plastic cups

Abstract

The invention relates to a deep-drawn plastic cup (4) for packaging solid or liquid adhesives, paints, or building materials. The plastic cup (4) is formed from a co-extruded plastic film (1). The plastic cup (4) has an inner functional layer (3) made of a silicon-polypropylene compound and an outer base layer (2) comprising polypropylene and recycled polypropylene.

Description

AREA OF INVENTION

[0001] The invention relates to a deep-drawn plastic cup according to the preamble of claim 1. The plastic cup is used for packaging solid, liquid or powdered adhesives, varnishes or building materials.

[0002] The invention further relates to a cup- or can-shaped composite packaging according to the preamble of claim 11. Accordingly, the composite packaging serves to package solid, liquid, or powdered adhesives, varnishes, or building materials. The composite packaging comprises an outer packaging component and an inner packaging component. The inner packaging component is separably arranged within the outer packaging component. After packaging, the (liquid or solid) adhesive, varnish, or (liquid / solid / powdered) building material is arranged within the inner packaging component.

[0003] The invention also relates to a method according to claim 13. The method relates to the manufacture of a plastic cup for packaging solid, liquid or powdered adhesives, varnishes or building materials.

[0004] Finally, the invention according to claims 19, 20 and 21 relates to a use of a composite packaging described herein for packaging a hot melt adhesive, a varnish and a building material respectively. TECHNOLOGICAL BACKGROUND

[0005] When packaging incompatible, especially reactive, chemicals, there is a regular technical requirement that the chemical can be removed from the packaging without leaving any residue, so that the packaging waste is not contaminated, or only to a minimal extent, with chemical residues. Furthermore, when packaging incompatible, especially reactive, chemicals, there is a regular technical requirement that the packaging material is not attacked or degraded by the contents, i.e., the chemical. Hot melt adhesives, paints, or building materials, for example, contain chemicals capable of contaminating and / or degrading packaging materials.

[0006] It is common practice in the art to use composite packaging for chemicals. For example, hot-melt adhesives are packaged in (metal) cans containing an inner plastic cup, which is made of a multi-component film. One film component stabilizes the cup, and at least one film component arranged on the inside of this cup serves as a non-stick and / or barrier layer. During manufacturing, the films or film components are first laminated together, and then the laminated films are deep-drawn to form a cup that fits snugly inside the can.

[0007] The problem is that handling the multi-component film is complex; two films on two separate rolls must be obtained, inserted into the thermoforming device, and guided within it in a controlled manner. This process is prone to errors and regularly leads to production interruptions. This is where the invention comes in. PRESENTATION OF THE INVENTION

[0008] The problem to be solved is to improve the production of composite packaging for hot-melt adhesives, paints, building materials, or other materials containing incompatible and / or reactive substances, or rather their handling, in an (ecologically) sustainable manner. This problem is solved with a thermoformed plastic cup according to claim 1. Further embodiments of the invention are described in the following claims. The thermoformed cup is thus formed from a co-extruded plastic film. By using a (composite or co-extruded) film, film handling during packaging production is significantly simplified; no additional film is required that would otherwise need to be fed (on large and heavy rolls) into the production line.The plastic cup, or rather the co-extruded film, has an inner functional layer made of a silicon-polypropylene compound and an outer base layer comprising polypropylene and recycled polypropylene. Because the base layer contains recycled material, i.e., material from a previous recycling process, the co-extruded film is significantly more environmentally sustainable than a film made exclusively from non-recycled plastic, i.e., so-called "virgin plastic," or from raw materials. The functional layer acts as a non-stick layer and / or a barrier layer. This ensures that the packaging contents (adhesive, varnish, etc.) do not leave any residue when the packaging is emptied (non-stick properties) and / or do not penetrate the base layer or any outer packaging of the plastic cup (barrier properties of the functional layer).After emptying the plastic cup, it can be disposed of in the lightweight packaging, plastic waste, or residual waste categories. If the plastic cup has outer packaging, this can be disposed of in the paper or scrap metal recycling categories.

