Method for producing a holding means for food and holding means for food

Abstract

Method for producing a holding means for food (1) comprising the following method steps: a. Providing a material (2) in the form of a thermoplastic natural material; b. plasticizing the material (2) by means of a plasticizing unit (3); c. Providing an injection molding tool (4) having a cavity (5); d. injecting a material (2) into the cavity (5) at a pressure between 80 MPa and 150 MPa; e. cooling the injected material (2) while maintaining a holding pressure of between 20 MPa and 40 MPa after injection, thereby forming the food holding means (1) to be produced; f. Removing the produced food holding means (1) from the injection molding tool (4); wherein the thermoplastic natural material is a thermoplastic fiber composite material which is a mixture of a natural resin, natural fibers and optionally further natural additives, wherein the natural resin is lignin, wherein the natural fibers are selected from seed fibers, bast fibers, hard fibers and fruit fibers.

Description

[0001] In a first aspect, the present invention relates to a method for producing a holding means for food. In a further aspect, the invention relates to a holding means for food.

[0002] Such a food holder could be an ice cream stick or ice cream cone, for example. Frozen ice cream is arranged on such ice cream sticks. The user can comfortably grip the stick and thus consume the ice cream. Until now, such ice cream sticks have been made from a hardwood, usually beechwood. For this purpose, panels are produced from which the ice cream sticks are then punched out. Such a manufacturing process requires a certain amount of material waste. Beechwood is valuable timber that is used in many areas. However, beech trees are also comparatively slow-growing trees. Accordingly, the demand for beechwood is high. The production of a disposable item from such a valuable natural raw material is therefore undesirable. Molded parts of this type made from thermoplastics are known, for example, from US 2017 / 0057146 A1.

[0003] On the other hand, due to the desire to utilize natural resources, the use of mineral oil-based plastics is discouraged. Such plastics reduce the already limited supply of mineral oil. Furthermore, they pollute the environment with non-biodegradable plastic waste.

[0004] The object of the invention is to provide a method for producing an alternative holding means for food or an alternative holding means for food which solves the problems mentioned above.

[0005] The object is achieved in a first aspect by a method for producing a holding means for foodstuffs comprising the following method steps: a. Providing a material in the form of a thermoplastic natural substance; b. Plasticizing the material by means of a plasticizing unit; c. Providing an injection molding tool having a cavity; d. Injecting a material into the cavity; e. cooling the injected material while maintaining a holding pressure of between 20 MPa and 40 MPa, thereby forming the food holding means to be produced; f. Removing the produced food holding means from the injection molding tool;wherein the thermoplastic natural material is a thermoplastic fiber composite material which is a mixture of a natural resin, natural fibers and optionally further natural additives, wherein the natural resin is lignin, wherein the natural fibers are selected from seed fibers, bast fibers, hard fibers and fruit fibers.

[0006] A natural thermoplastic is a material that exhibits properties similar to those of a thermoplastic. Furthermore, such a material can be used in an injection molding machine.

[0007] A natural material is one that is made predominantly or exclusively from renewable resources. Avoiding synthetic mineral oil-based plastics ensures the sustainable use of raw materials.

[0008] Furthermore, a natural substance is preferably a biodegradable or compostable material. Biodegradable means that the material can be broken down by living organisms (especially saprobiotics) or their enzymes. Ideally, this chemical metabolism proceeds completely to mineralization, so that the organic compound is broken down into inorganic substances such as carbon dioxide, oxygen, and ammonia; however, degradation can also stop with stable transformation products. Compostable means that the material is part of a biological process of the nutrient cycle, in which easily digestible organic material is broken down by bacteria and fungi (heterotrophic microorganisms) under the influence of atmospheric oxygen (aerobically). In this process, in addition to carbon dioxide, water-soluble minerals such as nitrates, ammonium salts, phosphates, potassium, and magnesium compounds are released, which act as fertilizers.Some of the intermediate products produced during this decomposition are converted into humus.

