DE102022114955A1 - Method for producing a tube body, tube body and manufacturing device - Google Patents

Abstract

The present invention relates to a method for producing a tube body (10) for packaging tubes (14), comprising a flexible and thin-walled tube tube (12). According to the invention, the tube tube (12), in particular a single-layer tube blank, is formed from a thermoplastic monomaterial and is created in an injection molding process in a mold (112), the plastic monomaterial being placed in a cavity (120) of the mold (112) is cast between a hollow mold (116) and a core element (118).

Description

The present invention relates to a method for producing a tube body for packaging tubes according to the preamble of claim 1, as well as a tube body and a device for producing such a tube body.

Packaging tubes with a flexible tube body are preferably intended for holding liquid or pasty contents, in particular products from the fields of cosmetics, food, medicine, in particular toothpaste, adhesives or sealants. The tube body can consist of a substantially cylindrical or prismatic tube tube, which is connected and/or connectable to a tube head at a first tube opening. A second tube opening, in particular a tube end, can be closed after filling with the liquid or pasty contents, usually by creating a final seal. The tube tube is preferably designed to be flexible and elastically or plastically deformable in order to be able to close the end of the tube with an end seal. In other words, the tube tube has a preferably circular, elliptical or polygonal cross-sectional shape, whereby when the tube end is closed, the cross-sectional shape can be changed over the entire length of the tube tube. Elastic deformation can be particularly preferred if air is allowed to get into the interior of the tube after a removal process. Plastic deformation may be preferred if inflowing air is to be prevented after the removal process.

The tube body with the flexible tube tube is preferably made of a plastic material that can be easily deformed by hand by a user in order to express the tube contents through an opening hole in the tube head and thus easily dispense a metered amount of the tube contents.

The opening hole in the tube head can be closed by a tube closure, in particular a rotating or folding lid and/or a stopper. The tube closure can additionally include means for detecting initial opening, in particular a removable film or a guarantee band. The tube closure is preferably detachably connected to the tube head, in particular by means of a rotary or snap connection.

The tube head can preferably be divided into a shoulder and neck area, with the shoulder area closing a large part of the first tube tube opening and the neck area having a tube attachment with holding means for the tube closure, in particular an external thread for a rotatable lid or a retaining ring for a push-on lid , trained. The neck area is preferably placed on the shoulder and forms a channel for removing the tube contents.

The primary requirements for the packaging are, on the one hand, the protection of the contents or products contained, in particular protection against outgassing, leakage, ingassing of gaseous ingredients of the contents, external electromagnetic waves, especially in the visible and UV range, and on the other hand Ensuring practical or user-friendly removal of the contents.

With regard to protecting the contents, the material of the tube body can be constructed in multiple layers as a laminate, with a layer element, in particular a barrier element, being integrated into the tube tube as a multi-layer composite. As described above, user-friendly removal of the tube contents can be achieved by using flexible tube materials by deforming the tube body for removal. This deformation also enables particularly easy handling.

As secondary requirements, the packaging should enable a customizable appearance, in particular through printability and a pleasant or user-friendly feel. With regard to these requirements, the tube body can have a further layer element, in particular an outer decorative layer on an outside of the tube tube, which can be printed accordingly and its surface quality can be adapted to a desired feel. In addition, a surface varnish or another transparent laminate layer can preferably serve to protect printing.

A variety of processes are known for producing the tube body. A fundamental distinction is made between multi-stage or discrete production and one-piece or single-stage production, with either the tube head and the tube tube being produced in separate process steps or in a common process step.

The tube body is understood to be a part of the packaging tube that does not include the tube lid and thus encloses the tube contents in the manufactured state. The tube body can therefore comprise a tube tube, a layer element, in particular a decorative layer and/or a barrier element, and the tube head. The cylindrical part in particular is used as a tube of the tube body, which can also be described as a tube tube blank.

The tube tube, in particular also a decorative layer of the tube body, can in principle be formed in a discrete process step by one of the preferred manufacturing methods listed below: extrusion of an endless tube which is cut to length; Forming and longitudinally connecting an optionally already decorated material web into an endless tube with subsequent cutting to length, the longitudinal connecting being able to take place, for example, by gluing, welding, in particular with or without the addition of additional, in particular weldable material, or by pressing; Providing a cut-to-length and optionally already decorated flat material and subsequent tube formation, in particular by wrapping a mandrel, forming a longitudinal connection; Injection molding of the tube tube, optionally in conjunction with an in-mold decoration process for the decorative layer; Reaction Injection Molding (RIM) or Reinforced Reaction Injection Molding (RRIM), whereby an in-mold decoration process can also be added here; Injection molding of a preform and expanding the hot preform in a mold, optionally also in conjunction with an in-mold decoration process for the decorative layer; deep drawing process; Cold flow process.

The tube head, optionally also with a decorative layer, can also be formed in a discrete process step by one of the following preferred manufacturing processes: injection molding, optionally in conjunction with an in-mold decoration process for the decorative layer; Compression molding, optionally in conjunction with an in-mold decoration process for the decorative layer; Reaction Injection Molding (RIM) or Reinforced Reaction Injection Molding (RRIM), here also optionally in conjunction with an in-mold decoration process for the decorative layer; Compression molding, especially in the principle of pressboard production; deep drawing; material-removing processes; Cold flow process.

A tube closure, in particular a lid, can be manufactured essentially in accordance with the aforementioned manufacturing methods of the tube head.

The tube head can be connected to the tube tube in particular by gluing, welding and/or pressing. Alternatively, the tube head can also be connected to a finished tube tube during its production, in particular by injection molding or during a compression molding process, in which the tube tube is introduced into a head mold before forming.

The tube closure can be connected to the tube head in particular by screwing on, plugging on, welding on a joint element located on the tube closure and/or gluing. Sticking is preferably used for tubes that are designed for single use.

It is also conceivable to connect the tube closure and the tube head together to the tube tube in one process step.

The manufacturing steps of the tube tube, tube head and the tube closure can be carried out independently of one another and in particular simultaneously at different locations, with the manufacturing steps preferably being completed before the individual elements are connected to one another.

In an alternative integrative, single-stage or semi-integrative production, the aforementioned manufacturing steps of the tube body can be produced in one process step or in partially combined process steps. It is important to pay attention to a suitable choice of material and/or process.

A tube tube can thus be fed into a mold of the tube head before or during the production of the tube head and can be connected directly. There is no need for a separate connection step.

As a further alternative, the tube tube and tube head can be manufactured in one piece and in a one-piece process step, in particular the tube tube being connected to a tube shoulder. Injection molding processes for plastic materials or biomaterials, in particular a so-called liquid wood, or extrusion processes, in particular for aluminum, are particularly suitable for this.

In addition, in a further manufacturing variant, an alternative one-piece manufacturing process can be selected, in particular an injection molding process, in which the entire packaging tube with tube tube, tube head and tube closure is manufactured in one process step. The tube closure, in particular a lid, can preferably be connected to the tube head by means of a bendable bridge and/or a hinge. In particular for this process step, in addition to an injection molding process, a reactive process can also be used or decorative layers can be used must be attached to a mold before the mold is poured out.

