WO2010052371A1

WO2010052371A1 - Disposable service items

Info

Publication number: WO2010052371A1
Application number: PCT/FI2009/050888
Authority: WO
Inventors: Jukka RÅBACK; Marko Pudas; Johanna Lehtinen; Matti MÄNTYSALO; Magnus Johansson
Original assignee: Raaback Jukka; Marko Pudas; Johanna Lehtinen; Maentysalo Matti; Magnus Johansson
Priority date: 2008-11-04
Filing date: 2009-11-04
Publication date: 2010-05-14
Also published as: FI20086048A0

Abstract

A disposable food service item according to the present invention typically consists essentially of a biodegradable material (1) and comprises a first surface intended to be in contact with food, and a second surface opposite to said first surface, wherein said first surface and a proportion of said second surface are coated with an amount of silicone rubber material (2).

Description

DISPOSABLE SERVICE ITEMS

The present invention relates to disposable service items. BACKGROUND OF THE INVENTION Disposable cups and plates are used in large quantities all over the world. The resulting waste amount is thus quite considerable. It would therefore be advantageous to have disposable cups and plates that would easily decompose in a compost, in a landfill site or in nature.

One problem associated with most of the known biodegradable polymers is that their softening temperature is below the temperature of hot beverages. The containers do thus not withstand the heat of the food but start to soften or even to decompose. One solution to the waste problem has been the use of paper cups, but they have the problem that they soften if the liquid is held in them for an extended period of time, such as several hours. Publication JP 11 115 964 presents a container made of grain such as rice or corn, and coated with a layer of polymer such as polyethylene or polystyrene. This solution however has the disadvantage that the outer side of the container may be sticky and thus unpleasant to use, and moreover, if the container is used for drinking, the edge of the cup may give some additional taste to the beverage. Document US 5,296,282 discloses degradable coated articles consisting of a biodegradable material which one side has been coated with non-biodegradable material (polyethylene) and a part of the other side is coated with nonbiodegradable material (fluoropolymer). Document JP 2205545 presents a paper container which one side has been coated with an olefin layer comprising added silicone resin. The aim of this coating is to improve the release characteristics of the container.

OBJECT AND SUMMARY OF THE INVENTION

An object of the present invention is to provide a disposable service item, such as a cup or a plate that is essentially biodegradable. The service item should be able to contain for example hot food or beverages for at least several days, and pleasant to use for the end-user, i.e. eater. The service item should also be easy to manufacture, such as by injection moulding. A disposable service item according to the present invention typically consists essentially of a biodegradable material and comprises a first surface intended to be in contact with food, and a second surface opposite to said first surface, wherein said first surface and a proportion of said second surface are coated with an amount of silicon rubber material.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 shows a first embodiment of a disposable service item according to the present invention.

Figure 2 shows a second embodiment of a disposable service item according to the present invention.

Figure 3 shows a third embodiment of a disposable service item according to the present invention.

Figure 4 shows a fourth embodiment of a disposable service item according to the present invention.

Figure 5 shows a fifth embodiment of a disposable service item according to the present invention.

Figure 6 shows a sixth embodiment of a disposable service item according to the present invention.

Figure 7 shows a seventh embodiment of a disposable service item according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A disposable service item according to the present invention typically consists essentially of a biodegradable material and comprises a first surface intended to be in contact with food, and a second surface opposite to said first surface, wherein said first surface and a proportion of said second surface are coated with an amount of silicone rubber material.

The present invention thus provides for a service item that is disposable and has the rigidity of traditional plastic food service items (such as cups). Moreover, the service item according to the present invention is suitable for hot beverages and food and also alcohol containing beverages, unlike traditional paper cups, for example. By food it is thus also meant different beverages.

