AU2447392A

AU2447392A - Machine and method for heat seal lamination of textile fabric

Info

Publication number: AU2447392A
Application number: AU24473/92A
Authority: AU
Inventors: George Barrett
Original assignee: PACKAGING CONCEPTS AND TECHNOLOGIES INTERNATIONAL Inc
Current assignee: PACKAGING CONCEPTS AND TECHNOLOGIES INTERNATIONAL Inc
Priority date: 1991-08-01
Filing date: 1992-08-03
Publication date: 1993-03-02
Also published as: JPH06501896A; EP0560952A1; WO1993002861A1; CA2093141A1; EP0560952A4

Description

TITLE OF INVENTION

MACHINE AND METHOD FOR HEAT SEAL LAMINATION OF TEXTILE FABRIC

BACKGROUND OF THE INVENTION

The present invention is generally in the field of forming a continuous sheet of laminate material containing superabsorbent polymer and relates specifically to lamination of large continuous sheets of fabric to form enclosed cells, each containing a measured quantity of superabsorbent polymer material. Such composite sheets have many uses and are important items of commerce. The superabsorbent material readily absorbs water and can then be frozen to provide a substitute for ice and dry ice.

The invention comprises a method and machine for rapidly and reliably producing a continuous composite sheet and forming it into uniform rolls. "Composite" as used here means a sheet comprising two layers of laminated textile material between which discrete quantities of a superabsorbent polymer are arrayed in a regular pattern. Those quantities of polymer are kept separate by the fusing or otherwise sealing together of the two layers of textile material. Each quantity of polymer is completely surrounded by a seal which prevents the escape of the polymer. One such quantity of polymer surrounded by a seal is referred to here as a "celJ." . The textile material allows passage of fluids, such as water, there-through but contains the water after absorption into the polymer within the cells. It is a requirement of composites of this type that th seals around the individual cells containing polymer b secure. The polymer is typically a powder-like material whic must be contained within the cells. These seals may be subject to stress in the intended use of the product, but it is important that their contents should not be released. The cells are usually relatively small, square, and of uniform size.

The laminated seals may be cut generally down their centerlines to separate out a smaller sheet. It is desired that the seals retain sufficient strength even when split to prevent the escape of cell contents during the use for which the product is intended. It is also desired that the seals withstand the application of perforations down seal centerlines for tearing, or separating along said perforations while retaining sufficient integrity to prevent the escape of cell contents under end use conditions.

The textile material used keeps cell contents from passing through said fabric in its original powered state or in expected subsequent conditions or states.

It is known to laminate fabrics to form a bond and seal. Such lamination has been previously done using heat to fuse or bond fabrics. The present invention uses lamination to make it possible to form large continuous sheets of composite material having discrete cells containing powder or granular material. method and apparatus for economically producing lar quantities of laminate material having discrete cells of powd or granules. It is another object of the invention to provi a continuous composite sheet that may be readily separated in sheets of desired size. Other objects of the invention wi become apparent from the detailed description to the preferr embodiment.

SUMMARY OF THE INVENTION

The present invention includes a method and apparatus f manufacturing a continuous quilt-like roll of materi comprising an upper and lower sheet of fabric material bond together along continuous intersecting lines to form discre pockets or cells between said sheets. The individual cell contain and hold a superabsorbent polymer or other simila material which is retained in individual cells by a fabri through which the material cannot pass either dry or afte having absorbed a fluid. The length and width of each cell i determined by the spacing of the longitudinally an transversely extending seal or bond lines. The seals or bond are formed by the application of heat and pressure from paire rollers, at least one of which has a raised pattern to transfe a desired pattern of cells to the two sheets of fabric passe there-between. The fabric allows forming such bonds b Arrangement of the rollers allows increasing and controlli the heat/pressure phase for producing the bond lines. delayed pressure roller helps cool and consolidate the bond. vibrator plate levels the powder-like material in the cells minimize distortion when forming the finished product in rolls.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic side view of the present invention,

Fig. 2 is a perspective view of the present invention wit sideframe partially broken away.

Fig. 3 is a detailed view of the apportioning roller.

Fig. 4 is a detailed view of the pattern roller.

Fig. 5 is a perspective view of the production blanket, vibratory plate, resilient mounts and vibratory drive unit.