In one-piece production, it is preferred that the material used is flowable, with any, often heated, thermoplastics or flowable metals, in particular cold-formable or castable metals, and substances or mixtures of substances which polymerize and/or crosslink in a mold being suitable. All materials used can be obtained from different raw materials, especially from recycled materials. The substances or mixtures of substances can also contain a proportion of natural or artificial fibers, in particular from wood, liquefied wood, cotton, ceramics, paper, in particular waste paper, bamboo, straw or other fillers, such as minerals, carbon, titanium dioxide, ceramic dust or any plastic additives exhibit. An extreme mixing ratio, in particular 0% fiber content to 99% fiber content, can preferably also be used. Depending on the base material, injection molding, compression molding, deep-drawing, blow molding or casting processes, as well as cold forming, are particularly suitable for one-piece production.

Advantageously, packaging tubes or tube bodies manufactured in one piece can be decorated after their production, preferably by applying a label, printing, hot stamping, cold stamping, lasering, as well as by in-mold processes during production. In an in-mold process, a label is introduced into a mold before shaping and is preferably back-injected or the mold itself has properties that have a decorative influence on the end product. A hologram or a relief can preferably be embossed on the surface of the end product. For example, there are also known decoration processes in which a decorative layer or a label is applied during a deep-drawing process.

In further embodiments, surfaces of the manufactured tube body, in particular a surface on the inside, can be partially or completely provided with additional layer elements after a conversion or the shaping step, in particular by spraying on lacquers, chemical vapor deposition (CVD), for example with SiOx, AlOx , metallization, electroplating, especially with metallic base material and/or by blow extrusion of a film into the tube body. These additional layer elements can, on the one hand, change the mechanical properties of the tube, for example increase the stability or influence the viscoelastic behavior, in particular promote springing back of the tube body after an ejection process through elastic deformation or prevent it through plastic deformation. In addition, the layer elements as barrier elements can improve the permeability properties of the tube body, prevent unwanted material contact of other layer elements with the inside of the tube, reduce UV or other radiation permeability, or reduce undesirable sticking of the tube body produced on the walls of a mold.

As an alternative to the single-stage process, the tube head and tube tube can be produced in a multi-stage manufacturing process in one of the separate process steps mentioned above. Depending on the choice of material, different processes are available for producing the tube. For example, the tube tube can be manufactured by rounding a flat material to form a side seam or by extruding and cutting a tube to length, and the tube head can be molded on, formed in a compression molding process or initially prefabricated and then welded, glued, crimped or in some other way be attached. The flat material can be a mono-material or a multi-layer material in which different layer elements take on different functions, for example the provision of a barrier element, coloring, light protection, particularly good printability of the outermost layer, and special chemical resistance of the innermost layer. Co-extrusion can also be used to achieve a multi-layer structure in extruded tubes. As described above for one-piece production, the head can be made from very different materials, decorated and its surfaces modified. It is also possible to extrude a tube in conjunction with an endless labeling process in which an outer decorative layer is applied continuously during the extrusion process.

An extrusion process of a tube tube is in particular from WO 2015/159234 A1 , the WO 2018/051235 A1 or the WO 2018/203210 A1 already known, wherein the extrusion process is combined with a labeling process in order to apply a decorative film to an outside of the extruded tube directly following the extrusion. The decorative film can be applied to the extruded tube in the molten state and thus firmly connected to it.

In particular, for the production of the tube head, it is possible, regardless of the type of production, subsequently or before attachment to the tube tube or even before molding To use layer elements that, for example, improve the barrier properties of the head or enable the addition of colored stripes when squeezing out the tube. The above-mentioned additional layers on the surfaces can also be applied subsequently to a finished tube body, in particular with or without a tube closure.

Furthermore, tube bodies made of multilayer laminates are known which have layer elements, in particular layers, which are difficult or difficult to weld, with side seams in these layer elements preferably being reinforced by inserting or attaching additional material. Such introduction or attachment of material is preferably also suitable for reliably preventing material contact between inner layer elements of the laminate and the product or contents of the tube body. In particular, the introduction or attachment of additional material is desired if the flowability of the innermost layer elements is not sufficient or the innermost layer is too thin to ensure contact with one another or a connection between the layer elements, in particular due to the material being too thin turns out weak.

The aforementioned manufacturing processes with the corresponding materials used can preferably be combined at least to a large extent in any way in order to produce a packaging tube with a tube body in individual combined or multi-stage process steps.

As already described above, the tube body is constructed in multiple layers to achieve the requirements for packaging tubes, in particular with the aforementioned barrier elements and/or decorative layers. A plastic layer can also be used, onto which a particularly thin adhesive layer (tie layer) is applied together with a barrier element. Furthermore, at least one further layer, in particular at least one plastic, adhesive, barrier and/or UV-impermeable layer, can be applied by means of an additional, preferably thin adhesive layer. In addition, layers can be applied or introduced to ensure haptic properties, in particular inexpensive filling material. A printable plastic layer can be arranged on the layer structure on the outside.

As a result, prior art tube bodies are constructed with a large number of layers made from a wide variety of materials to ensure functional properties for packaging tubes. However, a large number of complex manufacturing steps are required to create and/or connect the layers from different materials. Particularly due to the integration of layers of different materials within the layer structure, subsequent separation of the individual layers is practically impossible, which is why such tube bodies are not recyclable or can only be recycled to a limited extent.

As already described above, various processes can be used to produce tubes, with extrusion processes often also being used for flexible packaging tubes. Functional layer elements, in particular a barrier layer, of the tube can be produced either by coextrusion or in conjunction with a decorative film, with coextrusion in particular forming a non-recyclable multilayer material. Extrusion processes also have the disadvantage that they are very difficult to control for thin wall thicknesses. Particularly for thin-walled and flexible tubes, the tube surface can have waviness and the wall thickness is not homogeneous. In other words, it is difficult to keep a pipe diameter constant along an extrusion direction. In addition, the choice of geometry of a tube body is significantly restricted by the extrusion process, particularly if geometric variations are desired along a longitudinal direction of the tube body.

Extrusion processes also have the disadvantage that a significant amount of waste can occur when starting the extrusion process, which is why the process is not suitable for small batch sizes. In addition, machine costs for implementing the extrusion process are high. Furthermore, a device for carrying out the extrusion process requires a lot of space, in particular for intermediate storage, in order not to have to stop the extrusion process because of corrections to an extrusion head. In particular, the high costs and the space required by these buffers are disadvantages of the extrusion process.

The present invention has set itself the task of proposing a method for producing a tube body that conserves resources as much as possible while avoiding the problems known from the prior art and at the same time increases reproducibility.

Furthermore, the task is to provide a tube body and a device for producing such a tube body.

This object is achieved with regard to the method with the features of independent claim 1, with regard to the tube body with the features of claim 12 and with regard to the device with the features of claim 15. Advantageous embodiments are the subject of the subclaims.

