Method and apparatus for forming and / or mechanically processing drinking straws made from a starch-based dough

Abstract

Method for forming and / or mechanically processing drinking straws made from a starch-based dough, characterized in that the drinking straws (11) are heated before their forming and / or mechanical processing and are formed and / or mechanically processed in the heated state.

Description

The invention relates to a method for forming and / or mechanically processing drinking straws made of a starch-based dough. The invention further relates to a device for forming and / or mechanically processing drinking straws made of a starch-based dough, comprising a transport device and a processing device associated therewith for mechanically processing the drinking straws that are fed individually to the processing device by means of the transport device. It is known to equip beverage containers intended for immediate consumption with drinking straws attached to the outside of the packaging, allowing consumers to drink the contents using the provided straw. While plastic straws were generally used in the past, more recently – to avoid non-compostable waste – it has been suggested that straws made from a starch-based dough, essentially tubular pasta products (macaroni), should be used. Such drinking straws made from pasta dough have the disadvantage of being very brittle when dry and difficult to work with. Since it is not always possible to cut or otherwise process the pasta dough drinking straws immediately after extrusion while they are still soft, as proposed in EP 0 948 893 B1, methods have been sought to process them even in their hard, brittle state. CH 332 118 A proposes, for example, the use of a rotating cutting blade that cuts the pasta products, which are lying on a soft surface, to the desired length. It has been found that this technique presents considerable difficulties when the macaroni or other pasta products need to be cut at an angle to their length, for example, to create a point on a drinking straw that can be used to pierce the beverage container at the designated spot. From DE 10 2019 104 588 A1, a length-variable drinking straw made from a cellulose or paper starting material and a method for its production are known, mentioning various pre- and post-treatment steps that can be used during the processing of a part of the two-part drinking straw. From DE 20 2020 104 712 U1, aids for eating and drinking made from vegetable starch and vegetable thickening or gelling agent are known, including drinking straws made from a starch-based dough, which are completely hardened and disinfected by treatment with approximately 85° Celsius hot air and UV light. AT 34 696 E discloses a method and a device for producing the bending zone of a plastic drinking straw. The object of the invention is to provide a method and a device that makes it possible to reliably mechanically process tubular products, in particular drinking straws, made from a starch-based dough, without the processed product breaking or being otherwise damaged. This problem is solved according to the method by heating the drinking straws before their forming and / or mechanical processing and forming and / or mechanically processing them in the heated state. The device according to the invention is accordingly characterized in that a heating device is associated with the transport device and is positioned upstream of the processing device. By applying heat to the area of ​​the pasta dough straw blanks to be processed, they soften and thus temporarily lose their brittleness. They can therefore be easily reshaped or mechanically processed, in particular cut, without the risk of the straws breaking during this process and / or processing, rendering them unsuitable for their intended purpose. In particular, the invention makes it possible, in a particularly simple and reliable manner, to cut a tip at a very acute angle to the longitudinal axis of the straw. This tip can then be used to easily perforate a sealing film at an access opening of the beverage packaging, allowing the straw to be inserted into the packaging.By heating the drinking straw blank, it becomes sufficiently soft for processing; during the subsequent cooling, it reverts to its previously rather brittle consistency. Preferably, the heating is carried out locally in the area of ​​the drinking straw where the subsequent shaping and / or mechanical processing will take place. It is therefore not necessary to heat the entire drinking straw; it is sufficient to heat and thus plasticize only the area(s) where the straw will subsequently be cut or otherwise processed. The drinking straws can be heated in various ways. For example, they can be heated by convection using a warm, gaseous medium, by thermal radiation, and / or by conduction using a heat source that can be applied to the drinking straws. If a gaseous medium is used for heating, it is preferably hot air and / or dry steam; if heating is achieved by thermal radiation, the heat is preferably generated by an infrared or microwave heater.Both heating methods make it possible to heat and process the products in an essentially dry state, i.e. without the addition of moisture (water, wet steam), which is desirable in most cases. The reshaping and / or mechanical processing of the drinking straws, which as already mentioned are preferably made of a dry pasta dough, may include bending at a kink area and / or cutting the drinking straws at a separation area. Preferably, the drinking straws are heated to a temperature of 70–150°C, at least in the area to be subsequently processed. For mass processing, it has proven advantageous if the drinking straws are individually conveyed by a continuous conveyor, first passing a heating device to warm them locally, and then being shaped and / or mechanically processed, in particular cut, by means of a processing device spatially associated with the continuous conveyor. It is possible for the drinking straws to be cooled after shaping and / or mechanical processing, for example, by means of a cold air blower or other cooling device. To heat the products, the device according to the invention can include a heating element with at least one hot air or hot steam ejector, which is used to heat the moving drinking straw blanks. Alternatively or additionally, the heating element can include at least one radiant heater and / or a microwave generator. The processing device expediently includes at least one preferably rotating cutting blade and / or a bending device. Further features and advantages of the invention will become apparent from the following description and the drawing, in which a preferred embodiment of the invention is illustrated in more detail by way of an example. The single figure shows, in a simplified, schematic representation, a device according to the invention for carrying out the method according to the invention in a side view. The device designated as 10 in the drawing serves to mechanically process dry drinking straws 11 made from a starch-based dough (pasta or noodle dough), which in their shape and composition essentially correspond to macaroni, namely to cut them to length transversely to their longitudinal extent. The device 10 comprises a transport device 12 with an endlessly circulating conveyor belt on which the drinking straws 11 to be processed are arranged from a supply of drinking straws 13 such that their longitudinal extent runs transversely to the conveying direction 14 of the conveyor belt. The drinking straws are first fed to a singulation device 15, which forms a passage gap 16 with a height above the top of the conveying section of the conveyor belt that is adapted to the diameter of the drinking straws. This ensures that all drinking straws lie individually next to each other on the conveyor belt at the exit of the singulation device. In the direction of travel 14, downstream of the singulation device 15, a heating device 17 is provided at a short distance above the conveying section of the conveyor belt. This device heats the drinking straws 11 resting on the conveyor belt to a temperature of approximately 90°C in the area where they are to be subsequently mechanically processed. In this embodiment, a hot air ejector 18 is used as the heating device. Hot air 19 at a temperature of approximately 90 to 120°C is blown from a hot air nozzle against the surface of the drinking straws in the desired processing area from above. Alternatively, an infrared heater or another suitable heating device can be used for this purpose. The heating of the drinking straws 11 made of pasta dough not only causes a local heating of the drinking straws in the processing area exposed to hot air or heat radiation, but also a softening / plasticization of the drinking straw material, which is dry and brittle in the cold state, not yet exposed to the heating device, and therefore breaks easily.In the heated and thus softened processing area, the drinking straws 11 can be easily cut with a processing device 20 arranged in the transport direction 14 behind the heating device 17, with a rotating cutting blade, without the risk of the drinking straws 11 breaking or splintering during this mechanical processing step, because the distance between the heating device 17 and the cutting blade is so short that the drinking straws have not yet cooled down significantly on the path they have traveled between the two processing stations and the straws 11 are therefore still sufficiently soft in the processing area previously heated by the heating device and can be cut without damage.The processed drinking straws reach a collection chute 21 at the end of the conveyor belt and from there into a collection container 22, where they cool down completely and thus regain their original hardness even in the previously heated and therefore softened processing area. The invention is not limited to the illustrated and described embodiment. It is possible not only to cut the drinking straws transversely to their longitudinal direction, but also, advantageously, at an angle to their longitudinal extent, thus providing them with an angled, comparatively sharp tip, similar to medical syringe needles. A rotating knife with a circumferential cutting edge can also be used for this purpose if the drinking straws 11 are placed on the conveyor belt not transversely to the conveying direction, but at an angle of a comparatively acute angle. It is also understood that the processing is not limited to a separating or abrasive mechanical treatment, but can also include forming (bending, etc.), for example, if the drinking straws are to have a bent section.

