EP2931611B1 - Method for printing film bags - Google Patents

Description

The present invention relates to a method for printing water-soluble or water-dispersible film bags which contain a detergent or cleaning agent.

Detergents and cleaning agents, such as dishwashing detergents, are available to consumers in a variety of forms. In addition to traditional solid agents, flowable and in particular liquid to gel-like agents have become increasingly important in recent years. Above all, the consumer appreciates the quick solubility and the associated rapid availability of the ingredients in the washing and cleaning liquor, especially in short washing and dishwashing programs and at low temperatures.

Furthermore, consumers have become accustomed to convenient dosing of pre-portioned detergents and machine dishwashing detergents. In order to bring a liquid detergent or dishwashing detergent, which offers the above-mentioned advantages over solid compositions, into a pre-portioned supply form, the use of cold water-soluble films in the form of bags is common. The washing or cleaning agent can be made up in such a way that single servings are each packed separately.

The water-soluble covering is usually formed from a water-soluble or water-dispersible film material, in particular consisting of polymers or polymer mixtures. The covering can consist of one or two or more layers of water-soluble or water-dispersible film material. For example, films are often used which can be glued and / or sealed to packaging such as hoses or pillows after they have been filled with an agent.

In many products, the water-soluble or water-dispersible coating contains polyvinyl alcohol or a polyvinyl alcohol copolymer, since such coatings have good stability with a sufficiently high water solubility, in particular cold water solubility.

Liquid detergents and cleaning agents are currently offered in water-soluble film bags, the individual film bags containing single servings being offered in an outer packaging which contains a large number of film bags. While the outer packaging application and hazardous substance notices, as well as product names, manufacturers, etc. identifies, a single foil bag does not provide the user with this information. It is known to print the water-soluble film of such a film bag before shaping (thermoforming; deep-drawing), as is the case, for example, in the international patent publications WO 2010/135238 A1 and WO 2009/063355 A1 as well as the U.S. Patent 5,666,785 A1 described. The final print image is but whether the subsequent deep-drawing is difficult to influence and often distorted or warped. Another possibility is the use of labels, which can be glued to the foil bag, but this is associated with additional costs and complex production techniques.

The YouTube Internet publication "Pouch Pneumatic Pad Printing Machine" (www.youtube.com/watch?v=mvGsuu_SZbs) describes the basic application of a pad printing process for water-insoluble outer packaging bags to label them. Only a semi-automated printing process is disclosed, which still has an undesirably high amount of manual work.

From the WO 2009/063355 A1 is known a rubber printing process (flexography printing) for water-soluble films for the later creation of water-soluble bags. There is a fundamental difficulty here in positioning the print image on the film with a view to the later bag geometry.

The WO 2010/0135238 A1 discloses a comparable rubber printing process (flexography printing) for water-soluble films, which is immediately upstream of a downstream manufacturing process for detergent bags. Here, too, the difficulties already mentioned of exact positioning of the printed image on the final detergent pouch arise.

In addition, the WO 2007/034471 A1 the graphic of a film that can itself contain cleaning agents.

The WO 2008/004199 A2 finally describes water-soluble bags filled with detergents or cleaning agents, the bags being provided with an optical, tactile and / or audible indicator. Such a label can be applied to the bag in various ways on the one hand and can optionally be applied to the bag film before or after the bag production. In addition, there are also a variety of different process alternatives for generating the bag identification there, including printing processes such as the pad printing process. However, the procedural instructions there are only general and therefore abstract in nature.

It was therefore an object of the present invention to provide an improved possibility for presenting information on water-soluble or water-dispersible film bags which contain detergents or cleaning agents.

According to the present invention, this object is achieved in that the filled, finished Foil bags are printed in a pad printing process according to the invention. In a first aspect, the invention therefore relates to a method for printing a pouch filled with a detergent or cleaning agent from a water-soluble or water-dispersible film with an imprint, characterized in that the pouch is printed by means of a pad printing process.

In a further aspect, the invention is directed to the bags made of a water-soluble or water-dispersible film, which are produced, printed and filled with a washing or cleaning agent by means of the method according to the invention.

