pen case

Abstract

Pin sleeve, manufactured by at least the following steps: - Drying of a cellulose compound obtained as a mixture of at least two cellulose granules, - Feeding the dried cellulose compound into an extruder designed for processing cellulose granules, - optional addition of a blowing agent to the cellulose compound introduced into the extruder, - Melting of the cellulose compound introduced into the extruder in the extruder, - Producing a tubular strand from the cellulose compound melt using the extruder, - Calibrating and cooling the tubular strand supplied by the extruder using a vacuum calibration device, - Cutting the calibrated and cooled tubular strand to length to obtain the pin sleeve.

Description

Field of invention

[0001] The present invention relates generally to pen sleeves, such as those used in the cosmetics and stationery sectors, and in particular to pen sleeves made from composite materials comprising renewable raw materials. Background of the invention

[0002] Cosmetic and writing pens with a barrel are generally constructed so that a material is arranged within the hollow barrel, providing the respective cosmetic or writing function of the pen. Examples include, for instance, kohl pencils or eyeliners in cosmetics and, in stationery, pencils.

[0003] Pencil sleeves are typically made of wood or plastic. Wooden pencil sleeves are complex and expensive to manufacture and sometimes require wood species that are only available in limited quantities. Plastic pencil sleeves are made from thermoplastic materials such as polyvinyl chloride (PVC), polypropylene (PP), acrylonitrile butadiene styrene (ABS), and polystyrene (PS). A disadvantage of plastic pencil sleeves is that they may contain reprotoxic substances, emit odors, and be difficult to sharpen.

[0004] From DE 10 2008 034 013 A1 it is known to produce pen sleeves from cellulose by extrusion and to use them, for example, as a sleeve for a cosmetic pen or writing pen. Object of the present invention

[0005] The object of the present invention is to provide solutions for improved novel pin sleeves. Solution of the present invention

[0006] To solve the above problem, the present invention provides items according to the attached independent claims. Preferred embodiments are specified in the dependent claims.

[0007] The present invention provides a pin sleeve which is manufactured in the following manner: - Drying of a cellulose compound obtained as a mixture of at least two cellulose granules, - Feeding the dried cellulose compound into an extruder designed for processing cellulose granules, - optional addition of a blowing agent to the cellulose compound introduced into the extruder, - Melting of the cellulose compound introduced into the extruder in the extruder, - Producing a tubular strand from the cellulose compound melt using the extruder, - Calibrating and cooling the tubular strand supplied by the extruder using a vacuum calibration device, - Cutting the calibrated and cooled tubular strand to length to obtain the pin sleeve.

[0008] Preferably, the pin sleeve has at least one of the following properties: - a melt flow index (MFR) of more than 1.25 g / 10 min at 230°C and a test mass of 2.16 kg, - a tensile strength of more than 32 N / mm2, - an elongation at break of more than 6% - a bending modulus of elasticity of more than 3964 N / mm2, - an impact strength according to Charpy at 23°C of more than 21 kJ / m2, - a Charpy impact strength at 23°C of more than 3 kJ / m2, - a density of more than 1.2 g / cm3, - a migration threshold of more than 2, - a melting stability of more than MVR = 2.

[0009] One aspect of the present invention is to produce pen sleeves based on renewable raw materials, e.g., for the cosmetics or stationery industries. For example, pen sleeve material can be provided that, compared to conventional pen sleeve material (e.g., based on fossil raw materials; e.g., PVC, PP, and AES), has the highest possible proportion of renewable raw materials or essentially comprises only renewable raw materials. According to the invention, a mixture of at least two different types of cellulose granules is used in particular.

[0010] For example, a compound composition, and in particular a biopolymer compound composition, can be used to produce pin sleeves according to the invention. A compound composition can comprise two or more granules, at least one of which can be a mono-granule, i.e., a granule comprising a raw material in granular form.

[0011] The mono-granules are bio-based, meaning they are completely biodegradable and have mechanical properties comparable to impact-resistant plastics such as ABS. Depending on the formulation, they consist of materials such as biopolymers, polyhydroxyalkanoates, polyhydroxyalkanoates, butyrates, polyesters, starches, or lignin, etc.

