bottom CMD yarns interwoven with the bottom MD yarns to form a bottom fabric layer; and

a set of binding yarns that interweaves with and binds together the top and bottom fabric layers;

wherein the fabric has a Channel Factor (CF) of greater than 2.0, the CF being defined in Equation (1) as:

CF =( PSMW/PSML )×( SOA % PS/SOA % RS)   (1)

wherein:

PSMW=the CMD width of an interstice between adjacent top MD yarns;

PSML=the MD width of an interstice between adjacent top CMD yarns;

SOA % PS=surface open area in the top fabric layer;

SOA % RS=surface open area in the bottom fabric layer; and PSMW/PSML>1.

2. The papermaking fabric defined in claim 1 , wherein the binding yarns are CMD binding yarns.

3. The papermaking fabric defined in claim 1 , wherein:

RSMW=the CMD width of an interstice between adjacent bottom MD yarns;

RSML=the MD width of an interstice between adjacent bottom CMD yarns; and

RSMW/RSML<1.

4. The papermaking fabric defined in claim 1 , wherein the fabric has a Drainage Factor (DF) of greater than 2.0, the DF being defined in Equation (2) as:

DF=Warp coverage RS(%)/warp coverage PS(%)  (2)

wherein:

Warp coverage RS(%)=bottom MD yarns/cm×bottom MD yarn diameter (mm)×10; and

Warp coverage PS(%)=top MD yarns/cm×top MD yarn diameter (mm)×10.

5. The papermaking fabric defined in claim 1 , wherein the set of bottom MD yarns includes a first number of bottom MD yarns, the set of top MD yarns includes a second number of top MD yarns, and the first number is higher than the second number.

6. The papermaking fabric defined in claim 1 , wherein the set of top CMD yarns includes a third number of top CMD yarns, the set of stitching yarns comprises CMD stitching yarns, is arranged in pairs, and includes a fourth number of stitching yarn pairs, and the set of bottom CMD yarns includes a fifth number of bottom CMD yarns, and wherein the sum of the third and fourth number is greater than the fifth number.

7. A papermaking forming fabric, comprising:

a set of top MD yarns;

a set of top CMD yarns interwoven with the top MD yarns to form a top fabric layer;

a set of bottom MD yarns;

a set of bottom CMD yarns interwoven with the bottom MD yarns to form a bottom fabric layer; and

a set of binding yarns that interweaves with and binds together the top and bottom fabric layers;

wherein the fabric has a Drainage Factor (DF) of greater than 2.0, the DF being defined in Equation (2) as:

DF=Warp coverage RS(%)/warp coverage PS(%)  (2)

wherein:

Warp coverage RS(%)=bottom MD yarns/cm×bottom MD yarn diameter (mm)×10;

Warp coverage PS(%)=top MD yarns/cm×top MD yarn diameter (mm)×10; PSMW=the CMD width of an interstice between adjacent top MD yarns;

PSML=the MD width of an interstice between adjacent top CMD yarns;

RSMW=the CMD width of an interstice between adjacent bottom MD yarns;

RSML=the MD width of an interstice between adjacent bottom CMD yarns;

and RSMW/RSML<1, and PSMW>PSML.

8. The papermaking fabric defined in claim 7 , wherein the binding yarns are CMD binding yarns.

9. The papermaking fabric defined in claim 7 , wherein the set of bottom MD yarns includes a first number of bottom MD yarns, the set of top MD yarns includes a second number of top MD yarns, and the first number is higher than the second number.

10. The papermaking fabric defined in claim 7 , wherein the set of top CMD yarns includes a third number of top CMD yarns, the set of stitching yarns comprises CMD stitching yarns, is arranged in pairs, and includes a fourth number of stitching yarn pairs, and the set of bottom CMD yarns includes a fifth number of bottom CMD yarns, and wherein the sum of the third and fourth number is greater than the fifth number.

Assignments (8)