Pad printing processes are known in the prior art. Pad printing is an indirect gravure printing process in which the printing ink is transferred from the printing form to the printing material by means of an elastic tampon, usually made of silicone rubber. In this printing process, the printed image to be transferred is normally exposed on a cliché using a positive film (offset film). This cliché is then washed out, the exposed printed image remaining in a recessed manner on the surface of the cliché. The cliché can consist of a wide variety of materials, for example a distinction is made between steel and plastic clichés. Alternatively, the cliché can also consist of zinc or copper.

During the printing process, the printing ink is usually washed over the cliché using a metal or plastic squeegee and removed using a squeegee or a knife, the ink remaining in the recess. The tampon then attaches to this printing form, lifts off again with the printing ink and moves to the printing material. There the tampon lowers, adapts to the shape and leaves the color (the printed image) on the print material. Since the tampon itself is elastically deformable and can take on the shape of the body to be printed, this method enables printing on curved surfaces (convex, concave or irregular) without distorting or distorting the printed image. Depending on the material of the tampon or the type of color, the ink transfer to the substrate is up to 100%.

In various embodiments of the invention, the tampon used for printing on the film bags has a hardness which is selected such that it adapts to the shape of the bag and good contact is made between the tampon surface and the bag surface without the bag being damaged . For example, the tampon can preferably have a Shore-A hardness in the range from 0-20, preferably from 0-15, in particular approximately 5. In various embodiments, the tampon consists of silicone rubber and is elastic.

1. (i) Aufbringen einer Tinte oder eines Mediums, die/das eine farbgebende Substanz enthält, auf ein Klischee;
2. (ii) Abstreichen überschüssiger Tinte oder überschüssigen Mediums mittels eines Rakels;
3. (iii) Aufdrücken des Tampons auf das Klischee, wobei die Tinte oder das Medium von dem Klischee auf das Tampon übertragen wird; und
4. (iv) Aufdrücken des Tampons auf den Beutel, wobei die Tinte oder das Medium von dem Tampon auf den Beutel übertragen wird.

In various embodiments of the invention, the method according to the invention comprises the following steps:

1. (i) applying an ink or medium containing a colorant to a cliché;
2. (ii) wiping off excess ink or media using a squeegee;
3. (iii) pressing the tampon onto the plate, the ink or medium being transferred from the plate to the tampon; and
4. (iv) pressing the tampon onto the pouch, transferring the ink or medium from the tampon to the pouch.

In the method according to the invention, the bag is fixed in a holder in order to avoid slipping during the printing process. The holder can have a shape that is adapted to the shape of the film bag. For example, the holder can have a concave depression which corresponds to the convex surface of the bag. The lower part of the mold already used for molding (thermoforming; deep drawing) and / or filling the bag can also serve as such a holder.

The inks or color inks used for printing are chosen so that they are compatible with the material of the foil pouch, i.e. in particular, this does not dissolve or react in any other way with it and impair its structural integrity. It is furthermore provided that the color inks are water-soluble and preferably dissolve in water without residue. Furthermore, when using the washing or cleaning agent, they should not cause any residues or discolouration on the objects to be washed or cleaned. The printing inks / color inks can have any suitable viscosity which enables printing in the pad printing process. Suitable inks are available, for example, under the trade name Sun Chemical Aquadestruct (Sun Chemical, NJ, USA), Aqua Poly Super Opaque White QW000046 from Environmental Inks or Opta Film OPQ White W0L009656 from Water Ink Technologies Inc.

In certain embodiments of the method, steps (i) to (iv) can be repeated a number of times, preferably 1 to 3 times. Other inks or media containing a coloring substance are preferably used, so that multi-colored prints are also possible. The repetitions of steps (i) to (iv) can each be carried out in separate printing units which can be arranged one after the other in a continuous process.

The pad printing process can be carried out continuously and can be any known form of the pad printing process, for example a rotary pad printing process.

The bag consists of a water-soluble or water-dispersible envelope, which forms a closed structure which has one or more chambers inside for receiving one or more agents. The water-soluble or water-dispersible covering is formed by a water-soluble or water-dispersible film material.