[0009] The plastic cup described above is particularly easy to manufacture and suitable for further packaging handling if it has a round, especially circular, base and a cylindrical, especially hollow cylindrical, body, with the base and body being integrally joined. This cup shape can be formed by deep drawing with minimal machine effort and can then be easily demolded or removed from the deep-drawing tool.

[0010] To improve demoldability in the thermoforming tool or to simplify the insertion of the plastic cup into a cup-stabilizing (metal) can or cardboard roll or into a cardboard outer cup, it may be provided that the cross-section of the plastic cup tapers over the height of the cup, so that the cup has a smaller cross-section in the bottom area than in the area of ​​the cup opening.

[0011] As a stabilizing measure, a bead, particularly annular, can be provided in the outer shell of the plastic cup in the area of ​​the cup opening. The bead can be spaced apart from the upper rim of the cup, preferably between approximately 5 mm and approximately 15 mm, or more preferably approximately 10 mm. Since the plastic cup is made of a relatively thin film, the film material can be unstable, especially in the case of relatively large or tall cup shapes, causing the cup to buckle in places. By arranging the bead in the upper part of the cup, i.e., closer to the cup opening than to the bottom, buckling of the film is prevented.

[0012] With regard to user handling of the plastic cup, it can be advantageous if the plastic of the cup, i.e., the film, is transparent, translucent, or opaque (clouded). The plastic cup can be colored with at least one color, which is beneficial, for example, if the cup is to be visually associated with specific contents. For instance, a green cup can be used for green paint or for a first adhesive, or a red cup for red paint or a second adhesive that is chemically different from the first. Preferably, the plastic cup can be printable, preferably on the outside. The outer surface of the cup can have a rough surface, while the inner surface is preferably smooth to ensure non-stick properties.

[0013] The production and / or disposal of cups becomes ecologically sustainable when the thickness of the co-extruded film is between approximately 400 µm and 800 µm, preferably around 600 µm. At this (comparatively low) thickness, (plastic) material is saved during cup production, yet the cup remains dimensionally stable after removal from the thermoforming tool, simplifying subsequent filling or placement in outer packaging, such as a (white) tin can.

[0014] To ensure optimal material distribution with regard to the weight and stability of the cup, the wall thickness of the cup shell in the area of ​​the cup base can be less than the wall thickness in the area of ​​the cup opening.

[0015] For a pleasant cup feel and appearance, it can be advantageous if the recycled content in the base layer is between approximately 20% and approximately 50%, with a recycled content preferably being around 30%. This ensures that the cup's color, opacity (cloudiness), and / or feel are virtually indistinguishable from a cup containing no recycled content.

[0016] Improving the production of composite packaging for hot-melt adhesives, paints, building materials, or other materials containing incompatible and / or reactive substances, or improving their handling, can also be achieved in an (ecologically) sustainable manner by means of a cup- or can-shaped composite packaging according to claim 11. The composite packaging serves to package solid or liquid adhesives, paints, or building materials, and comprises an outer packaging component and an inner packaging component. The inner packaging component is formed from a plastic cup as described and claimed herein. Preferably, the outer packaging component is formed from a metal sheet, in particular tinplate, or from a plastic or cardboard.

[0017] Improving the production of composite packaging for hot-melt adhesives, paints, building materials, or other materials containing incompatible and / or reactive substances, or improving their handling, can also be achieved in an (ecologically) sustainable manner by means of a manufacturing process according to claim 13. The process serves to produce a plastic cup, particularly as described and claimed herein, for packaging solid, liquid, or powdered adhesives, paints, or building materials, and the process comprises the following steps: In a first step, a film is co-extruded. A base layer of the film is formed from a first extrudate, wherein the extrudate comprises or is formed from polypropylene and a polypropylene recyclate.A functional layer of the (composite or co-extruded) film is formed from a second extrudate, wherein the extrudate comprises or is formed from a polypropylene-silicon compound. According to a further, for example subsequent, process step, the film is deep-drawn into a substantially hollow cylindrical plastic cup, with the functional layer forming the inside of the plastic cup and the base layer the outside. According to a further, for example subsequent, process step, the deep-drawn cup is demolded and / or trimmed from a deep-drawing die.

