Coated fabric, a bag produced therefrom, a packaging machine for bags and a method for filling the bags

Abstract

A coated fabric (11), comprising a fabric (12) from polymer tapes (12a, 12b), wherein the fabric (12) is coated with a sealing layer (13), wherein at least a portion of the polymer tapes (12a, 12b) have a breaking tenacity of less than 45 cN/tex, preferably 15 to 40 cN/tex and an elongation at break of more than 30%, preferably of 40 to 90%, and/or wherein the sealing layer (13) is formed from a composition A comprising at least one ethylene/-olefin interpolymer, and wherein the composition has a density from 0.905 to 0.930 g/cc, preferably from 0.910 to 0.930 g/cc (1 cc=1 cm.sup.3), and a melt index (12) from 3 to 20 g/10 min and a bag comprising said fabric; a packaging machine (100) for filling gusseted (220) bags (10, 200) wherein the bag walls (202) of the bags (10, 200) consist of a woven fabric (11) of polymer tapes (12a, 12b) at least in part and wherein each of the ends (203, 204) of the bag wall (202) is provided with a filling mouth (211) for filling, wherein a closing device (125) is provided which is structured such that as the filling mouth (211) is closed a welding temperature of at least 50 Kelvin higher in the region of the gussets (220) than in a center region (223) of the bag wall (202) can be generated.

Claims

1. A coated fabric comprising: a first coated fabric welded with a second coated fabric, wherein the first coated fabric and the second coated fabric comprise fabrics formed from polymer tapes, wherein the first coated fabric and the second coated fabric are coated with a sealing layer, wherein the first coated fabric and the second coated fabric are welded together along the sealing layer, wherein the sealing layer is formed from a composition A comprising a combination of (i) a homogeneously branched ethylene/-olefin interpolymer and (ii) a heterogeneous ethylene/-olefin interpolymer, and wherein the composition A has a density from 0.905 to 0.930 g/cc (1 cc=1 cm.sup.3) and a melt index (I2) from 3 to 20 g/10 min (ASTM D-1238-04, condition 190 C./2.16 kg), wherein a seal formed where the first and second layer are welded together has a seal strength of at least 16.5 N/15 mm (11 N/cm) (determined using an INSTRON 5564 tensile tester, with a clamp distance of 30 mm, and a cross head speed of 100 mm/min).

2. A coated fabric according to claim 1, wherein the -olefin is selected from a C3-C10 -olefin.

3. A coated fabric according to claim 2, wherein the -olefin is selected from propylene, 1-butene, 1-hexene, or 1-octene.

4. A coated fabric according to claim 1, wherein the composition A has a melt index (I2) from 4 to 15 g/10 min (ASTM D-1238-04, condition 190 C./2.16 kg).

5. A coated fabric according to claim 1, further comprising an adhesive layer, which is formed from a composition B comprising at least one of a propylene-based polymer, a propylene/ethylene interpolymer, or a propylene/ethylene copolymer.

6. A coated fabric according to claim 5, wherein the composition B has a density from 0.860 to 0.930 g/cc and a melt flow rate (MFR) from 10 to 35 g/10 min (ASTM D-1238-04, condition 230 C./2.16 kg).

7. A coated fabric according to claim 5, wherein the composition B has a density from 0.865 to 0.925 g/cc.

8. A coated fabric according to claim 5, wherein the composition B has a melt flow rate from 12 to 30 g/10 min (ASTM D-1238-04, condition 230 C./2.16 kg).

9. A coated fabric according to claim 5, wherein composition B has at least one melting point (Tm) from 90 C. to 120 C. as determined by DSC.

10. A coated fabric according to claim 5, wherein the adhesive layer comprises at least one additional ethylene-based polymer.

11. A coated fabric according to claim 10, wherein the at least one additional ethylene-based polymer is an ethylene homopolymer with a density of 0.910 to 0.935 g/cc.

12. A coated fabric according to claim 1, wherein at least a part of the polymer tapes have a breaking tenacity of less than 45 cN/tex and an elongation at break of more than 30%.

13. A coated fabric according to claim 12, wherein the fabric contains warp tapes and weft tapes, wherein said warp tapes have said breaking tenacity of less than 45 cN/tex, and said elongation at break of more than 30%.

