CA2055980A1 - Laundry pouch and method of making same - Google Patents

Abstract

ABSTRACT
A pouch containing a laundry detergent and formed from a porous fabric includes top and bottom permanent seams and longitudinal side seams formed from a water-soluble adhesive.
The water-soluble adhesive is a thermoplastic material such as polyvinylacetate or polyvinylalcohol. The pouch contains a measured amount of detergent and is placed in the laundry wash water where the adhesive dissolves to open the pouch and release the detergent. The pouch is formed by attaching a strip of water soluble adhesive on a first web and passing the first web and a second web through a pair of laminating rollers. A metered quantity of detergent is deposited between the webs as they are fed to the laminating rollers to form pouches filled with the detergent.

Description

I.AUNDRY POUC~E AND ~IET~rOD OF MZ~RING 8AME
Field of The I~vention X~59~
The present invention is directed to a single use package containing a measured portion of laundry detergent and to a continuous method of manufacturing the packages. More particularly, the invention relates to a package containing a laundry detergent which readily releases the detergent to the wash water from the package during use.
BACRGROUND OF THE INVENTION
Laundry soaps and detergents typically are sold in large containers as powders or liquids. The consumer must then measure the required amount of the detergent and add the detergent to the wash water. In an effort to minimize handling and measuring of the detergent, individual portions of the detergent have been produced. These single use portions have been manufactured as solid cakes of compacted powder with a suitable binder and as pouches containing a measured quantity of the detergent. The compacted cakes have exhibited the disadvantage of breaking or crumbling during shipping and not completely dissolving in the wash water. The detergent tends to remain in the rinse cycle, resulting in a detergent residue on the clothes. The pouches containing the powdered detergent have exhibited similar tendencies of the detergent powder not to completely dissolve during the wash cycle. Further, the solid cakes or tablets are typically soft d easily break apart and crumble thereby defeating the convenience aspect of the cakes. ZC`~9 The pouches containing the detergent are generally produced from two sheets of a water-permeable, insoluble fabric or textile. The two sheets of fabric are joined together to form a pouch which is filled with the powdered detergent. In order to prevent the powder from spilling or sifting from the pouch during storage and handling, the pores of the fabric must be sufficiently smaller than the average particle size of the detergent powder. The entrapped detergent powder cannot be released from the pouch until it is first dissolved in the wash water. Thus the detergent concentration of the wash water within the pouch tends to be higher compared to the detergent concentration of the remainder of the wash water, which reduces the ability of the detergent powder particles to efficiently dissolve. This often results in a portion of the detergent not being adequately dissolved and not being released to the wash water.
This undissolved detergent may then be released in the rinse water, resulting in a detergent residue being deposited onto the clothes. The detergent residue on the clothing and the residual undissolved detergent remaining in the pouch have resulted in a decreased consumer acceptance of the products.
There is, accordingly, a need for an improved packaging which will completely release the detergent in the wash cycle.

'5~
8~RY OF T~E INVENTION
The present invention is directed to a pouch containing a single portion of a laundry detergent which is placed directly in the wash water with the laundry. The pouch is provided with at least one seam formed from a water-soluble adhesive which readily dissolves in the wash water to open the pouch and release the laundry detergent. A water-soluble adhesive seam is preferably formed along opposite edges of the pouch to form an open tube when the adhesive dissolves to readily lo release the detergentO It is preferred that the pouch material be water permeable.
In one preferred embodiment of the invention, the pouch material is a porous, non-woven fabric which is insoluble in water. In another embodiment of the invention, the pouch material may be an impermeable material. The pouch material can be made, for example, of cellulose, rayon, polyester~
nylon, polyamides or the like. The water-soluble adhesive is preferably a thermoplastic hot melt adhesive such as polyvinylacetate or polyvinylalcohol. In the preferred embodiment the pouch material is a heat-sealable fabric ~ormed from a thermoplstic polymeric material.
The pouches containing the detergent are manufactured by feeding two sheets of the pouch material material through a pouch-forming machine. The machine includes a means to apply a plurality of longitudinal strips of the water-soluble adhesive on a first ~heet of pouch material. The water-soluble adhesive is preferably applied along the opposite ;59~
ngitudinal edges of the sheet and in at least one longitudinal strip spaced inwardly from the outer edges. The first sheet of pouch material having the adhesive applied thereon is then fed along with a second sheet between a pair of complementary counter-rotating pouch-forming rollers. The pouch-forming rollers include a plurality of circumferential ribs and a plurality of axial ribs to form the seams of the pouch. The first and second sheets of the pouch material are passed between the pouch-forming rollers as a controlled and metered portion of the detergent is dispensed between the longitudinal strips of adhesive on the sheets. The pouch-forming rollers form separate pockets for the detergent and seal the sheets together between the circumferential and axial ribs of the roller to form a plurality of pouches connected together along their edges. The water-soluble adhesive strips are positioned to cooperate with the circumferential ribs of the rollers to form longitudinal water-soluble seams.
The sheets of bonded pouch material are then conveyed between a rotating cutting knife to separate the pouches by cutting longitudinally along the water-soluble adhesive seals and a shear knife to cut along the transverse heat seals.
The water-soluble adhesive is preferably applied as a tape from a continuous supply reel and secured onto the first sheet of pouch material by ultrasonic welding or stitching.
The first and second sheets of pouch material are preferably joined together by heating the rollers and pressing the sheets together at the longitudinal adhesive strips to heat seal the eets. The transverse seams are preferably formed by the heated roller to weld the two sheets together. Alternatively, the longitudinal seams may he formed by applying a bead or strip of adhesive, such as a hot melt glue.

