NL2000673C1 - Paint can and method for manufacturing a paint can. - Google Patents

Description

PAINT BOX AND METHOD FOR MANUFACTURING A PAINT BOX

The invention relates to a can, in particular a can intended to be filled with a liquid such as paint, with at least 3% volatile organic compounds, comprising a peripheral wall, a first end wall and a second end wall. The can can also be in the form of a bottle, wherein an end wall is provided with, for example, a screw cap opening, for storing, for example, volatile organic liquids.

Such a can is known from Dutch patent publication NL 1028302, which is made of plastic. Other such paint cans are also generally known, for example paint cans made entirely of metal. Paint mainly exists in two variants. The first variant is paint based on organic solvents, in which the liquid component is essentially an organic volatile solvent. The second variant is water-based paint, in which the liquid component is substantially water, but in which approximately 5-20% organic volatile solvent is still present. It is of great importance for the shelf life of the paint and for the prevention of undesirable odors and harmful substances in the space where the paint can is stored that the paint can does not allow these volatile substances to escape.

The invention has for its object to provide a can of the type described in the preamble which can be manufactured inexpensively, which promotes a good shelf life of the liquid, which does not harm public health, and / or which is environmentally friendly.

According to the invention, the peripheral wall of the can for this purpose consists of a laminate, which laminate, seen from the outside in, comprises at least a layer of cardboard, an adhesive layer, a layer of metal foil, and a layer of plastic.

2

In the context of the invention, the term cardboard must also be understood to mean (multi-layer) paper. Cardboard is an inexpensive and environmentally friendly packaging material compared to plastic and metal. Preferably the cardboard is kraft cardboard. The layer of cardboard is preferably between 300 dm and 2500 dm thick, more preferably between 400 dm and 1200 dm. In the preferred embodiment, the cardboard layer is approximately 600 dm thick. The layer of cardboard is preferably composed of several layers of cardboard glued together. In the preferred embodiment, the layer of cardboard consists of two layers of kraft cardboard each of 300 dm thick and a layer of 50 grams kraft paper which are mutually connected by means of an adhesive layer. Such a multi-layered structure gives strength to the wall.

Preferably the adhesive layer between the metal foil and the cardboard is also glue. In an alternative embodiment, this is polyethylene, and by melting it during the production of the laminate, a strong bond is also obtained. The polyethylene adhesive layer is preferably between 3 dm and 60 dm, more preferably between 5 dm and 30 dm thick. In the alternative preferred embodiment, the polyethylene adhesive layer is approximately 13 dm thick.

The layer of metal foil is preferably aluminum foil. The layer of metal foil is preferably between 3 dm and 50 dm, more preferably between 4 dm and 20 dm thick. In the preferred embodiment, the layer of metal foil is approximately 9 dm thick.

The volatile organic compounds in the liquid can for example comprise one or more substances from the group consisting of toluene, xylene, benzene, white spirit, hexane, thinner, peut, benzene, ketone, ester, glycol ether, alcohol, in particular butyglycol, butyl diglycol , ethyl glycol and methyl glycol. These are all known 3 solvents for paint. The plastic on the inside of the wall is preferably a plastic such as a polyolefin such as polypropylene or polyethylene, or polyethylene terephthalate that is durable to the volatile organic compounds. However, other resistant plastics are conceivable. The layer of plastic is preferably between 5 µm and 100 µm, more preferably between 10 and 50 µm thick. In the preferred embodiment, the layer of plastic is polypropylene and about 25 µm thick.

The metal foil, as well as the plastic layer, and in particular the combination thereof, ensure good impermeability of air, volatile organic compounds, water and water vapor.

In the preferred embodiment, one of the end walls 15 of the can is an upper wall consisting of a ring part with an opening and a lid fitting therein. In the preferred embodiment, the end walls of the circumferential wall are separate parts connected to the circumferential wall. The end walls are preferably made of a plastic, such as polypropylene, and are preferably made by injection molding. In this respect, the preferred embodiment is the same as the preferred embodiment as described in NL 1028302, with which the preferred embodiment described here differs only in the composition and construction of the circumferential wall. The mounting of the end walls on the peripheral wall is therefore the same as described in that document. The adhesion, by means of glue or ultrasonic welding, between the polypropylene end walls and the peripheral wall is very good due to the presence of the plastic layer on the inside.

The invention also relates to a method for manufacturing a plastic can, such as a paint can, comprising providing a peripheral wall, a first end wall and a second end wall, wherein the can 4 is filled with a liquid, such as paint, with at least 3% volatile organic compounds, and wherein the peripheral wall is made of a laminate, which laminate, viewed from the outside in, comprises at least a layer of cardboard, an adhesive layer, a layer of aluminum foil, and a layer of plastic.

The invention will be further elucidated in the following description with reference to the accompanying figures of exemplary embodiments.

Figure 1 shows a longitudinal section with omitted parts of a first embodiment of a bush according to the invention.

Figure 2 shows an exploded view of the can according to Figure 1.