14. A coated fabric according to claim 13, wherein at least a part of the weft tapes have a breaking tenacity and/or an elongation at break different from said warp yarns.

15. A coated fabric according to claim 12, wherein said polymer tapes comprise PP, PE, HDPE, LLDPE, or combinations thereof.

16. A tubular bag body formed from a flat fabric bonded along its longitudinal edges to form a tube, wherein the bag body comprises a coated fabric according to claim 1, wherein the sealing layer is on the inside of the tube.

17. A bag comprising a tubular bag body formed from a flat fabric bonded along the longitudinal edges to form a tube, wherein the bag body comprises a coated fabric according to claim 1.

18. A bag comprising a coated fabric according to claim 1.

19. A coated fabric according to claim 1, wherein the composition A has a density from 0.910 to 0.930 g/cc.

20. A coated fabric according to claim 5, wherein the composition B has a melt flow rate from 15 to 25 g/10 min (ASTM D-1238-04, condition 230 C./2.16 kg).

21. A coated fabric, comprising: a fabric formed from polymer tapes, wherein the fabric is coated with a sealing layer, the sealing layer being formed from a composition comprising: at least one ethylene/-olefin interpolymer, comprising a combination of: a homogenously branched ethylene/-olefin interpolymer; and a heterogeneous ethylene/-olefin interpolymer, wherein the composition comprises a density from 0.905 to 0.930 g/cc (1 cc=1 cm.sup.3); and wherein the composition comprises a melt index (I2) from 3 to 20 g/10 min (ASTM D-1238-04, condition 190 C./2.16 kg), and wherein the composition has at least one melting temperature (Tm) from 115 C. to 135 C. as determined by DSC, and wherein the coated fabric is welded with a second fabric at the sealing layer.

22. A coated fabric according to claim 1, wherein the composition A has at least one melting temperature (Tm) from 115 C. to 135 C. as determined by DSC.

23. A coated fabric according to claim 1, wherein the seal has a max seal strength (impulse sealing) of at least 140 N/50 mm (determined according to ASTM D882, with clamp distance 150 mm, test velocity 100 mm/min, and sample width 50 mm).

24. A coated fabric material, comprising: a first section of coated fabric and a second section of coated fabric each formed from polymer tapes, wherein each of the first section of coated fabric and second section of coated fabric includes a sealing layer formed from a composition comprising: at least one ethylene/-olefin interpolymer comprising a combination of a homogenously branched ethylene/-olefin interpolymer and a heterogeneous ethylene/-olefin interpolymer, wherein the composition comprises a density from 0.905 to 0.930 g/cc (1 cc=1 cm.sup.3), and wherein the composition comprises a melt index (I2) from 3 to 20 g/10 min (ASTM D-1238-04, condition 190 C./2.16 kg); wherein the first section of coated fabric and the second section of coated fabric are welded to one another along their sealing layers to form a seal, wherein the seal has a seal strength of at least 16.5 N/15 mm (11 N/cm) (determined using an INSTRON 5564 tensile tester, with a clamp distance of 30 mm, and a cross head speed of 100 mm/min).

Description

(1) The invention is now illustrated in further detail on the basis of non-limiting exemplary embodiments, with reference to the drawings.

(2) In the drawings:

(3) FIG. 1 shows a first embodiment of a coated fabric according to the invention in cross-section;

(4) FIG. 2 shows a second embodiment of a coated fabric according to the invention in cross-section;

(5) FIG. 3 shows a schematic illustration of a section of a fabric in top view;

(6) FIG. 4 shows a schematic illustration of a welding process according to the invention on two coated fabrics according to the invention;

(7) FIG. 5a, 5b show a tubular bag body in cross-section (FIG. 5a) and in top-view (FIG. 5b) according to the invention;

(8) FIG. 6 shows a schematic side view of a packaging machine according to the invention;

(9) FIG. 7 shows the welding device of the packing machine according to FIG. 6;

(10) FIG. 8 shows a bag manufactured by means of the packaging machine according to FIG. 6;

(11) FIG. 9 shows a schematic and perspective view of a filled bag;

(12) FIG. 10 shows a schematic and perspective view of a filled bag;

(13) FIG. 11 shows a profile of a welding strip of a welding jaw for the welding device according to FIG. 7;

(14) FIG. 12 shows a coated welding strip for the welding device according to FIG. 7; and

(15) FIG. 13 shows the seal strength versus sealing temperature of the coated fabrics.