EMBODIMENT

Fig. 1 shows a side view of the preferred embodiment of t laminating machine which is the subject invention, general designated 1. Continuous rolls of fabric 2 and 3, at least o of which is semi-permeable to moisture, are suspended rotatably mounted shafts 4 and 4a. The shafts 4 and 4a a readily removable for replacing the fabric rolls. The rolls fabric may be wound around a rigid core or tube which removably mounted on supporting shafts. The fabrics a selected to allow formation of a secure bond there-betwe using heat and pressure produced in the subject machin Fabric 3A from roll 3 feeds around roller shaft 5 near t bottom of powder bin 7 and then feeds down and around powd apportioning roll 8 shown in Fig. 3, thereby trapping powd deposits 12 which have fallen through the open bottom of powd bin 7 into cavities 9 of roller 8. The deposits 12 are stru off flush with the surface of roller 8 by doctor blade 10 f precise control of the quantity in powder deposits 12. T cavities 9 form a regular pattern of powder deposits 12 on t upper surface of fabric 3a. Fabric 2a from roll 2 simultaneously fed around smooth pinch roller 15. The fabr 2a passes around and down past roller 15 to enter the pin formed between roller 15 and heated pattern roller 11. Patterned roller 11 shown in Figs. 1 and 4 is heated means of electrical rod heaters mounted therein and suppli with power through sliding electrical pickups on the shaft roller 11. Alternately, heat may be supplied by a heat circulating fluid fed into and out of roll 11 through i central shaft via swivel couplings. Whatever heating system employed, control may be maintained by means of a conta thermal sensing device 16 contacting a surface of roll 11 in sliding relationship and providing thermostatic control of ro temperature which is selected, and set by the operato Alternately, a non-contact infra-red temperature probe may used for the same purpose.

The raised rib pattern 58 of heated roller 11 is shown Fig. 4 and coincides with the pattern of cavities 9 in roll 8. The raised rib pattern 58 is timed through chain dri sprockets 17 and 17a and drive chain 18 to place said deposi 12 in the approximate center of the opening between raised ri 54 of said pattern.

Pinch roller 15 is smooth and therefore has no timi requirement. Smooth pinch rollers 15 and 20 rotate throug surface friction of the fabric as it is pulled through th series of rollers by chain 18 acting through sprockets 17, 17a 17b and 17c on the powered rollers 8, 11, 21 and 27. weight. The shaft of roller 15 is free to move vertically frame slot 34 and thereby maintain pressure between rollers and 15. Roller 15 may be heated and temperature controlled a manner similar to that of roller 11 should such extra he input be desired.

Preliminary bonding between fabric 3a carrying powd deposits 12 and cover fabric 2a occurs between the raise heated ribs 54 of pattern 58 on roller 8 and the surface pinch roller 15. There is no pinching applied to said fabri 2a and 3a except where the raised ribs 54 of roller 11 conta the smooth surface of roller 15.

The indentations or recesses 54a of roller 11, as shown Fig. 4 limit bonding of the fabrics 2a and 3a to the conta areas of ribs 54 which bond the sheets of fabric passi there-between forming cells. The bond is formed under t influence of the heat and pressure thus applied to the bondi area. This bonding area extends completely around each powd deposit 12 forming cells 52, as shown in Fig. 2, which a square with a bond width and pattern size commensurate with t rib pattern 58 on roller 11. Longitudinal bond or seal lin 52a and transverse bond lines or seals 52b form the cells. T width of the bond or seal lines is generally such that sheet may be separated into groups of cells by cutting or splitti at the centerlines of the bond or seal lines. Four in squares with 1/2" bond or seal line width are typic dimensions of each cell.

The heat from roller 11 may not sufficiently penetrate a fully fuse fabric 2a and 3a to make a satisfactory seal fr the pressure and heat of rollers 11 and 15 since the dwell ti there-between is very short at production rolling speed Roller 19 is provided to allow additional contact time for he penetration and fusing by causing the composite sheet 25 remain in contact with heated roller 11 until said sheet enters a second pinch between roller 11 and roller 20. Sa second pinch roller 20 is carried on heated pattern roller and unheated pattern roller 21 approximately as shown in Fi 1. The weight of smooth pinch roller 20 creates a pin between rollers 20 and 11 and also between said roller 20 a roller 21. Shaft 32 of smooth roller 20 is free to sli vertically in slot 33 in sidewall 20 and maintain a unifor weight against the fabric layers 2a and 3a passing between sai rolls. It is understood that the opposite side of apparatus is the same as the side shown in Fig. 1. but without the driv chain 18 and its chain sprockets mounted on the shafts. Dotted lines outline a section of machine sidewall 50 Sidewalls 50 with cooperating crossmembers and attachments (no shown) comprise the frame of machine 1. Guide slots 33 and 3 for rollers 15 and 20 are the same on eac side. The sheet 25 r des n contact w r s on ea roller 11 and the seal areas remain on the raised ribs roller 11 until it has passed through the pinch created by t second pinch roller 20. This second application of force the ribs helps facilitate a bond or seal at bond or seal lin 52a and 52b to allow operation of the machine at higher spee or at lower roll temperatures than might be possible with single pinch roller. In most cases both higher speed and low temperatures will be possible while still producing an adequa seal or bond.

