EP1438914A1 - Disposable servingware - Google Patents

Abstract

The disposable plate or bowl (1) is of a wood veneer material which has not been treated chemically, and which is shaped in a press without cutting. The edge (2) is bent upwards from the base, with an undulating rim (3) which is formed during pressing. The wood veneer material has a residual moisture content of 4-12%, and the press shaping action is set according to the veneer type and thickness.

Description

The invention relates to a disposable tableware made of wood veneer according to claim 1 and a method for manufacturing the same according to claims 6 or 11.

The invention particularly relates to a disposable tableware in Plate or bowl shape made of non-cutting and chemical untreated plywood with a special shape in the area of the edge of the plate or bowl.

Biodegradable disposable tableware are basically already known. For example, palm leaf plates are commercially available and bowls. They are made from shed leaf sheaths made from palm trees. The leaf sheaths become one of them soaked, washed and finally in heated forms pressed. The material is tough and strong, but has because of the different grain for each leaf attachment always very different colors and patterns wavy, rough and tends to warp.

JP-2001-287721 shows a naturally decomposable tray with wooden components and a process for its production. The tray consists of a core of accordingly molded thermoplastic and biodegradable Resin and wood veneer laminated on both sides. The disadvantage here is that the tray made of different Materials and different layers are what several Process steps and thus a higher manufacturing effort means.

JP-2001-347509 shows a made from wood veneer Container with a bending edge. The wood veneer is chipless manufactured. The container is made by applying heat, Steam and pressure made in one mold. The bending edge has a variety of protruding ribs, but only serve the reinforcement and also not towards the outer edge of the bending edge.

JP-57140145 shows a dinnerware that consists of two layers is constructed. A base layer has a composition a wood pulp, synthetic fibers and resin. Another Layer consists of cherry tree bark. The shape of the Base layer and simultaneous bonding with the cherry tree bark layer done by hot pressing, but without the Use of steam. Finally, the entire surface of the Paint the cutlery with a coat of paint. One along the circumferential bending edge is not available.

The object of the invention is a disposable tableware made of wood veneer, the shape of which in the area of the Plate or bowl shape edge particularly gentle on material has and that is also particularly easy to manufacture, as well specify a process for its manufacture.

This task is accomplished through the combinations of features in the independent Claims 1, 6 and 11 solved.

Wood as a raw material has the disadvantage that it is sensitive reacts to material compression or overstretching. Become disposable dishes in plate or bowl shape with molding presses manufactured, there is particularly in the field of Bending edges pose a special risk of compression or overstretching. That is why the wood veneer becomes wet and warm prepared for the compression molding process. The wood veneer it becomes much more elastic. The solution for material-saving Manufacture of disposable tableware from wood veneer is that their bending edges are along their circumference be provided with a special waveform. Thereby can reduce the risk of defects due to excessive compression be completely avoided in these areas. To for this purpose, the waveform of the bending edge is in scope on the material compression of the wood veneer during the deformation of the raised bending edge. The required Waveform can be essentially derived from the steepness of the Derive bending edge.

It is preferable to produce without cutting and chemically untreated Wood veneer used as the raw material. This Wood veneer is (as required) in a first step by heating or by heating and moistening prepared and in a second step in one Dish shape pressed and dried.

The advantages are that practically all Types of wood can be used, but for cost reasons and in an ecologically meaningful way with us in Europe indigenous and untreated types of wood, such as Beech, birch, maple or walnut, as the sole starting material to be favoured. They are compostable, can but also because of the absence of chemicals be burned. Preferably, non-cutting, So measured or peeled veneers of about 0.4 - 3 mm thickness used. Disposable tableware made of wood veneer moreover a more uniform and beautiful surface as such from palm leaves.

The fineness and quality of the veneer surface can also further improved by suitable pre- or post-treatment become. For example, veneer surfaces can be used beforehand be sanded. But it can also be a post-treatment take place, for example with food-safe waxes, Oils or resins. So that a nicer surface or better moisture resistance can also be achieved.

The procedure can basically be used for different starting qualities of wood veneers. It is suitable is suitable for wet wood veneer in the range of about 40-90% moisture content, dried wood veneer in the range of about 20-40% moisture content and dried wood veneer in the Range of about 4-20% moisture content. The application and the duration of the respective humidification and / or heating must depending on the moisture content of the used wood veneer, the type of wood and the veneer layer thickness respectively.