[0009] Typically, a food storage device according to the invention is a disposable product that is disposed of after the food has been consumed. However, the storage device according to the invention does not produce any unnecessary non-degradable waste. Accordingly, a food storage device is provided whose production ensures the sustainable and careful use of raw materials. Furthermore, as a disposable item, the food storage device does not pose a burden on the environment after use.

[0010] By designing the food holder as an ice cream stick, beechwood stocks are conserved because no "real wood" is used. Likewise, synthetic petroleum-based plastics are not used. The ice cream stick manufacturer can thus advertise the protection of beechwood stocks and the avoidance of petroleum use. Furthermore, the end customer has the assurance that they have purchased a disposable item that does not waste valuable raw materials such as beechwood or petroleum.

[0011] According to the invention, the material in the form of a thermoplastic natural material is a mixture of a natural resin and natural fibers. The thermoplastic natural material is a mixture of a natural resin, natural fibers, and other natural additives. Such thermoplastic natural materials are also called thermoplastic fiber composites.

[0012] The natural resin is preferably a tree resin or thermoplastic starch. Examples of such resins include lignin, shellac, gutta-percha, mastic, rosin, or copal.

[0013] According to the invention, the natural resin is lignin. Lignin is a byproduct of the pulp industry and is produced worldwide in approximately 50 million tons annually. Until now, a large portion of this waste has been burned for energy production. Since the lignin is produced anyway, it can be used without additional effort to produce a food preservative. The wood and beech wood stocks currently used can thus be spared.

[0014] According to the invention, the natural fibers are selected from seed fibers, bast fibers, hard fibers, and fruit fibers. Seed fibers are, for example, fibers from cotton, kapok, or poplar fluff. Bast fibers are, for example, fibers from hemp, jute, linen, ramie, nettle, or bamboo. Hard fibers are, for example, fibers from wood, sisal, or manilla. Fruit fibers are, for example, coconut fibers. Any combination of these fibers should be possible.

[0015] Other natural additives can be, for example, antioxidants, plasticizers or natural fillers such as rice hulls or chitin.

[0016] In a particularly preferred embodiment, the material is a thermoplastic fiber composite, marketed under the name ARBOFORM®. ARBOFORM® is a granulate that can be processed (injection molded) like a thermoplastic. The resin base for this material is lignin. This lignin is preferably mixed with natural fibers, such as flax, hemp, or other plant fibers, and possibly other plant-based additives. ARBOFORM® is thus made from 100% renewable raw materials. ARBOFORM® is often referred to as "liquid wood."

[0017] According to a particularly preferred embodiment, the material is a composition of renewable raw materials and plastics, which is marketed under the name ARBOFILL®.

[0018] According to a particularly preferred embodiment, the material is a composition of various biopolymers, which is marketed under the name ARBOBLEND®. Depending on the formulation, ARBOBLEND® materials consist of various biopolymers such as polylactide, polyhydroxybutyric acid, starch, cellulose, Green PE, Bio-PA, Bio-PET, cellulose esters, lignin, natural resins, natural fatty acids, waxes, and / or additives.

[0019] The thermoplastic natural material is preferably provided as granules. The particle shape can be spherical, flake-like, or fibrous. The particle diameter can range from a few micrometers to a few millimeters.

[0020] According to a preferred aspect of the invention, the material in the form of a thermoplastic natural substance is dried and preheated in a dry air dryer prior to plasticizing. This is preferably dried and preheated for approximately 2 hours at 40°C.

[0021] Advantageously, the preheated material is plasticized in a plasticizing unit. Such a plasticizing unit includes, among other things, a feed zone, a plasticizing cylinder with a screw, and heating elements. The plasticized material is then fed into the corresponding cavity, preferably via a sprue.

[0022] According to an advantageous concept of the invention, the material in the form of a natural thermoplastic is injected into the cavity via a hot runner. The sprue system leading from the plasticizing unit to the respective injection nozzle is thus advantageously thermally insulated from the injection mold. With other sprue systems, the plastic material solidifies in the sprue system. The so-called sprue must then be separated from the molded part. This requires additional tools. Furthermore, the additional plastic material must be disposed of. When using a hot runner, the sprue system is kept at a sufficiently high temperature so that the sprue does not solidify.

