DE2348931B2 - METHOD OF MANUFACTURING A BODY FOR MOISTURE-PERMEABLE PACKAGING - Google Patents

Description

Recently, the requirements for highly moisture-impermeable packaging have increased for medical tablets, food, sensitive !! before machine parts and other moisture-sensitive goods tightened.

From US-PS 33 31 495 is a body made of a thermoplastic film with two or more bulges known, which is covered on the flat side with an aluminum foil and on which the bulges having side is enveloped on the outside by an aluminum foil, whereby the plastic film completely with the Aluminum foil is connected.

US Pat. No. 3,684,610 describes a process for producing a five-layer composite film. A thermoplastic film is covered on both sides with metal foils by means of adhesive interlayers coated

In DT-PS 5 88 953 a process for the production of both sides coated with metal foil is Cardboard container described in which one of the two metal foils is first applied with a vegetable glue the cardboard is glued on, while the other only after the pasted cardboard has completely dried out is glued on with a binding agent. Since the cardboard is completely dry, there are no undesirable side effects, such as blistering or cracks in the metal foil. In addition, flawless containers can be used formea if the a metal foil with a binder is applied and heated, since the metal foil is slidable on the heated binder. After this Processes can be used to create wrinkle-free boxes with smooth surfaces, but by no means moldings with indentations produce, which are lined with recesses of a cut metal foil.

The production of moisture-permeable bodies with only one indentation is, apart from Exceptional cases, practically not carried out, however, bodies are for packaging with two or more, in particular, many indentations for accommodating the contents of the packaging are widely used.

In the known processes for the production of moisture-impermeable bodies, in general a thermoplastic film that is already impermeable to moisture in itself, e.g. B. a polyvinyl chloride film, or a moisture-proof polyvinyl chloride film, or a moisture-proof one equipped thermoplastic film, e.g. B. a polyvinyl chloride film with polyvinylidene chloride in the form a coating or film is covered, heated to softening, whereupon the softened sheet means Applying pressure or negative pressure to a moisture-impermeable body with one or more Indentations to accommodate the package contents is deformed.

These known methods are stretch deformations, and so these methods are Applicable well to those materials that, when heated and softened, are considered thermoplastic films can be stretched 100 to 200 percent or more.

However, it has not been possible to make the moisture impervious Body with two or more indentations for receiving the packaging halts using a composite film that is glued in a conventional manner thermoplastic film and a metal foil has been Herge, since the metal foil in the course of de Stretch forming tears.

The reason why this body is not manufactured using conventional deformation methods This is because the elasticity of the material to be deformed is 100% or more must, however, the maximum elongation of the metal foil mi

; around 20 to 30%, even if the deformation is in Heat is made. Accordingly, the metal foil is destroyed when it is deformed.

The invention is based on the object of a method for producing a moisture-impermeable Body with at least two indentations using a composite film to create the has been produced by gluing a thermoplastic film with a metal foil without the Metal foil is destroyed, with the appearance of wrinkles in the area of curvature of the Einbuchfngen should be avoided for taking up the contents of the package. This object is achieved according to the invention solved by the features in the characterizing part of claim 1.

The approach disclosed in US Pat. No. 3,331,495 differs from the method according to the invention with regard to the means that ensure the moisture impermeability of a molded body a thermoplastic film must be used. From the teaching of US-PS 33 31 495 and the other documents that are completely different from the subject of the application in terms of task and solution the solution of the problem was by no means obvious to the average person skilled in the art. Since a metal foil in a Stretching of over 20 to 30% tears, recesses must be that can be deformed without tearing can be cut into the metal foil, so the metal foil must be pre-cut. Is also none of the patents to infer that a deformation of recesses of a metal foil with With the help of a hot melt adhesive, the hot melt adhesive acts as a lubricant.

In the method of the invention, the surrounding edges of the recess areas of the metal foil with progressive deformation after Center of the matrices are stretched, since the hot melt adhesive is softened and the softened Glue serves as a lubricant, and the surrounding edges of the recess areas are already cut. Therefore, the recess areas can be stretch-deformed without destroying the metal foil.