According to the invention, a method for producing a tube body for packaging tubes, comprising a flexible and thin-walled tube tube, is specified, wherein the tube tube, in particular a single-layer tube blank, is formed from a thermoplastic plastic monomaterial and is created in an injection molding process in a mold, the plastic Monomaterial is poured into a cavity of the mold between a hollow mold and a core element.

It was recognized by the present invention that the use of a thermoplastic monomaterial, in particular without intermediate layer elements, provides a product that is particularly easy to recycle. It was also recognized that thin-walled and therefore resource-saving tube tubes can also be produced using an injection molding process. In this context, it was also recognized that plastic monomaterials also remain flowable through a cavity with a thin gap and are suitable for production. In addition, through the use of the injection molding process, it has been found that the casting mold also enables a uniform wall thickness over the entire length of the tube tube for thin-walled tube tubes, with a constant geometry being able to be produced even when the process parameters are varied, in particular in contrast to extrusion methods.

In the context of the invention, a monomaterial is understood to mean a pure, in particular almost pure, material that can be completely reused in a recycling process and without the addition of complex chemical-physical separation processes.

Polyethylene or polypropylene monomaterials are preferably used, which are particularly suitable for a recycling process and reuse as new products, especially in a further injection molding process.

A polyethylene monomaterial is particularly preferably used in the injection molding process. Polyethylene materials are inexpensive and can preferably also be used for the production of other components of a packaging tube, in particular a tube head and/or a tube lid. Advantageously, a packaging tube can be made entirely from a pure polyolefin and the entire packaging tube can be fed into a recycling process.

In the injection molding process and/or in the mold, a plastic monomaterial with a melt flow index of at least 90 g/10min (190°C, 2.16kg), preferably at least 100g/10min (190°C, 2.16kg), is particularly preferred at least 130 g/10min (190°C, 2.16kg) is used, preferably a polyethylene monomaterial, particularly preferably a short-chain polyethylene monomaterial from a recycling process. In particular, such a plastic monomaterial has advantageous flow properties in order to produce a thin-walled tube tube using the injection molding process. For thin-walled tube pipes, the cavity of the mold has a thin gap, in particular with a thin gap distance along a radial direction, with a flow resistance correspondingly also increasing along a longitudinal direction. Due to the longer casting time and early crystallization of the plastic monomaterial, complete filling of the cavity could be prevented. However, the invention has recognized that especially for plastic monomaterials with the melt flow index specified above, flowability is improved in such a way that filling is also possible for thin and at the same time long tubes.

Particular preference is given to using a linear low-density polyethylene material (LLDPE) as the plastic monomaterial, in particular with a melt flow index of 100 g/10min (190°C, 2.16kg) or 130g/10min (190°C, 2.16kg). Alternatively, a polypropylene material with a melt flow index of 110 g/10min (190°C, 2.16kg) is preferably used as the plastic monomaterial.

The flexible tube tube made of the plastic monomaterial produced in the injection molding process preferably has a modulus of elasticity of less than 600MPa. Surprisingly, it has been found that a plastic monomaterial with the aforementioned melt flow index in the manufactured state of the tube tube remains particularly flexible with a low modulus of elasticity and has a high resistance to brittle cracks, in particular stress cracks.

In a preferred injection molding process, granules made of the plastic monomaterial are heated in an injection molding unit using a heating device and then liquefied and introduced into the mold via a screw device. The casting shape, essentially consisting of an outer hollow shape and an inner core element, forms a cavity that specifies the dimensions of the desired tube tube as a mirror-inverted template. The casting mold is particularly preferably made of a metal, in particular hardened steel. During injection, the plastic material flows through the mold in a liquid state and fills the cavity. Preferably, the mold is cooled in the injection molding process, preferably with coolants on the mold, and/or the injection molding process is carried out so quickly that the plastic material arrives at a rear end of the cavity, in particular at a casting stop, before the plastic material stops flowing due to solidification more is possible. Particularly preferably, the mold is kept so cold, in particular just below a crystallization temperature, very particularly preferably 5 ° C to 10 ° C below the crystallization temperature, that the plastic material just remains flowable. A warmer shape could promote flow behavior, but would result in a tube with low rigidity.

Preferably, the tool temperature is kept constantly below the crystallization temperature of the plastic material during the injection molding process. Compared to alternating heating and cooling, providing a constant temperature is energy efficient and can also enable faster cooling after the injection molding process and filling the mold with plastic material.

The casting mold preferably forms the tubular cavity along the longitudinal direction, wherein the annular gap-shaped cavity is formed on a sprue opening corresponding to a first tube tube opening and on a closure side corresponding to a second tube tube opening. Alternatively, it is also conceivable that the cavity on the closure side or the sprue opening is designed in accordance with the shape of a tube head in order to produce a tube tube with a tube head in a single-stage injection molding process.

To improve the flowability of the plastic monomaterial, the cavity in the area of the sprue opening can be designed with a larger gap along the radial direction than on the opposite side of the closure. Flow resistance in the area of the gate opening is therefore reduced and a casting material can be more easily distributed along the longitudinal direction of the cavity.

Preferably, the ends of the cavity are closed at one end with a closure element and at the other end with an injection mold. In the injection molding process, during the injection of the plastic material in the liquid state, it is passed through the injection mold, whereby it is distributed in the cavity along the longitudinal and circumferential directions and flows up to the closure element in order to form the tube shape.

In a preferred embodiment, at least the tube tube is connected on an outside in an in-mold process to a separate, in particular film-shaped, layer element in order to form a decorative layer and/or a barrier element, with the layer element being placed in the hollow shape of the mold in a preferred first step and is held on an inside of the hollow mold by fasteners and/or electrostatic attractive forces. In a preferred second step, the hollow mold is closed with the particularly cylindrical core element in order to form a tubular cavity, and the plastic monomaterial is then poured into the mold through at least one sprue opening.

In this in-mold process, it is particularly preferred to keep the temperature of the mold just below the crystallization temperature of the plastic material in order to avoid exposing the layer element inserted into the mold to temperature-dependent damage, in particular to melting, deformation and/or contraction.

The layer element is preferably designed as the decorative layer, in particular a label or label, in order to decorate the tube tube blank on the outside.

Additionally or alternatively, the layer element can be designed as a barrier element. The decorative layer is particularly preferably connected to the barrier element or has a barrier layer. Very particularly preferably, the layer element is formed from several layers, with an inner layer, which faces the outside of the tube tube blank, being designed as a barrier layer and an outer layer taking on a decorative function of the tube body.

In a particularly preferred embodiment, a weak adhesion promoter, in particular an adhesion promoter layer, is formed between the layer element and the tube tube, the adhesion promoter being designed in such a way that the layer element can be easily removed from a used tube tube. Preferably, the tube tube and/or the layer element can be recycled and/or immediately reused become. A thickness of the adhesion promoter layer is preferably 3 μm.

The adhesion promoter is preferably formed between the tube tube and the inner layer of the layer element, in particular the barrier layer. A thickness of the barrier layer is preferably 10µm to 25µm.