The bag can have any shape, the shape being largely adapted to the conditions of use, but is usually tubular, pillow, cylindrical, bottle or disc-shaped. In various embodiments, the film bag can have a length of 20 to 50 mm, a width of 15 to 50 mm and a height of 10 to 50 mm. The bags usually consist of two pieces of film placed one on top of the other, glued / welded to one another at the edge, and therefore have a cavity which is filled with the agent and are surrounded by film and a peripheral edge. If the basic shape of the film pieces is rectangular, a pillow shape can be created, and the basic shape can be around a disc shape. Alternatively, the film bag can also consist of a single film web that is rolled and glued / welded to itself, which can also result in tube and cylinder shapes.

In various embodiments, the pouch has two opposite, approximately convex surfaces that can be printed on. It is preferred that the film bag has no folds in the printing area. This can be achieved, for example, in that the bag has a higher internal pressure than external pressure after manufacture. In various embodiments of the invention, one surface, in other embodiments also both surfaces, is printed. The motif can be the same or different.

In general, the printed image is not restricted in any way, but it is usually letters, numbers, symbols, ornaments or the like, in particular lettering and / or graphic patterns. Specific examples are brand or product names as well as manufacturer logos, instructions for use, safety instructions, etc. The motif can be single or multi-colored, with multi-colored motifs different color inks can be printed in several steps (eg four-color printing). The size and placement of the printed image is preferably selected so that a complete printed image can be printed on each foil bag.

The film used for the production of the film bag can have a predefined area on which the imprint is printed by means of the method according to the invention. In various embodiments, this predefined area can be colored or colored differently from the rest of the film. For example, a white-printed area is conceivable. The area can also be covered or printed with a layer that separates the printed ink from the underlying water-soluble film. This layer can, for example, be a protective layer as described below.

The terms "water-soluble" and "water-dispersible" as used herein refer to the property of the film to dissolve or disintegrate on contact with water and to release the contents of the film bag. It is preferred that the components of the film can be dissolved or dispersed in water with as little residue as possible. In various embodiments, “water-soluble” means that the corresponding film dissolves in water at a temperature of 20 ° C. or less within 90 seconds. Corresponding test procedures are for example in US 6,787,512 B1 described.

Suitable water-soluble or water-dispersible films for producing the film bag are preferably based on a polymer or polymer mixture, in particular polyvinyl alcohol or a polyvinyl alcohol copolymer. Other suitable polymers include, but are not limited to, polyvinyl pyrrolidone, polyakylene oxide, acrylamide, acrylic acid, cellulose, cellulose ether, cellulose esters, cellulose amides, polyvinyl acetates, polycarboxylic acids and their salts, polyamino acids or peptides, polyamides, polyacrylamide, copolymers of maleic acid and acrylic acid, polysaccharides, including starch and gelatin, and natural rubbers such as xanthan gum and carrageenan. Preferred polymers are selected from polyacrylates and water-soluble acrylate copolymers, methyl cellulose, carboxymethyl cellulose, dextrin, ethyl cellulose, Hydroxyethyl cellulose, hydroxypropyl methyl cellulose, maltodextrin, polymethacrylates, and particularly preferably from polyvinyl alcohols (PVA), polyvinyl alcohol copolymers and hydroxypropyl methyl cellulose (HPMC) and combinations thereof. The pouch can be formed from one or two or more layers of the water-soluble or water-dispersible film material. The water-soluble or water-dispersible film material of the first layer and the further layers, if present, can be the same or different. Films which, for example, can be glued and / or sealed to form packaging, such as hoses or pillows, are particularly preferred after they have been filled with an agent.

The amount of polymer in the water-soluble or water-dispersible film, for example PVA, is usually at least 60% by weight. The molecular weight of the polymers, in particular of PVA or polyvinyl alcohol copolymers, can preferably be in the range from 10,000 to 1,000,000 gmol ^-1 , preferably from 20,000 to 500,000 gmol ^-1 , particularly preferably from 30,000 to 100,000 gmol ^-1 and in particular from 40,000 to 80,000 gmol ^-1 lie.

Polyvinyl alcohol is usually produced by hydrolysis of polyvinyl acetate, since the direct route of synthesis is not possible. The same applies to polyvinyl alcohol copolymers which are produced from polyvinyl acetate copolymers accordingly. It is preferred if at least one layer of the water-soluble or water-dispersible coating comprises a polyvinyl alcohol, the degree of hydrolysis of which is 70 to 100 mol%, preferably 80 to 90 mol%, particularly preferably 81 to 89 mol% and in particular 82 to 88 mol% .

