Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B3/00—Packaging plastic material, semiliquids, liquids or mixed solids and liquids, in individual containers or receptacles, e.g. bags, sacks, boxes, cartons, cans, or jars
  • B65B3/02—Machines characterised by the incorporation of means for making the containers or receptacles
  • B65B3/022—Making containers by moulding of a thermoplastic material

Definitions

• the invention relates to a method for packaging hot melt adhesive, in particular pressure sensitive hot melt adhesive, in a container having an opening, which is suitable for simultaneous melting with the contents of the container and can be mixed with it in the molten state, without the properties of the mixture being mixed
• Adhesive composition are significantly affected adversely, and which has no surface stickiness in the range of usual storage temperatures, especially at temperatures up to 50 ° C, wherein the melted hot melt adhesive is filled through the opening in the container.
• Hot melt adhesives are solvent-free adhesives that can wet material surfaces well in the heat and in the liquid state and adhere firmly to them after cooling and solidification. They usually consist of a mixture of substances that form the adhesive, the cohesive and the additive component.
• pressure-sensitive hot-melt adhesives ie. H. Hot melt adhesives with permanent stickiness, which are still sticky even at room temperature. They are also referred to as pressure-sensitive hot melt adhesives (PSA hot melts or HMPSA) because they simply adhere to a surface to be glued without the hot melt having to be heated or melted.
• thermoplastic adhesive compositions have a relatively low softening point, which is below 120 ° C and more particularly between 60 and 105 ° C.
• the usual foils, film tubes or foil bags used for packaging must therefore be sealed by welding after filling. It is known to fill such hot melt adhesives in flat shells consisting of siliconized polypropylene, which have a horizontally extending edge. To seal, a film made of the same material as the shell is placed. However, these shells are not suitable for being melted and processed by the user at the same time as the hot melt adhesive.
• the pressure sensitive hot melt adhesives used in the industry are delivered as blocks that are heated in melting tanks, which in turn supply adhesive pumps and nozzles to apply these adhesives to tabs on packaging boxes, for the production of adhesive tapes, books, disposable diapers for babies, hygiene products for women and the same as well as for the labeling of cans and bottles.
• the hot melt adhesive is used as a structural adhesive for such articles, in particular for disposable articles that can only be used once.
• the hot melt adhesives can be applied with different application systems depending on the type of article to be manufactured and the surfaces to be bonded.
• the pressure sensitive hot melt adhesive blocks are difficult to handle due to their high surface tack, require special packaging, which is generally expensive and must be disposed of after the hot melt adhesive has been removed, and also require a relatively long time to melt.
• a method of the type mentioned at the outset is known from EP 0 469 564 B1 (HB Busher Licensing & Financing, Inc.).
• a portion of a plasticized adhesive composition in particular heated to a temperature of 50 to 100 ° C., is filled from a melt extruder into a sack or plastic bag, which is sealed by welding after filling (p. 3, line Z. 20 to p. 4, line 35 and p. 16, lines 1 - 55).
• the sack or bag consists of a plastic film which is meltable together with the adhesive composition and is miscible with the melted adhesive composition, the type and amount of the plastic film being selected such that they do not adversely affect their properties when added to the adhesive composition.
• the plastic film used to produce the bag with a thickness of less than 200 ⁇ m forms the non-self-standing walls of the container, since the walls have to adapt and also adapt to the contents of the bag.
• the originally flat, rectangular pouch takes therefore, after filling and welding, the shape with the largest possible volume, namely the shape of a pillow. Due to the lack of dimensional stability, the bag must be closed. Simply gluing the bag opening with the same hot melt adhesive is not sufficient if, as is the case with many industrially used hot melt adhesives, it softens at normal storage temperatures, which can be up to 50 ° C., so that the bag contents flow out. In such cases, the bag opening must be welded, as is also proposed in this document.