An outer layer of the layer element and thus of the tube body is preferably designed as a paper layer. A thickness of the paper layer is preferably 60µm to 120µm. The paper layer is particularly preferably arranged as an outer layer on the aforementioned barrier layer, with the adhesion promoter layer being formed as the innermost layer. In particular, the paper layer can be particularly easily separated from a barrier layer and recycled. In this context, preferably in this context with the previously mentioned barrier layer with adhesion promoter, the barrier layer can be completely removed from a layer structure of the layer element and can also be recycled or reused. The paper layer has the advantage that it can provide UV protection for the tube body and can therefore form an additional external barrier layer. In addition, a layer element that is at least partially based on paper has the advantage that non-renewable resources can be conserved and can be recycled very easily.

The external arrangement of the layer element on the tube tube can advantageously prevent coextrusion with plastic layers, which in particular simplifies a later recycling process of the tube body. In addition, thanks to the use of a layer element, no dyes are necessary in the plastic monomaterial, which also has a positive effect on the recyclability and processability of the tube body.

The barrier element can preferably be a barrier layer, in particular made of aluminum, plastic with good barrier properties, such as EVOH, PA, PVOH, PET, metallized PET, vapor-deposited ceramics, in particular SiOx and/or AlOx. SiOX and/or AlOx are particularly suitable as barrier layers, since these layers can be formed with a very thin layer thickness and preferably do not have to be separated for reuse. Preferably, the aforementioned barrier element is arranged as an inner layer of the layer element and a material barrier, which in particular retains gaseous ingredients, with an outer layer preferably being formed by the paper layer described above, which in particular enables UV protection for the tube tube and Protects against electromagnetic waves, especially visible light and in the UV wavelength range.

It is also conceivable that a very thin barrier layer is vapor-deposited on an inside of the tube tube in order to improve the barrier properties of the tube tube.

It is also conceivable that one or more RFID chips and/or other electronic circuits can be integrated in the layer element.

A vacuum or a means generating negative pressure is particularly preferably used as a fastening means in the cavity in order to hold the layer element in the mold. Alternatively or additionally, the fastening means can also hold the layer element in the mold electrostatically and/or by means of adhesion, in particular a liquid film.

The layer element is advantageously applied to the outside of the tube tube in order to prevent an integral layer structure between two plastic layers within the tube blank. This results in a layer structure that can be easily detached from the tube tube in a later recycling step, in particular after a recycling step after the tube tube has been completed into a packaging tube and used accordingly.

To produce the tube body, the layer element, in particular with open end sections, is preferably placed in the hollow mold, the end sections preferably either being in abutting contact or partially overlapping one another. Preferably, during the injection molding process, the end sections are connected to one another, in particular welded, in particular through contact with the heated plastic melt and/or the heated mold. This results in the advantage that film-shaped layer elements can be used that are not prefabricated into a cylindrical shape in a previous process step. In this way, an additional process step can advantageously be avoided and insertion of the layer element into the hollow mold can also be made easier.

Preferably, after injection and cooling in an injection molding process, the cast tube tube is removed from the mold. For demolding, the tube tube is preferably demolded by pulling out and/or deforming the core element, the end injection mold and/or the closure element of the mold is opened and the tube tube is removed from the mold, in particular by adjusting the hollow mold.

As soon as the formed and cooling tube has solidified sufficiently, the mold is opened. After demolding, the mold is preferably closed again in order to enable a further injection molding process.

Preferably, a core element that is adjustable along a radial direction, in particular a folding core, is used to remove or close the mold. In a preferred embodiment, the core element has at least three first and at least three second core segments or an integer multiple thereof along the circumferential direction, with the first and second core segments each being arranged alternately along the circumferential direction. The first core segments have a larger circumference than the second core segments and form sliding surfaces for the second core segments on an inside. In order to adjust the core element along the radial direction, the second core segments are first adjusted uniformly and then the first core segments are adjusted.

Particularly preferably, in a casting mold setup process, replaceable inserts, in particular at least one sleeve, can be inserted on a closure side of the mold opposite the injection mold, in particular an injection or injection opening, with the hollow mold and the core element then being closed in order to fix the inserts, and wherein the insert means form a casting stop on a side opposite the injection mold, wherein in the injection molding process the tube tube is cast with a length reduced by a width of the insert means. In other words, the cavity between the hollow mold and the core element on a side opposite the injection mold is preferably delimited by the insert means as adjustable casting stops in order to cast tube pipe blanks with different lengths. In particular, the insert means can be used to adjust the length of a tube tube blank to be produced without having to redesign or change the mold itself.

Preferably, the insert element is designed such that a length of the cavity along the longitudinal axis of the mold and thus a length of a tube tube that can be produced can be shortened.

The insert element is particularly preferably ring-shaped or cylindrical, preferably made of a metal. In particular for cylindrical cavities, a length of the cavity of the mold along the longitudinal axis can also be varied by selecting the width of the insert element, in particular along the longitudinal direction. Advantageously, a hollow mold can be adapted in this way without having to change the entire, particularly expensive, casting mold. In particular, analogous to extrusion processes, the length of a tube body can be easily adjusted.

In a further preferred embodiment, the insert element can be cup-shaped and the core element can be designed to enclose the end, such an insert element preferably being connectable or connected to the closure element by a fastening element, in particular a screw connection.

The use of an insert element also has the advantage that one mold can be used for different materials. Thus, a material with limited fluidity can be used by shortening the length of the cavity.

It is particularly preferred to use the core element, which is adjustable in the radial direction, in particular a folding core, for inserting the insert into the mold. The inserts, in particular the at least one sleeve, are preferably placed in the hollow mold in an open state of the casting mold. The core element is then adjusted along the radial direction in order to form the cavity in the mold and to fix the inserts. In particular, a contact pressure can be formed on the insert means along the radial direction in order to enable a sealed casting stop along the longitudinal direction of the casting mold.

In other words, the means of use are understood to mean, in particular, mold inserts, preferably in a cylindrical sleeve shape, whereby one or more sleeves with a predefined width could preferably be used to adjust a length in order to be able to flexibly adjust a desired length of the tube tube to be produced. The insert means are particularly preferably adapted to the shape of the cavity in order to enable positive insertion.

In a further preferred embodiment, in the injection molding process, the plastic monomaterial is guided through a plurality of sprue openings in the injection mold of the casting mold into the cavity between the hollow mold and the core element. It is preferred that the injection mold is tube-shaped on one end side along the longitudinal axis of the gene, in particular cylindrical, cavity is arranged and the sprue openings are preferably arranged evenly spaced along a circumferential direction of the cavity. This can advantageously improve flow behavior through the mold and also use plastic monomaterial with a low melt flow index.

Furthermore, it is preferably provided that in the injection molding process the plastic monomaterial is guided through at least one flow channel formed on an outside of the core element through the cavity between the hollow mold and the core element from the injection side along the longitudinal direction of the cavity to the closure side of the mold.

Preferably, the at least one flow channel is formed in the core element so that the outside, in particular the surface, of the tube tube produced is not changed and the at least one flow channel also does not influence a connection method with a layer element on the outside of the tube tube.

