Heat resistant separation fabric

Abstract

A warp knitted heat resistant separation fabric is provided, having at least two sets of warp yarns. A first set of warp yarns is positioned over the width of the fabric and formed with pillar stitches; and a second set of warp yarns positioned over the width of the fabric shows in its repeat in the fabric an underlap under at least two pillars that are formed by the first set of warp yarns.

Claims

1. Warp knitted heat resistant separation fabric for mould covering in the bending of car glass, wherein the warp knitted heat resistant separation fabric comprises at least two sets of warp yarns, wherein a first set of warp yarns positioned over the width of the fabric forms pillar stitches; and wherein a second set of warp yarns positioned over the width of the fabric shows in its repeat in the fabric an underlap under at least two pillars formed by the first set of warp yarns.

2. Warp knitted heat resistant separation fabric as in claim 1, wherein said fabric does not contain tuck warp yarns.

3. Warp knitted heat resistant separation fabric as in claim 1, wherein said pillar stitch is an open pillar stitch.

4. Warp knitted heat resistant separation fabric as in claim 1, wherein said second set of warp yarns comprises in its repeat an arrangement of two consecutive stitches that are knitted in consecutive courses and in wales that are at least two wales away from each other.

5. Warp knitted heat resistant separation fabric as in claim 1, wherein said underlap of said second set of warp yarns is created by an inlay, wherein in the inlay, the yarns of the second set of warp yarns not building stitches but are laid as an underlap in between overlaps and the underlaps of other yarns that are building stitches.

6. Warp knitted heat resistant separation fabric as claim 1, wherein the number of courses per centimeter is higher than three.

7. Warp knitted heat resistant separation fabric as in claim 1, wherein the number of wales per centimeter is higher than three.

8. Warp knitted heat resistant separation fabric as in claim 1, wherein said first set of warp yarns and/or said second set of warp yarns comprise stainless steel fibers.

9. Warp knitted heat resistant fabric as in claim 1, wherein said first set of warp yarns and/or said second set of warp yarns comprise glass fibers.

10. Warp knitted heat resistant fabric as in claim 1, wherein said first set of warp yarns and/or said second set of warp yarns comprise PBO-fibers.

11. Method for the production of a warp knitted heat resistant separation fabric for mould covering in the bending of car glass, wherein the warp knitted heat resistant separation fabric for mould covering in the bending of car glass comprises at least two sets of warp yarns, wherein a first set of warp yarns positioned over the width of the fabric forms pillar stitches, and wherein a second set of warp yarns positioned over the width of the fabric shows in its repeat in the fabric an underlap under at least two pillars formed by the first set of warp yarns, wherein the method comprises the step of knitting the warp knitted heat resistant fabric on a warp knitting machine or on a raschel machine or on a warp knitting crochet machine.

12. Method for the production of a warp knitted heat resistant fabric as in claim 11, wherein the gauge of said machine is finer than or equal to 8 needles per inch.

13. Method of using a warp knitted heat resistant separation fabric in glass manufacturing, wherein the warp knitted heat resistant separation fabric for mould covering in the bending of car glass comprises at least two sets of warp yarns, wherein a first set of warp yarns positioned over the width of the fabric forms pillar stitches, and wherein a second set of warp yarns positioned over the width of the fabric shows in its repeat in the fabric an underlap under at least two pillars formed by the first set of warp yarns, wherein the method comprises the step of covering a mold with said heat resistant separation fabric.

14. Method as in claim 13, wherein the warp knitted heat resistant separation fabric comprises a technical face, wherein the method comprises the step of contacting the mold covered with said heat resistant separation fabric with glass, wherein the technical face of the warp knitted heat separation fabric is in contact with the glass.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a first example of a warp knitted heat resistant fabric according to the invention.

(2) FIG. 2 shows a second example of a warp knitted heat resistant fabric according to the invention.

