Food-safe container

Abstract

Food-safe container (14), in particular a beverage bottle, wherein the container (14) is made from a material mixture (2) for a biodegradable substance, in particular for the production of food-safe containers (14) from bacterial cellulose (3), polylactic acid (10) and chitosan (11), characterized in that the container (14) has an oxygen-impermeable barrier coating (16) and that the barrier coating (16) is made from an acrylic resin.

Description

[0001] The invention relates to a food-safe container which can be produced from a material mixture for a biodegradable substance, wherein the material mixture is made from bacterial cellulose, polylactic acid and chitosan.

[0002] Materials for the production of food-safe containers are already known. For example, containers made of polyethylene terephthalate are widely used for food storage. However, the negative environmental impacts associated with the production of such containers from polyethylene terephthalate, both during the chemical manufacturing process and during the container production itself, cannot be avoided. Furthermore, polyethylene terephthalate and containers made of this material are not biodegradable, necessitating a complex recycling process, which can only partially recycle the material.

[0003] Biodegradable packaging is also known. EP 0 802 804 B1 describes a biodegradable container made from a trans-polymer-based material mixture. The disadvantage here is that the trans-polymer must be produced using a conventional polymerization process. DE 196 33 405 A1 discloses a composite material with a cellulose matrix in which cellulose fibers are embedded, in which the cellulose matrix is ​​formed by the precipitation of cellulose dissolved in an amine oxide / water system. The disadvantage here is that the production of amine oxides requires the use of hydrogen peroxide or peracids (e.g., meta-chloroperbenzoic acid, peracetic acid, or peroxomonosulfuric acid). These substances are classified as hazardous substances, the use of which poses significant risks to the environment.WO 2011 / 116 051 A1 discloses a food container made of a starch-based biofoam, the production of which, however, requires diatomaceous earth. This is particularly disadvantageous because diatomaceous earth is a finite fossil raw material required for a variety of applications, particularly in the chemical industry. A food-safe container with the features mentioned above is known, for example, from JP H06 218 878 A or JP 2006 1 973 A.

[0004] It is seen as an object of the present invention to provide a food-safe container made of a material mixture that is biodegradable, environmentally friendly and suitable for food use.

[0005] This object is achieved according to the invention in that the container has an oxygen-impermeable barrier coating, and the barrier coating is made of an acrylic resin. All three components of the material mixture are biodegradable and can be broken down naturally, for example, through use as fertilizer, so that the environment is not polluted with non-degradable residues of the material mixture. The material mixture according to the invention is also fully recyclable.

[0006] The components of the material mixture according to the invention are tasteless and inexpensive to produce, making the material mixture food-safe and suitable for the cost-effective production of food-safe containers. The individual components of the material mixture and the material mixture itself can be easily processed using an injection molding process, further reducing the manufacturing costs of food-safe containers.

[0007] Compared to currently commonly used materials for the production of food-grade containers, polylactic acid and chitosan are antibacterial, making the material blend advantageous for food-grade containers. In addition, the material blend according to the invention exhibits increased temperature resistance, tear-resistant properties, and high transparency.

[0008] Compared to the currently common containers made of polyethylene terephthalate, the food-grade container according to the invention is biodegradable and thus environmentally friendly.

[0009] The food-grade container according to the invention can be biodegraded, for example, as fertilizer, completely recycled, or reused multiple times. If the container according to the invention is used multiple times, it can be cleaned, for example, with acetic acid or steam.

[0010] According to the invention, the container has an oxygen-impermeable barrier coating. The barrier coating can be used, for example, to protect foodstuffs contained in the container according to the invention from oxygen and to increase its shelf life. Thus, the container according to the invention can be used not only for storing water, but also, for example, for storing milk and other oxygen-sensitive foods.

[0011] The invention further provides for the barrier coating to be made of an acrylic resin. Acrylic resin is durable, transparent, and protects the food contained in the containers according to the invention from oxygen. Furthermore, the acrylic resin is printable, allowing the barrier coating to be easily overprinted and the container according to the invention to be visually designed.

[0012] According to the invention, the barrier coating can optionally also comprise an additive. The additive can, for example, influence the transparency or temperature resistance of the container and improve its processing. The resistance of the container according to the invention to UV radiation can also be improved by the additive.

[0013] In order to be able to change the visual appearance of the food-safe container, the additive can contain dyes and / or dye pigments. According to the invention, the dyes or dye pigments can be food-safe or chemically incorporated into the barrier coating in such a way that the properties of the container are not negatively affected and the container remains food-safe.

[0014] The dyes or dye pigments can be used both to improve the optical design of the container and to modify other properties, such as the transmittance of visible radiation. It is also possible to use the dyes or dye pigments as a primer layer for further printing of the container according to the invention, for example, with UV-curing inks.