B~IEF DE8CRIPq~ION OF T~IE DR~WING~;
The invention is to be viewed in conjunction with the d;awings of which the following is a brief description.
Figure 1 is a plan view of the pouch in accordance with the preferred embodiment of the invention.
Figure 2 is a plan view of an alternative embodiment of the invention.
Figure 3 is a schematic drawing of the pouch forming apparatus in accordance with the preferred embodiment.
Figure 4 is a perspective view of the pouch forming rollers of the apparatus of Figure 3.
D~TAILED D~SCRIPTION OF T~E INVENTION
The present invention obviates the di~advantages and limitations of the previous laundry detergent packages while providing an efficient method and apparatus of producing the packages. The present invention is primarily directed to a novel pouch containing a portion of a water-dispersible material and, in particular, a powdered laundry detergent and to a method of manufacturing the pouch.
The pouch in accordance with the invention is preferably a substantially square pouch as shown in Figure 1. The pouch includes a pair of side walls 10 sealed together along the 5~
~ngitudinal edges 12 and 14 and the transverse edges 16 and 18. The pouch is formed from two sheets or webs of material, and preferably a water-permeable material, laminated together about the outer edges to form longitudinal seals 20 and 22 and transverse seals 24 and 26. The two sheets of material are joined together to define the pouch having a measured quantity of a laundry detergent. In preferred embodiments of the invention, the longitudinal seals are formed from a water-soluble adhesive and the transverse seals are a substantially permanent bond. The transverse seams are preferably formed by heat sealing the two sheets together to form a heat-welded seam. Alternatively, the seam may be formed by the use of a suitable adhesive, such as for example, a hot melt adhesive.
The longitudinal seams are preferably formed by a water-soluble adhesive which is placed on one sheet of material andlaminated to the second sheet of material by the application of heat and pressure. The water-soluble adhesive is preferably applied to the material sheet as a tape or strip from a supply roll. It is preferably attached to the sheet by stitching or ultrasonic bonding. Alternatively, the adhesive may be applied as a hot melt from a suitable hot melt glue gun, nozæle or other glue dispensing apparatus.
The water-soluble adhesive material is preferably soluble in cold water, as well as warm water, such that the adhesive will easily dissolve in typical laundering processes at most commonly used water temperatures. In preferred embodiments of the invention, the adhesive is a tape or strip of water-5~
luble thermoplastic hot melt adhesive, such as for example, polyvinylacetate or polyvinylalcohol. The water-soluble adhesive may alternatively be applied as a paste such as a carboxymethyl cellulose paste or the like.
The sheet material can be water-permeable or water-impermeable, but is preferably a fabric formed from water-insoluble fibrous materials, such as for example, rayon, nylon polyester, polyamide polyacetate, cellulose blends, and the like. The fabric may be a woven material, although non-woven materials are generally preferred for economic reasons. In a further embodiment, the matexial may be a porous, open-cell foam material. Preferably, the fabric is a thermoplastic material which can be heat bonded or welded to an adjacent sheet of fabric to form the packet by the application of a heated roller.
The detergent contained in the pouch may be any suitable laundry detergent as is well known in the art. The detergent is typically a granulated powder which easily dissolves in the wash water. The detergent may further contain a whitening agent and/or a fabric softening agent.
In one preferred embodiment of the invention the fabric sheets may include a coating of a suitable polymeric antistatic agent or fabric-softening material which is heat activated. In this manner the detergent-containing pouch may be passed through a wash cycle to dispense the detergent and then transferred to a drier with the washed laundry to release the polymeric antistatic agent or fabric softener. Such ~c`~s~
~ lymeric antistatic agents and fabric softeners are well known by those skilled in the art.
In use, the pouch contains a measured quantity of laundry detergent sufficient for a single wash cycle in a standard household washing machine. The pouch is placed unopened in the washing machine with the laundry to be washed. During the wash cycle, the detergent begins to dissolve as soon as wetted by the wash water and is dispersed to the wash water through the pores oP the fabric of the pouch. Within a short period of time after immersing in the wash water, the water-soluble seam dissolves to open the pouch and readily disperse the remaining detergent in the pouch to the wash water such that all of the detergent is more easily dissolved.
In a further preferred embodiment, the pouch may be compartmentalized to contain two or more different materials, such as for example, a laundry detergent and fabric softening agent. One example of such a compartmentalized pouch 30 is shown in Figure 2 and includes a longitudinal seam 32 extending substantially through the center of the pouch 30 to define two compartments. In this embodiment permanent transverse seams 34 are formed, for example, by heat sealing two sheets together, and extend continuously along the upper and lower edges. A longitudinal seam 36 is formed along each longitudinal edge to define the closed compartment.
Preferably each of the longitudinal seams 36 are formed from a water-soluble adhesive as discussed above.