[0012] The pin sleeve can have at least one of the following additional properties: - essentially no air inclusions in the pin sleeve material, - Heat resistance, - Stiffness, - Impact resistance, - Stress crack susceptibility, - Solvent compatibility, - Sharpening capability with essentially uniform chip formation, - Adhesion of paint or full-surface hot stamping foil (HTF)

[0013] The above properties offer advantages over pencil sleeves made at least partially of plastic. This will be illustrated using the example of sharpenability. Plastic pencil sleeves, such as those used in the cosmetics industry, typically require special sharpeners due to the material. Also due to the plastic material, these sleeves produce a continuous shaving, making sharpening difficult. Furthermore, the shavings pose an environmental hazard. In contrast, pencil sleeves according to the invention do not require special sharpeners; instead, conventional sharpeners from the stationery sector can be used, just as with a traditional wooden pencil. Moreover, pencil sleeves according to the invention produce a uniform, partitioned shaving, resulting in a pleasant sharpening process.The resulting wood shavings are, so to speak, a bio-product, essentially biodegradable and therefore not, or at most only marginally, harmful to the environment.

[0014] The cellulose granules used to manufacture the pin sleeve can comprise one or more different individual granules, which are mixed together (e.g. compounded) according to a recipe depending on the desired pin sleeve properties.

[0015] The pin sleeve can have a wall thickness ranging from 1.0 mm to 8 mm.

[0016] The pin sleeve can have a length ranging from 80 mm to 200 mm.

[0017] The pin sleeve can have an outer diameter ranging from 3 mm to 20 mm.

[0018] The pin sleeve can have an inner diameter ranging from 2 mm to 17 mm.

[0019] The pin sleeve can have at least one helical recess or groove on its inner side. Such a recess or groove can serve to secure a lead to be arranged in the pin sleeve, and / or as a thread by means of which a lead arranged in the pin sleeve can be moved within the pin sleeve, preferably moved out of it.

[0020] The recess or groove can have a depth in the range of 0.1 mm to 0.2 mm.

[0021] The pencil sleeve can have a section at at least one end whose outer diameter decreases towards that end. A pencil sleeve shaped in this way has the advantage, among others, that the end with the decreasing diameter can be more easily inserted into a pencil sharpener.

[0022] In particular, it is intended that the pin sleeve contains no traces of plastic or essentially no plastic at all. In further embodiments, the pin sleeve may contain a small proportion of plastic, e.g., between 5 and 20%, depending on the desired formulation or sleeve properties.

[0023] Furthermore, it is intended that the pen sleeve can be used as a cosmetic pen sleeve or a writing pen sleeve.

[0024] Furthermore, the present invention provides a pin sleeve manufacturing device comprising: - an extruder, - a drying device designed to dry a cellulose compound obtained as a mixture of at least two cellulose granules, - a feeding device designed to feed the dried cellulose compound into the extruder, the extruder being designed for processing cellulose granules and the extruder comprising a melting device designed to melt the introduced cellulose compound and a tool designed to produce a tubular strand from the cellulose compound melt, - a vacuum calibration device designed to calibrate and cool the tubular strand provided by the extruder.

[0025] The pin sleeve manufacturing device can further comprise a blowing agent supply device designed to supply blowing agent to the cellulose compound in the extruder, preferably upstream of the melting device, wherein the blowing agent comprises at least a foaming agent with a low-density polyethylene (LDPE) carrier material.

[0026] The pin sleeve manufacturing device may further comprise a cooling section downstream of the vacuum calibration device, designed to further cool the calibrated tubular strand.

[0027] The pin sleeve manufacturing device may further include a moisture detection device designed and arranged to detect and control the moisture content of the cellulose compound prior to its introduction into the extruder.

[0028] The pin sleeve manufacturing device may further include a dimensional monitoring device designed and arranged to detect the dimensions of the cooled, calibrated tubular strand or the sleeves produced therefrom. In particular, the dimensional monitoring device is designed to monitor the wall thickness and / or the outer diameter and / or the inner diameter of a pin sleeve or the underlying strand, and, depending on the result, to adjust the strand production process as necessary to obtain desired or specified dimensions.

[0029] Furthermore, the present invention provides a method for manufacturing a pin sleeve, which comprises: - Drying of a cellulose compound obtained as a mixture of at least two cellulose granules, - Feeding the dried cellulose compound into an extruder designed for processing cellulose granules and comprising a melting device designed to melt the introduced cellulose compound, as well as a tool designed to produce a tubular strand from the cellulose compound melt, - Melting of the introduced cellulose compound using the melting device of the extruder, - Creating a tubular strand from the cellulose compound melt using the extruder tool - Calibrating and cooling the tubular strand provided by the extruder using a vacuum calibration device.

[0030] In this process, blowing agent can be supplied to the cellulose compound in the extruder before the melting device by means of a blowing agent supply device.