[0023] According to a further preferred aspect of the invention, the injection molding tool comprises at least two tool halves that are movable relative to one another. Preferably, both tool halves can be movable, and one tool half can be stationary and the other tool half movable.

[0024] The two mold halves have corresponding recesses so that, when the injection mold is closed, i.e., the two mold halves are in contact with each other, the cavity is formed. Advantageously, the shape of the cavity corresponds to the shape of the food-grade holder to be produced. The injection nozzle can be positioned anywhere, for example, on a side wall of one mold half. The injection nozzle is preferably arranged centrally along a length of the cavity.

[0025] The material, in the form of a thermoplastic natural substance, is injected into the cavity via an injection nozzle. When using ARBOFORM®, the temperature of the material at the injection nozzle is preferably between 110°C and 180°C, more preferably between 150°C and 180°C, and most preferably approximately 165°C. Temperatures above 180°C are unsuitable, as the natural fibers char at such temperatures. Temperatures below 110°C are also unsuitable, as the lignin only fully melts at this temperature.

[0026] Preferably, the temperature of the material in the feed zone is approximately 125°C and in the plasticizing cylinder approximately 140°C.

[0027] During the injection phase, the plasticized material in the form of a natural thermoplastic is preferably injected into the cavity via the injection nozzle under high pressure. According to the invention, the pressure is in a range between 80 MPa and 150 MPa, particularly preferably approximately 110 MPa.

[0028] The mold halves forming the cavity have a temperature of preferably between 30°C and 80°C, more preferably between 30°C and 50°C, and most preferably approximately 40°C. Upon contact with the comparatively cold wall areas of the cavity, the plastic solidifies upon reaching the solidification point of the respective material. To ensure the most homogeneous distribution of the plastic material in the cavity, the plastic material must be introduced into the cavity quickly. Accordingly, the material is preferably injected at approximately 110 MPa in approximately 1.6 seconds.

[0029] After injection, according to the invention, a holding pressure is maintained in a range between 20 MPa and 40 MPa, particularly preferably at approximately 30 MPa. The holding pressure serves to compensate for shrinkage, i.e., the thermally induced volume reduction of the injected molded part.

[0030] Preferably, the remaining cooling time is in a range between 5 s and 40 s, more preferably in a range between 10 s and 30 s, particularly preferably approximately 20 s. Due to the further volume shrinkage, a certain demolding from the cavity already takes place.

[0031] Preferably, the food holding device is ejected by means of an ejector after the mold halves have been opened. A cam-type ejector is particularly preferred. This type of cam-type ejector has the advantage that no ejection marks are visible on the finished food holding device.

[0032] According to a further preferred embodiment, the food holding devices are subjected to a further sterilization process. During the injection molding process itself, the material is heated to a maximum of 180°C, as already described. This already provides a certain degree of sterilization. However, particularly when handling food, a high level of sterility or freedom from germs is often desired. Accordingly, the food holding devices can be subjected to a further sterilization process after the injection molding process. The sterilization process is preferably sterilization with ionizing radiation. This can be UV radiation, X-rays, gamma radiation, or electron bombardment (electron beam sterilization).

[0033] According to another preferred embodiment, a colorant and / or pigments and / or effect particles are added to the material in the form of a thermoplastic natural substance prior to injection. This addition can occur before or after plasticizing. These colorants, pigments and / or effect particles are preferably natural substances that are also biodegradable or compostable. Effect particles are, for example, colored, glittering particles that are accordingly prominent in the finished product.

[0034] According to a further aspect of the invention, the object is achieved by a holding means for food which is produced by a method according to the previously described embodiments.

[0035] The advantages and features of the above-mentioned embodiment of the manufacturing process should accordingly also apply to the holding means for food.

[0036] In a particularly preferred embodiment, the food holder is made of ARBOFORM®. In addition to the advantages already mentioned, the use of this material also offers the advantage of a visual impression very similar to that of wood. Therefore, it is almost impossible for the consumer to distinguish whether the holder is made of real wood or ARBOFORM®.