A polyvinyl alcohol-containing film material suitable for producing the water-soluble or water-dispersible coating can additionally be a polymer selected from the group comprising (meth) acrylic acid-containing (co) polymers, polyacrylamides, oxazoline polymers, polystyrene sulfonates, polyurethanes, polyesters, polyethers, polylactic acid or mixtures of the above polymers may be added. A preferred additional polymer is polylactic acid.

In addition to vinyl alcohol, preferred polyvinyl alcohol copolymers comprise dicarboxylic acids as further monomers. Suitable dicarboxylic acids are itaconic acid, malonic acid, succinic acid and mixtures thereof, itaconic acid being preferred.

Also preferred polyvinyl alcohol copolymers include, in addition to vinyl alcohol, an ethylenically unsaturated carboxylic acid, its salt or its ester. Such polyvinyl alcohol copolymers particularly preferably contain, in addition to vinyl alcohol, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester or mixtures thereof.

It may be preferred that the film material contains further additives. The film material can contain, for example, plasticizers such as dipropylene glycol, ethylene glycol, diethylene glycol, propylene glycol, glycerin, sorbitol, mannitol or mixtures thereof. Other additives include, for example, release aids, fillers, crosslinking agents, surfactants, antioxidants, UV absorbers, antiblocking agents, anti-adhesive agents or mixtures thereof.

Suitable water-soluble or water-dispersible films for use in the water-soluble or water-dispersible wrappings of the water-soluble or water-dispersible packaging according to the invention are films which are sold by MonoSol LLC, for example under the name M8630, C8400 or M8900. Other suitable films include films with the designation Solublon® PT, Solublon® GA, Solublon® KC or Solublon® KL from Aicello Chemical Europe GmbH or the films VF-HP from Kuraray.

The film bags are usually produced by deep drawing (thermoforming), i.e. the heating and forming of thermoplastic materials, in this case the water-soluble or water-dispersible film. In this process, the film is heated and brought into the desired shape. These shaping processes include a step for filling the preformed film bag and a further step for subsequently closing the filled film bag.

In general, there are several options for producing the water-soluble or water-dispersible film bags. In addition to the vertical form-fill-seal process, the use of a horizontal form-fill-seal process is also particularly suitable.

1. a) Ausbilden wenigstens einer Kavität in einer ersten wasserlöslichen oder wasserdispergierbaren Folienbahn,
2. b) Befüllen der wenigstens einen Kavität mit einem Mittel und
3. c) Verschließen der Kavität mit einer zweiten wasserlöslichen oder wasserdispergierbaren Folienbahn.

The production of a water-soluble or water-dispersible film bag can include the following steps:

1. a) forming at least one cavity in a first water-soluble or water-dispersible film web,
2. b) filling the at least one cavity with an agent and
3. c) closing the cavity with a second water-soluble or water-dispersible film web.

This method can precede the printing method according to the invention, so that the steps for producing a water-soluble or water-dispersible packaging are included in one embodiment of the printing method according to the invention. In such a method, step c) is followed by a further method step d), which is the at least partial printing on the outer surface of the water-soluble or water-dispersible coating with an ink or other medium containing a coloring substance. Step d) can be repeated any number of times, so that several identical or different printed areas are formed on the outer surface of the water-soluble or water-dispersible coating. Step d) can be the pad printing process of the invention.

In various embodiments of the method, several foil bags can be printed on simultaneously. For this purpose, the film bags can be produced, for example, in such a way that two or more film bags are still connected to one another after filling and closing, and these are printed at the same time and optionally separated from one another only after printing. In such a process for the production and printing of film bags, a plurality of cavities are formed in the first film web and filled with a medium, and the corresponding cavities are then closed with a second film web. For this purpose, the two film webs can be welded around the respective cavities, so that several bags are connected to one another via the welded edges. If desired, these can then be dismembered in a further step, for example by cutting, so that individual film bags or a defined number of film bags connected to one another are obtained.

The printing of a large number of interconnected foil bags has the advantage that the placement, also register in multi-color printing, is simplified.