A third pinch is provided between unheated pattern roll 21 and pinch roller 20. Pattern roller 21 is preferably t same as pattern roller 11, except that it is unheated. Patte roller 21 is timed to pattern roller 11 so that the raised ri 55 and recesses 55a of roller 21 will coincide with the bond seal lines 52a and 52b already established on sheet 25. Roll 21 is adjusted in its rotational relationship to roller directly over the pattern established by roller 11 by looseni sprocket 17b on shaft 28 of roller 21, making said rotation adjustment and relocking the sprocket to said shaft. When th is done with chain 18 tightly over sprockets 17a, 17b, a under sprocket 36, the new rotational relationship will fixed. The longitudinal seal line 52a of the square rectangular sealing pattern employed in the machine satisfied by laterally locating pattern rollers 11 and 21 that the circumferential components of the ribs 54 creating longitudinal seal line 52a of said seals are accurately alig in the machine. Adjustments of roller 19 and/or sprocket will have no effect on said lateral alignment.

The effect of the pinch between cold pattern roller 21 a roller 20 is to consolidate the seal between fabric 2a a fabric 3a. In the passage between the last contact with heat roller 11 and the pinch between smooth rollers 20 and 2 thermoplastic bonding forming the seal will have had time cool and gain considerable physical strength. Subjecting t seal lines 52a and 52b to yet another application of pressu in its bonded areas insures that the bonds produced may recei a pattern of heating times, repeated pressure applications a bond tempering (or cooling) to insure good results with a wi range of heat bondable fabric materials or surface adhesi treatments.

Sheet 25 is now complete after passing between smoo roller 20 and pattern roller 21. The sheet 25 may be qui lumpy because of the mounded condition of powder deposits which were deliberately placed in small mounds so that sea lines 52a and 52b which would later by formed around sai deposits would maintain a maximum distance from any seal to an powder deposit margin in order to avoid possible inclusions o powder within said seals. Storage and handling consideration of finished production rolls make it desirable that they be a . the aforementioned lu piness of the production sheet preferably reduced.

Sheet 25 is passed over flat plate 37 as it approac pick-up roll 22. Sheet 25 lies horizontally and in cont with said plate which is vibrated by an eccentric vibrator u 39 fastened to plate 37 by bracket 40, screws 41 and weldi Plate 37 and vibrator 39 are mounted in position on frame 50 means of resilient mounts 38 which allow elastic movemen between their two mounting ends. Thus, sheet 25 may subjected to high frequency vibration causing powder 12 distribute itself more evenly over the area bounded by t seals 52a and 52b in each cell 52 of sheet 25, thereby reduci sheet 25 to a more uniform thickness and improving i suitability for rolling up neatly and compactly on take-up ro 22.

Take-up drive roll 22 may also be powered from chain through its sprocket 17c. Said take-up drive roll 22 employed to furnish a drive means for the actual producti take-up roll 2g because a difficult problem exists at th point in production. Friction between the semi-plast composite sheet and the various smooth and pinch rollers very low, so that any tendency to "overfeed", that is, to ro up the production blanket faster than the fabric was passi through the patterned rollers may cause one or both fabr s ee s o s p roug one or more p nc es , regular pattern and possible getting powder into a seal ar It is also possible to stretch some fabrics in the transverse seals 52a while they are softened in the hea zones over ribb 54. Conversely, not enough take up sp results in possible loosening of fabric 3a as it passes aro roller 8. This will allow powder to fall out of cavities prematurely and thus to contaminate seal areas of th satisfactory seals could not be made.

Therefore actual procluction take up roll 26 cannot shaft-driven since its diameter is always changing a therefore it cannot be geared tot he machine drive witho producing unstable "take up rates".

It is possible, however, to drive roll 26 through the u of a relatively high subface friction rubber surfaced roller which is always the same diameter and will therefore alwa produce the same feed rate regardless of the diameter of t rolled up production sheet 26. By starting the roll on roller core tube 23 and placing through-shaft 22 in sidewall slots 24. The roll 26 may grow from small to large diamet while maintaining a constant take-up rate equal to the surfa speed of driver roll 27 matched to surface speed of rollers 11 and 21. Production speed of the machine is set controlling the speed of variable speed D.C. motor 53. Sa motor may be closely controlled in RPM over a wide range making adjustments and threading in new materials.

Sprocket 46 takes up the slack in chain 18 resulting f wear or repositioning of sprocket 35 during timing of patt rolls 11 and 17. Shaft 47 of sprocket 46 lies in slot 48 frame sidewall 50 and is urged upwardly by spring 49 maintain a tension in drive chain 18. Variable speed elect motor 53 provides power through drive gear 53a to po energizing chain 18 and thereby control the through-put sp of production sheet 25.

