EP0842094B1 - Wooden container - Google Patents

Abstract

PCT No. PCT/FR96/00870 Sec. 371 Date Apr. 24, 1998 Sec. 102(e) Date Apr. 24, 1998 PCT Filed Jun. 7, 1996 PCT Pub. No. WO97/02990 PCT Pub. Date Jan. 30, 1997A method for preparing a food product to be cooked or reheated in a thermal oven, wherein the food is placed in a container made of a single peeled-wood blank that is folded and assembled at the folded side walls thereof. A tray particularly suitable for use in the method is also disclosed.

Description

The present invention relates to packaging of food products, in particular products ready to cook or reheat, as well as trays intended in particular for such an application.

Ready-to-cook products are usually packaged in shaped packages with aluminum foil or a plastic bag plastic. With the appearance of microwave ovens, metal packaging tends to disappear at profit from plastic packaging. Such packaging are certainly suitable for cooking or reheating, but gives the product a presentation industrial unsatisfactory.

It has also been proposed in the state of the technical packaging of ready meals when reheated in a microwave only. This packaging has been described in the German patent OS3812118. It is an agglomerated wooden container made of cup-shaped, covered with an internal coating polyethylene or polyester.

We also proposed in the patent English 707,453 a bread baking process in a cardboard or wooden container.

It appeared surprisingly that a packed in a folded wooden tray and assembled makes it possible to cook a food product in a traditional baker's oven. He is in particular appeared that such conditioning was suitable for presentation and baking of bread dough or brioche, cakes, etc., and more generally any food product requiring cooking of more than thirty minutes in a thermal oven, at temperatures above 200 ° C or even 250 ° C.

The object of the present invention is first place to offer a packaging process combining a traditional aspect before use, and the possibility of forming the baking mold allowing the use of a thermal oven. The invention provides a packaging method further comprising the advantage of a low manufacturing cost and does not requiring no high investment for the industrial production, unlike containers in molded wood described in the aforementioned German patent.

To this end, the invention relates to a method packaging for food products can be cooked in a thermal oven, consisting in introducing the food product in the state uncooked dough, such as bread dough, brioche or cake or other pastries in a tray formed by folding and assembling a cut having a central part forming the bottom of the tray, cut or not, extended at two opposite ends by two sides separated from the central part by lines pre-grooved, and by the two other opposite ends by faces separated from the central part by pre-grooved lines extended laterally by connecting lugs separated from the faces by lines pre-cooked, the dough thus conditioned in its tray made of wood to be baked in an oven thermal.

According to a first variant, the assembly side walls is made by stapling.

According to a second preferred variant, the side walls are assembled by bonding with cyanoacrylate type glue. This guy is particularly well suited for reasons which will be explained in the following, and due to the heat resistance, unlike other adhesives industrial products such as hot-melt adhesives.

According to a preferred embodiment, the food product is introduced into the container the state of uncooked dough, the dough being intended to be cooked in a thermal oven.

Alternatively, a sheet of paper cooking or a fatty substance is interposed between the tray and food product to avoid adhesion of the dough on the tray at the time of cooking.

Another object of the invention is to offer trays that can be put in work for the aforementioned conditioning process.

We know in the state of the art of many variants of wooden trays unfolded. The best known trays are made by interlacing of small width strips, connected by stapling. Such trays have a unattractive appearance and suitable for uses banal transport and storage. Interest main of this type of tray is its very low cost price.

When looking for a more presentation nice, we also proposed in the state of technique of making trays by cutting a unrolled wood sheet and stapling of the faces side.

Stapling is for Man of Profession almost the only assembly solution compatible with mass production, involving working with wood coming directly of the unwinding station without it being economically possible to dry before using.

The stapling, however, presents several disadvantages for trays intended for use food. First, the staples are not inert and may rust, causing the denaturing of the food contained in the tray. Through elsewhere, staples improperly installed, or coming off for various reasons, may mix with the product food contained in the tray, and present then serious risks if swallowed.

We have certainly proposed in patent FR-A-2240633 to make a tray by gluing by distributing glue on the side flaps, to join them between them. The use of glue, however, poses many problems with industrial production of trays, with short manufacturing times. In indeed, the glues traditionally used for glued wood are wood glues requiring the prolonged maintenance (approximately 24 hours) of pressing the assembled faces, before the socket is sufficient.

We also know the use of glue hot-melt whose application requires costly techniques and dispensing devices complex, requiring permanent maintenance and which can only be applied on dry wood.

The skilled person who would be brought to take an interest in a bonding solution would encounter significant difficulties for the implementation industrial work.

None of the prior art documents would lead to the use of one-component adhesives. At on the contrary, if he considered using such a glue, the teaching of the prior art would lead him to rule out such a solution for the application on unrolled wood that has not been dried prior.

