Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/38—Moulds or cores; Details thereof or accessories therefor characterised by the material or the manufacturing process
  • B29C33/40—Plastics, e.g. foam or rubber
  • B29C33/405—Elastomers, e.g. rubber
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
  • B29C39/22—Component parts, details or accessories; Auxiliary operations
  • B29C39/26—Moulds or cores
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
  • B29C39/22—Component parts, details or accessories; Auxiliary operations
  • B29C39/36—Removing moulded articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/44—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles
  • B29C33/48—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles with means for collapsing or disassembling
  • B29C33/50—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles with means for collapsing or disassembling elastic or flexible
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2083/00—Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/0097—Glues or adhesives, e.g. hot melts or thermofusible adhesives

Definitions

• the invention relates to a method for producing a portion package of a thermoplastic material, the portion package of the thermoplastic material itself and the use of a suitable casting mold for producing the portion package of the thermoplastic material.
• thermoplastic material is understood to mean a material which is solid at room temperature, can be liquefied or made to flow by heating and solidifies again on cooling, the process being able to be repeated several times. Solid means that the material has a crystalline to waxy or gummy consistency at room temperature (e.g. 20-22 ° C).
• the invention relates in particular to thermoplastic materials from the group of thermoplastic adhesives, coating or sealing agents.
• thermoplastic adhesives includes, for example, hot melt adhesives.
• Hotmelt adhesives are adhesives that are applied as a melt to the substrates to be bonded and that, after being joined, harden when they cool down.
• Hotmelt PSAs in solvent-free form are permanently sticky at 20 ° C, remain adhesive and adhere immediately to almost all substrates with low substrate specificity and light pressure.
• Adhesive composites made with hotmelt PSAs can usually be removed without destroying the bonded substrates.
• Reactive hot melt adhesives are hot melt adhesives with reactive groups, for example one or two component hot melt adhesives based on polyurethanes with free isocyanate groups.
• thermoplastic materials in particular from the group of adhesives.
• Some processes use direct filling in film tubes made of meltable plastic film, which can be melted and applied together with the adhesive.
• the plastic film thus becomes part of the adhesive, the additional work step of removing the adhesive before use is omitted and the packaging film does not have to be disposed of separately.
• Processes of this type are disclosed, for example, for strand-packed hotmelt PSAs in DE 3138222 and DE 3234 065, for granulated hotmelt PSAs in WO 00/34129 and for block-type hotmelt adhesives in DE 3625358.
• portions of adhesive in the form of so-called co-extruded adhesive pillows, packed in a film which can be melted together with the adhesive, are known, for example, from WO 97/00813.
• Adhesive pillows packaged in this way are suitable for hotmelt PSAs with softening points below 120 ° C.
• thermoplastic material in molten form is filled into a casting mold lined with foil.
• the film forms an adhesive-free coating on the surface of the solidified thermoplastic material.
• a disadvantage of film-wrapped thermoplastic materials that are melted together with the film is often the floating of solid film residues on the surface of the thermoplastic material melt. This is caused, for example, by the difference in density between plastic film and thermoplastic material, a wide melting range of the plastic film and / or by air which is enclosed in the film. Film residues that are not completely melted can cause clogging of the nozzles of application devices and thus production problems.
• thermoplastic materials are preferably used for the continuous packaging of thermoplastic materials in large-scale production and are carried out without a large amount of personnel.
• high investment costs are associated with the processes of this type.
• thermoplastic materials are sticky materials
• the areas of the packaging material that can come into direct contact with the sticky thermoplastic material are generally additionally provided with an anti-adhesive layer.
• EP 0496626 A1 discloses a container containing a solid hot-melt material, the solid hot-melt material being separated from the inner surfaces of the container by an anti-adhesive coating.
• the anti-adhesive coating can consist, for example, of an emulsion, dispersion, wax or powder.
• the anti-adhesive coating makes it easier to remove the solid hot-melt material from the container.
• a disadvantage of this coating is that a complete homogeneous coating of the inner surfaces is frequently not achieved, and residues of the hot-melt material remain on the inner surface. If the container is to be used again for filling, the coating of the inner surface must be renewed after the hot-melt material has been removed, since part of the coating usually remains on the hot-melt material.