• Another disadvantage of the known method is the difficulty in labeling the packaged container. It is not possible to stamp it into the soft, non-dimensionally stable bag wall, and it is forbidden to stick on conventional paper labels because the entire container is to be processed in the melting tank of the user.
• EP 0 469 564 B1 also speaks of the possibility of using a bag made of a film which consists of ethylene-vinyl acetate copolymer with a vinyl acetate content of between 10 and 33%.
• a bag made of a film which consists of ethylene-vinyl acetate copolymer with a vinyl acetate content of between 10 and 33% Such films with the usual thickness of less than 50 ⁇ m cannot be produced without considerable difficulties, since the films tear very easily during production. For this reason, films made of polyethylene are used in practice for the production of bags, which are then filled with the hot melt adhesive.
• a possible content of ethylene-vinyl acetate copolymer in the film is well below 8%.
• the invention has for its object to carry out a method of the type mentioned, wherein the packaging completely wraps the adhesive and does not need to be disposed of by the user and without the opening of the container having to be sealed after filling, even if flowable at normal storage temperatures Hot melt adhesives are to be packed.
• the safety during the transport of adhesives with "cold flow” and during their storage is to be significantly improved.
• the container is dimensionally stable at temperatures below 50 ° C., that the container is cooled at the same time as the hot-melt adhesive is filled and the container is completely closed after filling.
• the container is dimensionally stable.
• dimensionally stable is understood here to mean the property of the container that, in contrast to foils, foil tubes, foil bags, sacks or nets, it cannot be deformed by the content, so that the shape of the container does not adapt to the content. As a rule, this also means that the container has self-standing walls. It is not excluded that the walls of the container are elastic, so that the container can be temporarily deformed, but then returns to its original shape.
• the inventive cooling of the container which is carried out simultaneously with the filling of the hot adhesive, is necessary in order to exclude thin spots or even holes in the container wall.
• the method can be used for packaging all conventional hotmelt adhesives and is particularly suitable for packaging hotmelt adhesives with so-called "cold flow”.
• Another advantage of the method according to the invention lies in the possibility of labeling the packaged container without additional effort. This is done simultaneously with the manufacture of the container, for. B. in the extrusion blow molding process, the selected lettering is stamped into the container wall.
• the container from the outside, for. B. to cool with water so that a container material with a melting or softening point can be used, which is approximately equal to the filling temperature of the hot melt adhesive or lower.
• the container wall can be sprayed with water from the outside or the container can be arranged in a water bath during the filling process and also afterwards for further cooling.
• the container is not to be closed, it is preferred if the container is designed as a bottle with a bottle neck, so that the opening has a relatively small outlet cross section compared to the container.
• the material of the container has a melting or softening point above 90 ° C and below 130 ° C.
• the material of the container can be selected from one of the groups which consist of ethylene-based polymers, such as ethylene / vinyl acetate, ethylene acrylate, ethylene methacrylate, ethylene methyl acrylate, ethylene methyl methacrylate, high and low density polyethylene, polyethylene mixtures and chemically modified polyethylene, copoly - mers of ethylene and di-unsaturated monomers, polybutadiene rubber, polyesters such as polyethylene terephthalate, polybutylene terephthalate; thermoplastic polycarbonates, atactic poly- ⁇ -olefins, including atactic Polypropylene and others; thermoplastic polyacrylamides, homo- and copolymers - especially block copolymers - of acrylonitrile and other monomers such as butadiene and styrene; Polymethylpentene, polyphenylene sulfide, polyurethanes;
• ethylene-based polymers such as ethylene / vinyl acetate, ethylene acrylate,
• other similar materials can also be used that match the properties of the packaged adhesive.