[0018] Preferably, the film can be transparent, translucent, or opaque (clouded). It is also possible for the film to be colored.

[0019] To improve the stability of the cup in the area of ​​the cup opening and to prevent the cup from buckling during (hot) adhesive filling, a bead, particularly annular, can be arranged in the cup shell of the plastic cup in the area of ​​the cup opening. The bead is preferably spaced apart from the upper edge of the cup, with the distance between the bead and the cup edge preferably being in a range of approximately 5 mm to approximately 15 mm, or more preferably approximately 10 mm. The bead can be formed, for example, by means of an undercut.

[0020] To optimize dimensional stability while minimizing material requirements, it can be advantageous to co-extrude the film so that its thickness ranges between approximately 400 µm and approximately 800 µm, with a thickness preferably being approximately 600 µm. According to a preferred method variant, the film can, for example, be printed on the outside, i.e., on the base layer.

[0021] To ensure that the filled plastic cup reaches the user safely and securely, it can be placed in an outer packaging made of sheet metal, particularly tinplate, or of plastic or cardboard. After emptying the packaging, i.e., after removing the contents, the user can separate the plastic cup and the outer packaging and then dispose of them in different waste streams. For example, the empty plastic cup can be disposed of with other lightweight packaging (dual system, "yellow bin," etc.) or with residual waste, while the outer packaging can be disposed of with paper waste or scrap metal.From an ecological point of view, the composite packaging described herein is a packaging that can be produced with economical material expenditure and use, and can be separated and sustainably disposed of after use, leaving hardly any residue of the packaging contents.

[0022] Improving the production of composite packaging for hot-melt adhesives, paints, building materials, or other materials containing incompatible and / or reactive substances, or improving their handling, can also be achieved in an (ecologically) sustainable manner by using composite packaging according to claim 19. Accordingly, a composite packaging described and claimed herein is used for packaging a hot-melt adhesive for bonding materials or workpieces. Because the inner plastic cup is dimensionally stable, the adhesive manufacturer can easily and securely position the plastic cup within the outer packaging component. Filling the plastic cup is also simplified, particularly since the inner plastic cup is dimensionally stable. The functional layer with non-stick properties allows the adhesive user to empty the inner plastic cup almost without leaving any residue.The adhesive user can separate the composite packaging into its components, disposing of the inner plastic cup in the plastic waste stream and the outer packaging component, for example, in the paper or scrap metal stream. The functional layer also forms a barrier layer for reactive adhesive components, preventing degradation or penetration of the base layer.

[0023] Improving the production of composite packaging for hot melt adhesives, paints, building materials, or other materials containing incompatible and / or reactive substances, or improving their handling, can also be achieved in an (ecologically) sustainable manner by using composite packaging according to claim 20. Accordingly, a composite packaging described and claimed herein is used for packaging a paint for coating materials or workpieces.

[0024] Improving the production of composite packaging for hot melt adhesives, paints, building materials, or other materials containing incompatible and / or reactive substances, or improving their handling, can also be achieved in an (ecologically) sustainable manner by using composite packaging according to claim 21. Accordingly, a composite packaging described and claimed herein is used for packaging a building material for processing when handling materials or workpieces.

[0025] The aforementioned components, as well as those claimed and described in the exemplary embodiments, to be used according to the invention, are not subject to any special exceptional conditions with regard to their size, shape, material selection and technical concept, so that the selection criteria known in the field of application can be applied without restriction.