Claims

Method for forming and / or mechanically processing drinking straws made from a starch-based dough, characterized in that the drinking straws (11) are heated before their forming and / or mechanical processing and are formed and / or mechanically processed in the heated state. Method according to claim 1, characterized in that the heating takes place locally in such an area of ​​the drinking straws (11) in which the forming and / or mechanical processing takes place. Method according to claim 1 or 2, characterized in that the drinking straws (11) are heated by convection using a warm, gaseous medium, by thermal radiation and / or thermal conduction using a heat source that can be applied to the drinking straws (11). Method according to claim 3, characterized in that the gaseous medium is hot air (19) and / or dry superheated steam. Method according to claim 3, characterized in that the heat radiation is generated by an infrared emitter or a microwave heat emitter. Method according to one of claims 1 to 5, characterized in that the forming and / or mechanical processing comprises bending the drinking straws at a bending area and / or cutting the drinking straws (11) at a separation area. Method according to one of claims 1 to 6, characterized in that the drinking straws consist of a dry pasta dough. Method according to one of claims 1 to 7, characterized in that the drinking straws (11) are heated to a temperature of 70 - 150 C at least in the subsequently processed area. Method according to one of claims 1 to 8, characterized in that the drinking straws (11) are moved individually by means of a transport device (12), namely a continuous conveyor, first past a heating device (17) which acts upon them for their preferably local heating and are subsequently reshaped and / or mechanically processed by means of a processing device (20) spatially assigned to the continuous conveyor (12). Method according to one of claims 1 to 9, characterized in that the drinking straws (11) are cooled after their forming and / or mechanical processing. Device for shaping and / or mechanically processing drinking straws (11) made of a starch-based dough, comprising a transport device (12) and a processing device (20) associated therewith for mechanically processing the drinking straws supplied individually to the processing device (20) by means of the transport device (12), characterized in that a heating device (17) upstream of the processing device (20) is associated with the transport device (12). Device according to claim 11, characterized in that the heating device (17) has at least one hot air or hot steam ejector (18). Device according to claim 11 or 12, characterized in that the heating device (17) comprises at least one heat radiator and / or a microwave generator. Device according to one of claims 11 to 13, characterized in that the processing device (20) has at least one preferably rotating cutting blade and / or a bending device.

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