Particularly preferably, the at least one flow channel is aligned along the longitudinal direction of the cavity, wherein in the injection process the thermoplastic cast material flows more quickly from an injection side through the at least one flow channel and as soon as the at least one flow channel is filled, the cavity, in particular between a plurality of flow channels, through a combined Flow is filled in the longitudinal and circumferential directions. This allows the flow of the plastic monomaterial to be accelerated and/or the injection molding process to be suitable for materials with a low melt flow index.

Particularly preferably, several, in particular three, flow channels are formed along the longitudinal direction in the core element, which are further preferably evenly distributed along the circumferential direction.

In a further preferred embodiment, the at least one flow channel can be formed helically along the longitudinal direction in the core element in order to improve distribution of the plastic monomaterial along the longitudinal and at the same time the circumferential direction.

In a preferred injection molding process, a ratio of a length to a wall thickness of the tube tube produced by injection molding is greater than 300, preferably greater than 400, the wall thickness preferably being between 0.35mm and 0.6mm. In particular, with the previously described plastic monomaterial with good flow properties, a particularly thin and relatively long tube tube can be produced using the injection molding process.

More preferably, a length of the tube tube is between 60mm and 200mm and/or a diameter of the tube tube is between 25mm and 65mm.

In a further embodiment, additives, in particular wax-like additives, can be added to a thermoplastic starting material before entering the mold in order to improve the flowability of the plastic monomaterial. Preferably, wax is mixed into the starting granulate to achieve a low average molecular weight and a high melt flow index.

To produce the tube body, comprising the tube tube described above and a tube head, the tube head is preferably molded onto the tube tube in a compression molding process and connected to the tube tube.

In particular, a two-stage production of the tube head and tube tube has the advantage that significantly simpler molds can be used and if the geometry of one of the components changes, only one mold has to be adjusted. Particularly with such a change in geometry, there are cost advantages for a two-stage manufacturing process.

The tube head is preferably also made from a plastic monomaterial, preferably at least the base material, in particular a polyethylene or polypropylene material, of the tube head and the tube tube being identical. In one embodiment, it may be preferred that different types of polyethylene or polypropylene are used for the tube head and the tube tube, in particular with differences in molecular weight distribution and/or color additives. However, it is particularly preferred to use identical monomaterials in order to improve recyclability as much as possible.

In particular, if the tube tube has projections or support points corresponding to the sprue opening of the mold, the tube head is preferably attached to this sprue end of the tube tube in such a way that the projections are hidden by the head material.

The invention also relates to a tube body, which is produced in particular according to a method mentioned above, comprising a flexible and thin-walled tube tube, wherein the tube tube, in particular a single-layer Tube tube blank, formed from a thermoplastic plastic monomaterial and can be produced or manufactured in an injection molding process.

In a preferred embodiment, the tube tube is connected or connectable on an outside to a separate, in particular film-shaped layer element, which forms a decorative layer and/or a barrier element.

Particularly preferably, the layer element is a barrier element which is designed as a laminate, with a layer facing the tube tube assuming a barrier function and an outer layer being designed as a decorative layer. Preferably, the previously described layer element is used, in particular with an inner, easily removable adhesion promoter layer, a barrier layer and/or an outer paper layer.

The layer element preferably has end sections which are connected along the longitudinal direction and form a connection point, in particular a butt-shaped arrangement of the end sections. In particular, such a layer element can be used advantageously in the previously described in-mold process, whereby in particular insertion into the mold can be simplified.

Further preferably, the tube tube has projections on an inside, in particular strut-shaped projections, which are formed by means of a casting mold with at least one flow channel in an outside of a core element. The projections have the advantage that the remaining wall thickness of the tube tube can be further reduced for a given material, which leads to an overall reduction in material. In addition, the stability of the tube tube is reinforced by the projections, in particular by strut-shaped projections formed along the longitudinal direction of the tube tube. In particular, tube bodies with thin walls may tend to collapse during use and/or no longer be able to stand on the lid, such instability being advantageously prevented by the projections.

The invention also relates to a packaging tube with a previously described tube body, comprising a tube tube, a tube head and preferably a tube lid, the packaging tube being made from a thermoplastic type of plastic, in particular a polyethylene material, particularly preferably a polyethylene monomaterial.

The plastic material can be a type of plastic, for example a polyethylene or a polypropylene material, although these can still have different compositions. This makes the recycling process easier, but still offers advantages in terms of the processing and requirements of the different components.

Alternatively or particularly preferably, the packaging tube can be made from a plastic monomaterial in order to improve the recyclability of the entire packaging tube.

The invention also relates to an injection molding device for producing a tube body, in particular according to a method mentioned above, with a mold, the device having an injection molding unit with a heating device and an extruder device in order to convey a thermoplastic plastic monomaterial into the mold, the Casting mold forms a particularly cylindrical cavity by means of a hollow mold and a core element.

In a preferred embodiment, the device has a mold which has a plurality of injection openings on an injection mold, which are distributed along a circumferential direction, in particular at uniform intervals, in order to distribute the plastic monomaterial in the cavity. By using multiple injection openings, the plastic monomaterial introduced in the injection molding process can advantageously be distributed more evenly over the cavity, thereby enabling in particular the formation of very thin-walled and/or long tube tubes.

Preferably, the mold has at least one flow channel on an outside of the core element, in particular in a longitudinal direction, in order to distribute the plastic monomaterial in the cavity.

In a particularly preferred embodiment, the casting mold between the hollow mold and the core element on a closure side opposite an injection mold has an exchangeable insert, in particular at least one sleeve, in order to reduce the cavity between the hollow mold and the core element along a longitudinal direction and a casting stop for a length adjustment of the tube tube to be produced.

In this context, the casting mold advantageously has a core element that is adjustable or deformable along a radial direction in order to be able to place the insert means within the hollow mold and then fix it.

Further advantages and details of the invention emerge from the following description of preferred embodiments of the invention and from purely schematic drawings.

• 1 a: eine perspektivische Ansicht eines Tubenrohrs,
• 1 b: eine Querschnittsansicht entlang einer Längsrichtung L einer Spritzgussvorrichtung,
• 2a: eine Querschnittsansicht des Tubenrohrs gemäß der 1a in einer Ebene senkrecht zu der Längsrichtung L und mit einem Schichtelement,
• 2b: eine Querschnittsansicht auf die Spritzgussvorrichtung gemäß der 1 b mit einem Schichtelement in einem Hohlraum einer Gussform,
• 3a: eine Querschnittsansicht auf ein Kernelement der Spritzgussvorrichtung gemäß der 1b in einer Ebene senkrecht zu der Längsrichtung L,
• 3b: eine Querschnittsansicht auf das Kernelement gemäß der 3b in einem entlang einer Radialrichtung R geöffnetem Zustand,
• 4a: eine Querschnittsansicht der Spritzgussvorrichtung gemäß der 1b in einem geöffneten Zustand und mit Einsatzmitteln,
• 4b: eine Querschnittsansicht der Spritzgussvorrichtung gemäß der 4a in einem geschlossenen Zustand,
• 4c: eine Querschnittsansicht der Spritzgussvorrichtung gemäß der 4b mit einem becherförmigen Einsatzmittel,
• 5a: eine Querschnittsansicht auf das Kernelement gemäß der 3a mit Fließkanälen,
• 5b: eine Querschnittsansicht der Spritzgussvorrichtung gemäß der 1b mit einem Kernelement gemäß der 5a,
• 6a: Querschnittsansicht entlang der Längsrichtung L auf einen Tubenkörper mit Tubenrohr und Tubenkopf,
• 6b: eine perspektivische Ansicht des Tubenkörpers gemäß der 6a,
• 7a: eine perspektivische Ansicht auf eine Einspritzeinheit einer Spritzgussvorrichtung mit mehreren Einspritzformen,
• 7b: eine perspektivische Ansicht auf eine Spritzgussvorrichtung mit mehreren Gusseinheiten und
• 8: eine Draufsicht auf eine automatisierte Fertigungsanlage für die Herstellung von Verpackungstuben.