1. a) Ausbilden wenigstens einer Kavität in einer ersten wasserlöslichen oder wasserdispergierbaren Folienbahn,
2. b) Befüllen der wenigstens einen Kavität mit einem Produkt,
3. c) Verschließen der Kavität mit einer zweiten wasserlöslichen oder wasserdispergierbaren Folienbahn und
4. d) zumindest teilweise Bedrucken der äußeren Oberfläche der wasserlöslichen oder wasserdispergierbare Folie mit einer Tinte oder einem Medium, die/das die farbgebende Substanz enthält, mittels eines Tampondruckverfahrens.

Another object of the invention is accordingly a method for producing a bag filled with a detergent or cleaning agent from a water-soluble or water-dispersible film with an imprint, comprising the steps:

1. a) forming at least one cavity in a first water-soluble or water-dispersible film web,
2. b) filling the at least one cavity with a product,
3. c) closing the cavity with a second water-soluble or water-dispersible film web and
4. d) at least partially printing on the outer surface of the water-soluble or water-dispersible film with an ink or a medium which contains the coloring substance, by means of a pad printing process.

In various embodiments, printing step d) is carried out as described above in connection with the printing method according to the invention. In particular, all of the embodiments of the printing process disclosed as preferred in this context can also be transferred to the printing step of the production process. The film surface is preferably printed in the area of the film that covers or envelops the cavity.

"At least one" as used herein refers to 1 or more, preferably at least 2, 3, 4, 5, 10, 15, 20 or more.

As already described above, in various embodiments of the method, a plurality of cavities can be formed and filled in a first film web and closed with a second film web, the printing then taking place before the film bag is cut out of a double, preferably partially welded film web containing several closed cavities.

In one embodiment of the method, therefore, at least two cavities are formed, filled and closed, and areas of the respective surfaces of the film which form the cavities, in particular the convex surfaces of the cavities, are simultaneously printed in step d). After the printing step, there can optionally be a step for forming the individual or several film bags connected to one another, for example a step for cutting out the film bags from the glued / welded film web.

The films (webs) used can be free of coloring substances, but can also contain one or more coloring substances. The printing with the coloring substance can take place on colored and / or non-colored areas of the covering, which is at least partially colored with a coloring substance.

In all embodiments of the method for producing a water-soluble or water-dispersible film bag, the printing of the first water-soluble or water-dispersible film with the coloring substance takes place after the formation and the sealing of the cavity filled with the agent.

An advantage of the printing after the production of the film bags is that the printing can be individualized, that is, according to the requirements / circumstances, for example with regard to shape and content, of the respective, currently produced water-soluble or water-dispersible packaging. When using pre-printed films, the film web must be replaced on the one hand when the composition of the water-soluble or water-dispersible packaging changes, and the manufacturing process must be interrupted, and on the other hand it must be ensured that the water-soluble or water-dispersible wrapping is at least partially colored by means of scatter printing on the pre-printed film web. In contrast to the present invention, a targeted positioning of the coloring is not possible.

The printing process can optionally be followed by a drying process in which the solvent contained in the ink or in the medium which contains the coloring substance is evaporated / removed by blowing up or blowing over tempered gas, passing through a drying oven or irradiation with infrared light . Alternatively, a curing process with UV light can follow the printing process.

In addition, when printing on the outer surface of the water-soluble or water-dispersible film covering, it can be advantageous that a water-soluble or water-dispersible protective lacquer is applied to the printed areas of the water-soluble or water-dispersible covering in order to blur and / or disappear the coloring due to atmospheric moisture and / or to prevent mechanical stress such as friction. This is preferably also printed on using a pad printing process. This protective lacquer layer is preferably clear and contains no color particles. Appropriate materials are known in the prior art.

The washing or cleaning agent contained in the film bags can be solid, in particular powdery, or liquid, but is preferably liquid. The term "liquid" also includes gel-like or pasty agents, with or without a flow limit. The cleaning agents are preferably automatic dishwashing agents. In general, all suitable detergents or cleaning agents can be contained in the film bags, but the detergents or cleaning agents are preferably low-water to water-free in order to avoid premature dissolution of the film covering.