DETAILED DESCRIPTION THE INVENTION

(3) FIG. 1 shows an example of a warp knitted heat separation fabric 100 according to the invention. The fabric can be made on a single needle bed warp knitting machine and has a single needle bed structure. A first set of warp yarns 110 is fully threaded in its guide bar (which is the second guide bar on the knitting machine) and is forming an open pillar stich, with lapping pattern 0-1/1-0//. The second set of warp yarns 120 is fully threaded in its guide bar (which is the first guide bar on the knitting machine) and is forming a satin stich with lapping 1-0/3-4//, with an underlap (0/3) under three pillars.

(4) Fabrics with such pattern have been made in gauge 8 and gauge 12. The fabric made on a machine with gauge 8 was knitted with Nm 11/2 stainless steel yarns for both sets of warp yarns, made from 12 μm equivalent diameter bundle drawn steel fibers of an alloy according to EN 1.4404. The fabric showed to have 3.5 wales per centimeter and 4.1 courses per centimeter. The fabric weight was 740.3 g/m.sup.2. The air permeability (tested according to ISO 9237:1995; the test is performed at a pressure of 100 bar) was 1446 l/(dm.sup.2*min). Fabric thickness, measured according to ISO 5084:1996, was 1.69 mm. Tensile testing was performed according to ISO 13934-1:1999. The tensile strength in wale direction was 216.24 N and the elongation at break in wale direction was 38.92%. The tensile strength in course direction was 250.39 N and the elongation at break in course direction was 60.82%.

(5) The fabric made on a machine with gauge 12 was knitted with Nm 15/2 stainless steel yarns for both sets of warp yarns, made from 12 μm equivalent diameter bundle drawn steel fibers of an alloy according to EN 1.4404. The fabric showed to have 5.5 wales per centimeter and 4.2 courses per centimeter. The fabric weight was 734.5 g/m.sup.2. The air permeability (tested according to ISO 9237:1995; the test is performed at a pressure of 100 bar) was 1138 l/(dm.sup.2*min). Fabric thickness, measured according to ISO 5084:1996, was 1.95 mm. Tensile testing was performed according to ISO 13934-1:1999. The tensile strength in wale direction was 304.21 N and the elongation at break in wale direction was 31.21%. The tensile strength in course direction was 169.02 N and the elongation at break in course direction was 100.13%.

(6) FIG. 2 shows another example of a warp knitted heat separation fabric 200 according to the invention. The fabric can be made on a single needle bed warp knitting machine and has a single needle bed structure. A first set of warp yarns 210 is fully threaded in its guide bar (which is the first or front guide bar on the knitting machine) and is forming an open pillar stich, with lapping pattern 1-0/0-1//. The second set of warp yarns 230 is fully threaded in its guide bar (which is the second guide bar on the knitting machine) and is forming an inlay with lapping 4-4/0-0//, with an underlap (4/0) under four pillars.

(7) Two such fabrics have been made, with differing number of courses per centimeter. Both fabrics were made on a 12 gauge single bed knitting machine with in both sets of warp yarns a 15/2 Nm yarn spun from 12 μm equivalent diameter stainless steel fibers of alloy according to EN 1.4404. The first fabric had 4.3 wales per centimeter and 4.1 courses per centimeter. The fabric weight was 460.62 g/m.sup.2. The air permeability (tested according to ISO 9237:1995; the test is performed at a pressure of 100 bar) was 1966 l/(dm.sup.2*min). Fabric thickness, measured according to ISO 5084:1996, was 1.40 mm. Tensile testing was performed according to ISO 13934-1:1999. The tensile strength in wale direction was 211.21 N and the elongation at break in wale direction was 29.76%. The tensile strength in course direction was 135.51 N and the elongation at break in course direction was 74.89%.

(8) The second fabric (with higher number of courses per cm) had 4.3 wales per centimeter and 5.1 courses per centimeter. The fabric weight was 532.55 g/m.sup.2. The air permeability (tested according to ISO 9237:1995; the test is performed at a pressure of 100 bar) was 1750 l/(dm.sup.2*min). Fabric thickness, measured according to ISO 5084:1996, was 1.18 mm. Tensile testing was performed according to ISO 13934-1:1999. The tensile strength in wale direction was 276.67 N and the elongation at break in wale direction was 24.24%. The tensile strength in course direction was 174.74 N and the elongation at break in course direction was 50.61%.