Examples of thermoplastic films that can be used in the process according to the invention, are foils made of polyvinyl chloride, polyethylene, polypropylene, polyesters or polycarbonates. Preferably Polyvinyl chloride films are used as thermoplastic films. The thickness of the thermoplastic films is generally 100 to 500 μ, preferably 150 up to 300 μ and in particular 150 to 200 μ.

Examples of the metal foils which can be used in the process according to the invention are foils made of aluminum, Tin, copper or iron. Aluminum foils are preferred. The metal foils preferably have a Thickness of 30 to 150 μ, in particular 40 to 70 μ.

Preferably hot melt adhesives based on ethylene-vinyl acetate copolymers are used for the method of the invention, Polyvinyl acetate, polyvinyl butyral, polyethylene or polyamides used, these polymers as the main component z. B. with Colophony, ester gums or paraffin are mixed as additives. The thickness of the hot melt adhesive is preferably 3 to 30 μ, in particular 10 to 15 μ.

The appearance of wrinkles or shrinkage is effectively prevented if you are already familiar with the The composite foil provided with the incisions in the metal foil on the metal side with a further thermoplastic The film is glued and the five-layer composite film obtained in this way is subjected to stretching deformation. Through this the compressive force of the holding jaws or the sheet metal holder can be increased during the stretching deformation, so that the stretching deformation of the composite film without the occurrence of wrinkles or shrinkage is possible.

For bonding the thermoplastic film to the metal film, an adhesive is preferably made of a saturated polyester resin or a saturated polyester / isocyanate adhesive is used. The thickness of this The adhesive layer is preferably 3 to 30 μ, in particular 5 to 10 μ.

Due to the fact that the metal foil has already been cut, the gluing of the carried out the lowest thermoplastic film with the metal foil using a hot melt adhesive. According to the invention, the metal foil can then be stretch-deformed without tearing. For bonding the thermoplastic film with the surface of the metal foil can be a hot melt adhesive or a normal Glue can be used. In the case of using a hot melt adhesive, at the time of the stretching deformation both the hot melt adhesive on the surface and the hot melt adhesive on the back of the Softened metal foil. Thus, the hot melt adhesive on the back of the metal foil serves as a Lubricant. The force applied when compressing the jaws or sheet metal holders can be due to the Presence of the thermoplastic film on the surface of the metal foil can be increased, and that The occurrence of wrinkling or shrinkage in the edge or curvature area can be avoided. in the Case of using the aforementioned »Vylon 300« or glue on the basis of saturated Polyesters and isocyanates become the metal foil and the thermoplastic foil at the same time during the deformation deformed towards the center of the die. The metal foil can thus by the presence of the thermoplastic film to be reinforced at the time of deformation. In addition, due to the The fact that the force applied when pressing the jaws or blank holders together is increased can, no wrinkles or shrinkage in the edge or Curvature area of the indentations instead. the inventive production of moisture-impermeable bodies with two indentations for The inclusion of the contents of the package is described below with reference to the drawings.

It shows

F i g. 1 shows a plan view of an embodiment of a composite film,

F i g. 2 shows a section along the line 1-1 of FIG. 1,

3 shows a plan view of a moisture-impermeable Body with two indentations to accommodate the contents of the package, which is Deformation of the in the F i g. 1 and 2 shown composite film has been obtained,

F i g. 4 shows a section along line 11-11 of FIG. 3,

5 shows a cross section of a stretch forming measure machine, the mainly two punches and the corresponding die as well as the state of the ver bunch film shows how it can be seen from Figs. 1 and 2 before the stretching deformation results,

Fig. 6 is a cross section of a stretch forming machine machine, the mainly two punches and the corresponding die as well as the condition of the ver shows the bundle film after the stretching deformation,

F i g. 7 shows a cross section of another embodiment of a composite film;

F i g. 8 shows a plan view of a further embodiment of a composite film;

FIG. 9 shows a section along the line 1II-III of FIG. 8,

Fig. 10 is a plan view of a moisture impermeable Body with two indentations to accommodate the contents of the package, which are after the Deformation of the composite film of Figure 8 has been obtained,

F i g. 11 shows a cross section along the line IV-IV of FIG Fig. 10,

Figure 12 shows a cross section of a further embodiment a composite film and

Fig. 13 is a cross-section of a package made using the moisture-impermeable Body has been manufactured with two indentations and which contains the contents of the package.