The lower the moisture content of the wood veneer, the more rather, the pretreatment naturally requires moistening of the wood veneer. It is also possible that the humidification especially in the area of the parts to be deformed Wood veneer. The humidification can, for example by spraying with water vapor or also by complete or partial immersion in boiling water. advantageously, the compression-molded is pressed and dried Object in a single operation. at The drying process can still be partially moistened be abbreviated.

Experiments have shown that if it is not too "high" curved edges (bending edges of low slope) under Humidification can be dispensed with under certain circumstances. In In such cases the preparatory step is not necessary humidification and the process of making the disposable tableware can basically be done in a single step (Heating and press molding). How The procedure mentioned depends essentially on the natural Moisture content of the wood veneer used.

Furthermore, to improve the bending stiffness of the Disposable tableware in the edge areas of the bending edge additional Measures should be provided.

Embodiments of the invention are based on figures explained.

Fig. 1.

ein erfindungsgemässes Wegwerfgeschirr in perspektivischer Darstellung,

Fig. 2

ein Wegwerfgeschirr nach Fig. 1 in einer Ansicht von oben,

Fig. 3a

ein weiteres Wegwerfgeschirr in der Art nach Fig. 1 in einem Schnitt entlang der Linie B - B, und

Fig. 3b

das Wegwerfgeschirr nach Fig. 3a in einem Schnitt entlang der Linie A - A.

Show it

Fig. 1.

a disposable tableware according to the invention in a perspective view,

Fig. 2

1 in a view from above,

Fig. 3a

1 in a section along the line B - B, and

Fig. 3b

3a in a section along the line A - A.

A plate or bowl-shaped disposable tableware 1 according to the figure 1 has a bending edge 2. Under the bending edge 2 is otherwise only one versus a substantially flat one The bottom of the dishes is raised and runs along the circumference Edge to understand what makes the dishes their suitability, e.g. as a dinner plate. The bending edge 2 points a waveform 3 along its circumference.

The waveform 3 is so pronounced that it has a circumference on the material compression or expansion of the wood veneer is coordinated with the deformation of the bending edge.

If an attempt was made to press a previously flat, round veneer panel with an outer circumference U _f into a shape similar to the shell-like shape shown without a wavy circumferential course by press molding, then it can easily be seen that the outer circumference of the raised bending edge ultimately has a circumference U _h that is smaller than U _f . The difference meant an upset that should be avoided. Due to the introduction of the waveform 3, the outer circumference of the bending edge 2 still has the value U _f even after the press molding. The required waveform can thus essentially be derived from the steepness of the bending edge. With very flat plates, only a weak waveform is necessary.

In order to achieve freedom from compression, the stamps are or Therefore, dies of the compression molding tools in the area of the bending edges wavy.

The starting material for the production of a Disposable tableware is usually rectangular veneer. Before further processing, these veneer sheets are made round starting parts punched or cut. In two The main method steps then become the one according to the invention Disposable tableware made. In a first step the wood veneer increases elasticity either only by heating or by moistening and Prepared for heating. In a second process step the wood veneer in a dish form by means of a stamp or Matrices pressed and dried in the same step.

Whether in the first step of the process only warmed up or also moistened and being heated depends, of course, on the Moisture content of the raw materials, but also of the type of wood and the plywood thickness. This essentially does distinguished between wet wood veneers approx. 40-90% moisture content, dried wood veneers with approx. 20-40% moisture content and dried wood veneers with approx. 4-20% moisture content. Wet wood veneer is preferably warmed before being placed in the dishware and is pressed. Dried wood veneer comes first moistened and warmed before being placed in the dishes and is pressed. With dried wood veneers or with certain types of wood one may be sufficient previous heating if the starting material is already sufficient Contains moisture. Both measures (humidification and Heating) serve to make the starting material more elastic make and enable a crack-free and stable deformation. As mentioned, in some cases one is sufficient local humidification in those zones of deformation subject to, or may not even need Moisturize if the edges are only slightly raised there is little deformation.

Example of use:

To produce a disposable tableware made of beech wood veneer with a thickness of 1.5 mm, for example, the starting material is immersed in boiling water for approx. 30 seconds or sprayed with steam on both sides for approx. 45 seconds. The disposable tableware is then pressed in the dish form at 90 ° C for about 1.5-2 minutes and at a pressure of about 15 kg / cm ² . In a finishing process, the edge can be sanded afterwards and a finishing treatment with a food-grade wax, oil or resin can also be carried out.