[0026] Further details, features, and advantages of the subject matter of the invention will become apparent from the dependent claims, as well as from the following description and the accompanying drawing, in which—by way of example—an embodiment of a coextruded film structure for a plastic cup is schematically illustrated. Individual features of the claims or embodiments can also be combined with other features of other claims and embodiments. BRIEF DESCRIPTION OF THE FIGURES

[0027] The drawing shows Fig. 1 a coextruded film in schematic sectional view and Fig. 2 a plastic cup in schematic sectional view. DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION

[0028] A schematic view of the layer structure of a (composite or coextruded) film 1 is shown in Fig. Figure 1 shows that a film 1 is formed by co-extrusion of two extrudates, comprising a base layer 2 and a functional layer 3. The base layer 2 comprises polypropylene (PP) with a recycled content of, for example, 30% or higher. The functional layer 2 comprises a silicon-polypropylene compound (Si-PP compound).

[0029] The polypropylene and the compound are fed in granular form into a (two-component) extruder, heated, co-extruded into a film 1, and applied to a (transport) roll. The film roll is then processed in a thermoforming machine. In the thermoforming machine, the film 1 is heated and formed into a hollow cylindrical plastic cup 4. The cup 4 is demolded from the thermoforming machine, trimmed at the edges if necessary, and packed in stacks. The cup 4 can be placed in outer packaging, for example, a tin can. The internal volume of the tin can corresponds (almost) to the external volume of the plastic cup 4, and the cup 4 can be arranged in the can in a form-fitting manner.

[0030] The layer thickness of the coextruded film 1 is approximately 600 µm. Therefore, the cup wall 7 is comparatively thin, meaning that the cup 4 would change its shape during filling, for example, during hot filling with a hot-melt adhesive. This is prevented by the outer packaging; inside the outer packaging (can), the plastic cup 4 retains its (hollow cylindrical) shape.

[0031] To prevent the relatively thin cup wall 7 from buckling during (hot) filling, a groove 6 is arranged in the upper area of ​​the cup 4, approximately 5 mm from the cup opening 5. The groove 6 is in Fig. Figure 2 shows a schematic vertical section through the cup 4. The cup shell, or rather the cup wall (7) and the cup bottom 8 are made of the coextruded film 1 according to Fig.The functional layer 3 of the film 1 is located on the inside, while the base layer 2 is on the outside of the cup. The bead 6 is annular and stabilizes the cup wall 7, forming cup wall reinforcement where the cup structure is weakest, namely in the area of ​​the cup opening 5. The bead 6 is formed in the film 1 during deep drawing. The bead 6 can include or be formed from an inward and / or outward bulge in the film 1.

[0032] By reinforcing the cup wall 7 in the area of ​​the cup opening 5, the cup 4 can be filled more easily and safely after being placed in the outer packaging (can). This is particularly important with hot melt adhesives, as it prevents adhesive from getting between the cup 4 and the outer packaging during filling, which would contaminate both the outside of the cup (base layer 2) and the inside of the outer packaging / can with the adhesive. REFERENCE MARK LIST 1 (Composite / Coextrusion) film 2 Base layer 3 functional layers 4 cups 5 cup opening 6 groove 7 Cup wall / cup shell 8 cup bottom