In Fig. 1, A represents a composite film in the state before stretch deformation, a thermoplastic film 1 is glued to a metal film 3 by means of a hot melt adhesive 2 and two recess areas, 4 'and Λ "are made by cutting only the metal foil 3, as shown by the line Bm F i g. 2 is indicated.

In the F i g. 3 and 4, A represents the moisture-impermeable body for the packaging, which is produced by stretching according to FIGS. 1 and 2 has been obtained. The body consists of a thermoplastic film 1, a hot-melt adhesive 2, a metal film 3, the edge areas 4, indentations for receiving the package contents 5 and gaps 6, which are caused by the wandering of the peripheral edges of the two recess areas Λ 'and A "(cf. 1) the metal foil 3 was created at the time of the stretching deformation. B means the cutting line of the metal foil 3.

In the following, the process of stretching deformation is described by the methods shown in FIGS. 1 and 2 shown Composite films for the in the F i g. 3 and 4 shown moisture-impermeable bodies with two inlets indentations for receiving the contents of the package based on the F i g. 5 and 6, the main show the punch and die of the stretch forming machine.

In the F i g. 5 and 6, A represents a composite film. A jaw or a sheet metal holder 7 is used to prevent wrinkling or shrinkage. The stretch-forming machine contains a die 8 with a cooling device 10, a punch 9, a heating device 11 which is provided in the jaw 7, and a plate 12 as a support for the punch 9. The jaw 7 has a shallow recess C _{1 in the lower part} to facilitate the stretching deformation.

When the method is carried out in practice, the composite film A is placed on the die 8, which is cooled by means of the cooling device 10. The recess areas A ' and A "of the composite film are arranged so that they are located under the punches 9 and 9. The composite film is arranged between the die 8 and the jaw 7, which is heated by the heater 11. This prevents the occurrence of In this case, a temperature is used for the deformation at which the hot-melt adhesive 2 and the thermoplastic film are softened.

As shown in FIG. 6, the stamps 9 and 9 connected to the plate 12 are then lowered, the recess areas Λ 'and / I "of the composite film A being stretched. Then the stamps 9 and 9 are raised again, and the moisture-impermeable body with two indentations to The contents of the package are recorded after the hot-melt adhesive 2 has solidified.

Instead of the composite film described above, the composite film according to FIG. 7 can also be used be used.

In Figure 7, the composite film consists of thermoplastic Foils 1 and Γ, the hot melt adhesive 2, a metal foil 3 and an ordinary adhesive 13. The The cutting line for producing the recess areas is denoted by ß. In the case of the composite film, there is a The advantage that the metal foil 3 can be reinforced during and / or after the stretching deformation because the thermoplastic film 1 is glued to the metal film 3.

Furthermore, the method can also be carried out with the composite film shown in FIGS will.

8 shows the composite film A in the state before the stretching deformation, which is obtained by the following method: A thermoplastic film 1 is bonded to a metal film 3 using a hot-melt adhesive, and only the metal film is applied to form the recess areas A ' and A " in cut into the metal foil, as indicated by a dashed line B

and also a solid line B is shown, and the thermoplastic film 15 is bonded to the surface of the metal foil 3 with an adhesive 14.

In Figs. 10 and 11, A represents a moisture-impermeable body for packaging use which

by stretching the composite film of FIG. 8 and 9 is obtained. In the F i g. 10 and 11 consists of Body made of a thermoplastic film 1, a hot melt adhesive 2, a metal foil 3, a hot melt adhesive or ordinary adhesive 14, a thermoplastic

see film 15, an edge or curvature area 16, an indentation 17 for receiving the package contents and a gap 18, which is caused by the migration of the peripheral edges of the two recess areas A ' and Λ "(see. Fig. 8) of the metal foil 3

occurred at the time of the stretching deformation. B means the cutting line of the metal foil 3.