Show it:

• 1 a : a perspective view of a tube tube,
• 1 b : a cross-sectional view along a longitudinal direction L of an injection molding device,
• 2a : a cross-sectional view of the tube according to the 1a in a plane perpendicular to the longitudinal direction L and with a layer element,
• 2 B : a cross-sectional view of the injection molding device according to 1 b with a layer element in a cavity of a mold,
• 3a : a cross-sectional view of a core element of the injection molding device according to 1b in a plane perpendicular to the longitudinal direction L,
• 3b : a cross-sectional view of the core element according to 3b in a state opened along a radial direction R,
• 4a : a cross-sectional view of the injection molding device according to 1b in an open state and with resources,
• 4b : a cross-sectional view of the injection molding device according to 4a in a closed state,
• 4c : a cross-sectional view of the injection molding device according to 4b with a cup-shaped insert,
• 5a : a cross-sectional view of the core element according to 3a with flow channels,
• 5b : a cross-sectional view of the injection molding device according to 1b with a core element according to 5a ,
• 6a : Cross-sectional view along the longitudinal direction L of a tube body with tube tube and tube head,
• 6b : a perspective view of the tube body according to the 6a ,
• 7a : a perspective view of an injection unit of an injection molding device with several injection molds,
• 7b : a perspective view of an injection molding device with several casting units and
• 8th : a top view of an automated production line for the production of packaging tubes.

The same elements or elements with the same function are provided with the same reference numbers in the figures.

The 1a shows a tube body 10 for packaging tubes, which comprises a flexible and thin-walled tube tube 12, in particular a tube tube blank for further processing into the packaging tube. The tube tube 12 shown is in particular formed in a single layer from a thermoplastic monomaterial. In other words, the tube tube 12 forms a main or base layer of the tube body 10, preferably no material compositions of different polymers or a multi-layer structure being used in this base layer in order to improve the recyclability of the tube body 10 and thus also of the packaging tube.

As well as from the 1a can be seen, it is preferably a very thin-walled tube tube 12 with a preferred wall thickness t between 0.35mm and 0.6mm, with a length l of the tube tube 12 preferably being between 60mm and 200mm. A diameter d of the tube tube 12 is preferably between 25 mm and 65 mm, in particular an outside diameter. This results in a particularly high ratio of length l to wall thickness t of greater than 300, preferably greater than 400, whereby the invention has surprisingly recognized that such tube tubes 12 can also be produced from the plastic monomaterial using the injection molding process. On the one hand, the thin-walled tubes 12 have the advantage that they are flexible and preferably elastically deformable, and require a small amount of material and thus conserve resources. Preferably through the use of the plastic monomaterial, the tube body 10 is particularly easy to recycle, especially in comparison to a tube tube constructed like a laminate.

In the 1b is an injection molding device 100 with a mold 112 shown, which is essentially formed from a hollow mold 116 and a core element 118 to create a, in particular cylindrical, cavity 120 for producing the in the 1a to form the tube tube 12 shown. To introduce a casting material, the casting mold 112 has an injection mold 114, with a closure element 122 being arranged on a side opposite the injection mold, which forms a casting stop 124 of the casting mold 112. The injection mold 114 is preferably connected to an injection molding unit, not shown, with a heater device and a conveyor device as part of the injection molding device 100 connected or connectable in order to convert the thermoplastic plastic monomaterial into a flowable, in particular molten, state and to convey it into the mold 112 through feed channels 126 in the injection mold 114.

Corresponding to the aforementioned dimensions of the tube tube 12, the cavity 120 is also dimensioned as a type of negative mold, whereby it has been shown that a plastic monomaterial can flow or flows through the very thin gap of the cavity 120 along the longitudinal direction L, even in the injection molding process. It has been particularly found that plastic monomaterials with a melt flow index of at least 90 g/10min (190°C, 2.16kg), preferably at least 100g/10min (190°C, 2.16kg), most preferably at least 130g/10min (190°C, 2.16kg) are suitable for the production of thin-walled tube tubes 12 by injection molding.

In a method for producing the tube tube 12, the thermoplastic plastic monomaterial is preferably melted, fed to the injection mold 114 and poured through at least one sprue opening 128 into the cavity 120 between the hollow mold 116 and the core element 118, the plastic material being cast along the longitudinal direction L up to flows through the cast stop 124 and fills the cavity 120.

In the 2a is the cross section of a preferred embodiment of the tube body 10 with the tube tube 12 shown, with a separate, in particular film-shaped layer element 18 being arranged on an outside 16 of the tube tube 12, which preferably forms a decorative layer and / or a barrier element of the tube body 10.

The layer element 18 is preferably designed as a barrier element, in particular with a layer thickness of 10 μm to 25 μm, and a paper layer, in particular with a layer thickness of 60 μm to 120 μm. The layer element 18 preferably has a weak adhesion promoter layer, in particular with a layer thickness of 2 μm, in order to connect the barrier element to the outside 16 of the tube tube 12. The paper layer is preferably connected to the barrier element and thus forms the outermost layer 17 of the tube body 10. In particular, the use of a paper layer can preferably represent a decorative layer and additionally a barrier function, in particular protection against external influences such as electromagnetic waves, in particular UV radiation. The use of the adhesion promoter layer has the advantage that the layer element 18 can be easily separated from the tube tube 12 again after the tube body 10 has been used, so that the tube tube 12 can be fed into a recycling process. The paper layer can also be very easily separated from the barrier element in order to be able to recycle or immediately reuse the barrier element.

Particularly preferred is the layer element 18 in an in-mold process in the injection molding device 100 according to 2 B connected to the tube tube 12. In a preferred first step, the layer element 18 is inserted into the hollow mold 116 of the casting mold 112 and held on an inside 130 of the hollow mold 116 by fastening means, not shown here. Particularly preferably, a vacuum channel (not shown) can be formed in the injection molding device 100, in particular between the hollow mold 116 and the closure element 122, in order to convey the layer element 18 into the cavity 120 and/or fix it therein by applying a negative pressure.

Subsequently, in a preferred second step, the hollow mold 116 is closed with the core element 118 in order to form the tubular cavity 120. The layer element 18 is located in the cavity 120 while in a preferred third step the plastic monomaterial is poured into the mold 112 through the at least one sprue opening 128 and the layer element 18 is thus back-injected.