The service item consists essentially of a biodegradable material. Thus, a biodegradable and disposable item can be obtained, that is still pleasant and safe for use for the eater. The advantage of coating the first surface, i.e. the inside of the item is that the food is not in contact with the biodegradable material, which contact would start the decomposition process immediately. On the other hand, a coating on a proportion of the second surface, i.e. the outside of the item prevents the user's lips for example, to be in contact with the biodegradable material, as this contact would have the same effect mentioned above. Moreover, it is pleasant for the user to drink a beverage without having an additional taste from the biodegradable material.

The item according to the present invention thus retains its original shape and rigidity even over times up to weeks, as the coating prevents the biodegradable material to become into contact with the food or beverage.

The silicon rubber material may be biodegradable or not. By biodegradable material is here meant material that eventually degrade completely into organic compounds that can be used by microorganisms and do not cause any harm to the environment.

In the service item according to the invention, the first surface and a proportion of the second surface of the item are coated with an amount of a non-biodegradable silicone rubber material. The silicone rubber material is preferably selected such that its decompose or melting temperature is over 100 ⁰C, preferably over 200 ⁰C and typically 250 - 350 ⁰C.

The silicone rubber material can either adhere to the biodegradable material naturally, or the adhesion may be enhanced by using an appropriate primer or adhesion promoting agent. The adhesion may also be enhanced by appropriate treatment of the biodegradable material, such as surface treatment or grafting. Furthermore the adhesion is promoted by rigidity of biodegradable material surface and its pores where silicone rubber can flow during the manufacture process.

An advantage of the use of silicone rubber material is that it is an inert material that does not form any harmful gases or fumes when it is subjected to heating. Moreover, it is quite well decomposed by UV-light, i.e. its destruction, especially in this application where it is used as a thin film, is quite fast in the compost or similar.

When biodegradable material is used, the partial coating of the second surface of the item has the further advantage that as part of the surface is not coated, this part, once the decomposition is supposed to start, can be in direct contact with the surrounding atmosphere and the decomposition can start immediately. Once the biodegradable material has degraded, only the thin film of coating remains. Small mechanical forces will break this film in ambient conditions. Preferably, the coating material is selected such that it decomposes under the effect of ozone or light (such as UV-light). As the film is thin, it may also be shredded into small pieces by small mechanical forces, thus increasing its speed of degradation.

Said biodegradable material may be selected from the group consisting of biodegradable polymer materials, cellulose, seeds, paper, board and mixtures thereof. By seeds, it is meant material such as corn, corn starch, rice, rice starch etc. The biodegradable polymer material may be any suitable materials, such as polylactic acid polymers and copolymers, polyhydroxybutyrates and its derivatives, polyvinyl alcohols, polyanhydhdes and copolymers and mixtures thereof.

According to another embodiment, the service item consists essentially of a material having a filler content of more than 50 % (per weight or volume, depending on the filler material used). The filler material can be for example talc, calcite or recycled cellulose fibres. The amount of the filler material can be for example more than 50 %, over 55 %, 55-80 %, 60-90 % or any other amount. It is also possible to make a disposable service item that consists essentially of other than biodegradable material having a high filler content, wherein it is also possible to then use as a coating a biodegradable material, as long as it is selected such that it supports a short contact with food or beverage. The biodegradable material can be for example a polymer that withstands these conditions and can easily be applied in manufacturing process, such as polylactic acid polymers and copolymers, polyhydroxybutyrates and its derivatives, polyvinyl alcohols, polyanhydhdes and copolymers and mixtures thereof.