Indeed, the German patent DE-A-3421360 by example describes a process for bonding porous surfaces or hydrophilic, indicating that such a cyanoacrylate is poorly suited to this type of surface, without treatment prior. This document states that it is necessary to "glue" the glue to be able to use it.

Another document, the English patent GB1123360 explains that the traces of humidity are likely to reduce the stability or effectiveness of the adhesive material. The state of the art not only does not suggest the use of cyanoacrylate adhesives for the assembly of non-dried peeled wood, but still contains such indications as even if the skilled tradesman would have been interested, he would have set aside.

The object of the invention is to remedy the disadvantages of stapled trays by offering a tray compatible with industrial manufacturing in high speed, and not presenting the risks of trays of the prior art.

To this end, the tray according to the invention consists of a cut of unwound unrolled wood having a central part and by extensions side assembled by gluing the extensions side with cyanoacrylate type glue.

Preferably, the lateral extensions are bonded using an adhesive monocomponent ethyl cyanoacrylate. So surprisingly, such adhesives have a very good grip fast when used with peeled wood not dried. Typically, the relative humidity level of the unsealed peeled wood is between 20 and 50%.

Advantageously, the cut presents a central part forming the bottom of the tray, cut out or not, extended at two opposite ends by two sides separated from the central part by pre-grooved lines, and at the other two ends opposite by sides separated from the central part by pre-grooved lines and extended laterally by legs connection separated from the faces by lines prérainées.

According to an advantageous embodiment, the width of the base of the faces extending the part lower is slightly less than the dimension of the central part measured in the same direction of so that the shaped tray has hollow corners.

This embodiment allows the expansion of the product contained in the tray, which may be interesting for products such as dough Brioche. The tray filled with dough can be directly introduced into the furnace, and the expansion of the dough will form "ears" overflowing with openings at four corners.

According to another embodiment, two at least opposite sides are substantially shaped trapezoidal so that the tray shape has a substantially frustoconical shape authorizing stacking of empty trays.

According to another variant, two faces opposite have holes to receive nipples complementary laterally extending a cut forming a transverse partition parallel to the bottom for form a cover, or perpendicular to the bottom to form a separation.

The invention also relates to a method of manufacture of a tray, especially for products food, by folding a cut having a central part and by lateral extensions, formed in a sheet of peeled wood, preferably poplar wood, and by connecting extensions lateral, characterized in that the connection between two lateral extensions is formed by gluing using one-component ethyl cyanoacrylate adhesive applied on unseasoned peeled wood, and by a pressure applied to the glued surfaces during a duration less than 10 seconds. Preferably, the pressure on the glued surfaces is more than 20 kilograms.

Surprisingly, such adhesives which are deemed to require careful preparation surfaces to which they are applied, exhibit improved performance when applied on un-dried or prepared unrolled wood. The improvement in performance concerns in particular obtaining a much faster grip, and notably significantly faster than on products dried.

Advantageously, the adhesive is applied monocomponent ethyl cyanoacrylate in a plurality of flat cutting area using a head dispenser and in what you apply immediately after normal pressures on the glued areas using of a shaping mold.

Preferably, apply the adhesive monocomponent ethyl cyanoacrylate on peeled wood not dried and a pressure of more than 20 is exerted kilograms normally to the glued areas during a duration between 2 and 5 seconds.

The invention also relates to a method of packaging of a ready-to-cook food product or to be reheated, characterized in that it is prepared in a tray according to the invention.

According to a particular mode of implementation, we partially fill the tray with a paste ready to cook.

• la figure 1 représente une vue de face de la découpe ;
• les figures 2 et 3 représentent, à une échelle réduite, des vues de faces de découpe formant respectivement une cloison transversale et un couvercle;
• la figure 4 représente une vue en perspective d'un exemple de réalisation d'une barquette selon l'invention ;
• la figure 5 représente une vue de face d'une variante de découpe ;
• la figure 6 représente un exemple de courbe de performance de l'adhésif en fonction de l'humidité du matériau ;
• la figure 7 représente un exemple de courbe de performance de l'adhésif en fonction de la durée du collage et de l'humidité relative du matériau ;
• la figure 8 représente une vue de face d'une autre variante de découpe ;
• la figure 9 représente une vue de face d'une variante de couvercle.