[0037] According to a particularly preferred embodiment, the food holding means is an ice cream stick or ice cream stick. Frozen ice cream is placed on such a stick. Using the stick, the consumer can conveniently hold and consume the ice cream.

[0038] According to a further embodiment, the food holding means is a skewer for stringing together pieces of food, for example a shish kebab skewer or a skewer for stringing together pieces of vegetables or fruit.

[0039] According to another embodiment, the food holding device is a chopstick or a piece of cutlery. Chopsticks are a pair of equally long sticks used as cutlery in Asia.

[0040] According to a further embodiment, decorative elements and / or lettering and / or patterns or symbols are formed on the food holder. In contrast to, for example, food holders, in particular ice cream sticks, which are also punched from beechwood panels, the food holders according to the invention can be designed in a variety of ways. For example, the food holder can be designed with the manufacturer's lettering, patterns, logos, etc., simply through the shape of the cavity. These elements can be protruding or designed as recesses.

[0041] Furthermore, the food holder can be designed with any decorative elements. The shape of these decorative elements is also determined by the shape of the cavity or the mold halves.

[0042] According to a further embodiment, additional haptic elements are formed on the food holding means. Such a haptic element can, for example, be a surface ribbing. These haptic elements are also determined solely by the design of the cavity.

[0043] According to a further embodiment, the food holding means comprises a handle portion and a holding portion. A projection is preferably arranged between the handle portion and the holding portion. Such a projection can serve as a drip guard. Accordingly, the projection could also be designed in a trough-like manner.

[0044] Further advantages, objects, and features of the present invention will become apparent from the following description of the accompanying figures. Similar components may have the same reference numerals in the various embodiments.

[0045] The figures show: Fig. 1 an embodiment of a holding means for food; Fig. 2 shows a further embodiment of a holding means for food; Fig. 3 shows a further embodiment of a holding means for food; Fig. 4 shows a further embodiment of a holding means for food; Fig. 5 a view of an injection molding tool; Fig. 6 another view of an injection molding tool.

[0046] In the Fig. 1 to 4 show various embodiments of a holding device for food. These holding devices are used to hold ice cream. The holding device according to Fig. 1 and Fig. 2 has a constant width along its entire length and is rounded at the ends. The embodiments according to the Fig. 2 and Fig. 4 have a waist in the middle of their total length. The width of the holding means is therefore smallest in the middle of the total length and increases continuously towards the ends. The ends of the embodiment according to Fig. 4 are also rounded. In the example according to Fig. 3, only one end is rounded. A decorative element (7) is arranged at the other end. Such a decorative element (7) can essentially be designed in any desired way and is determined by the design of the cavity (5).

[0047] The holding devices according to Fig. 3 and Fig. 4 have lettering (8). Depending on the design of the cavity (5), this lettering (8) can be a protruding lettering (8) or a recess.

[0048] The embodiments according to the Fig. 3 and Fig. 4 further comprise a handle portion (9) and a holding portion (10). A projection (11) is arranged between the handle portion (9) and the holding portion (10), which serves as a drip guard for the ice. This drip guard (11) can preferably also be trough-shaped.

[0049] The food holding means (1) is manufactured by a method comprising the following steps: a. Providing a material (2) in the form of a thermoplastic natural material: b. plasticizing the material (2) by means of a plasticizing unit (3); c. Providing an injection molding tool (4) having a cavity (5); d. injecting a material (2) into the cavity (5) at a pressure between 80 MPa and 150 MPa; e. cooling the injected material (2) while maintaining a holding pressure of between 20 MPa and 40 MPa, whereby the food holding means (1) to be produced is formed; f. Removing the produced food holding means (1) from the injection molding tool (4);wherein the thermoplastic natural material is a thermoplastic fiber composite material which is a mixture of a natural resin, natural fibers and optionally further natural additives, wherein the natural resin is lignin, wherein the natural fibers are selected from seed fibers, bast fibers, hard fibers and fruit fibers.