In one embodiment, the film bag has a chamber for receiving the agent. In this embodiment, the agent can preferably comprise a powder, a granulate, a gel or a liquid. In a further embodiment, the film bag has two chambers. In this embodiment, the first chamber preferably contains a liquid agent and the second chamber contains a solid or a liquid agent. Alternatively, both chambers can contain a solid agent. If the film bag has three compartments, they can each contain a liquid or a solid agent. However, it is also possible for one chamber to contain a solid agent and two chambers to contain a liquid agent. It is also possible that a solid agent is contained in two chambers and a liquid agent is contained in one chamber.

In the case of water-soluble or water-dispersible packaging with four or more chambers, there are correspondingly more possible combinations in terms of the number of chambers with a solid or a liquid medium.

The compositions contained in the different chambers of a water-soluble or water-dispersible film bag can have the same composition. In a water-soluble or water-dispersible film bag with at least two chambers, the agents preferably have compositions which differ in at least one ingredient or at least in the content of one ingredient.

The agent contains ingredients that do not destroy the structural integrity of the water-soluble or water-dispersible coating. If the agent used is a liquid or solid washing or cleaning agent, it can contain one or more substances from the group of surfactants, builders, bleaching agents, bleach activators, bleaching catalysts, enzymes, enzyme stabilizers, electrolytes, pH regulators, perfumes, perfume carriers, fluorescent agents, dyes, hydrotropes, foam inhibitors, silicone oils, antiredeposition agents, graying inhibitors, shrink preventatives, anticrease agents, dye transfer inhibitors, antimicrobial agents, non-aqueous solvent, germicides, fungicides, antioxidants, preservatives, corrosion inhibitors, antistatic agents, bitter agents, ironing aids, waterproofing and impregnating agents, opacifying agents, skin benefit agents, Contain swelling and anti-slip agents, plasticizing components, fillers and UV absorbers.

As already mentioned above, the liquid washing or cleaning agents can be low in water or water-free.

The term "low water" as used herein means that the composition so characterized contains less than 25% by weight of water, preferably less than 20% by weight of water. In particular, this term includes compositions which contain 1 to 20% by weight of water, 1 to 15% by weight of water, 5-15% by weight of water or 10 to less than 20% by weight of water.

"Anhydrous" as used herein means that a composition contains less than 5% by weight, especially less than 3% by weight, preferably less than 1% by weight of water.

The water content as defined herein relates to the water content determined by means of the Karl Fischer titration.

In all versions with two foils or sheets, several foils can be used one above the other e.g. to reinforce the pouch, or to form superimposed chambers. Such configurations with superimposed chambers are known from the prior art.

Claims (5)

1. A method for printing a pouch filled with a washing or cleaning agent and made of a water-soluble or water-dispersible film with an imprint by means of a pad printing method, characterized in that the method comprises the steps of:

   (i) applying an ink or medium containing a chromophoric substance to a printing plate;

   (ii) wiping off excess ink or excess medium using a doctor blade;

   (iii) pressing the pad, which has a Shore A hardness in the range 0-20, preferably in the range 0-15, onto the printing plate, the ink or medium being transferred from the printing plate onto the pad, and

   (iv) pressing the pad onto the pouch, the ink or medium being transferred from the pad onto the pouch;

   the ink or medium being water-soluble and the pouch being fixed in a holder which is the lower part of the mold already used for shaping and/or filling the pouch.
2. The method according to claim 1, characterized in that the pad consists of resilient silicone rubber.
3. The method according to claim 1, characterized in that steps (i) to (iv) are repeated several times with different inks or media.
4. The method according to one of the preceding claims, characterized in that the water-soluble or water-dispersible film contains polyvinyl alcohol or a polyvinyl alcohol copolymer.
5. A method for producing a pouch filled with a washing or cleaning agent, made of a water-soluble or water-dispersible film and having an imprint, characterized in that the method comprises the steps of:

   (a) forming at least one cavity in a first water-soluble or water-dispersible film web,

   (b) filling the at least one cavity with the washing or cleaning agent,

   (c) closing the cavity using a second water-soluble or water-dispersible film web and

   (d) at least partially printing on the outer surface of the pouch with an ink or a medium containing a chromophoric substance by means of a pad printing method, step (d) being carried out by means of a method according to one of claims 1-4.