Furthermore, the method can also be carried out using a seven-layer composite film according to FIG FIG. 12 instead of the aforementioned one shown in FIG. 9

Composite film.

In Fig. 12, the body consists of a thermoplastic Foil 1, a hot melt adhesive 2, a metal foil 3, an ordinary adhesive 19, a thermoplastic Film 20, a hot melt adhesive or ordinary

Chen adhesive 21 and a thermoplastic film 22. B represents the cutting line of the metal foil to form the recess areas.

To produce a complete package using the produced body, e.g. B.

a moisture-proof film in which a metal foil is coated with a heat-sealable adhesive is glued to the moisture-impermeable body for packaging purposes according to FIG. The package of FIG. 13 consists of one

thermoplastic film 1, a hot-melt adhesive 2, a metal foil 3, a heat-sealable adhesive 23, an edge or curvature region 24, a Indentation for accommodating the contents of the package 25,

i a gap 26, which is caused by migration of the peripheral edges the two recess areas of the metal foil was created, a heat-sealable adhesive 27, one Metal foil 28 and the contents 29.

Of course, the number of indentations is not limited in the method. Accordingly The bodies produced can have a large number of indentations, in particular 100 or more indentations for taking up the contents of the package.

As already mentioned, the body produced is impermeable to moisture because the metal foil is not is destroyed and no wrinkling or shrinkage in the edge or curvature area of the indentations for taking up the contents of the package.

By cutting into the metal foil alone, recess areas are formed on the composite foil correspond in size to the contents of the package. After stretching the recess areas a body with several indentations is obtained, which is covered with a wrinkle-free and non-torn metal foil is lined. The edges of the metal foil at the gaps are still in the undeformed plane of the Composite foil and can be covered directly with an aluminum foil so that it is impermeable to moisture. Every The indentation is therefore completely surrounded by a metal foil, that is to say completely protected from moisture. Breaking one indentation and removing any agent remains on the other indentation without consequences, since all indentations are separately surrounded and sealed with a metal foil.

example 1

A hot melt adhesive made of ethylene-vinyl acetate copolymer with a softening point of 60 to 70 ° C is applied in an amount of 15 g / m ² to a rigid polyvinyl chloride film with a thickness of 150 μ; then the coated PVC film is glued to a 60 μ thick, soft aluminum film. The aluminum surface of the three-layer composite film is coated with a heat-sealable vinyl chloride-vinyl acetate lacquer. Then only the aluminum foil is cut in such a way that two circular recess areas with a diameter of 24 mm are created.

Using a die with a clearance of 12.6 mm and a punch with a The composite film obtained between the die and the jaw has an outer diameter of 12.0 mm arranged, as shown in Fig. 5, by a Heating device is heated. While the temperature of the die is kept below 50 "C, the Stamp, as shown in Fig. 6, pressed into the die, whereby the recess areas of the composite film are stretch-deformed so that two indentations are obtained, each with a depth of 5 mm. As a result, the outer diameter of the recess areas of the soft aluminum foil is reduced to one outer diameter of! 4 mm is drawn, and the rigid PVC film is also stretch-deformed.

Example 2

Instead of the aluminum foil of Example 1, a soft aluminum foil with a thickness of 50 μ is used used and mii uci Po! yviüy! ch! oridfo! i <\ die only 30μ thick, using a polyester (saturated) / isocyanate adhesive instead of the heat sealable one Lacquer from example 1 glued. Then the rigid polyvinyl chloride film with a thickness of 150 μ glued to the aluminum surface using the hot melt adhesive from Example I. With the so obtained composite film are both the polyvinyl chloride film with a thickness of 30 μ and the cut into soft aluminum foil with a thickness of 50 μ, so that circular recess areas with a diameter of 24 mm. The recess areas of the composite film are according to Example 1 stretched. A result similar to that in Example 1 is obtained.