• This can be a plastic or a plastic composition that is not a component of the hot melt adhesive, but is suitable for simultaneous melting with the contents of the container and is miscible with it in the molten state, without the properties of the adhesive composition being mixed be significantly adversely affected.
• the material of the container is selected from the components of the composition desired when the hot-melt adhesive is used.
• such a composition is filled into the container so that the composition of the contents of the container plus the material of the container corresponds to the composition desired when the hot-melt adhesive is used.
• the type and amount of the container material corresponds to the difference between the filled composition and the desired adhesive composition.
• the container can therefore consist of a hot-melt adhesive composition which, together with the contents of the container, results in a pressure-sensitive hot-melt adhesive after melting. In this case, it is excluded that the container material adversely affects the properties of the adhesive composition in any way.
• Ethylene-vinyl acetate copolymer with a vinyl acetate content of 10 to 45%, in particular 15 to 30%, and a softening point of 80 to 130 ° C. is proposed as a container shark that is particularly suitable in this case.
• Their melt index is in the range from approximately 1 to 800, in particular approximately 20 to 200.
• Thermoplastic elastomers such as styrene block copolymers are also very suitable for the production of the containers. The same applies to polyisoprene.
• the melting or softening temperature of the polymers is too high, it can be mixed by mixing with other adhesive components, e.g. B. with waxes or plasticizers. Of course, the mixture must not become tacky. If possible, it should not lead to blocking.
• a preferred composition for producing the container is described in EP 557 573. It essentially consists of the following components: a) about 20 to 80, preferably about 50% by weight of a styrene block copolymer of the ABA type, b) 0 to about 50, in particular 30% by weight of an aromatic hydrocarbon resin , c) 0 to approx. 30, in particular 10% by weight of a suitable mineral oil, d) 0 to approx. 40, in particular 10% by weight of a wax and e) 0 to approx. 5, in particular 3% by weight a stabilizer, especially an antioxidant.
• the styrene block copolymer is preferably a styrene / isoprene / styrene or a styrene / butadiene / styrene block copolymer with at least 20% by weight of styrene, based on the block copolymer as a whole.
• the aromatic hydrocarbon resin is a pure hydrocarbon resin. However, it can also be mixed with aliphatic hydrocarbon resins.
• the aromatic hydrocarbon resin is a mixture of copolymers of ⁇ -methylstyrene and styrene or of vinyltoluene and ⁇ -methylstyrene, in particular in a weight ratio of approx. 50:50.
• the wax is preferably a paraffin wax with a melting point of approx. 60 to 70 ° C or above this range.
• a sterically hindered phenolic antioxidant is preferably used as the stabilizer.
• the viscosity of the composition for the container is 40,000 to 200,000 cP at 163 ° C according to Brookfield (ASTM D3236-73).
• the wall thickness of the container should be sufficiently thick to ensure the dimensional stability and allow the wall to be embossed, but it should be low in order to achieve a good mixing of the container material with the container content in the melting tank of the user and, if the container material is not from one Part of the desired adhesive composition is to keep the impairment of the adhesive properties as low as possible. It is proposed that the wall thickness of the container is 0.3 to 0.8 mm.
• the mass of the filled container is 200 to 1000 g, in particular approximately 500 to 600 g.
• the mass of the container is 1 to 5% by weight of the adhesive composition filled in the container.
• the smallest possible proportion of packaging should be aimed for, since the container material will then be distributed particularly quickly in the melting tank of the user and thus in the adhesive.
• the cross-section of the container has a rectangular, in particular an essentially square, shape.
• the container can advantageously be produced by means of the extrusion blow molding process, the container being filled with the hot-melt adhesive immediately thereafter, that is to say without removing the container from its blow mold.
• the container material is deformed in the deflection head of an extruder to form a freely emerging tube, which is enclosed in a second step by a two-part blowing tool.
• the lower end of the hose is pressed together and welded so that the bottom of the container forms.
• the blown air is supplied, which presses the hose against the wall of the blower tool with high pressure, so that the final shape of the container is achieved.