The layer element 18 is preferably a thin-walled film which only takes on a tubular shape when it is placed into the mold 112. In particular, the 2a can be removed, that the layer element 18 preferably has end sections 20a, 20b, which are arranged in a joint or partially overlapping manner after being inserted into the hollow mold 116. The end sections 20a, 20b are preferably connected to one another in the aforementioned third method step to form a seam 22, in particular by at least partially melting the layer element 18.

Following the aforementioned injection molding process, the tube body 10 produced can be removed from the mold by pulling out and/or deforming the core element 118, with the closure element 122 and/or the injection mold 114 first being opened and then the tube body 10 being removed from the mold 112. Preferably, the tube body 10 is blown out of the mold 112.

In a preferred embodiment, for demoulding the tube body 10 or for preparing the mold 112 in a setup process, a core element 118 which is adjustable along a radial direction R is used according to FIG 3a and 3b used, with the tube body 10 being sketched as a dashed line. Preferably, the core element 118 has first core segments 132a and second core segments 132b, which are arranged alternately along a circumferential direction U. The first core segments 132a contribute more to the circumference than the second core segments 132b and form sliding surfaces 133 for the second core segments 132b on an inside. In order to adjust the core element 118 along the radial direction R, the second core segments 132b are first adjusted uniformly in the radial direction and then the first core segments 132a are adjusted. Such an adjustment of the core element 118 is in an adjusted state in the 3b shown, wherein the core element 118 detaches from an inside of the tube body 10 and is thus released for removal.

In the 4a and the 4b A particularly preferred embodiment of the injection molding device 100 is shown, wherein in order to reduce the size of the cavity 120 along the longitudinal direction L, the injection molding device has replaceable inserts 134 on a closure side 135 opposite the injection mold 114. The insert means 134 are preferably designed as a sleeve, as shown here, or several sleeves with predetermined widths b in order to be able to adjust a length l of the cavity 120 along the longitudinal direction L depending on the width b of the sleeve and/or the number of sleeves used .

To produce a tube tube 12 with a reduced length I, the replaceable insert means 134 is preferably inserted into the mold 112 on the closure side 135 in a setup process, with the hollow mold 116 and the core element 118 then being shaped accordingly 4b be closed to fix the inserts 134. Alternatively or additionally, the insert means 134, in particular the at least one sleeve, can preferably have a projection, not shown, which cooperates with a groove, not shown, in the hollow mold 116, in particular as a snap lock, in order to fix the insert means 134.

The insert means 134 preferably delimit the cavity 120 on a side opposite the injection mold 114 and thus form a casting stop 124 which is offset along the longitudinal direction L compared to the closure element 122. In a preferably subsequent injection molding process, a tube tube 12 is cast with a length l reduced by the width b of the insert 134.

Preferably, in the setup process for inserting the inserts 134, the previously described core element 118, which is adjustable along the radial direction R, is used 3a and 3b used to open the cavity 120 between the core element 118 and the hollow mold 116 and thus facilitate the insertion of the inserts 134. In particular, through the radial adjustment, the insert means 134 can also be clamped against the hollow mold 116 in order to form a sealed cast stop 124. In this context, a wall thickness of the sleeve-like insert means 134 is preferably selected to be slightly larger than a gap thickness of the cavity 120.

In the 4c a further embodiment of the insert means 134 is shown, which are in particular cup-shaped or designed as a cup element and engage around the core element 118 on the closure side 135. More preferably, the cup-shaped insert means 134 can be connected to the closure element 122 with a fastening element 137, in particular a screw connection, and/or connected to the mold 112 in the assembled and closed state. In particular, such an embodiment has the advantage that it is positioned within the mold 112 through the use of the fastening element 137 and is secured against slipping. Analogous to the previously described resources 134, the ones in the 4c shown cup-shaped insert means 134 can adjust, in particular shorten, the length l of the cavity 120 along the longitudinal direction L by a suitable choice of the width b.

In a further preferred embodiment, the injection molding device 100 in the injection mold 114 has a plurality of sprue openings 128 in order to distribute and introduce the plastic monomaterial in the liquid state evenly along the circumferential direction U onto the cavity 120 in the injection molding process. The multiple sprue openings 128 are in particular the 2 B to be taken, whereby the 2a correspondingly shows a tube tube 12 manufactured with several injection openings 128. It may be preferred that the core element 118 has recesses (not shown) at the sprue openings 128, which correspondingly lead to projections 24, in particular three projections 24, on an inside 22 of the tube tube 12. In particular, the gate openings 128 and the recesses are arranged evenly distributed along the circumferential direction U.

It is also conceivable that according to the 5a and the 5b To improve the flowability of the cast plastic monomaterial, the casting mold 112 has at least one flow channel on an outer side 136 of the core element 118, preferably the three flow channels 138 shown here, which are particularly preferably arranged in accordance with the aforementioned sprue openings 128 along the circumferential direction U. During the injection molding process, the flow channels 138 serve to guide the molten plastic monomaterial from the gate opening 128 or an injection side 140 in the mold 112 along the longitudinal direction L of the cavity 120 to the closure side 135. The flow channels 138 form a locally lower flow resistance in order to guide the plastic monomaterial therein in an improved manner along the longitudinal direction L and then distribute it evenly along the circumferential direction U over the cavity 120. Alternatively or additionally, it is conceivable that the at least one flow channel 138 is wound helically along the longitudinal direction L around the core element 118 in order to enable a preferred distribution both along the longitudinal direction L and the circumferential direction U.

In the 6a and the 6b the tube body 10 is shown with the tube tube 12 and a tube head 26, the tube head 26 preferably being connected to the tube tube 12 in a separate process step. A compression molding process is particularly preferably used to form the end of the tube head 26 onto the tube tube 12. Particularly preferred is the tube head 26 on a sprue side 28 of the tube tube 12 according to 1a and the 6a molded onto the tube tube 12 in order to incorporate or cover projections 24 on the inside 22 of the tube tube 12 in the compression molding process.

The tube head 26 preferably has a shoulder 30 and a threaded element 32, as well as a filling opening 34, the threaded element 32 being designed for releasable connection to a tube lid, not shown. In a further method step, the tube body 10 can be filled and closed on a side opposite the tube head 26, in particular by compressing and welding the flexible tube tube 12.

In the 7a and the 7b an embodiment of the injection molding device 100 is shown with a casting unit 142, which contains several molds, here two molds 112 in an injection molding tool, in order to be able to produce several tube tubes 12 in parallel in one process step. This shows 7a an injection unit 144 with two injection molds 114, with feed channels 126 of the two injection molds 114 being connected to one another in order to advantageously be able to injection mold the plastic monomaterial via a feed opening 146 into several tube tubes 12. Advantageously, the production of tube tubes 12 can be accelerated in this way. In the 7b the casting unit 142 is shown in a closed state, with a closure unit 148 being arranged opposite the injection unit 144.