Z~`5~
In the embodiment of Figure 2, the pouch may, for example, contain a detergent in one compartment 37 and a fabric softening agent, whitener or antistatic agent in the other compartment 38. The water-soluble adhesives forming the closure for each compartment may be the same or different.
Where different water-soluble adhesives are used, the relative solubility of each seam is determined to provide for a controlled release of the components. For example, an adhesive may be used to form the seam enclosing the detergent-containing compartment. A different adhesive having limitedsolubility may be used to form the seal enclosing, for example, fabric softener. The pouch may then be placed in the wash water to dissolve the first seal to fully release the detergent, while the seal enclosing the fabric softener is not fully dissolved until later in the wash cycle, such as for example, in the rinse cycle.
In yet a further preferred embodiment, the packets may be made from a porous woven or non-woven fabric which is coated or impregnated with a water-soluble, film-forming material.
The film-forming material serves to encapsulate the contents of the pouch and control the dispensing of the contents. When the pouch is placed in the wash water, the film will dissolve to begin dispensing the detergent. The coating of the film-forming material further reduces the premature loss of volatile fragrances until placed in the wash water. In this manner, reduced amounts of the fragrances can be used and still provide an effective amount to the wash water.

2~'5~
Referring to Figure 3 a schematic view of the pouch-forming apparatus is depicted. The pouch is produced by feeding a first continuous web of the porous, water-insoluble fabric material 40 from a supply reel 42 through guide rollers 44 and 46. The first web continues between a second pair of rollers 48 and 50 to the packaging apparatus 52. A second continuous web of fabric material 54 is fed from a supply roll 56 to the packaging apparatus as discussed in greater detail hereinafter.
A plurality of supply rolls 58 dispense a water-soluble, heat-seal adhesive strip 60 and feed the strip to the rollers 44 and 62. As shown in Figure 3, the adhesive 60 is in the form of a continuous tape or strip which is fed from a number of spaced-apart rolls 58. The tape of adhesive 60 is passed over roller 46 and between ultrasonic horn 66 and anvil roller 64 along with the first web 40 to form parallel adhesive strips on the surface of the first web 40. The rolls 58 of the adhesive are spaced apart a distance corresponding to the desired width of the pouch. In the preferred embodiment adhesive strips are spaced at given distances across the width of the web 40, including on each edge.
The web 40 and the adhesive strips 60 are then passed through attachment means to secure the tape of adhesive to the web. This can be a conventional stitchin~ machine. In the preferred embodiment as shown in Figure 3 the attachment means is an ultrasonic welding apparatus to stitch thP tape of adhesive to the web. Generally, it is necessary to only ;S9~
`ghtly tack the tape of adhesive to the web since the adhesive will be tightly bonded to the web in a later package-forming step. As shown in Figure 3, the attachment means preferably includes a plurality of roller anvils 64 positioned above the web 40 and aligned to contact the tape of adhesive 60 as the web and tape pass between the ultrasonic horn 66 and the roller anvils 64. A plurality of complementary ultrasonic horns 66 are positioned below the web 40 to cooperatively engage the roller anvils 64. The roller anvils 64 preferably include teeth or ridges 68 to ultrasonically stitch the tape of adhesive to the web intermittently, rather than in a continuous seam. In an alternative embodiment the tape may be continuously attached to the web by ultrasonic welding means, a heated roller or disc or by other means known in the art.
The water-soluble adhesive may alternatively be applied as a continuous bead from a suitable dispensing nozzle (not shown). Such an adhesive is preferably a hot melt thermoplastic adhesive dispensed from a glue gun or nozzle.
The tape of adhesive 60, once secured to the web 40, is then transferred to the packaging apparatus 52 for laminating with a secGnd web 54. The first web 40 and the second web 54 are passed between a pair of complementary counter-rotating nip rollers 70 and 72. A dispensing means 86 is disposed above the rollers 71 and 72 to intermittently meter a predetermined quantity of granular material between the webs.