(16) In FIG. 1, a first embodiment of a coated fabric 11 according to the invention is illustrated in cross-section. Said coated fabric 11 comprises a schematically shown fabric 12. Fabric 12 comprises polymer tapes 12a, 12b. The polymer tapes 12a, 12b illustrated by way of example form the weft 12b and warp 12a of the fabric 12 are shown in more detail in FIG. 3. The tape fabric 12 is coated with a sealing layer 13 from a thermoplastic synthetic material. Preferably the melting point of said sealing layer 13 is below the crystallite melting point of the fabric tape material.

(17) In FIG. 2, a second embodiment of a coated fabric 11 according to the invention is illustrated, which likewise comprises a fabric 12 from polymer tapes 12a, 12b as well as a sealing layer 13 from a thermoplastic synthetic material the melting point of which is below the crystallite melting point of the fabric tape material. The present embodiment of the coated fabric 11 differs from the above first embodiment only in that an additional adhesive layer 14 is arranged between the fabric and the sealing layer 13.

(18) In FIG. 3 a schematic representation of a section of a fabric 12 is shown. The fabric 12 consists of tapes 12a, 12b, namely weft tapes 12b and warp tapes 12a. According to the invention at least a portion of the tapes 12a, 12b, preferably of the warp tapes 12a, has a breaking tenacity of less than 45 cN/tex, preferably 15 to 40 cN/tex and an elongation at break of more than 30%, preferably of 40 to 90%. In a more preferred embodiment all of the warp tapes 12a have a breaking tenacity of less than 45 cN/tex, preferably 15 to 40 cN/tex and an elongation at break of more than 30%, preferably of 40 to 90%, whereas the weft tapes 12b have a different breaking tenacity and/or elongation at break.

(19) Coming back to FIG. 1, the weft tapes 12b may consist of polypropylene which typically has a crystallite melting point of above 160 C. The polymer tapes 12a, 12b may be monoaxially drawn. In a first variant, the sealing layer 13 comprises LD-PE the melting point of which is approx. 105 C. Other suitable polymer compositions are described as composition A above and will be described in more detail below. Polyethylene has the disadvantage that it adheres poorly to polypropylene. Therefore, polymers which exhibit a low melting point and adhere properly to polypropylene are also suitable as an alternative to polyethylene as a sealing layer 13. The advantage of using a sealing layer with a lower melting point than the polymer tapes 12a, 12b has the advantage that the orientation of the molecules in the monoaxially drawn tapes 12a, 12b is not destroyed by the sealing process. By heating the polymer tapes 12a, 12b up to the crystallite melting point the orientation of the molecules in the monoaxially drawn tapes 12a, 12b may be destroyed.

(20) Coming back to FIG. 2, a possibility of eliminating the drawback of poor adhesion between PE and PP as described with reference to FIG. 1 is the introduction of the adhesive layer 14. The adhesive layer may consist of a composition B as described above and will be described in more detail below.

(21) In an alternative embodiment the polymer tapes 12a, 12b may also have other properties with respect to breaking tenacity and enlongation at break. In this case it is important to use a sealing layer 13 with the composition A as described above and in further detail below.

(22) The coated fabrics 11, 11 according to the invention are suitable for interconnecting by welding, wherein the welded joint produced exhibits high strength. Thus, they are particularly well suited for use in the production of bags, in particular for the form, fill and seal (FFS) process. They are also very well suited for ultrasonic welding, heated tool welding, infrared welding or laser beam welding. High frequency welding or microwave welding are alternative suitable welding techniques, but may require addition of high frequency or microwave sensitive additives (e.g. metal particles, graphite, carbon or others) and or polar polymers to the polyethylene or propylene sealing layer since these polyolefin resins are normally insensitive to high frequency energy. Preferably using one of these welding processes, welding is performed so that the welding line or welding seam is substantially rectangular to the warp tapes 12a. With reference to FIG. 3 the welding seams then would be vertical.