[0015] It is also conceivable and intended that the dyes or dye pigments are optically activated by electromagnetic radiation in the barrier coating already applied to the container only after the container has been manufactured. For example, instead of printing the container, the dyes or dye pigments can be optically activated in specific areas of the barrier coating, thus creating an optical design for the container. The composition of the dyes or dye pigments in the barrier coating enables both a multi-colored and a single-colored design of the container according to the invention.

[0016] Advantageously, the container can be provided with an additional coating. The additional coating can be used, for example, to improve the optical properties of the container according to the invention or as an antistatic layer. For example, films made of bacterial cellulose or chitosan can be used, which improve the advantageous properties of the container and are also biodegradable and thus environmentally friendly.

[0017] Optionally, the additional coating can also be made of polylactic acid. The polylactic acid is also biodegradable and can therefore be degraded, recycled, or reused together with the container according to the invention. Structuring the additional coating can achieve additional optical effects. For example, structuring the additional coating with a laser can create a 3D effect, further enhancing the container according to the invention.

[0018] The biodegradable material mixture according to the invention can also be advantageously used in the packaging, textile, automotive, and medical industries. For example, applications of the material mixture according to the invention are conceivable for the production of bottle crates, ion filters, shoe soles, and for the visual enhancement of books, newspapers, and other printed articles. Depending on the proportions of the individual components in the material mixture according to the invention, the properties of the material mixture according to the invention can be adapted to the respective application.

[0019] Advantageously, the invention provides that the bacterial cellulose is produced biotechnologically in a cellulose production process, wherein the glucose is produced from waste paper or from a biomaterial using a glucose extraction process by cellulases, which is then processed into the bacterial cellulose in a fermentation process by cellulose-forming microorganisms.

[0020] In the glucose recovery process, the waste paper or biomaterial, such as freshwater and saltwater algae, can first be processed into glucose using cellulases, such as molds from the Trichoderma group, and especially Trichoderma reesei. The glucose recovery process can be carried out, for example, in a bioreactor at room temperature, so no additional costs are incurred due to temperature control. An output-to-input ratio of more than 5% can be achieved with the glucose recovery process.

[0021] The glucose produced in the glucose production process can then be fermented by cellulose-forming microorganisms, such as bacteria from the Acetobacteraceae group, and especially Acetobacter xylinum, to produce bacterial cellulose. The glucose produced in the glucose production process can be separated from the remaining components by a membrane to obtain the purest possible bacterial cellulose. The fermentation process can be carried out relatively simply and quickly, allowing the bacterial cellulose to be easily produced in the required quantities.

[0022] Optionally, the polylactic acid is produced biotechnologically in a fermentation process from the bacterial cellulose by lactic acid bacteria. According to the invention, the fermentation process can be carried out after the fermentation process, and the bacterial cellulose produced in the fermentation process can be partially or completely processed into polylactic acid by lactic acid bacteria, in particular Lactobacillus casei, Lactobacillus bulgaricus, Lactobacillus helveticus, Lactobacillus delbrueckii, or Lactobacillus pentosus. During the fermentation process, the proportions of the individual components in the material mixture according to the invention can be varied by varying the duration and intensity of the fermentation process.Depending on the proportions of the individual components - bacterial cellulose, polylactic acid and chitosan - in the material mixture, the properties of the material mixture according to the invention can be adapted to the respective application of the material mixture.

[0023] Advantageously, the chitosan can be produced biotechnologically from polylactic acid by fungi in a chitosan production process. Fungi of the order Mucorale, and in particular Mucor rouxii, Absidia coerulea, and Rhizopus oryzae, can be used in the chitosan production process. The proportions of the individual components in the material mixture according to the invention can be easily varied in the chitosan production process in order to alter the properties of the material mixture. For example, the material mixture can consist predominantly of chitosan, polylactic acid, or bacterial cellulose and accordingly exhibit different properties.

[0024] To modify the properties of the material mixture and further adapt it to the specific application, it is possible to add an additive. The additive can, for example, influence the temperature resistance, transparency, oxygen permeability, and other properties of the material mixture.

[0025] The additive may also contain fillers. For example, the additive may contain calcium carbonate to improve the processing of the material mixture according to the invention in the injection molding process.

[0026] It is also conceivable for the material mixture to contain dyes or dye pigments. These dyes or dye pigments can, for example, improve the visual appearance of the articles made from the material mixture or influence the transparency of the material mixture.

[0027] Optionally, the additive is food-safe or chemically integrated into the material mixture in such a way that it cannot adversely affect the food. Furthermore, the additive can also be biodegradable, so that the material mixture can also be biodegraded with the additive and is environmentally friendly.