As best shown in Figure 4, the package-forming apparatus includes the nip rollers 70 and 72 and a plurality of pressure 9~ 0 scs 74 and 76 and cutting means 98. The nip rollers 70 and 72 are provided with a plurality of circumferential rib elements 80 spaced apart a distance corresponding to the width of the pouch to be formed. Recesses 82 are provided on the rollers 70 and 72 between the radial ribs to define the package-forming area. Axial nip ribs 84 extend longitudinally on the rollers 71 and 72~ The circumferential ribs 80 and the axial ribs 84 of each roller 70 and 72 are driven in a counter-rotating manner by a drive means (not shown). The rotation of the rollers 70 and 72 are synchronized whereby the circumferential ribs 80 and the axial ribs contact a complementary rib on the other roller such that the recessed portions 82 complement each other to form the pouch. The rollers are further heated whereby the circumferential ribs 80 and the axial ribs 84 form heated sealing elements to heat seal and laminate the webs together.
It will be appreciated from Figure 4 that the tape of water soluble the~moplastic adhesive material 60 is applied to the first web 40 longitudinally in spaced-apart rows so as to cooperate with the circumfsrential ribs 80 of the rollers 70, 72. The rollers ~urther rotate in a synchronized fashion to form pouches by sealing the webs 54, 40 together along the adhesive strips. The axial ribs cooperate to bond the webs together forming the upper and lower edges of the pouch.
A dispensing means 86 as shown in Figure 3 is disposed above the rollers 70 and 72 to intermittently meter a quantity of granular detergent between rollers. The dispensing means 2~s~ o Icludes a plurality of nozzles or chutes 88 cooperating with the pouch-forming recesses of the roller. The metering means of the dispensing means delivers the metered granular material between the circumferential ribs in a sequence cooperating with the rotation of the axial ribs during rotation of the rollers 70 and 72 to fill the space between the webs formed by the recesses 82. As shown in Figure 4, the rollers 70 and 72 are provided with five circumferential ribs 80 and four dispensing nozzles are provided to form four pouches simultaneously with the rotation of the rollers.
As best shown in Figure 4, the first and second webs are laminated by the rollers 70 and 72 to form a continuous web of pouches 90. The rollers 70 and 72 form continuous longitudinal seals 92 and transverse seals 94 to define the pouches 90. The longitudinal seals 92 are formed by the water-soluble adhesive material. The transverse seals are, in the preferred embodiment, permanent seals formed by heat sealing the webs together. The web of pouches pass between a pair of cooperating roller discs 74 and 76 to apply pressure to the thermoplastic adhesive to ensure proper bonding of the first and second webs until the adhesive has cooled.
The web of pouches 90 then passes through a cutting means which as shown in Figure 4 includes a cutting roller 96 and platen 98 to cut the web at longitudinally-spaced positions.
As shown in Figure 4, the cutting roller 96 and platen 98 are positioned to cut the web along the longitudinal seal formed by the water-soluble adhesive at about the midpoint of the am such that each packet has a seam formed from the water soluble adhesive.
A transverse cutting means 100 is positioned downstream of the clltting roller g6 and platen 98 to sevPr the web along the transverse seal 94 to form the individual pouches as shown in Figure 3. In the preferred embodiment as depicted in Figure 3, the transverse cutting means includes a reciprocating cutting blade 102 and a cooperating platen 104.
A control system (not shown) actuates the cutting blade 102 to sever the pouches from the web at the transverse seam 94. The pouches severed from the web drop by gravity to a conveyor 106 where they are transferred to a packaging station.
In operation of the apparatus, a first web of fabric 40 is fed to the ultrasonic welding means 64, 66 to stitch a tape of a water-soluble, hot melt adhesive 60 in longitudinal strips to the web. The web is then passed to the pouch-fsrming rollers 70, 72 where the first web is laminated to a second web along the longitudinal adhesive strips and along the transverse seams to define a plurality of pouches 90. The pouches 90 are filled with a detergent simultaneously with the formation of the pouches by dispensing a guantity of the detergent between the rollers 70, 72. The laminated web of pouches is then severed along the longitudinal seams and the transverse seams into distinct pouches. The pouches are then conveyed to a suitable packaging apparatus.
The apparatus is able to producP pouches of a granular material having a transverse top and bottom seam ~nd a water-~ luble longitudinal seam. The number of pouches whi ~
formed may be varied by the position of the rollers and the number of sealing ribs on the rollers. It will be understood that other modifications of the pouch and the method of producing the pouch can be made by one skilled in the art without departing from the spirit and scope of the invention.