(23) Such polymer tapes 12a, 12b according to the invention are advantageously made of thermoplastic polymer material. They may be monoaxially drawn polymers. According to a first example the polymer tapes are made of HDPE (T4). A breaking tenacity of 38.6 cN/tex, with an elongation at break of 56.7% has been reached. In this case the sealing layer consisted of Composition A. An expensive adhesive layer could be omitted as HDPE and the sealing layer showed good adhesion. Also the energy dissipation is higher compared to PP tapes fabrics. In a second example PP tapes with similar mechanical properties were used (T3). A breaking tenacity of 36 cN/tex, with an elongation at break of 40.9% has been reached. However, an additional adhesive layer, as described by Composition B between the sealing layer and woven materials was needed.

(24) On the basis of FIG. 4, the interwelding of two of the coated fabrics 11 depicted in FIG. 2 is now illustrated schematically. At first, the two coated fabrics 11, 11 are placed on top of each other such that their sealing layers 13, 13 face each other. Then, at least one of the coated fabrics 11, 11 is heated from the side of the fabric 12 from monoaxially drawn polymer tapes, i.e., from outside, to a temperature (arrow T) which is below the crystallite melting temperature of the fabric tape material, using at least one welding element 15, 16. The supply of heat occurs until the sealing layers 13 are caused to melt and, in doing so, tightly bond to each other, as indicated by the area 18 with a dashed line. The application of pressure occurs directly via the welding elements 15, 16. If the welding process is configured as ultrasonic welding, the welding element 15 is designed as an ultrasonic actuator and the welding element 16 as a counterpart is shaped in the form of an anvil. If the welding process is configured as heated tool welding, the welding element 15 is designed as a heating element, and the welding element 16 is designed either also as a heating element or as a bearing. If the welding process is configured as infrared or laser beam welding, the welding element 15 is designed as an infrared radiator or a laser beam source.

(25) FIG. 5a and FIG. 5b show a tubular bag body 1 formed from a flat fabric 12 bonded along its longitudinal edges 9a, 9b to form a tube. The tube is folded several times so to form an essentially rectangular body upon filling. The bag body comprises coated fabrics 12. As can be seen from FIG. 5b the tubular bag body comprises a sealing seam or weld which is substantially rectangular to the length of the tubular body (and to the warp tapes 12a of the fabric).

(26) The packaging machine 100 illustrated in FIG. 6 in a schematic cross-section serves for filling bags 200 with products 208. This product may for example be bulk material, powdery products or loose fill material with particles. Or else it is conceivable to fill the bags 200 with other products 201 such as liquid or paste-like products.

(27) The packaging machine 100 is configured as an FFS packaging machine and comprises a sheet stockpile 101 having at least one sheet roll. The sheet stockpile 101 contains rolled up tubular sheet 102 used for manufacturing the bags 200. The providing of a sheet stockpile 101 with one or more sheet rolls allows to manufacture bags 200 as needed. The length of the bags is in particular flexibly variable and can readily be adapted to the desired filled quantity.

(28) The tubular bag body or sheet 102 fed off the sheet roll of the sheet stockpile 101 is conveyed via the sheet storage 103 into the interior of the packaging machine 100 and further to the corner welding device 104. In the corner welding device 104 the corners are welded as they are shown in FIG. 8 as corner weld seams 207.

(29) These corner weld seams or corner welds 207 achieve a brick-shaped form of the filled bag so as to achieve simple and optically appealing stackability. This facilitates transport, handling, and sales.

(30) When the corner weld seams 207 have been manufactured the tubular sheet 102 with the corner weld seams 207 produced in the gussets 220 proceeds to the bag length adjuster 106 which serves to equalize the indexed operation of the packaging machine 100. The bag length adjuster 106 allows steady unwinding of the sheet stockpile 101 from the sheet roll while the packaging machine performs in its interior an indexed operation for forming and filling and subsequently sealing the bags 200.

(31) The sheet drive 107 serves to convey the tubular sheet 102. The tubular sheet 102 is fed to the welding device 112 where first the tubular sheet 102 is clamped by means of the clamping device 105 before (see FIG. 7) the welding jaws 108 make a weld seam in the tubular sheet 102.

(32) The welding device 112 with the welding strips 128 of the welding jaws 108 simultaneously welds the center region and the gusseted regions although with considerably different welding temperatures. Firstly the bag bottom with the closing seam 205 is formed. The closing seam 205 extends across the entire traverse width 212 of the bag 200.