The 8th shows a preferred manufacturing system for producing a packaging tube, preferably in a first manufacturing station 150a, preferably several tube tubes 12 being cast in parallel in a casting unit 142 and then being transferred to a carrier device 152. The carrier device 152 preferably sorts the tube tubes 12 into a storage device 154. In a preferred second production station 150b, the tube tubes 12 are connected to tube heads 26, preferably in a compression molding process. In a preferred third manufacturing station 150c, the tube bodies 10 with tube tube 12 and tube head 26 can be connected to a tube lid, preferably by the tube lids being fed to the tube head 26 by a lid feed system 156. The tube bodies 10 can then be packaged in a preferred fourth production station 150d.

Reference symbol list

10

tube body

12

tube tube

14

Packaging tube

16

Outside of the tube tube

17

Outermost layer of the tube body

18

Layer element

20a,b

End sections of the layer element

22

Inside of the tube tube

24

Projections

26

tube head

28

sprue side

30

Tubal shoulder

100

Injection molding device

112

mold

114

Injection mold

116

Hollow shape

118

core element

120

cavity

122

Closure element

124

Cast stop

126

Feed channels

128

sprue opening

130

Inside of the hollow mold

132a,132b

first and second core segments

133

sliding surface

134

resources

135

Closing side

136

Outside of the core element

137

Fastening element of the insert

138

Flow channels

140

injection side

142

Casting unit

144

Injection unit

146

feed opening

148

Locking unit

150a,b,c,d

first, second, third and fourth production stations

152

Carrier device

154

Storage device

156

Robot arm

I

Length of the tube tube

t

Wall thickness of the tube tube

d

Diameter of the tube tube

b

Breadth of resources

L

Longitudinal direction

U

Circumferential direction

R

Radial direction

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2015/159234 A1 [0026]
• WO 2018/051235 A1 [0026]
• WO 2018/203210 A1 [0026]

Claims (18)

Method for producing a tube body (10) for packaging tubes, comprising a flexible and thin-walled tube tube (12), characterized in that the tube tube (12), in particular a single-layer tube blank, is formed from a thermoplastic monomaterial and in an injection molding process in one Mold (112) is created, wherein the plastic monomaterial is poured into a cavity (120) of the mold (112) between a hollow mold (116) and a core element (118). Procedure according to the Claim 1 , characterized in that in the injection molding process and / or in the mold (112) a plastic monomaterial with a melt flow index of at least 90 g / 10min (190 ° C, 2.16kg), preferably at least 100 g / 10min (190 ° C, 2.16kg), very preferably at least 130 g / 10min (190 ° C, 2.16kg) is used, preferably a polyethylene monomaterial, particularly preferably a short-chain polyethylene monomaterial from a recycling process. Procedure according to the Claim 1 or 2 , characterized in that the tube tube (12) is connected on an outside (16) in an in-mold process to a separate, in particular film-shaped layer element (18) in order to form a decorative layer and / or a barrier element, - the layer element ( 18) is placed in the hollow mold (116) and held by fasteners on an inside (130) of the hollow mold (116), - the hollow mold (116) is closed with the particularly cylindrical core element (118) to form a tubular cavity (120) - and wherein the plastic monomaterial is then poured into the mold (112) through at least one sprue opening (128). Procedure according to one of the Claims 1 until 3 , characterized in that the tube body (10) is removed from the mold by pulling out and/or deforming the core element (118), an end-side injection mold (114) and/or a closure element (122) of the mold (112) being opened and the tube body ( 10) is removed from the mold (112), in particular by adjusting the hollow mold (116). Procedure according to one of the Claims 1 until 4 , characterized in that in a mold setting process, replaceable inserts (134), in particular at least one sleeve, are inserted on a closure side (135) of the mold (112) opposite an injection mold (114), the hollow mold (116) and the core element ( 118) are then closed in order to fix the insert means (134), and wherein the insert means (134) form a casting stop (124) on a side opposite the injection mold (114), wherein in the injection molding process a tube tube (12) with a um a width (b) of the input means (134) is cast to a reduced length (I). Procedure according to one of the Claims 1 until 5 , characterized in that in the injection molding process the plastic monomaterial is guided into the cavity (120) through a plurality of sprue openings (128) in an injection mold (114) of the mold (112). Procedure according to one of the Claims 1 until 6 , characterized in that in the injection molding process the plastic monomaterial is passed through at least one flow channel (138) formed on an outer side (136) of the core element (118) through the cavity (120) from an injection side (140) along a longitudinal direction (L) of the Cavity (120) is guided to a closure side (135) of the mold (112). Procedure according to one of the Claims 1 until 7 , characterized in that a ratio of a length (I) to a wall thickness (t) of the tube tube (12) produced by injection molding is greater than 300, preferably greater than 400, the wall thickness (t) preferably being between 0.35mm and 0.6mm . Procedure according to one of the Claims 1 until 8th , characterized in that a length (I) of the tube tube (12) is between 60mm and 200mm and/or a diameter (d) of the tube tube (12) is between 25mm and 65mm. Procedure according to one of the Claims 1 until 9 , characterized in that additives, in particular wax-like additives, are added to a plastic starting material before entering the mold (112) in order to improve the flowability of the plastic monomaterial. Procedure according to one of the Claims 1 until 10 , characterized in that the tube body (10) comprises a tube head (26), the tube head (26) being molded onto the tube tube (12) in a compression molding process and connected to the tube tube (12). Tube body, in particular produced by a process according to Claims 1 until 10 , comprising a flexible and thin-walled tube tube (12), wherein the tube tube (12), in particular a single-layer tube tube blank, is formed from a thermoplastic monomaterial and can be produced or manufactured in an injection molding process. tube body after Claim 12 , characterized in that the tube tube (12) is connected or connectable on an outside (16) to a separate, in particular film-shaped layer element (18), which forms a decorative layer and / or a barrier element. Packaging tube with a tube body (10) according to one of the Claims 12 or 13 , comprising a tube tube (12), a tube head (26) and preferably a tube lid, the packaging tube (14) being made from a thermoplastic type of plastic, in particular a polyethylene material, particularly preferably a polyethylene monomaterial. Injection molding device for producing a tube body (10), in particular according to a method according to Claims 1 until 11 , with a mold (112), the injection molding device (100) having an injection molding unit with a heating device and an extruder device in order to convey a thermoplastic plastic monomaterial into the mold (112), the mold (112) being formed by means of a hollow mold (116 ) and a core element (118) forms a particularly cylindrical cavity (120). Injection molding device according to the Claim 15 , characterized in that the casting mold (112) has an injection mold (114) with a plurality of sprue openings (128) which are distributed along a circumferential direction (U), in particular at uniform intervals. Injection molding device according to the Claim 15 or 16 , characterized in that the mold (112) has at least one flow channel (138) in a longitudinal direction (L) on an outer side (136) of the core element (118) in order to move the plastic monomaterial along the longitudinal direction (L) in the cavity ( 120) to distribute. Injection molding device according to one of the Claims 15 until 17 , characterized in that the casting mold (112) has replaceable insert means (134) between the hollow mold (116) and the core element (118) on a closure side (135) opposite an injection mold (114), in particular at least one sleeve which covers the cavity ( 120) along a longitudinal direction (L) and form a cast stop (124) in order to adjust the length of the cast tube tube (12).

Images