[0031] Preferably, the blowing agent comprises at least one foaming agent with a low-density polyethylene (LDPE) carrier material.

[0032] In this process, the calibrated tubular strand can be further cooled by means of a cooling section downstream of the vacuum calibration device.

[0033] In this process, the moisture content of the cellulose compound can be detected and controlled before it is introduced into the extruder using a moisture detection device.

[0034] In this process, dimensions of the cooled calibrated tubular strand or sleeves produced from it can be recorded using a dimension monitoring device.

[0035] Furthermore, the process may include mixing at least two cellulose granules to obtain the cellulose compound. Brief description of the drawings

[0036] In the following, embodiments of the present invention are described with reference to the accompanying drawings, which show: Fig. 1 Schematic views of a pin sleeve according to the invention in one embodiment, Fig. 2 schematic views of a pin sleeve according to a further embodiment of the invention, Fig. 3 (a) and (b) schematic views of a pen manufacturing device according to the invention.

[0037] Descriptions given for different embodiments also apply to all other embodiments, unless otherwise stated. Furthermore, reference is made below to all drawings as a whole, unless otherwise indicated or specific drawings are referenced. In the drawings, elements that are at least essentially functionally identical have the same reference numerals. Description of preferred embodiments

[0038] Fig. 1 and Fig. Figure 2 shows exemplary embodiments of the pin sleeves according to the invention. Fig. Figure 1 schematically shows a pin sleeve in an embodiment which, compared to the embodiment of Fig. 2 is shorter and has a larger outer diameter.

[0039] The pin sleeves SH shown have an outer surface 2, an inner surface 4, and a wall thickness 6, as well as a rear end 8 and a front end 10. The term "rear end" indicates that this end is the end which is the rear end of a pin manufactured using the pin sleeve SH, or to which a component forming the rear end of a pin manufactured using the pin sleeve SH can be attached. The term "front end" indicates that this end is the end which is the front end of a pin manufactured using the pin sleeve SH, or from which a lead of a pin manufactured using the pin sleeve SH extends (generally).

[0040] A helical recess or groove 12 (hereinafter referred to as recess 12) can be formed on the inner side 4. The recess 12 can be shaped as shown in Fig. 1 and Fig. As shown in Figure 2, the recess extends only over a central region of the inner surface 4. In further embodiments, the recess extends substantially along the entire inner surface 4; extends only adjacent to one of the ends 8 and 10; or extends adjacent to both ends 8 and 10, with an intermediate region of the inner surface 4 having no recess.

[0041] The inner surface 4 defines a substantially constant inner diameter 14. The outer surface 2 defines a substantially constant outer diameter 16, except that the outer diameter may be smaller in the areas adjacent to the ends 8 and 10. For example, a region 18 extends from the front end 10 towards the rear end 8, the outer diameter of which at the front end 10 is substantially equal to the inner diameter 14 and where the region 14 ends is substantially equal to the outer diameter 16. In further embodiments, such a region may also be provided at the rear end 8, either directly or alternatively.

[0042] As shown in the top illustration of Fig. 1, indicated by the reference numeral B, the pin sleeve SH can be elastic in the longitudinal direction, for example so that one of the ends 8 / 10 can be deflected relative to the other end 10 / 8 by a maximum of, for example, 0.1 mm.

[0043] In the embodiment of Fig. For example, 1 is provided with a length L of approximately 80 mm, an inner diameter 14 of approximately 7 mm and an outer diameter 16 of approximately 12 mm.

[0044] In the embodiment of Fig. For example, in 2 a length L of approximately 110 mm, an inner diameter 14 of approximately 4 mm and an outer diameter 16 of approximately 8 mm is provided.

[0045] The area 18 can be designed such that its outer circumferential surface has an opening angle α of, for example, approximately 30° in the direction of the opposite, rear end 8.

[0046] Fig. Figure 3 schematically illustrates a pin sleeve manufacturing device SHHV according to the invention.

[0047] The pin sleeve manufacturing device SHHV comprises an extruder 100, a mixing device with a moisture detection device (not shown), a drying device 104, a feeding device 106, a blowing agent supply device, a vacuum calibration device 110, a downstream cooling section 112, a dimension monitoring device 114 and a cutting device 116.

[0048] The mixing device mixes at least two cellulose granules to obtain a cellulose compound. This compound is then introduced into the drying device 104, where it is dried. The drying process can be monitored and controlled by means of the moisture detection device.