• a label is embossed on the outside of the container wall during the manufacture of the container. Since the labeling is specified in the inner wall of the blowing tool, no additional work step is required.
• An increase in the shape stability of the container or a reduction in the wall thickness while maintaining the shape stability can be achieved by a corrugated or corrugated structure of the container wall. This structure can also be produced by an appropriate design of the inner wall of the blowing tool without an additional work step.
• the container be made from several components of the hot melt adhesive.
• the container is made from a combination of materials consisting of several layers.
• a thin outer layer made of polyethylene and a thicker inner layer made of ethylene-vinyl acetate copolymer or another component of the hot melt adhesive can be provided.
• the outer layer can also serve as a barrier layer against plasticizers.
• the container which is completely sealed according to the invention, has considerable advantages, in particular when a container which is filled with a flowable (“cold flow”) hot melt adhesive tips over.
• a container which is filled with a flowable (“cold flow") hot melt adhesive tips over.
• the container is designed as a bottle with a bottle neck and that after the hot melt adhesive has been filled, the opening is closed by squeezing the bottle neck. It is also possible for the opening to be closed after the hot-melt adhesive has been filled by inserting a stopper, which preferably consists of the container material.
• the opening is closed by filling in a sufficient amount of the melted container material. Safe and fast packaging without air pockets and foreign material is obtained quickly and easily. It is particularly advantageous if the opening of the container is designed as an undercut bottle neck so that the material formed from the melted container material After cooling, the closure is pressed tightly onto the surface of the contents of the container and cannot be removed unintentionally.
• the invention relates to a packaged hotmelt adhesive which has been produced in the method explained above.
• the method according to the invention is suitable for packaging practically any type of hot-melt adhesive composition, provided that it is compatible with the selected material of the container, so that the container can be easily dissolved in the melted hot-melt adhesive by the user.
• the hot melt adhesive systems comprise a variety of base polymers which are mixed with other ingredients such as plasticizers, tackifiers, stabilizers, waxes and extenders to form the adhesive.
• the basic polymers essentially determine the properties of the adhesive layer with regard to adhesion, strength and temperature behavior. The most important basic polymers are polyofines, polyamides and polyurethanes.
• Container olefinic materials such as polyethylene and poly (ethyien-co-vinyl acetate) are compatible with aliphatic and aromatic hydrocarbon hot melt adhesives.
• Commercial hot melt adhesive compositions of this type contain hot melt adhesives based on ethylene vinyl acetate.
• Copolymer and of amorphous propylene alpha olefin are also included.
• hot melt adhesives based on styrene-butadiene-styrene (SBS) copolymer-ABABA-Multiblock construction hot-melt adhesives based on radial styrene-butadiene-styrene, (SB) n copolymers and construction tion hot melt adhesives based on styrene-isoprene-styrene (SIS) and ABA block copolymers.
• SBS styrene-butadiene-styrene
• SB construction hot-melt adhesives based on radial styrene-butadiene-styrene
• SB n copolymers
• Hotmelt adhesives based on polyamides can also be packaged using the method according to the invention, a container made of a corresponding polyamide being preferred which is compatible with the hotmelt adhesive when it is melted together.
• Possible polyamides are PA6.6, PA6.10, PA6 and especially polyamides made from diamines and dimerized fatty acids, in particular from ethylenediamine and dimerized linoleic acid.
• copolymers are also possible, e.g. B. polyamide / EVA copolymers, polyamide / siloxane copolymers, polyester amides, polyether amides, polyester amidimides and polyether ester amides.
• the packaging method of the present invention can be applied to hot melt adhesives made from polymers and copolymers of synthetic resins, rubbers, polyethylene, polypropylene, polyurethane, polyacrylic, polyvinyl acetate, ethylene vinyl acetate copolymer and polyvinyl alcohol.