According to an embodiment of the invention, the non-biodegradable silicone rubber material has low viscosity. One example of a suitable material is Elastosil® RT 601 by Wacker Chemie Ag. Another FDA accepted alternative is DEHESIVE® 430 and DEHESIVE® 440. Some other examples of non-biodegradable polymers suitable for use in the present invention, together with the silicone rubber material, are unsaturated rubbers, such as natural rubber, polyisoprene, copolymers of isobutylene and isoprene (butyl rubbers), halogenated copolymers of isobutylene and isoprene, polybutadiene, copolymers of polystyrene and polybutadiene (styrene butadiene rubbers), copolymers of polybutadiene and acrylonitrile (nitrile rubbers), hydrogenated copolymers of polybutadiene and acrylonitrile, chloroprene rubber. Other examples are saturated rubbers, such as copolymers of ethylene and propylene (ethylene propylene rubbers), ethylene propylene diene rubbers, epichlorohydrin rubber, polyacrylic rubber, fluorosilicone rubber, fluoroelastomers, perfluoroelastomers, polyether block amides, chlorosulfonated polyethylene, ethylene vinyl acetate. Yet further possible elastomers are polyurethanes and alkoxysilicones.

The service item according to the present invention has a coating on a proportion of its second surface, i.e. the surface that is not in contact with food. According to one embodiment, this proportion is 1 -80 % of the total of the second surface. Said proportion can also be 5-50 % or 10-25 %. The proportion can vary from 1 , 2, 5, 7, 10, 11 , 15, 20 or 25% up to 40, 50, 55, 70 or 85 %. The proportion of the second surface that is coated is preferably the proportion where the user touches the item with lips or moist hands, such as in the case of a cup, the upper edges of the cup.

According to another embodiment, the non-biodegradable material coating extends over the edges of the item for a distance a. This distance can be for example from 0.5 - 7 cm, preferably 1 - 3 cm, or 1 - 15 % of the total height of the item, preferably 1 - 10 % of the total height of the item.

When the service item according to the present invention is left to decompose in a compost or in nature, only the thin layer of silicone rubber material is left after a few weeks or months, when the biodegradable material has degraded. Silicone rubber materials typically decompose under the action of ozone or UV-light from outside environment. The layer being so thin, also small mechanical forces such as animals or wind can break the residue film. The film is also harmless to environment.

According to one embodiment of the invention, a service item is manufactured by injection moulding or by any other suitable method such as deep drawing, sheet extrusion, thermoforming, or casting. At the same time or in a later step, one surface of the item, typically the surface that is intended to be in contact with the food, for example the inner surface of a cup, is coated with a thin layer of a non- biodegradable silicone rubber material. The thickness of the coating can be for example 0.0001 - 2 mm, preferably 0.001 - 0.1 mm, more preferably 0.002 - 0.02 mm.

The coating of this surface can be made by any appropriate method known to a person skilled in the art. One example is to apply the coating material in liquid from, or to integrate it in the injection moulding process.

The disposable service item according to the present invention may also further comprise, on the second surface, an isolating layer on at least part of the surface. The aim of this isolating layer is to prevent the user from burning or freezing fingers while holding the service item. This layer is preferably made of such a material that the isolating layer can be manufactured at the same time as the food service item. The layer may also be made of an isolating material such as rubber.

According to one embodiment of the invention, the isolating layer is made within the mould, i.e. the mould makes at least a part of the wall having a double structure with air between the layers. Air between layers is well known to isolate heat and cold effectively. According to another embodiment, the second surface of the service item, for example the outer surface of a cup, can have an additional layer of material attached to it in a stage after the production of the service item itself. The additional layer is preferably attached in such a way that some space remains between the layers. Most preferably this isolating layer is made of a biodegradable material.

The service item according to the present invention can thus have the rigidity and the strength of a traditional plastic food service item as well as the thermally isolating structure.

The disposable service item according to the present invention can be any item required, such as a food service item. According to one embodiment of the invention, it is selected from the group consisting of plates, cups, trays, containers and straws. In the case of straws, the inside as well as the outside of both ends of the straw can be coated according to the present invention. The item can also be for example a package for ice cream or candy or a package for take away food. The item according to the present invention can also be a disposable waste container, for example for use in breakfast services for egg shells etc. A disposable waste container according to this invention can thus be such that it stands wet or liquid contents but is also decomposing. The item can also be a medical device such as kidney dish, where the content may be liquid, or the content may not be in contact of the fibres of the material (i.e, stay clean and sterile).