[0028] The invention also relates in particular to a beverage bottle. Further advantageous embodiments of the material mixture according to the invention and the food-safe container according to the invention are explained in more detail with reference to embodiments illustrated in the drawing. It shows: Fig. 1 a schematic view of a manufacturing process of a material mixture according to the invention; Fig. Figure 2 is a schematic view of a food-grade container; Fig. 3 a sectional view of a section of a container according to the invention.

[0029] Fig. 1 shows a schematic view of a manufacturing process 1 of a material mixture 2. In this process, the bacterial cellulose 3 is first produced biotechnologically in a cellulose manufacturing process 4, wherein, for example, glucose 7 is produced from a biomaterial 5 using a glucose extraction process 6 by cellulases, which is then processed into the bacterial cellulose 3 in a subsequent fermentation process 8 by cellulose-forming microorganisms.

[0030] After the fermentation process 8, polylactic acid 10 is biotechnologically produced from the bacterial cellulose 3 by lactic acid bacteria in a fermentation process 9. The bacterial cellulose 3 produced in the fermentation process 8 can be partially or completely processed into polylactic acid 10 in the fermentation process 9. During the fermentation process 9, the proportions of the individual components in the material mixture 2 according to the invention can be changed, thereby adapting the properties of the material mixture 2 according to the invention to the respective application of the material mixture 2.

[0031] After the fermentation process 9, chitosan 11 can be produced biotechnologically from polylactic acid 10 by fungi in a chitosan production process 12. The proportions of the individual components in the material mixture 2 according to the invention can also be easily modified in the chitosan production process 12 in order to change the properties of the material mixture 2.

[0032] All three components of material mixture 2—bacterial cellulose 3, polylactic acid 10, and chitosan 11—are biodegradable and fully recyclable. Additionally, the properties of material mixture 2 can be modified by an additive 13, which may contain a filler or dyes or dye pigments.

[0033] Fig. Figure 2 shows a schematic view of a food-grade container 14 in the form of a beverage bottle. The container 14 is made of material mixture 2 and, compared to the currently common containers made of polyethylene terephthalate, is biodegradable and thus environmentally friendly. An additional coating 15 is applied to the container 14, which can be printed or textured, for example.

[0034] In Fig. 3 is a sectional view of a section of the Fig.2. The container 14 is made of the material mixture 2, which comprises the additive 13. According to the invention, the additive 13 can be food-safe or chemically incorporated into the material mixture 2, so that the container 14 remains food-safe. An oxygen-impermeable barrier coating 16, for example, acrylic resin, protects food contained in the container 14 and increases its shelf life. The barrier coating 16 additionally comprises an additive 17, which contains, for example, dyes or dye pigments.

[0035] Furthermore, the container 14 has an additional coating 15, which can be used, for example, to improve the optical properties of the container 14 or as an antistatic layer. A surface 18 of the additional coating 15 can be structured in such a way that further optical effects, such as a 3D effect, can be achieved.

Claims

[1] A food-grade container (14), in particular a beverage bottle, wherein the container (14) is made of a material mixture (2) for a biodegradable substance, in particular for the production of food-grade containers (14) made of bacterial cellulose (3), polylactic acid (10) and chitosan (11), characterized by that the container (14) has an oxygen-impermeable barrier coating (16) and that the barrier coating (16) is made of an acrylic resin. [2] Food-grade container (14) according to claim 1, characterized by that the barrier coating (16) comprises an additive (17). [3] Food-grade container (14) according to claim 2, characterized by that the additive (17) contains dyes and / or dye pigments. [4] Food-grade container (14) according to one of the preceding claims, characterized by that the container (14) has an additional coating (15). [5] Food-grade container (14) according to claim 4, characterized by that the additional coating (15) is made of polylactic acid (10). [6] Food-grade container (14) according to one of the preceding claims, characterized by that the bacterial cellulose (3) of the material mixture (2) is produced biotechnologically in a cellulose production process (4), wherein the glucose (7) is produced from a waste paper or from a biomaterial (5) using a glucose extraction process (6) by cellulases, which glucose is processed in a fermentation process (8) by cellulose-forming microorganisms to form the bacterial cellulose (3). [7] Food-grade container (14) according to one of the preceding claims, characterized by that the polylactic acid (10) of the material mixture (2) is produced biotechnologically in a fermentation process (9) from the bacterial cellulose (3) by lactic acid bacteria. [8] Food-grade container (14) according to one of the preceding claims, characterized by that the chitosan (11) of the material mixture (2) is produced biotechnologically in a chitosan production process (12) from the polylactic acid (10) by fungi. [9] Food-grade container (14) according to one of the preceding claims, characterized by that the material mixture (2) has an additive (13) for changing properties of the material mixture (2). [10] Food-grade container (14) according to claim 9, characterized by that the additive (13) of the material mixture (2) contains dyes and / or dye pigments and / or fillers.

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