The invention will be better understood on reading the description of a nonlimiting exemplary embodiment which follows, referring to the appended drawings in which:

• Figure 1 shows a front view of the blank;
• Figures 2 and 3 show, on a reduced scale, views of cutting faces respectively forming a transverse partition and a cover;
• FIG. 4 represents a perspective view of an exemplary embodiment of a tray according to the invention;
• FIG. 5 represents a front view of an alternative cutting;
• FIG. 6 represents an example of a performance curve for the adhesive as a function of the humidity of the material;
• FIG. 7 represents an example of the performance curve of the adhesive as a function of the duration of the bonding and of the relative humidity of the material;
• FIG. 8 represents a front view of another variant of cutting;
• Figure 9 shows a front view of a variant cover.

Figure 1 shows a front view of a nonlimiting example of cutting for the realization of a tray according to the invention. She is cut out in a poplar leaf peeled from the unwinding installation. Cutting is done using of a matrix for example. This matrix includes sharp and non-sharp areas intended to form the prérainé lines then constituting joints.

The cutout has a central part (1) forming the bottom of the tray. This central part (1) can be full or cut to allow the flow of juice or liquids for example. This central part (1) is extended on two opposite edges by symmetrical faces (2, 3) and on the other two edges opposite by two other faces (4, 5).

The two faces (2, 3) constitute the small sides of the tray after shaping. They have a substantially trapezoidal shape, with a slightly narrower base than the central part (1). Pre-drilled lines (12, 13) facilitate the folding of these faces (2, 3) relative to the central part (1).

The other two faces (4, 5) constitute the large sides of the tray after shaping. They have a zone of substantially trapezoidal shape, their base being a little shorter than the length of the central part (1). The trapezoidal area is extended by lugs (6, 7, 8, 9) in the form of ears. They are approximately symmetrical with respect to a midline (22, 23, 24, 25) which will be, after setting shape of the tray, parallel to the lower edge of the face (2, 3), and the prérainée line (12, 13).

Preaine lines (10,11) facilitate the folding of these faces (4, 5) relative to the part central (1). Likewise, pre-worked lines (14 to 17) facilitate the folding of the legs (6 to 9).

The faces (4, 5) also have holes. These holes (18, 19, 20) are intended to receive lugs extending a cover, or (holes (20, 21)) lugs extending a partition wall. The Figures 2 and 3 show, on a reduced scale, views of cutting faces respectively forming a transverse partition and a cover. They are trained by cutting from an unrolled sheet of wood, or another elastically deformable material, and have nipples (26 to 31) which can be accommodated in the holes (18 to 21). The stiffness of the material ensures maintaining the partition or cover in position transverse, thanks to the cooperation between the nipples and the holes.

The tray is shown in Figure 4 in perspective view.

Adhesive dots (32) are deposited on the inner surface of the side legs (6 to 9) visible in Figure 1.

Immediately after removing the adhesive, the cutting is introduced into a shaping press comprising a matrix whose section corresponds substantially on the surface of the central part (1) and a counter-matrix ensuring the folding of the faces (2 to 5) and the folding of the lateral legs (6 to 9). The side tabs (6, 7) of the face (4) are folded down on the faces (2,3), and the lateral tabs (8, 9) of the face (5) are then folded over the first legs (6, 7).

FIG. 5 represents a front view of a cutting variant. It differs from cutting represented in figure 1 by the position of the lines predominantly.

The side faces (4, 5) are not delimited from the central part by prérainé lines. So when formatting, the tray will have curved surfaces. The paws lateral (7 to 9) are separated from the lateral faces (4, 5) by a pair of pre-marked lines (40, 41) for facilitate folding and allow the formation of lines curves with relatively small radius of curvature.

Similarly, the faces (2, 3) are separated from the central part (1) by two predetermined lines (42, 43) substantially parallel.

FIG. 6 represents an example of an adhesive performance curve as a function of the humidity of the material, measured using a humidity controller whose reading range is between 4% and 60% of relative humidity, with an accuracy of 0.5%. The experiment was carried out with poplar test pieces unrolled with different degrees of humidity. The humidity level was adjusted by partial drying, or on the contrary by re-humidification of the test pieces. Two 10 cm ² strips were bonded using an ethyl cyanoacrylate type adhesive. A drop was deposited on one of the surfaces of one of the strips with a pipette whose outlet section is 1 mm, and a pressure of 10 kg was exerted perpendicular to the surface of the strips for a fixed time of 5 seconds.

The slats were then subjected to a traction in a direction perpendicular to the area bonding, increasing the tensile force up to the separation of the two lamellae. Tensile force exercised at the time of the uprooting was noted, in order to allow the drawing of a reproduced curve schematically in Figure 6. It should be noted that under certain conditions of residual humidity and docking time, the shear strength of the adhesive is far superior to the resistance to tensile test pieces. In this case, there is destruction of the test piece before takeoff.

The shear strength curve depending on the humidity of the material thus determined has a maximum value. This maximum value roughly corresponds to the state of fresh wood coming to be unfolded.