[0049] The dried cellulose compound is introduced into the extruder 100 by means of the feeding device 106.

[0050] As shown, the drying device 104 and the feeding device 106 are arranged adjacent to each other and in particular such that dried cellulose compound can be fed directly from the drying device 104 into the feeding device 106 and from there directly into the extruder 100.

[0051] In further embodiments, the drying device 104 and the feeding device 106 can be spatially separated from each other, which may make it necessary to provide an intermediate device that conveys dried cellulose compound from the drying device 104 to the feeding device 106.

[0052] Blowing agent can be added to the cellulose compound in extruder 100 via the blowing agent feed device. The use of a blowing agent is optional and may be particularly useful when extruder 100 is used to produce fine-celled foam with small cell sizes (e.g., less than 10 µm) and high cell density (e.g., in the range of 10). 9 up to 10 12 cells / cm 3 ) is to be generated.

[0053] The Extruder 100 is specifically designed for processing cellulose granules, optionally with added blowing agents. The extruder is controlled via a digital control panel. Depending on the recipe, the desired process parameters can be saved in the control unit. An X / Y laser is installed before the extruder exit point, automatically reporting deviations to the control panel so that automatic adjustments can be made. The extruder operator is alerted to deviations by a warning light.

[0054] The extruder 100 includes a melting device designed to melt the introduced cellulose compound or, if applicable, the mixture of cellulose compound and blowing agent.

[0055] The extruder 100 has a tool or nozzle through which the cellulose compound melt or the cellulose compound blowing agent melt is forced to produce a tubular strand.

[0056] Processing with the Extruder 100 can be carried out, for example, as explained below. A blowing agent is added to the cellulose compound, and the resulting mixture is melted. The melt is heated to a predetermined melting temperature according to the granulate manufacturer and extruded through the die of the Extruder 100. Due to the pressure drop at the die exit, the melt becomes supersaturated, possibly with blowing agent, leading to its outgassing and the associated cell formation. When extruding microcellular foams, as intended here, homogeneous nucleation of the melt is desired. The nucleation rate can be determined by the proportion of blowing agent; for example, the nucleation rate can be increased by adding more blowing agent to achieve, as mentioned above, a high cell density and narrow cell size distribution. For this purpose, rapid pressure release is crucial for cell nucleation.For example, a pressure relief (also pressure gradient) of 1 GPa / s (i.e. 10,000 bar / s) can be provided.

[0057] The tubular strand of material supplied by extruder 100 is fed to the vacuum calibration device 110 for calibration and cooling. The vacuum chambers are partially filled with a liquid. Several vacuum valves allow for precise chamber control, ensuring an adjustment of the outer diameter accurate to one hundredth of a millimeter.

[0058] In the optional cooling section 112 downstream of the vacuum calibration device 110, the previously calibrated strand can be cooled further.

[0059] Subsequently, at least one dimension of the calibrated and cooled tubular strand can be detected by means of the dimension monitoring device 114 and used to adjust the manufacturing process if necessary, should the detected dimension not be within a predetermined range. In particular, it is intended to detect the outer diameter 14 and / or the inner diameter 16 and the wall thickness 6.

[0060] Using the cutting device 116, pieces, i.e. the pin sleeves to be produced, are cut from the strand in the respective length that the pin sleeves are to have. REFERENCE MARK LIST SH pin sleeve 2 Outside 4 Inside 6 Wall thickness 8 Rear end 10 Front end 12 In-depth study 14 inner diameter 16 outer diameter 18 Area with changing outer diameter L Length Pin Sleeve α Opening angle of the area SHHV pin sleeve manufacturing device 100 extruders 104 Drying device 106 Insertion device 110 Vacuum Calibration Device 112 downstream cooling section 114 Dimensional monitoring device 116 Cutting device