15

The can 1 shown in figures 1 and 2 comprises a peripheral wall 3, a first end wall in the form of a bottom 12, and a second end wall or top wall 5, consists of a ring part with an opening 6 for a lid fitting therein. The top wall 5 comprises a circumferential surface 9 which extends into a slot 8 at the top of the top wall 5. The circumferential wall 3 is slid into the top wall 5, such that the surface 9 abuts the inside of the circumferential wall 3 and the upper edge of the circumferential wall protrudes into the slot 8. The top wall 5 is received in a liquid-tight manner in the circumferential wall 3 in that, for example, an adhesive layer is applied between the surface 9 and the circumferential wall. Another connection, for example by ultrasonic welding, can also be realized. The end walls are particularly preferably fixed to the circumferential wall by means of an APOA-30 hot melt.

The top wall 5 is provided with a wall 7 which extends obliquely to the opening 6, which ensures that when the can 1 is poured empty, the entire contents can be poured from the can 5. An environmentally friendly aspect is thus achieved. The can 1 ultimately to be processed as waste will contain no or practically no residues of the original content of the can 1.

The bottom 12 comprises a slot 13 in which the lower edge of the circumferential wall 3 is received. The connection of the bottom 12 with the peripheral wall 3 can be realized in a suitable manner, for example by gluing or ultrasonic welding, or the said APOA hot melt.

The bottom 12 is provided with a part running with a rounding radius 14 from the horizontal bottom surface to the peripheral wall 3, which also contributes to the good discharge of the contents from the can.

Although a preferred embodiment is shown in Figures 1 and 2, the invention is not limited to this embodiment. The top wall and the bottom can be shaped in different ways.

According to the invention, the peripheral wall 3 of the can is made of a laminate which, viewed from the outside in, comprises at least a layer of cardboard, an adhesive layer, a layer of metal foil, and a layer of plastic.

In the preferred embodiment described here, the laminate consists of the following layers, seen from the outside in: 25 - kraft cardboard (300 μημ 200 g / m2) - glue (1.5 g / m2) - kraft cardboard (300 µm, 200 g / m2) ) - glue (1.5 g / m2) - kraft paper (50 g / m2) 30 - glue (1.5 g / m2) - aluminum foil (9 μηι, 24 g / m2) - glue (1.5 g / m2) ) - polypropylene (25 μημ 25 g / m2) 6

For example, the circumferential wall is made by gluing a sheet of aluminum foil to a sheet of polypropylene, and placing this glued assembly around a cylindrical mandrel. The seam. where the ends overlap each other, sealing is done by heating them so that the polypropylene melts. The kraft paper and cardboard layers are then wrapped around it with glue.

The adhesive used is, for example, Euroflex (TM) 2038/4 from EOC Belgium Adhesive Division, an adhesive based on vinyl acetate polymer and polyvinyl alcohol.

The kraft paper and the kraft cardboard ensure the strength of the wall, and the aluminum foil and polypropylene ensure a good seal against air, water and the volatile substances in the paint.

15

Claims (15)

1. Canister comprising a peripheral wall, a first end wall and a second end wall, which can is filled with a liquid, such as paint, with at least 3% volatile organic compounds, and wherein the peripheral wall consists of a laminate, which laminate from outside to seen in at least one layer of cardboard, an adhesive layer, a layer of metal foil, and a layer of plastic. The can according to claim 1, wherein the cardboard is kraft cardboard. A can according to claim 1 or 2, wherein the layer of cardboard is between 300 μιη and 2500 μιη thick, preferably between 400 μιη and 1200 μιη. Can according to claim 1, 2 or 3, wherein the layer of cardboard is made up of several layers of cardboard adhered to each other. 5. Can as claimed in any of the foregoing claims, wherein adhesive layer between cardboard and metal foil is glue or polyethylene. A can according to any one of the preceding claims, wherein the layer of metal foil is aluminum foil. 7. Can as claimed in any of the foregoing claims, wherein the layer of metal foil is between 3 μιη and 50 μιη, preferably between 4 μιη and 20 μιη thick. 8. Can according to any of the preceding claims, wherein the volatile organic compounds comprise one or more substances from the group consisting of toluene, xylene, benzene, turpentine, hexane, thinner, peut, benzene, ketone, ester, glycol ether, alcohol, in particular butyglycol, butyl diglycol, ethyl glycol and methyl glycol. The can according to any one of the preceding claims, wherein the plastic is a plastic that is permanently resistant to the volatile organic compounds, such as a polyolefin such as polypropylene or polyethylene, or polyethylene terephthalate. 10. Can according to any one of the preceding claims, wherein the layer of plastic is between 5 μιη and 100 μιη, preferably between 10 and 50 μιη thick. 11. Can as claimed in any of the foregoing claims, wherein one of the end walls is an upper wall consisting of a ring part with an opening and a cover fitting therein. 12. A can according to any one of the preceding claims, wherein the end walls are made of a plastic, such as polypropylene. A can according to any one of the preceding claims, wherein the end walls are made by injection molding. 14. Canister comprising a peripheral wall, a first end wall and a second end wall, wherein the peripheral wall consists of a laminate, which laminate, viewed from the outside in, comprises at least one layer of cardboard, an adhesive layer, a layer of metal foil, and a layer of plastic, which can is intended to be filled with a liquid, such as paint, with at least 3% volatile organic compounds. 15. A method of manufacturing a can, such as a paint can, comprising providing a peripheral wall, a first end wall and a second end wall, the peripheral wall being made of a laminate, said laminate having at least a layer of cardboard, an adhesive layer, a layer of aluminum foil, and a layer of plastic, and wherein the can is filled with a liquid, such as paint, with at least 3% volatile organic compounds.