• the inventive method is of particular advantage for hot melt adhesives with serious handling problems, eg. B. for the above-mentioned, even at room temperature still tacky hot melt adhesives (PSA hot melts).
• hot melt adhesives made from the following components:
• Elastic polymers such as block copolymers, e.g. B. styrene-butadiene, styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene-butylene-styrene, styrene-ethylene-propylene-styrene;
• ethylene vinyl acetate polymers other ethylene esters and copolymers, e.g. B. ethylene methacrylate, ethylene n-butyl acrylate and ethylene acrylic acid;
• polyolefins such as polyethylene and polypropylene
• Aldehydes containing resins such as phenol aldehyde, urea aldehyde, melamine aldehyde and the like.
• Components for strengthening the adhesion plasticizers, wax components, diluents, stabilizers, antioxidants, dyes and fillers may also be present.
• components for improving the adhesion are:
• diluents are liquid polybutene or polypropylene, petroleum waxes such as paraffin and microcrystalline waxes, semi-liquid polyethylene, hydrogenated animal, fish and vegetable fats, mineral oil and synthetic waxes and hydrocarbon oils.
• the packaging method according to the invention preferably comprises the following steps analogously to US Pat. No. 5,878,794:
• the hot melt adhesive is made from its components in the melt.
• the type and the amount of the composition for the container are expediently taken into account.
• the hot melt adhesive is poured into the container, which is preferably based on rubber, at a temperature of 100 to 130, preferably 110 to 120 ° C.
• the container is stable and has a wall thickness of at least 0.1 to 0.25 mm and a maximum thickness of 3, in particular 2 mm.
• the container is cooled, preferably with water. Cooling can begin before filling, but cooling is particularly important during filling and especially after filling.
• the container is completely closed, especially by welding. It may be necessary to use a lid.
• FIG. 1 schematically shows an installation for carrying out the method according to the invention.
• a pressure sensitive hot melt adhesive is placed, which has the following composition: Polymers: 30% tackifying resin: 50% plasticizer: 20%.
• a granulate made of EVA copolymer with a vinyl acetate content of 28% and a melt index of 40 g / 10 min is fed via a hopper 2 to an extruder 3 which forms part of a system for extrusion blow molding of bottles.
• the granules plasticized in the extruder 3 are shaped in a deflection head 4 to form a hose 5 which emerges freely downwards.
• the tube 5 is enclosed by a two-part blowing tool 6, which is provided with cooling bores, the lower end of the tube being compressed and welded so that the bottom of the bottle is formed.
• a blow mandrel not shown in the drawing, is introduced, which forms the bottle neck, squeezes off the remainder and supplies the blown air, with which the hose is pressed under a pressure of 5 to 10 bar against the inner wall of the blow tool.
• the pressure-sensitive hot-melt adhesive is filled into the bottle formed in this way via a pump 7, a line 8 and the deflection head 4.
• the bottle neck is closed by adding EVA copolymer in flowable or liquid form.
• the EVA copolymer has the same composition as the bottle material used above.
• the one completely covered by the EVA copolymer and thus packaged hot melt adhesive 9 cools in the blow mold and falls out after opening the mold.
• the said shaping of the containers is achieved by:
• Said containers are then melted by the customer in heated tank systems for use and applied by small spray nozzles, nozzles or extrusion plates.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Auxiliary Devices For And Details Of Packaging Control (AREA)
• Packages (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

Family

ID=7877708

Family Applications (1)

Country Status (10)

Cited By (3)

Families Citing this family (1)

Family Cites Families (3)

• 1999
  • 1999-07-23 DE DE19934705A patent/DE19934705A1/de not_active Withdrawn
  • 1999-08-12 TW TW88113779A patent/TW446666B/zh active
  • 1999-08-13 AR ARP990104064 patent/AR020184A1/es unknown
  • 1999-08-13 CO CO99051609A patent/CO5111030A1/es unknown
  • 1999-08-14 AU AU57348/99A patent/AU5734899A/en not_active Abandoned
  • 1999-08-14 JP JP2000564867A patent/JP2002529319A/ja active Pending
  • 1999-08-14 BR BR9913128-5A patent/BR9913128A/pt not_active Application Discontinuation
  • 1999-08-14 WO PCT/EP1999/005979 patent/WO2000009401A2/de not_active Ceased
  • 1999-08-14 EP EP99944399A patent/EP1105309A1/de not_active Withdrawn
  • 1999-08-16 GT GT199900135A patent/GT199900135A/es unknown

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