• US 5,992,130 discloses a rigid container for packaging and transporting a reactive hot-melt adhesive composition that crosslinks in the presence of moisture.
• the outer wall of the container is made of a moisture-resistant material and the inner wall is coated with a material that does not stick to the adhesive.
• the coating consists, for example, of polymers based on silicone or fluorine components and is applied starting from a resin or varnish.
• the container Before the adhesive composition is removed, the container must be heated in a heating device. The container is not suitable for reuse. Since it is made up of different materials, these have to be separated before recycling.
• a general disadvantage of the prior art described above is that after the sticky thermoplastic material has been removed from the container, packaging waste arises which has to be disposed of.
• thermoplastic material can, for example, be wrapped in foil or coated with an anti-adhesive layer.
• DE 4205919 A1 describes a method in which a shaped body with possibly movable end and side walls rests on a conveyor belt made of thermally conductive material and a packaging material in the form of a film is applied to this shaped body. Liquefied adhesive is introduced onto the packaging material and into the molded body, and the area not yet enclosed by the packaging material is covered with packaging material.
• the adhesive packaged in this way is removed from the molded body and can then be stacked and transported.
• the shaped body is designed in the manner of an armored chain and can be used repeatedly in the context of continuous production.
• the object of the present invention was to provide an environmentally friendly method for packaging thermoplastic materials which overcomes the disadvantages of the prior art. There is a need, in particular, for a method which enables thermoplastic materials to be filled directly into a packaging material at temperatures up to 280 ° C. without causing damage to the packaging material. Another object of the invention was to provide a method for packaging sticky thermoplastic materials.
• Another object of the invention was to provide a method which enables the filling and packaging of thermoplastic materials which are used in direct or indirect contact with food.
• thermoplastic material essentially consists in a process for producing a portion pack of a thermoplastic material by a) filling the thermoplastic material in a flowable state into a casting mold in a first process step, b) allowing the filled thermoplastic material to solidify in the casting mold and in a second process step c) the solidified thermoplastic material is packaged, wherein d) a mold is selected as the casting mold, which is composed of at least one silicone elastomer, which is obtained by a platinum crosslinking process.
• the process according to the invention has the particular advantage that the flowable thermoplastic material at temperatures from 40 ° C to 280 ° C, preferably from 60 ° C to 260 ° C and particularly preferably from 80 ° C to 240 ° C.
• the mold can be filled and cooled in it for solidification without the surface of the silicone elastomer, which is in direct contact with the hot thermoplastic material, being damaged during filling.
• the filling takes place directly, for example after the production of the thermoplastic material, if it is still flowable, or indirectly, that is, for example, from a storage container.
• the storage container is permanently heated so that the thermoplastic material contained therein is flowable or the storage container is heated if necessary in order to make the thermoplastic material contained therein flowable.
• the cooling of a filled amount of painter of 2 kg takes approx. 2-3 hours in air and approx. 1.5 hours in a water bath, depending on the filling temperature.
• the solidified thermoplastic material is packaged.
• the casting mold is closed with a lid, the lid preferably consisting predominantly of the same material as the casting mold.
• the lid is either already attached to the casting mold or is placed in a separate step after the thermoplastic material has been filled to close the casting mold.
• the lid is preferably designed in such a way that it protects the contents, such as preferably a reactive hot melt adhesive, from atmospheric moisture.
• the thermoplastic material is separated from the casting mold in the second process step before packaging.
• the solidified thermoplastic material can be removed very easily from the casting mold without the casting mold being damaged and without the casting mold having to be equipped with a separating layer.
• the casting mold has, on the one hand, sufficient shape stability when filling in the liquid thermoplastic material and, on the other hand, a sufficiently high elasticity which, for example, enables the casting mold to be pulled off a cooled block of the thermoplastic material.
• the elasticity of the casting mold results from the material used - the casting mold is made up of at least one silicone elastomer.
• Elastomers are wide-mesh, cross-linked, high-molecular polymers with rubber-elastic behavior, which can be repeatedly stretched at least twice their length at room temperature and, once the constraint required for the stretching has been removed, immediately return to their original length.