FIG. 2 shows a disposable tableware 1 according to FIG. 1 in one View from above. A (usually visible) grain 4 of the wood veneer, creating a "Grain direction" that is essentially parallel to a line A - A runs, is defined. "Across the grain" is thus understood as a direction that is essentially parallel runs to a line B - B. Now becomes the disposable tableware 1 a bend around an axis along the grain (A - A), the disposable tableware 1 tends in one particularly stressed danger area 5 (by dotted Lines indicated) to crack formation. Through additional measures however, there may be a risk of cracking in this area can be reduced.

3a shows a further disposable tableware 1 'in the manner of Fig. 1 in a section along the line B - B. Also that Disposable tableware 1 'has a bending edge 2 with which earlier mentioned waveform 3. In an outermost edge area of the bending edge 2 there is no flattening.

FIG. 3b shows the disposable tableware 1 'according to FIG. 3a in one Section along the line A - A. The outermost edge area of the bending edge shows a clear flattening 6. The Flattening 6 serves the bending stiffness in this area of the disposable tableware 1 'and thereby improve the Reduce susceptibility to crack formation in hazardous area 5.

The shape transitions (flattening) advantageously take place 6) the formations of the outermost edge areas between the "Grain direction" and "cross grain direction" continuously, the flattenings 6 can be more or less strong pronounced extent also provided along the entire circumference his.

Another way (not shown) for improvement the bending stiffness is in the hazardous areas 5 install reinforcement. This can for example in the form of an adhesive tape (e.g. paper adhesive tape) or a glue thread (a glue-soaked thread). In principle, such reinforcements can or can also be attached after the pressing process.

It has also been shown that disposable tableware of the type described can also be produced by first glue at least two layers of wood veneer. For example, such a plate can consist of a single plate Veneer sheet with a thickness of 1.5 mm, or else made from two glued veneer sheets, each 0.6 mm thick become.

Claims (12)

Disposable tableware (1, 1 ') in the form of a plate or bowl made of chipless wood veneer, the plate or bowl shape having a bending edge (2), characterized in that the bending edge has a wave shape (3) along the circumference and the wave shape (3 ) of the bending edge (2) is adjusted to the extent of the material compression or the material expansion of the wood veneer when the bending edge is deformed. Disposable tableware (1, 1 ') according to claim 1, characterized in that there is a flattening (6) on the outer edge of the bending edge (2) at least in a danger area (5) which extends essentially transversely to the fiber direction. Disposable tableware (1, 1 ') according to claim 1 or 2, characterized in that a reinforcement of the type of an adhesive tape or a glue thread is present on the outer edge of the bending edge (2) at least in a danger area (5) which extends essentially transversely to the fiber direction is. Disposable tableware (1,1 ') according to one of the claims 1 to 3, characterized in that at least part of the surface of the disposable tableware (1,1') is treated with a food-grade wax, oil or resin. Disposable tableware (1, 1 ') according to one of the claims 1 to 4, characterized in that the wood veneer consists of at least two glued wood veneer layers. A process for the production of a disposable tableware (1, 1 ') in the form of a plate or bowl made of wood veneer according to claim 1, characterized in that the wood veneer is prepared in a first step by heating or by moistening and heating, and pressed in a tableware form in a second step or pressed and dried. A method according to claim 6, characterized in that wet wood veneer in the range of 40-90% moisture content, dried wood veneer in the range 20-40% moisture content or dried wood veneer in the range 4-20% moisture content is used and the application and duration of the humidification and / or heating depending on the moisture content of the wood veneer used, the type of wood and the veneer layer thickness. Method according to claim 7, characterized in that moistening takes place especially in the area of the parts of the wood veneer to be deformed. Method according to one of claims 6 to 8, characterized in that the moistening is carried out by spraying with water vapor or by complete or partial immersion in boiling water. Method according to one of Claims 6 to 9, characterized in that the pressing in the dish form is carried out with a die or a stamp, the dish shape with the die or the stamp in the region of a bending edge (2) along the circumference of the bending edge (2) has a wave shape (3) which is matched in scope to the local material compression or overextension of the wood veneer when the bending edge (2) is deformed during the pressing. A process for the production of a disposable tableware (1, 1 ') in the form of a plate or bowl made of wood veneer according to claim 1, characterized in that the wood veneer is pressed into a tableware form, a wood veneer with a moisture content of 4 - 12% being used and the extent the deformation during pressing is matched to the type and thickness of the wood veneer. Method according to claim 11, characterized in that the pressing takes place in a dish form with a die or a stamp, the dish shape with the die or the stamp having a wave shape (3) in the region of a bending edge (2) along the circumference of the bending edge (2) ), the extent of which is matched to the local material compression or overstretching of the wood veneer when the bending edge (2) is deformed during the pressing.

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