(33) As FIG. 7 shows enlarged, a cutting blade 109 is provided which after making the closing seam 205 at the bag bottom 215 and advancing the tubular material severs the tubular sheet 102 in the region of the second end 204 of the bag formed. The bag 200 configured as an open bag 210 now comprises a bag bottom 215 and at its upper end is provided with a filling mouth 211 at the bag opening 209. The filling mouth does not extend over the entire width of the bag 200 since the region of the gussets 220 is left out by way of the corner weld seams.

(34) Thereafter the closing seam 205 at the bag bottom 215 may be cooled down by means of a cooling device 113 to achieve adequate stability with a high throughput.

(35) By means of a swing conveyor 115 the bag 200 is conveyed further by means of the pivotal swing arms 116 and opened by means of a bag opener 110. At the next cycle the bag 200 is attached to the filling spout 123 with its filling mouth 211 and filled with the product 208 from the product feed 124.

(36) After the filling operation the bag 200 is fed via the swing conveyor 115 to the closing device 125 which in turn comprises a clamping device 105 and welding jaws 108 with welding strips 128.

(37) At the closing device 125 the second end 204 of the bag 200 is closed by way of a closing seam 206 as a head seam. The gusset 220 region is again welded shut at a significantly increased temperature.

(38) FIG. 8 illustrates an open side gusseted bag 210 as a bag 200 comprising closing seams 205 and 206 at each of its first 203 and second ends 204.

(39) Both the closing seams 205 and 206 configured as welded seams 221 extend across the entire bag 200 width, allowing the bag interior to be sealed tight.

(40) The bag 200 has been filled at its second end 204 through the filling mouth 211 of the bag opening 209. The filling mouth extends over nearly the entire bag width. The region of the corner weld seams 207 is separated and does not form part of the filling mouth 211.

(41) The bag comprises four layers at the gussets 220 in the gusset region 222 while only two layers need to be welded in the center area 223. The overlapping region 224 with three layers may be provided in case that the tubular sheet 102 is manufactured from a flat sheet or a cut-open tubular sheet is manufactured and the edges 226 and 227 overlap in the joining region.

(42) FIG. 9 shows a schematic and perspective view of the filled bag having a brick-shaped and readily stackable form.

(43) FIG. 10 illustrates a conventional bag in which the weld seam in the gussets had not been strong enough such that the areas 201 have come undone while the bag is still sealed tight. The invention remedies this effect.

(44) The FIGS. 11 and 12 illustrate two different welding strips 128 for the welding jaws 108 for the packaging machine 100.

(45) The welding strip 128 illustrated in FIG. 11 has a distinct cross-sectional profile 214. The welding strip 128 is configured as an electrical resistance welding strip such that the local temperature is dependent on the local electrical resistance of the welding strip 128.

(46) In regions where a high temperature is required the cross-section is small. In regions where no high temperature is required or necessary a larger cross-section is provided. This is why the cross-section is particularly high in the end region 225 since it extends beyond the bag width and no welding occurs in this area. The cross-section selected is particularly low in the gusset regions 222 and in the center area 223, comparatively large. In this way the welding temperature achieved in the gusset region 222 is 60 to 100 Kelvin and presently 80 Kelvin higher and results in secure sealing of the head seam including in the region of the gussets. Areas 201 coming undone at the gussets can be avoided so as to achieve good stackability. The cross-section selected is somewhat lower in the overlapping region 224 to obtain secure welding of the three layers present there.

(47) In FIG. 12 another embodiment is illustrated in which the locally different conductivity and thus temperature during welding is achieved by locally different coatings. A combination of a cross-sectional profile with local coatings is conceivable as well.

(48) The coating 126 selected in the end regions 225 is particularly highly conductive. In the gusset regions 222 no coating at all or coating having very low conductivity is applied. A medium conductive coating 127 is provided in the center area 223. In the gusset region 222 in turn the welding temperature achieved is increased by 60 to 100 Kelvin and presently approximately 70 to 90 Kelvin so as to securely interconnect the regions of the gussets 220. In an optionally provided overlapping region 224 a slightly less conductive coating is selected to generate a correspondingly higher welding temperature.

EXPERIMENTAL

(49) Four different tapes for the woven webs have been produced on a Starlinger tape line starEX 1500ES/E120T according to the specification listed in TABLE 1.

