FR2584891A1 - Cultivation plate made of thermoformed material for cultivating seedlings - Google Patents

Abstract

The present invention relates to a cultivation plate made of thermoformed material comprising cells which are open at the top and closed individually at the bottom by flat bottoms situated in one and the same plane. This cultivation plate is characterised in that it is rigidified by a sheet 8 of small thickness made of a rigid or semi-rigid non-extensible material which adheres to the bottoms 3 of the cells 1.

Description

 The present invention relates to a culture plate made of thermoformed material for growing young plants.

 The production of young seedlings, horticultural, nursery or forest plants is done more and more in honeycomb cultures. The most commonly used material for making these plates is expanded polystyrene. If the advantages of this material are numerous, namely ease of molding, lightness, rigidity, high mold cost, allowing many models to be easily created, its disadvantages are also numerous, namely the high cost of the material, low durability, large size due to the obligation for this type of material to have relatively thick walls, finally penetration of the roots into the material itself, causing damage during unloading .

 Another material used is injected plastic.

The advantages of the plates manufactured with this type of material are the solidity, the rigidity, the durability, the presence of smooth walls impenetrable by the roots. The very high price, on the other hand, makes it compulsory to have multiple reuse to make them profitable, in any case obliging the professional who employs them to make a significant investment.

 The sheets of thermoformed material, compared to the other types of aforementioned manufacturing, offer the advantages according to low manufacturing cost allowing single use, smooth walls and impenetrabies by the Racinese, reduced bulk, relatively low cost. However, a major drawback currently makes their marginal production their lack of rigidity. If it is possible, for small dimensions of plates, to reinforce the holding by grooves and particular forms, all these devices become very expensive and illusory as soon as one wants to produce piaques around the currently current dimensions of 30 x 50 cm.

 The present invention aims to remedy these drawbacks by providing culture plates made of ther eriform material, inexpensive and rigid.

 To this end, this culture plate made of thermoformed material comprising cells open at the top and closed individually, at the bottom, by planar bottoms located in the same plane, is characterized in that it is stiffened by a thin sheet. , in a rigid or semi-rigid non-stretchable material, adhering to the bottoms of the cells.

 The sheet of non-stretchable material, rigid or semi-rigid, can be constituted by a plastic film or by a thermoformed or injected plastic plate, this plate then ensuring, in addition to the rigidity, the accumulation of a some water reserve.

Because the sheet is made of a non-stretchable material, this sheet ensures the non-deformability of the culture plate during the handling thereof.
The sheet can be fixed to the bottom of the cells by any suitable means, in particular by gluing or welding.

Various embodiments of the present invention will be described below, by way of non-limiting examples, with reference to the appended drawing in which
FIG. 1 is a view in vertical section of a culture plate made of thermoformed material according to the invention.

 Figures 2 and 3 are schematic sectional views illustrating the resistance of the culture plate to forces exerted on it.

 Figure 4 is a sectional view of an alternative embodiment of a culture medium.

 Figure 5 is a sectional view of another alternative embodiment.

 The culture plate according to the invention represented in FIG. I comprises, at its upper part, a thermoformed plate proper 1, of any shape but whose bottom surface is imperatively flat.

this thermoformed plate I has cells 2 of frustoconical shape, adjacent to each other, which are flared upwards and which are closed, at their upper parts, by individual bottoms 3 constituting the small bases of the trunks of cones. The large bases of the frustoconical cells 2 are connected between them by plane portions 4 of the upper surface of the thermoformed plate 1.

 The lateral surface of each cell is pierced, in the immediate vicinity of its bottom 3, with at least one drainage orifice 5 whose upper edge is located at a level slightly higher than the level of the bottom 3. In each cell 2 is shown a mass of growing medium 6, such as a clod of earth, in which a young piant 7 has grown.

 To ensure the stiffening of the thermoformed plate I, the latter includes a sheet 8 fixed to its underside, that is, b-dife to the individual bottoms 3 of the cells 2. This sheet 8 is made of a non-stretchable material under the usual conditions of use, rigid or semi-rigid. The sheet 8 can be fixed to the bottoms 3 of the cells 2 by any suitable means, in particular by gluing or welding, and it can be pierced or not.

 The stiffening sheet 8 can be made of the same material as the thermoformed upper plate 1, for example made of polystyrene.

 Thanks to the non-stretchability of the sheet 8, ie lamination or welding of this sheet 8 on the bottoms 3 ensures the non-deformability of the culture plate in the case where this plate is subjected to forces represented by the arrows f in FIG. 2, these arrows indicating the direction of the forces at play during the usual handling of the plates. The sheet 8 also provides stiffening in the opposite direction, as indicated in FIG. 3, thanks to its intrinsic rigidity which prevents it from becoming trapped in the areas 8a of the sheet 8 lying between the individual bottoms 3.

 In the variant embodiment of the invention represented in FIG. 4, the stiffening sheet is constituted by a plate 9 made of thermoformed or injected piastic material, this plate 9 which is glued to the individual bottoms of the cells 2, ensuring, in addition to ia rigidity, the accumulation of a certain reserve of water.

 Finally, in the alternative embodiment of the invention shown in FIG. 5, each cell I has in its bottom 3 at least one drainage hole 10 coinciding with an equivalent hole it drilled in the stiffening sheet 1, the two holes 10,11 which can be pierced simultaneously after coloring sheet 1, or successively at the time of cutting of each of the elements of the plate.

Claims (7)

 1.- Culture plate in thermoformed material comprising cells open upwards and closed individually, downwards, by planar bottoms located in the same plane, characterized in that it is stiffened by a sheet (8) of low thickness, in a rigid or semi-rigid non-stretchable material, adhere to the bottoms (3) of the cells.  2. Culture plate according to claim 1 characterized in that the stiffening sheet (8) is constituted by a plastic film.  3. Culture plate according to claim 1, characterized in that the rigidifloation sheet (8) is replaced by a plate (9) made of thermoformed or injected plastic, this plate then ensuring, in addition to the rigidity, the accumulation of a certain reserve of water.  4. Culture plate according to any one of the preceding claims, characterized in that the sheet (8) is glued to the bottoms (3) of the cells (1).  5. Culture plate according to any one of claims 1 to 3 characterized in that the sheet (8) is welded to the bottoms (3) of the cells (1).  6. Culture plate according to any one of the preceding claims, characterized in that each cell (1) has in its lateral surface (2), close to its bottom (3), at least one drain hole (5 ).  7. Culture plate according to any one of claims l to 4 characterized in that each cell (lE has, in its bottom (3), at least one drain hole (10) coinciding with an equivalent hole (11) drilled in the stiffening ia feiiie (8), the two holes proving to be drilled simultaneously or successively.