• the elasticity is described by the elastic modulus of elasticity "E", which is the ratio of the tensile stress (force per cross-sectional area) to the longitudinal expansion.
• Crosslinking is generally achieved by vulcanizing natural or synthetic rubbers.
• the casting mold is preferably produced from silicone rubbers using the casting method. These are masses which can be converted into the rubber-elastic state and which, as base polymers, contain polydiorganosiloxanes which have groups accessible to crosslinking reactions. As such, for example, H atoms, OH or vinyl groups are suitable, which are located at the chain ends or can also be incorporated in the chain.
• the HTV silicone rubbers are vulcanized in the presence of crosslinking catalysts, usually organic peroxide, at temperatures> 100 ° C., preferably 150 to 160 ° C.
• Precious metal compounds are also used as crosslinking catalysts. Platinum is generally used as the precious metal compound.
• the cold-curing or RTV silicone rubber compounds can be differentiated into one and two-component systems. Polymerize or crosslink the former by condensation of SiOH groups with the formation of Si-O bonds, for example under the influence of atmospheric humidity.
• z. B mixtures of silicic acid esters and tin-organic compounds are used, the crosslinking reaction being the formation of an Si-O-Si bridge from “Si-OR” and “Si-OH” groups by elimination of alcohol.
• Platinum is preferably used and is known from the prior art as a crosslinking catalyst, in particular when the crosslinking is carried out by polyaddition and not by polycondensation.
• the molded body is preferably produced from high molecular weight polymethylsiloxanes.
• Silicone rubbers and casting processes for the production of moldings from silicone elastomers are known from FR 9609004 A1. Usable silicone elastomers are also described in US 2001/0043977.
• the casting mold is particularly preferably constructed from a silicone elastomer which is obtained by a platinum crosslinking process.
• a silicone elastomer which is obtained by a platinum crosslinking process.
• Such crosslinked silicone elastomers have little, if any, contamination from by-products and are therefore suitable for the food sector. It has surprisingly been found that these silicones are rubber-elastic over a wide temperature range and have no color changes at temperatures up to 280 ° C.
• the silicones obtained by a platinum crosslinking process are particularly preferably hot-crosslinked (HTV) silicones.
• they are methyl vinyl polysiloxanes.
• Such siloxanes are described in EP 0 992 195 B1 and in EP 0 519 372 B1.
• the at least one silicone elastomer is antiadhesive to the thermoplastic material:
• a sticky thermoplastic material, in particular a hot melt pressure sensitive adhesive, which is filled into the casting mold, which is made up of at least one silicone elastomer, which is obtained by a platinum crosslinking process, can after Cool the mold can be removed without the remnants of the sticky thermoplastic material sticking to the wall.
• the casting mold remains rubber-elastic in a temperature range from -40 ° C to 280 ° C.
• the casting mold can be designed in different geometries, for example in the form of a plate with mold cavities, as in DE 19922439 A1 or in the form of a bowl-shaped container, as described in US 2002/0171027 A1.
• a rectangular shape is preferred, the geometry is known from DE 4205919.
• the filling space of the casting mold has a base area of 8 to 12 cm ⁇ 20 to 26 cm and a height of 6 to 8 cm.
• the present invention also relates to the use of a casting mold, produced on the basis of at least one silicone elastomer, which is obtained by a platinum crosslinking process, for packaging thermoplastic materials.
• thermoplastic material from the group of thermoplastic adhesives, coating or sealing agents is used as the thermoplastic material in the method according to the invention.
• the thermoplastic material is preferably a thermoplastic hot melt adhesive, in particular a thermoplastic hot melt pressure sensitive adhesive.
• the invention therefore also relates to a portion pack consisting essentially of a) a thermoplastic adhesive, coating or sealing agent and b) a casting mold made of at least one silicone elastomer, which is obtained by a platinum crosslinking process.
• Suitable hot melt adhesives which can be packaged by the process according to the invention are described in EP 0469564 B1 on ropes 4, line 44 to page 8, line 48.