(50) TABLE-US-00001 TABLE 1 Tape specification Elon- Tenac- gation Tape Linear ity at Tape Tape width density cN/ break ID polymer Grade mm tex tex % T1 PP Chempetrol 3.01 101.5 48.6 28.38 Mosten TB 003 T2 PP Chempetrol 3.01 102.5 47.1 28.86 Mosten TB 003 T3 PP Chempetrol 3.03 102.7 36 40.88 Mosten TB 003 T4 HDPE Borealis VL 5580 2.96 102.9 38.6 56.72 T5 LLDPE Huntsman Rexell 2.27 207.6 22.0 78.75 M3105

(51) From these tapes four different webs have been prepared on Starlinger alpha 61 looms. These machines produce a tubular fabric and then slit the tube into two flat webs by means of an ultrasonic cutting and sealing device. The composition of each fabric is described in TABLE 2.

(52) TABLE-US-00002 TABLE 2 Fabric specification Fabric Fabric Fabric Weft Warp weight ID polymer Grade tape ID tape ID g/m.sup.2 PP1 PP Chempetrol Mosten TB 003 T1 T1 67.62 PP2 PP Chempetrol Mosten TB 003 T3 T3 68.52 PP3 PP Chempetrol Mosten TB 003 T2 T3 67.21 HD1 HDPE Borealis VL 5580 T4 T4 71.99

(53) The extrusion coating of these selected webs has been done on a Starlinger stacoTEC 1500COEX extrusion coating line with two extruders. The webs have been preheated before they have been extrusion coated with selected polymer compositions described in TABLE 3 and TABLE 4. TABLE 5 shows the performance of the produced substrates.

(54) TABLE-US-00003 TABLE 3 Compositions for Extrusion Coating MFR (g/10 min, Density 2.16 kg) Tm Vicat Composition (g/cc) at 230 ( C.) ( C.) Type (ExCo PP)* 0.885 20 108 66 Propylene/ethylene (230 C.) copolymer MFI Density (g/10 min, Tm Vicat Composition (g/cc) 2.16 kg) ( C.) ( C.) Type (ExCo PE1)** 0.911 7.0 124 102 Ethylene/Octene (190 C.) Copolymer Blend (ExCo PE2)*** 0.919 8.0 124 102 Ethylene/Octene (190 C.) Copolymer Blend *DP 5000.01, Developmental Plastomer, available from The Dow Chemical Company **ELITE 5800 Enhanced Polyethylene Resin, available from The Dow Chemical Company ***ELITE 5811 Enhanced Polyethylene Resin, available from The Dow Chemical Company

(55) TABLE-US-00004 TABLE 4 Coated Fabrics Nominal Nominal Coated Coated Coating Coating Fabric Fabric (11) Composition Weight (13) Composition Weight (14) Fabric Weight ID* Layer (13) (g/m2) Layer (14) (g/m2) (12) ID (g/m2) V126b (ExCo PE2) 35 (ExCo PP) 5 PP 1 106.9 V130 (ExCo PE2) 35 (ExCo PP) 5 PP 2 109.2 V131 (ExCo PE2) 35 (ExCo PP) 5 PP 3 107.8 V132 (ExCo PE2) 40 no no HD 1 112.8 V133 (ExCo PE1) 40 no no HD 1 113.7

(56) TABLE-US-00005 TABLE 5 Performance of the Coated Fabrics listed in Table 4 Seal Bag Bag Bag Strength Max Seal Drop Drop Drop (Fabric) Strength Test- Test- Test- Coated (Heat (Seal) Elongation gusseted flat sealing Fabric Elongation Elongation Sealing) (Impulse at Break side side side (11) at Break % at Break % 130 C. Sealing) (Impulse (height) (height) (height) ID* MD % CD % N/15 mm N/50 mm Sealing) % meters meters meters V126b 22.4 25.58 20.8 164 NA* 0.6 2 2 V130 30.4 30.32 16.5 140 22 0.5 2 2 V132 32.8 34.29 65.4 207 19 0.9 2 2 V133 33.4 33.97 58.4 192 21 1.1 2 2 NA = not available.