Claims (30)

1. A water-activated dispensing package comprising first and second substantially insoluble webs, wherein said first and second webs are laminated to each other about peripheral edges to define a pouch, at least one water-dispersible component contained in the pouch, wherein at least a portion of said peripheral edges of said pouch include a seal formed from a water-soluble adhesive whereby said seal dissolves when said pouch is placed in water to open said pouch and release the component to the water.

2. The package of Claim 1 wherein said package includes a pair of opposite longitudinal seams and a pair of opposite transverse seams, wherein said longitudinal seams are sealed with said water-soluble adhesive.

3. The package of Claim 1 wherein said water-soluble adhesive is a thermoplastic adhesive.

4. The package of Claim 3 wherein said water-soluble adhesive is selected from the group consisting of carboxymethyl cellulose, polyvinylalcohol and polyvinylacetate.

5. The package of Claim 1 wherein said web includes a coating of a heat-activated antistatic agent to be released during a heated drying cycle.

6. The package of Claim 3 wherein said thermoplastic adhesive is a tape.

7. The package of Claim 2 wherein said first and second webs are heat welded together along said transverse seams.

8. The package of Claim 1 wherein said webs are a thermoplastic heat-sealable fabric.

9. The package of Claim 1 wherein said first and second webs are porous.

10. The package of Claim 1 wherein at least one of said first and second webs are substantially water impervious.

11. The package of Claim 1 wherein said water-dispersible component is a detergent.

12. The package of Claim 1 wherein said pouch includes transverse top and bottom seams, first and second longitudinal side seams and a third longitudinal seam spaced between said side seams to define first and second compartments in the pouch, a detergent contained in the first compartment and at least one second component contained in the second compartment, wherein at least one of said first and third longitudinal seams are formed from a water-soluble adhesive.

13. The package of Claim 12 wherein said second component is a fabric softening agent.

14. The package of Claim 12 wherein said first longitudinal seam is formed from a first water-soluble adhesive and said second and third longitudinal seams are formed from a second water-soluble adhesive, wherein said first adhesive is readily soluble to dispense the detergent in said first compartment before dispensing the component in the second compartment.