Claims

[1] Deep-drawn plastic cup (4) for packaging solid or liquid adhesives, paints or building materials, characterized by , that the plastic cup (4) is formed from a co-extruded plastic film (1), that the plastic cup (4) has an internal functional layer (3) made of a silicon-polypropylene compound, and that the plastic cup (4) has on the outside a base layer (2) comprising polypropylene and polypropylene recycled material. [2] Plastic cup (4) according to claim 1, characterized by , that the plastic cup (4) has a round, in particular circular, cup base (8) and a cylindrical, in particular hollow cylindrical, cup shell (7), wherein the cup base (8) and cup shell (7) are integrally connected. [3] Plastic cup (4) according to claim 2, characterized by, that the cross-section of the plastic cup (4) tapers over the height of the cup, so that the cup (4) has a smaller cross-section in the bottom area than in the area of ​​the cup opening (5). [4] Plastic cups (4) according to claim 2 or 3, characterized by , that in the cup shell (7) in the area of ​​the cup opening (5) a bead, in particular annular, is arranged (6). [5] Plastic cup (4) according to claim 4, characterized by that the groove (6) is spaced apart from the upper edge of the cup, wherein the distance of the groove (6) to the edge of the cup is preferably in a distance range between about 5 mm and about 15 mm, or preferably about 10 mm. [6] Plastic cup (4) according to any one of claims 1 to 5, characterized by , that the plastic of the cup (4) is transparent, translucent or opaque, and / or that the plastic cup (4) is colored with at least one cup color. [7] Plastic cup (4) according to any one of claims 1 to 6, characterized by that the plastic cup (4) is printable, preferably on the outside. [8] Plastic cup (4) according to any one of claims 1 to 7, characterized by , that the thickness of the coextruded film (1) is in a thickness range between about 400 µm and about 800 µm, wherein the thickness of the coextruded film (1) is preferably about 600 µm. [9] Plastic cup (4) according to any one of claims 1 to 8, characterized by , that the wall thickness of the cup shell (7) in the area of ​​the cup bottom (8) is less than the wall thickness in the area of ​​the cup opening (5). [10] Plastic cup (4) according to any one of claims 1 to 9, characterized by , that the recycled content in the base layer (2) is in a proportion range between about 20% and about 50%, with the proportion preferably being about 30%. [11] Cup- or can-shaped composite packaging for packaging solid or liquid adhesives, varnishes or building materials, wherein the composite packaging comprises an outer packaging component and an inner packaging component, characterized by , that the inner packaging component is formed from a plastic cup (4) according to one of claims 1 to 10. [12] Composite packaging according to claim 11, characterized by that the outer packaging component is made of a metal sheet, in particular tinplate, or of plastic or cardboard. [13] Method for producing a plastic cup for packaging solid or liquid adhesives, paints or building materials, in particular a plastic cup according to any one of claims 1 to 10, wherein the method comprises: the co-extrusion of a film from a first extrudate, which forms a base layer of the film and comprises or is formed from polypropylene and a polypropylene recyclate, and from a second extrudate, which forms a functional layer of the film and comprises or is formed from a polypropylene-silicon compound; the deep drawing of the film into an essentially hollow cylindrical plastic cup, wherein the functional layer forms the inside of the plastic cup and the base layer the outside of the plastic cup; and The demolding and / or trimming of the deep-drawn cup from a deep-drawing tool. [14] Manufacturing method according to claim 13, wherein the film is made transparent, translucent or opaque, and / or wherein the film is colored. [15] Manufacturing method according to claim 13 or 14, wherein a bead, in particular annular, is arranged in the cup shell of the plastic cup in the area of ​​the cup opening, wherein the bead is preferably spaced apart from the upper edge of the cup, wherein the distance of the bead to the edge of the cup is preferably in a distance range between about 5 mm and about 15 mm, or preferably about 10 mm. [16] Manufacturing process according to one of claims 13 to 15, wherein the film is co-extruded such that the thickness of the film is in a thickness range between about 400 µm and about 800 µm, wherein the thickness of the film is preferably about 600 µm. [17] Manufacturing method according to any one of claims 13 to 16, wherein the film is printed. [18] Manufacturing method according to any one of claims 13 to 17, wherein the plastic cup is arranged in an outer packaging, wherein the outer packaging is made of a metal sheet, in particular tinplate, or of a plastic or of cardboard. [19] Use of a composite packaging according to claim 11 or 12 for packaging a hot melt adhesive for bonding materials or workpieces. [20] Use of a composite packaging according to claim 11 or 12 for packaging a varnish for coating materials or workpieces. [21] Use of a composite packaging according to claim 11 or 12 for packaging a building material for processing when handling materials or workpieces.

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