METHOD FOR MANUFACTURING A COMPOSTABLE PLATE

Abstract

A method for manufacturing a compostable plate which comprises: a step of manufacturing a supporting layer made of compostable cardboard; a step of printing at least one portion to be printed of the supporting layer made of compostable cardboard in order to obtain at least one respective printed portion, the step of printing being carried out using compostable inks; a step of spreading, at least over the surface that defines the at least one printed portion, a compostable biopolymer in order to provide a protective layer; a step of forming in order to provide a compostable plate, the step of forming comprising a thermoforming by insertion, between a male mold part and a female mold part, of the supporting layer which has the printed portion or portions and the protective layer.

Claims

1-6. (canceled)

7. A method for manufacturing a compostable plate which comprises: a step of manufacturing a supporting layer made of compostable cardboard; a step of printing at least one portion to be printed of said supporting layer made of compostable cardboard in order to obtain at least one respective printed portion, said step of printing being carried out using compostable inks; a step of spreading, at least over the surface that defines said at least one printed portion, a compostable biopolymer in order to provide a protective layer; a step of forming in order to provide a compostable plate, said step of forming comprising a thermoforming by insertion, between a male mold part and a female mold part, of said supporting layer which has the printed portion or portions and the protective layer.

8. The method according to claim 7, wherein said thermoforming is performed at a temperature comprised between 60 C. and 75 C. as regards the male mold part and between 120 C. and 130 C. as regards the female mold part.

9. The method according to claim 7, wherein said male mold part has a coupling surface which is designed to press against the protective layer, said coupling surface of the male mold part having a plastic coating that is adapted to limit a temperature of said coupling surface.

10. The method according to claim 9, wherein said plastic coating comprises a layer of Teflon.

11. The method according to claim 7, wherein said compostable biopolymer used to provide said protective layer is mixed, prior to the step of spreading, with a master batch of granules which is adapted to fluidify the biopolymer and to facilitate the step of spreading.

12. The method according to claim 7, wherein said step of printing is carried out using a compostable ink that is free from amines.

Description

[0014] Further characteristics and advantages of the invention will become better apparent from the description of some preferred, but not exclusive, embodiments of the compostable plate and of the method for manufacturing a compostable plate according to the invention, which are illustrated for the purposes of non-limiting example in the accompanying drawings wherein:

[0015] FIG. 1 is a cutaway perspective view of a supporting layer associated with a printed design and covered by a protective layer;

[0016] FIG. 2 is a view similar to FIG. 1;

[0017] FIG. 3 is a perspective view of the cardboard of the supporting layer associated with a printed design and covered by a protective layer after cutting or die-punching;

[0018] FIG. 4 is a perspective view of a plate;

[0019] FIGS. 5 to 7 are views that are similar, respectively, to those in FIGS. 2 to 4, of a variation of embodiment of the printed design.

[0020] With reference to the figures, the compostable plate, generally designated by the reference numeral 1, comprises a supporting layer 2 made of compostable cardboard which has at least one printed portion 3 which is printed with compostable ink.

[0021] The plate further has at least one protective layer 5, which is arranged at least above the surface that defines each printed portion 3.

[0022] In particular, the protective layer 5 comprises a compostable biopolymer.

[0023] The protective layer 5 is arranged at the surface that is intended to provide the concave part of the compostable plate 1.

[0024] Advantageously, the compostable biopolymer comprises a film with a thickness comprised between 12 m and 30 m, and preferably between 19 m and 23.8 m.

[0025] Such film can be obtained by way of extrusion or spreading of the biopolymer on the supporting layer 2, at the surface that defines the printed portion 3 or the printed portions 3.

[0026] Conveniently, the compostable biopolymer has a melting temperature of more than 135 C.

[0027] The product commercially designated with the wording MATER-BI CX01A made by Novamont SpA, Italy has been found to be particularly adapted to the purpose.

[0028] Conveniently, the supporting layer 2 made of compostable paper comprises substantially cellulose paste.

[0029] With regard to the compostable inks, an ink commercially designated with the wording Hidromat-B 463 made by La Sorgente S.P.A., Italy has been found to be particularly adapted to the purpose.

[0030] According to a further aspect, the present invention relates to a method for manufacturing a compostable plate 1.

[0031] The method comprises: [0032] a step of manufacturing a supporting layer 2 made of compostable cardboard; [0033] a step of printing at least one portion to be printed of the supporting layer 2 made of compostable cardboard in order to obtain at least one respective printed portion 3, the step of printing being carried out using compostable inks; [0034] a step of spreading, at least at the surface that defines the printed portion or portions 3, a compostable biopolymer in order to provide a protective layer 5; [0035] a step of forming in order to provide a compostable plate.

[0036] To provide the protective layer, it has been found to be particularly adapted to use the product commercially designated with the wording MATER-BI CX01A made by Novamont SpA, Italy.

[0037] Preferably, the compostable biopolymer used to provide the protective layer 5 is mixed, prior to the step of spreading, with a master batch of granules.

[0038] In particular, such master batch is adapted to fluidify the biopolymer and therefore to facilitate the step of spreading.

[0039] It has been found to be particularly efficacious to use a compostable ink that is free from amines.

[0040] In this regard, it has been found to be particularly suitable to use a product commercially designated with the wording Hidromat-B 463 made by La Sorgente S.P.A., Italy.

[0041] The step of forming comprises a thermoforming.

[0042] Specifically, the thermoforming is carried out by insertion, between a male mold part and a female mold part, of the supporting layer 2 which has the printed portion or portions 3 and the protective layer 5.

[0043] The thermoforming is performed at a temperature comprised between 60 C. and 75 C. as regards the male mold part and between 120 C. and 130 C. as regards the female mold part.

[0044] The male mold part has a coupling surface which is designed to press against the protective layer 5.

[0045] The coupling surface of the male mold part has a plastic coating that is adapted to limit the temperature of the coupling surface.

[0046] Preferably, such plastic coating comprises a layer of Teflon.

[0047] In practice it has been found that the invention fully achieves the intended aim and objects by providing a method for manufacturing compostable plates that is extremely reliable and capable of ensuring a high ratio of quality to production cost.

[0048] The present invention makes it possible to provide a completely compostable plate provided by way of a thermoforming process.

[0049] By virtue of identifying the compostable biopolymer intended to provide the protective layer 5, a solution has been obtained that makes it possible, notwithstanding the pressures and temperatures of thermoforming, to obtain a plate that is completely compostable and printed.

[0050] Furthermore, with the same performance, a product has been obtained that is lighter and less voluminous, as well as printed, decorated or personalized.

[0051] The possibility for personalization is very important for large companies which thus can highlight their respect for the environment by using compostable products with their brand and therefore preferring them to plates made from recycled cardboard.

[0052] The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

[0053] In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

[0054] The disclosures in Italian Patent Application No. 102017000059261 from which this application claims priority are incorporated herein by reference.