15. A method of producing a water-activated pouch containing a laundry detergent, said method comprising:
a. applying a plurality of spaced-apart longitudinal strips of water-soluble adhesive on a first continuous web of a heat-sealable material to define a pouch perimeter;
b. feeding said first web and a second web of heat-sealable material to a laminating means;
c. feeding a metered quantity of a powdered detergent between said first and second webs above said laminating means and between said strips of adhesive;
d. laminating said first and second webs together along said strips of water soluble adhesive to form longitudinal seams and laminating said first and second webs together transversely to form transverse seams, thereby forming a continuous web of pouches containing said metered quantity of powdered detergent:
e. separating said pouches by cutting said web of pouches along said transverse and longitudinal seams to form a plurality of pouches, each pouch having a first and second permanent heat-sealed transverse top and bottom seam and at least one longitudinal water-soluble seam.

16. The method of Claim 15 wherein said water soluble adhesive is a tape of thermoplastic adhesive and is attached to said first sheet by ultrasonic welding.

17. The method of Claim 15 wherein said first and second webs are laminated by heat welding to form said transverse and longitudinal seams.

18. The method of Claim 15 wherein longitudinal strips of water-soluble adhesive are applied along longitudinal edges of said first web and said webs are laminated along the longitudinal edges of said webs.

19. The method of Claim 15 wherein said water-soluble adhesive is a thermoplastic adhesive selected from the group consisting of polyvinylacetate and polyvinylalcohol.

20. The method of Claim 15 wherein said first and second webs of fabric include a coating of a heat-activated antistatic agent.

21. A water-activated dispensing pouch for dispensing a detergent and at least one second component comprising first and second webs of a porous, substantially water-insoluble heat-sealable fabric, said first and second webs laminated together to form a top and bottom permanent heat-sealed transverse seam, a first and second longitudinal side seam formed from a water-soluble adhesive and a third longitudinal seam disposed between said first and second longitudinal seams to define a first compartment containing a detergent and a second compartment to contain a second component, wherein said water-soluble seams dissolve in water to dispense said detergent and second component.

22. A method of producing a water-activated pouch comprising:

a. applying longitudinal strips of a water-soluble, thermoplastic adhesive adjacent longitudinal edges a first web of a heat sealable fabric:
b. passing said first web and a second web of heat sealable fabric between a pair of counter rotating heated rollers, each of said rollers having complementary circumferential ribs and axial ribs, and simultaneously depositing a metered quantity of a water-dispersible component on said first and second webs between said rollers whereby said circumferential ribs heat seal said first and second webs together along said thermoplastic adhesive to form a longitudinal seam and said axial ribs heat seal said first and second webs together to form a transverse seam thereby forming a plurality of pouches containing said water-dispersible component;
c. severing said webs along said longitudinal seam and transverse seam to form pouches having water-soluble longitudinal seams and water-insoluble transverse seams.

23. The method of Claim 22 wherein said thermoplastic adhesive is a tape and is attached to said first web.

24. The method of Claim 23 wherein said thermoplastic adhesive is ultrasonically stitched to said first web.

25. The method of Claim 22 comprising a plurality of spaced-apart strips of water-soluble adhesive longitudinally on said first web to define a pouch perimeter, wherein said rollers include a complementary number of circumferential ribs ?ereby said webs are laminated along said plurality of strips of adhesive.

26. An apparatus for producing a sealed, water-activated pouch containing a laundry detergent comprising;
a. supply means to supply continuous first and second webs of heat sealable fabric;
b. means to apply at least one continuous water-soluble adhesive strip longitudinally on said first web;
c. means to feed said first and second webs to a pair of first and second cooperating laminating rollers, each roller having means to close off successive pouches and to form a web of pouches defined by longitudinal seams and transverse seams;
d. means to intermittently feed a granular detergent to a location above said laminating rollers and said laminating rollers and deposit a metered quantity of said detergent between the first and second webs: and e. means to cut said webs along said transverse seams and along said longitudinal seams to form a plurality of pouches, wherein pouches have at least one water-soluble transverse seam.

27. The apparatus of Claim 26 comprising means to apply tape of water-soluble, thermoplastic adhesive on said first web.

28. The apparatus of Claim 27 including means to adhesively secure said tape to said first web.

29. The apparatus of Claim 28 wherein said means to secure said tape comprises ultrasonic stitching means.

30. The apparatus of Claim 26 comprising means to apply a plurality of spaced-apart strips of said water-soluble adhesive longitudinally on said first web, wherein said strips are positioned to cooperate with said laminating rollers to form a plurality of longitudinal water-soluble seams formed by said strips of adhesive.