• reactive hot melt adhesives are preferably packed together with the casting mold in a further container which protects the reactive adhesive from moisture or electromagnetic radiation (daylight, UV light) protects.
• a further container which protects the reactive adhesive from moisture or electromagnetic radiation (daylight, UV light) protects.
• This can be, for example, a tightly closable metal box or metal box.
• the cooled reactive hot melt adhesive can also be removed from the mold and packed in a foil bag made of aluminum / polyethylene (PE).
• PE polyethylene
• the foil pouch is sealed with the inner PE foil.
• the aluminum foil on the outside protects the contents of the package from moisture and electromagnetic radiation.
• a hotmelt pressure-sensitive adhesive filled by the process according to the invention can be removed from the casting mold again without residue after cooling. It is not necessary to equip the casting mold with aids, for example separating layers made of siliconized paper, plastic film or anti-adhesive coatings.
• the hotmelt pressure-sensitive adhesive removed from the casting mold is optionally coated with an anti-adhesive coating for further assembly and packaging, for example with a wax or with a polymer. Coatings of this type are disclosed, for example, in DE 3327289. From WO 84/03457 and WO 84/03468 it is known to provide blocks of hot melt adhesives with a powdery release agent.
• the adhesive removed from the casting mold in particular a hotmelt PSA
• a hotmelt PSA can also be packaged in a known manner in plastic film, which if necessary is melted together with the adhesive and applied to the substrate to be bonded.
• Films suitable for the packaging of hotmelt PSAs can be found in DE 4205191 A1 on page 2, line 46 to page 3, line 9.
• the hotmelt PSA is filled into the casting mold, cooled, packaged, for example into a cardboard box or a cardboard box, the casting molds filled with adhesive also being stackable on top of one another, removed from the end user for the application and emptied Casting mold returned to the manufacturer or the process for refilling.
• the method according to the invention is particularly suitable for filling very highly viscous thermoplastic materials.
• Highly viscous thermoplastic materials are understood to mean materials that have a viscosity of 5000 mPas to 100,000 mPas at a temperature of 180 ° C., measured according to Brookfield, spindle 27.
• the process is also particularly suitable for small series and in production facilities where an investment in a continuous system does not appear to be profitable and which therefore give priority to the process of discontinuous packaging of thermoplastic materials.
• the process saves expensive, specially anti-adhesive packaging, such as siliconized cardboard boxes.
• the hot melt adhesive Technomelt Q 8718 (manufacturer: Henkel KGaA; composition about 45% SIS / SBS, 50% terpene resin, 5% mineral oil) with a viscosity of 45,000 mPas at 180 ° C (measured according to Brookfield, spindle 27.5) was used for a melt temperature of 180 ° C filled directly into the mold. After cooling, the adhesive could be removed from the molded article without leaving any residue.
• the hot melt adhesive Technomelt 5418 manufactured Henkel KGaA; composition about 50% polyolefin, 30% KW resin, 20% mineral oil) with a viscosity of 1600 mPas at 150 ° C (measured according to Brookfield, spindle 27.5) was at a temperature of The melt at 120 ° C is filled directly into the mold. After cooling, the adhesive could be removed from the mold without residue.
• the mold used in each case could be filled and emptied 20 times without any negative influence on the quality (appearance, surface quality, etc.) being observed.
• a rectangular container made of a silicone elastomer with the dimensions 24.0 ⁇ 10.5 ⁇ 7 cm was used as the casting mold. It is a molded body from the "Milleforme" series, manufacturer: Pavoni Italia S.p.A, 24040 Suisio (BG), Italia.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Packages (AREA)
• Adhesives Or Adhesive Processes (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2003
  • 2003-12-10 DE DE2003161988 patent/DE10361988A1/de not_active Withdrawn
• 2004
  • 2004-02-26 EP EP04714745A patent/EP1599325A1/de not_active Withdrawn
  • 2004-02-26 WO PCT/EP2004/001888 patent/WO2004078448A1/de not_active Application Discontinuation
  • 2004-02-26 CN CN 200480005753 patent/CN1756635A/zh active Pending

Non-Patent Citations (1)

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