DETAILED DESCRIPTION OF THE DRAWING

Figure 1 shows a first embodiment of a disposable service item according to the present invention. In this embodiment, the disposable service item is a cup having its body 1 , i.e. the essential component of the cup made of a biodegradable polymer. The body 1 is coated, on the inner surface of the cup with a layer 2 of a non-biodegradable material. The layer 2 extends over the edge of the cup in order to protect the border of the cup from moisture. Figure 2 shows a second embodiment of a disposable service item according to the present invention, where the service item has a different shape.

Figure 3 shows a third embodiment of a disposable service item according to the present invention. In this embodiment, the service item further comprises an isolating layer 3 arranged around the item on its bottom and a part of its sides.

Figure 4 shows a fourth embodiment of a disposable service item according to the present invention. In this embodiment the isolating layer is formed from the same material as the body of the cup. The material of the body is folded at the edge of the cup to form the isolating layer. Figure 5 shows a fifth embodiment of a disposable service item according to the present invention with a similar idea as shown in Figure 4.

Figures 6 and 7 show the sixth and seventh embodiments of a disposable service item according to the present invention, and more particularly two different ways of manufacturing a disposable cup according to the present invention. In Figure 6, the cup is coated on its inner side with a coating 2 according to the present invention. In the parts where the parts of the cup are attached to each other, the sealing is achieved by adhesive or conventional hot wax 4. In Figure 7, another way of manufacturing a cup is presented, with a so-called curling bottom. Here the sealing is also made by adhesive or conventional hot wax 4. These solutions enable the producer to avoid using special adhesives to attach silicon rubber material to itself.

As is evident, the proportions and thicknesses of the layers and body parts in the Figures are not in scale. EXPERIMENTAL PART

The following Examples were carried out in order to test a few materials. A coating of RT601 silicone polymer was applied on cardboard. Test samples consisted of 10 x 10 cm smooth cardboard pieces, and the coating was applied by different methods, namely by doctoring method, by roller coating or by dipping.

In order to evaluate the water absorbance of the samples, a COBB sizing test was used according to standard practice in the field (according to standards TAPPI T441 -ISO 535-NF Q-03-018-NF Q-03-035-FEFCO 7-DIN 53132-EN20535-SCAN P12. The lower the COBB120 result is, the less the sample absorbs water. The results are given in Table 1 below. A typical value for COBB120 for currently used cardboard containers is 0.7 and thus it can be seen that the coating according to the present invention improves the results.

Claims

1. A disposable service item consisting essentially of a biodegradable material and comprising

- a first surface intended to be in contact with food, and - a second surface opposite to said first surface, wherein said first surface and a proportion of said second surface are coated with an amount of silicon rubber material.

2. A disposable service item according to claim 1 , characterised in that said biodegradable material is selected from the group consisting of biodegradable polymer materials, cellulose, seeds, paper, board and mixtures thereof.

3. A disposable service item according to any of the previous claims, characterised in that the biodegradable polymer material is selected from the group consisting of polylactic acid polymers and copolymers, polyhydroxybutyrates and its derivatives, polyvinyl alcohols, polyanhydhdes and copolymers and mixtures thereof.

4. A disposable service item according to any of the previous claims, characterised in that the food service item consists essentially of a material having a filler content of more than 50 %.

5. A disposable service item according to any of the previous claims, characterised in that said proportion of said second surface is 1-80 %.

6. A disposable service item according to claim 5, characterised in that the proportion is 5-50 %.

7. A disposable service item according to any of the previous claims, characterised in that it further comprises, on at least part of its second surface, an isolating layer.

8. A disposable service item according to any of the previous claims, characterised in that it is a disposable food service item selected from the group consisting of plates, cups, trays, containers and straws.

9. A disposable service item according to any of the previous claims, characterised in that it is a disposable waste container.