Figure 7 shows an example of a network adhesive performance curves as a function of the duration of bonding. The experiment was carried out with poplar test pieces peeled with different humidity degrees.

We changed the duration of the period during which we exert constant pressure on the test tube, just after docking. We observed that for humidity levels corresponding to wood freshly unwound, for example wood from poplar, it is possible to reduce this duration without damage to the bonding strength.

Figure 8 shows a view of the cutout for the realization of a variant of tray. The cutout has two pre-worked lines (40, 41) parallel to the median axis (42) and extending over the three side faces of the cutout. No line prérainée does not delimit the two other edges perpendicular to the central part (1).

Two other prérainé lines are divided into three segments. The central segment (44, 47) is parallel to the median axis (42). The end segments (43, 45, 46, 48) diverge and form an angle of approximately 10 ° relative to the median axis (42). The surfaces (48, 49, 50, 51) between the prérainé lines form side panels giving the tray a shape polygonal. These surfaces present near their outer edge of the oblong cutouts (52 to 56) of which the main axis is oriented perpendicular to the axis median (42).

These cutouts are intended to receive ears (57 to 60) provided at each corner of the cover of which an example of cutting is shown in figure 9. These ears extend beyond the edges sides of the cover to form protrusions protruding. The cross section of these ears (57, 60) is substantially also along the length of the axis principal of oblong cuts (52 to 56). Lid can be placed on the tray by deformation elastic. The ears then come to lodge in the cuts. When the cover returns to its planar shape rest, the ears lock the cover on the tray. The cover can nevertheless be removed by elastically deforming.

Claims (13)

1. Packaging process for food products that may be baked in a thermal oven, consisting of inserting the food product as unbaked dough, for example for making bread, buns or cakes or other Viennese pastry in a tray formed by folding and assembling a cutout with a central part forming the bottom of the tray, cutout or not cutout, extended at two opposite ends by two faces separated from the central part by preformed grooves, and at the other two opposite ends by faces separated from the central part by preformed grooves and extended laterally by connection tabs separated from the faces by preformed grooves, the dough thus packaged in its wood tray being intended to be baked in a thermal oven.
2. Packaging process according to claim 1, characterized in that the side walls are assembled by stapling.
3. Packaging process according to claim 1, characterized in that the side walls are assembled by gluing with a cyonoacrylate type glue.
4. Tray for packaging unbaked dough, for example for making bread, buns or cakes or other Viennese pastry in a thermal oven, characterized in that it is composed of an unwound wood cutout with a central part (1) and side extensions assembled by gluing using a cyanoacrylate type glue.
5. Tray according to claim 4, characterized in that the side extensions are bonded by gluing with a single component ethyl cyanoacrylate type adhesive.
6. Tray according to claim 4 or 5, characterized in that the cutout has a central part forming the bottom of the tray, cutout or not cutout, extended at the two opposite ends by two faces separated from the central part by preformed grooves, and at the two opposite ends by faces separated from the central part by preformed grooves and extended laterally by connection tabs separated from the faces by preformed grooves.
7. Tray according to claim 6, characterized in that the width of the bottom of the faces extending the lower part is slightly less than the dimension of the central part measured along the same direction such that the shaped tray has recessed corners.
8. Tray according to claim 6 or 7, characterized in that at least the two opposite faces are approximately trapezoidal, such that the shape of the shaped tray is approximately the shape of a truncated cone so that empty trays can be stacked.
9. Tray according to any one of claims 4 to 8, characterized in that holes are formed in the two opposite faces into which complementary studs can fit, creating a lateral extension to a cutout forming a transverse partition parallel to the bottom to form a cover, or perpendicular to the bottom to form a separation.
10. Manufacturing process for a tray according to claim 4 by folding a cutout with a central part and with side extensions, formed in a sheet of unwound wood, preferably poplar, and connected to lateral extensions, characterized in that the bond between two lateral extensions is formed by gluing using a single component ethyl cyanoacrylate adhesive applied on the undried peeled wood, and by applied pressure on the glued surfaces for less than 10 seconds.
11. Process for manufacturing a tray according to claim 10, characterized in that the single component ethyl cyanoacrylate adhesive is applied in several areas on the flat cutout by means of a distribution head, and that normal pressures are then immediately applied on the glued areas using a shaping mold.
12. Process for manufacturing a tray according to claim 10 or 11, characterized in that the single component ethyl cyanoacrylate adhesive is applied on the undried peeled wood, and that a pressure exceeding 10 kilograms is applied on the glued surfaces for less than 10 seconds.
13. Process for manufacturing a tray according to claim 12, characterized in that normal pressure is applied on the glued areas for between 2 and 5 seconds.

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