(57) Test conditions for Max Seal Strength (Impulse Sealing) and Elongation at Break:

(58) Machine: Zwick/Roell Zwickiline 2.5

(59) Clamp distance: 150 mm

(60) Test velocity: 100 mm/min

(61) Sample width: 50 mm

(62) For each adjustment we tested three samples.

(63) The test is in accordance with ASTM D882 with the mentioned changes due to the special requirements of the fabric.

(64) The coated fabrics listed in Table 4 were heat sealed. For each coated fabric the layer 13 was sealed to itself. All samples were sealed using a KOPP Sealer, according to ASTM F2099. After contacting the layer 13 to layer 13, as described in FIG. 4, heat was applied from fabric 12. Heat seal strength was determine by preparing seal samples at different temperatures, all samples were conditioned for 48 hour under ambient conditions before testing. Seal condition was as follows: One second contact time with 500N force, both sealing bars heated to the specified temperature (each seal bar is TEFLON coated; width=5 mm for a bond area of 5 mm15 mm in center of sample). Sample size used to determine seal strength was 100 mm length15 mm width.

(65) Seal strength of each coated substrate was determined using an INSTRON 5564 tensile tester, with a clamp distance of 30 mm, and a cross head speed of 100 mm/min. For each temperature, at least five samples (seals) were tested in cross direction and the average seal strength was reported. The seal performance of each coated substrate is shown in FIG. 13. For sealing temperatures greater than 130 C., the web started to shrink when sealed.

(66) Elongation at Break of coated fabrics was determined according to ASTM D-882.

(67) The densities of the ethylene-based polymers and propylene-based polymers, and blends thereof, are measured in accordance with ASTM D-792-08.

(68) Melt indexes (I2) of ethylene-based polymers, and blends thereof, are measured in accordance with ASTM D-1238-04, condition 190 C./2.16 kg. The melt flow rates (MFR) of propylene-based polymers, and blends thereof, are measured in accordance with ASTM D-1238-04, condition 230 C./2.16 kg.

(69) The melting point (Tm) for ethylene-based and propylene-based polymers, and blends thereof, can be determined by Differential Scanning calorimetry (DSC) using a TA Instruments Model Q1000 Differential Scanning calorimeter. A sample of around 5 to 8 mg size is cut from the material to be tested, and placed directly in the DSC pan for analysis. The sample is first heated, at a rate of about 10 C./min, to 180 C. for ethylene-based polymers (230 C. for propylene-based polymers), and held isothermally for three minutes at that temperature, to ensure complete melting (the first heat). Then the sample is cooled at a rate of 10 C. per minute to 60 C. for ethylene-based polymers (40 C. for propylene-based polymers), and held there isothermally for three minutes, after which, it is again heated (the second heat) at a rate of 10 C. per minute, until complete melting. The thermogram from this second heat is referred to as the second heat curve. Thermograms are plotted as watts/gram versus temperature.

(70) The melting point(s) (Tm) of the polymers can be determined from the second heat curve obtained from DSC, as described above. The crystallization temperature (Tc) can be determined from the first cooling curve.

(71) Vicat softening temperatures, or Vicat temperatures, are measured in accordance with ASTM D1525-07. The term softening temperature, as used herein, refers to the Vicat softening temperature.

(72) TABLE-US-00006 List of reference numerals: 1 tubular bag body 9a, 9b longitudinal edges 10 bag 11 coated fabric 12 fabric 12a warp tapes 12b weft tapes 13 sealing layer 15, 16 welding element 100 packaging machine 101 sheet stockpile/sheet roll 102 tubular sheet 103 sheet storage 104 corner welding device 105 clamping device 106 bag length adjuster 107 sheet drive 108 welding jaw 109 cutting blade 110 bag opener 112 welding device 113 cooling device 114 bag forming device 115 swing conveyor 116 swing arm 117 welding jaw 118 clamping device 119 sheet gripper 120 swing rod 121 discharging belt 122 scissors table 123 filling spout 124 product feed 125 closing device 126 coating 127 coating 128 welding strip 200 bag 201 region 202 bag wall 203 first end 204 second end 205 closing seam 206 closing seam 207 corner weld seam 208 product 209 bag opening 210 open bag/open-mouth bag 211 filling mouth 212 traverse width 213 longitudinal side 214 cross-sectional profile 215 bag bottom 220 gusset 221 weld seam 222 gusset region 223 center area