Example 3

An existing from Äthylcn-vinyl acetate copolymer hot-melt adhesive having a softening point of 60 to 70 ⁰ C is applied in an amount of 10 g / m ² on a rigid polyvinyl chloride sheet having a thickness of 150 μ. Then an aluminum foil with a thickness of 70 μ is glued on. In the composite film obtained, only the aluminum foil is cut, so that two circular recess areas with a diameter of 24 mm are obtained.

The aluminum surface of the composite film consisting of three layers is then ^{coated with a polyester adhesive in an amount of 10 g / m 2} , after which a rigid polyvinyl chloride film with a thickness of 30 μ is glued to form a composite film consisting of five layers.

A die with a clearance of 12.6 mm and a punch with an outer diameter of 12.0 mm are used. The jaw is heated so that a temperature is maintained of from 80 to 9O ⁰ C. At the time of deformation, the temperature of the die is kept at a temperature below 50 ° C. by means of cooling. The composite film is placed between the jaw and the die. During the deformation, the thermoplastic film and the hot-melt adhesive are softened, and two punches are pressed into the die, so that two indentations with a depth of 5 mm are created on the two recess areas of the composite film. As a result, the drawing reduces the outer diameter of the aluminum foil from 24 to 14 mm, and the rigid polyvinyl chloride sheet is stretch-deformed. The aluminum foil of the body obtained is not torn, and no wrinkling or shrinkage is observed in the edge or curvature area of the two indentations.

Example 4

Example 3 is using a hot melt adhesive made of ethylene-vinyl acetate copolymer instead of the polyester glue repeatedly. Results similar to those in Example 3 are obtained.

The moisture impermeable wedge of the bodies obtained in the case of 3 and 4 with two indentations for the inclusion of the contents of the package

bo only about> / s that of a commercially available body same shape with the lowest moisture permeability. The known body is made in such a way that ma a polyvinyl chloride film with a thickness of 150 μm Polyvinylidene chloride resin in a thickness of 25

h5 coated and coated in the same way ten Polyvinylchloridtoiie glued.

For this purpose 3 sheets of drawings

709 547/2

»Ϊ́ .ei

Claims (9)

'Patent claims: 1. A method for producing a body for moisture-impermeable packaging, oVr 7 _W ei or more indentations for the Aufnahi Jes packaging content and consists of a mii a metal foil covered thermoplastic film, characterized in that the metal foil is first applied to the thermoplastic film with a hot melt adhesive aufklebt forms on the obtained composite film by cutting only the metal foil two or more relief surfaces which dimensionally match the packaging content, and the Aussparungsflächun the encryption ^'5 composite film at a temperature at which the hot melt adhesive and the thermoplastic film to soften, to form the indentations stretched. 2. The method according to claim 1, characterized in that the already with the incisions in the metal foil provided composite foil on the metal side with a further thermoplastic The film is glued and the five-layer composite film obtained in this way is subjected to stretching deformation. 3. The method according to claim 1 or 2, characterized in that the thermoplastic film a film made of polyvinyl chloride, polyethylene, polypropylene, polyester or polycarbonate is used. 4. The method according to claim 3, characterized in that thermoplastic films with a Thickness of 100 to 500 μ, preferably 150 to 300 μ and in particular 150 to 200 μ used. 5. The method according to claim 1 or 2, characterized in that a metal foil is made Aluminum, tin, copper or iron are used. 6. The method according to claim 5, characterized in that metal foils with a thickness of 30 to 150 μ, preferably 40 to 70 μ used. 7. The method according to claim 1 or 2, characterized in that there is a hot melt adhesive used, the main component of which is ethylene-vinyl acetate copolymers, Polyvinyl acetate, polyvinyl butyral, polyethylene or polyamides and, as additives, colophony, ester gums or Contains paraffin. 8. The method according to claim 7, characterized in that the hot melt adhesive in a thickness from 3 to 30 μ, preferably 10 to 15 μ, used. 9. The method according to claim 2, characterized in that the provided without incisions five-layer composite film provided with incisions, one of the thermoplastic films and the Penetrate metal foil, and the surface of the incised thermoplastic film underneath Use of a hot melt adhesive or an ordinary adhesive with another thermoplastic Film glued, and the resulting seven-layer composite film of the stretching deformation subject.