Claims

[1] Pin sleeve, manufactured by at least the following steps: - Drying of a cellulose compound obtained as a mixture of at least two cellulose granules, - Feeding the dried cellulose compound into an extruder designed for processing cellulose granules, - optional addition of a blowing agent to the cellulose compound introduced into the extruder, - Melting of the cellulose compound introduced into the extruder in the extruder, - Producing a tubular strand from the cellulose compound melt using the extruder, - Calibrating and cooling the tubular strand supplied by the extruder using a vacuum calibration device, - Cutting the calibrated and cooled tubular strand to length to obtain the pin sleeve. [2] Pin sleeve according to claim 1, further comprising the step of mixing the at least two cellulose granules to obtain the cellulose compound. [3] Pin sleeve according to claim 1 or 2, wherein the pin sleeve has at least one of the following features: - a melt flow index (MFR) of more than 1.25 g / 10 min at 230°C and a test mass of 2.16 kg, - a tensile strength of more than 32 N / mm 2 , - an elongation at break of more than 6% - a bending modulus of elasticity of more than 3964 N / mm 2 , - an impact strength according to Charpy at 23°C of more than 21 kJ / m² 2 , - a Charpy impact strength at 23°C of more than 3 kJ / m 2 , - a density of more than 1.2 g / cm³ 3 , - a migration threshold of more than 2, - a melting stability of more than MVR = 2. [4] Pin sleeve according to one of the preceding claims, wherein the cellulose granules are composed of mono-granules comprising biopolymers, polyhydroxyalkanoates, polyhydroxyal butyrates, polyesters, starch and lignin. [5] Pin sleeve according to one of the preceding claims, wherein the pin sleeve has at least one helical depression or groove on its inside. [6] Pin sleeve according to one of the preceding claims, wherein the pin sleeve has at least at one end a region whose outer diameter becomes smaller towards the end. [7] Pin sleeve according to one of the preceding claims, wherein the pin sleeve essentially does not contain any plastic. [8] Pin sleeve according to one of the preceding claims, wherein the pin sleeve - a cosmetic pencil case or - a pen barrel. [9] Use of a pen sleeve according to any one of claims 1 to 7 as a pen sleeve for a cosmetic pen or a writing pen. [10] Pin sleeve manufacturing apparatus comprising: - an extruder (100), - a drying device (104) designed to dry a cellulose compound obtained as a mixture of at least two cellulose granules, - a feeding device (106) designed to feed the dried cellulose compound into the extruder (100), wherein the extruder (100) is designed for processing cellulose granules and the extruder (100) comprises a melting device designed to melt the introduced cellulose compound and a tool designed to produce a tubular strand from the cellulose compound melt, - a vacuum calibration device (110) designed to calibrate and cool the tubular strand provided by the extruder. [11] Pin sleeve manufacturing apparatus according to claim 10, further comprising a mixing device designed to mix the at least two cellulose granules to obtain the cellulose compound. [12] Pin sleeve manufacturing apparatus according to claim 10 or 11, further comprising a blowing agent supply device designed to supply blowing agent to the cellulose compound in the extruder (100) prior to the melting device, wherein the blowing agent comprises at least a foaming agent with a low density polyethylene LDPE carrier material. [13] Pin sleeve manufacturing device according to claim 10 or 12, further comprising a cooling section (112) downstream of the vacuum calibration device (110), which is designed to further cool the calibrated tubular strand. [14] Pin sleeve manufacturing apparatus according to one of claims 10 to 13, further comprising a moisture detection device designed and arranged to detect and control the moisture of the cellulose compound prior to its introduction into the extruder (100). [15] Pin sleeve manufacturing device according to one of claims 10 to 14, further comprising a dimension monitoring device (114) designed and arranged to detect dimensions of the cooled calibrated tubular strand or sleeves produced therefrom. [16] Method for manufacturing a pin sleeve, comprising: - Drying of a cellulose compound obtained as a mixture of at least two cellulose granules, - Feeding the dried cellulose compound into an extruder designed for processing cellulose granules and comprising a melting device designed to melt the introduced cellulose compound, as well as a tool designed to produce a tubular strand from the cellulose compound melt, - Melting of the introduced cellulose compound using the melting device of the extruder, - Creating a tubular strand from the cellulose compound melt using the extruder tool - Calibrating and cooling the tubular strand provided by the extruder using a vacuum calibration device. [17] Method according to claim 16, further comprising mixing the at least two cellulose granules to obtain the cellulose compound. [18] Method according to claim 16 or 17, wherein blowing agent is supplied to the cellulose compound in the extruder prior to the melting device by means of a blowing agent supply device, wherein the blowing agent comprises at least a foaming agent with a low density polyethylene LDPE carrier material. [19] Method according to one of claims 16 to 18, wherein the calibrated tubular strand is further cooled by means of a cooling section downstream of the vacuum calibration device. [20] Method according to any one of claims 16 to 19, wherein the moisture content of the cellulose compound is detected and controlled by means of a moisture detection device before being introduced into the extruder. [21] Method according to any one of claims 16 to 20, wherein dimensions of the cooled calibrated tubular strand or sleeves produced therefrom are detected by means of a dimension monitoring device.

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