Coordination of the location of powder deposits 12 with t center of square cells 52 established by roller 11 will n change except when one or both of these rollers are replace The lateral component of said coordination is original established by adjusting the rotational relationship of roll

8 to sprocket 17 with drive chain 18 in place before locki said sprocket 17 to the shaft of roller 8. The longitudin component of said relationship is established by later spacing of rollers 8 and 11 so that the centerline of caviti

9 line up halfway between raised ribs 54 of pattern 58 roller 11. Bearing blocks 56, 56a, 56b, 56c, 56d and 5 rotatably support roller shafts to frame sidewalls 50.

It will be apparent to those skilled in the art th various modifications and variations can be made in t foregoing method and apparatus of the present invention and the construction of the foregoing method and apparatus of t present invention without departing from the scope or spirit the invention. Thus, it is intended that the present inventi cover the modifications and variations of this inventio provided they come within the scope of the appended claims a their equivalents.

I CLAIM

1. An apparatus for producing a continuous composite fabr sheet having discrete cells, each cell containing a measur volume of superabsorbent material, comprising:

a means for dispensing a superabsorbent material onto cylindrical apportioning roller;

said apportioning roller having surface cavities fo receiving predetermined quantities of said powder and a mean for striking off excess powder from said apportioning roller:

a continuous roll of fluid permeable fabric for feedin around the surface of said apportioning roller to hold sai superabsorbent material in said cavities and to receive pattern of deposits of superabsorbent material from sai cavities;

Claims

a second continuous roll of fabric for contacting s first fabric sheet with its pattern of individual pow deposits to form a continuous composite sheet;

a heated pattern roller having raised areas defining c patterns larger than the area covered by each deposit superabsorbent material on said fabric;

a pinch roller in contact with said pattern roller f receiving said composite sheet to apply heat and pressure selected areas of said composite sheet to selectively bond sa fabrics for forming cells having the pattern of the heat pattern roller and containing said individual powder deposit and

a second pinch roller in contact with said heated patte roller for receiving said composite sheet also passi there-between to maintain sufficient contact time and pressu with the heated pattern roller to provide adequate fusion form the individual cells in the continuous composite sheet.
2. The apparatus of Claim 1, including:

a second pinch roller in contact with said pattern roll for receiving said continuous sheet for consolidation of t seal pattern on the composite sheet passing there-between.
3. The apparatus of Claim 1, including:

a take-up roll for receiving said continuous composi sheet.
4. The apparatus of Claim 1, including:

means to synchronize the location of the pattern roller t coincide with the deposits of superabsorbent material.
5. The apparatus of Claim 1, including:

a vibratory means for more evenly distributing the deposit of superabsorbent material in the cells of the composite shee after forming.
6. The apparatus of Claim 3, including:

a "take up" drive roller imparting uniform speed to collecting roll of varying diameter ????
7. A method for producing a continuous composite fabric she having discrete cells, each cell containing a measured volu of superabsorbent material, comprising:

dispensing a pattern of discrete quantities superabsorbent material onto a continuous sheet of flu permeable fabric;

feeding a second continuous sheet of fabric in contact wi said first fabric sheet with its pattern of superabsorbe deposits to form a continuous composite sheet;

feeding said composite sheet between a heated patte roller having raised areas defining cell patterns larger th the area covered by the deposits of superabsorbent material said fabric and a pinch roller in contact with said patte roller to apply heat and pressure to selected areas of sa fabric to selectively bond said fabrics to form cells havi the pattern of said heated roller and containing sa individual deposits of superabsorbent material; and feeding said composite sheet between a second pinch roll in contact with said heated pattern roller with the composi sheet also passing there-between to maintain sufficient conta time and pressure with the heated pattern roller to provi adequate fusion at said selective bonds.
8. The methods of Claim 7, including:

feeding said composite sheet between a second patte roller and a contacting third pinch roller receiving sa continuous sheet for consolidation of the seal pattern on t composite sheet passing there-between.
9. The method of Claim 7, including:

feeding the completed composite sheets onto a take-up roll.
10. The method of Claim 7, including:

synchronizing the pattern roller to coincide with th deposits of superabsorbent material to form said cells.
11. The method of Claim 7, including:

applying a vibratory force to said completed composi sheet for distributing the deposits of superabsorbent materi in the cells of the composite sheet after forming.
12. The method of Claim 9, including:

maintaining the circumferential speed of the take-up roll with the speed of the continuous composite sheet to compensa for the increase in size as the continuous composite sheet wound therearound.