[0050] A corresponding device by means of which the method can be carried out is described in the Fig. 5 and Fig. 6 is shown schematically. However, the size ratios of the injection molding tool (4, 4a, 4b) or the cavity (5) to the other elements, for example the plasticizing unit (4), are not shown to scale. Fig. 5 shows a top view of a tool half (4a, 4b). Fig. Figure 5 shows a side section of the closed injection mold (4), so that a cavity (5) corresponding to the height of the food holding element (1) is shown.

[0051] The material (2) in the form of a thermoplastic natural material is first dried and preheated in a dry air dryer (12).

[0052] The preheated, dried material (2) is placed in the feed zone (13) of the plasticizing unit (3). The material is then plasticized in the plasticizing unit (3). For this purpose, the material (2) is heated by heating elements (14) until it melts. The plasticizing screw (13) builds up a back pressure, causing the plasticized material (2) to enter the hot runner (6) under pressure.

[0053] The injection molding tool (4) comprises two tool halves (4a, 4b) which are movable relative to one another. Preferably, on the one hand, both tool halves (4a, 4b) can be movable, and on the other hand, one tool half (4a, 4b) can be stationary and the other tool half (4a, 4b) can be movable. The two tool halves (4a, 4b) have corresponding recesses so that, when the injection molding tool (4) is closed, the cavity (5) is formed. The shape of the cavity (5) corresponds to the shape of the food holder (1) to be produced. The injection nozzle (16) is placed on a side wall centrally along a length of the cavity (5) of one tool half (4a, 4b).

[0054] The removal of the manufactured food holding device (1) from the injection molding tool (4) is carried out by means of a link ejector (not shown in the figures).

[0055] The food holding devices (1) can then be fed into a sterilization device. List of reference symbols 1 holding device for food 2 Material 3 Plasticizing unit 4 injection molding tool 4a first tool half 4b second tool half 5 Cavity 6 hot runner 7 decorative element 8 lettering 9 Handle section 10 stopping section 11 lead 12 dry air dryers 13 catchment area 14 heating elements 15 Plasticizing screw 16 Injector nozzle

Claims

[1] Method for producing a holding means for food (1) comprising the following method steps: a. Providing a material (2) in the form of a thermoplastic natural material; b. plasticizing the material (2) by means of a plasticizing unit (3); c. Providing an injection molding tool (4) having a cavity (5); d. injecting a material (2) into the cavity (5) at a pressure between 80 MPa and 150 MPa; e. cooling the injected material (2) while maintaining a holding pressure of between 20 MPa and 40 MPa after injection, thereby forming the food holding means (1) to be produced; f. Removing the produced food holding means (1) from the injection molding tool (4); wherein the thermoplastic natural material is a thermoplastic fiber composite material which is a mixture of a natural resin, natural fibers and optionally further natural additives, wherein the natural resin is lignin, wherein the natural fibers are selected from seed fibers, bast fibers, hard fibers and fruit fibers. [2] Method for producing a food holding means (1) according to claim 1, characterized by that the material (2) in the form of a thermoplastic natural material is dried and preheated in a dry air dryer (12) before plasticizing, wherein the material in the form of a thermoplastic natural material is injected into the cavity (5) via a hot runner (6), wherein the removal of the produced holding means for food (1) from the injection molding tool (4) takes place by means of a slotted ejector. [3] Method for producing a holding means for food (1) according to one of the preceding claims characterized by that the food holding means (1) is subjected to a sterilization process, wherein the sterilization process is sterilization with ionizing radiation. [4] Method for producing a food holding means (1) according to one of the preceding claims, characterized by that a colorant and / or pigments and / or effect particles are added to the material (2) in the form of a thermoplastic natural material before injection. [5] Holding means for food (1) manufactured according to one of the preceding claims. [6] Holding means for food (1) according to claim 5, characterized by that the means for holding food (1) is an ice cream stick, a skewer for stringing together pieces of food, a chopstick or a piece of eating utensil. [7] Holding means for food (1) according to claim 5 or 6, characterized by that decorative elements and / or lettering and / or patterns and / or haptic elements are formed on the food holding means (1). [8] Holding means for food (1) according to one of claims 5 to 7, characterized by that the holding means for food has a handle portion (9) and a holding portion (10), wherein a projection (11) is arranged between the handle portion and the holding portion.

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