Manufacturing process for objects having microstructures, materials and uses of materials

Abstract

The present invention relates to a process for manufacturing an object having a microstructure. In the manufacture of the object, an injection mould is used which has an inverse structure to the desired microstructure of the object, the inverse structure of the injection mould being obtainable by laser structuring. The material and the objects manufactured therefrom have been found to be surprisingly robust, durable and non-slip, so that they are particularly well suited for the manufacture of machine tool handles. In a further aspect, the present invention relates to a material comprising at least one thermoplastic elastomer material, the depth of the texture of which is in the range of 250-400 μm, preferably in the range of 300-380 μm, more preferably about 325 μm. In a still further aspect, the present invention relates to the use of the material as a surface material in machine tools.

Description

[Technical Field]

[0001] The present invention relates to a method for producing an object having a microstructure. The production of the object involves the use of an injection mold having an inverse structure to the desired microstructure of the object, where the inverse structure of the injection mold can be obtained by laser structuring. This material and objects produced therefrom have proven surprisingly robust, wear-resistant, and non-slip, making them particularly suitable for the production of power tool handles. In a further aspect, the present invention relates to a material comprising at least one thermoplastic elastomer material, wherein the texture depth of the material is in the range of 250-400 μm, preferably in the range of 300-380 μm, and more preferably about 325 μm. In yet another aspect, the present invention relates to the use of the material as a surface material for a power tool. [Background technology]

[0002] Power tools having handles are known in the prior art. Power tool handles are often made of plastic, which easily get dirty, are not very robust, do not fit well in the hand, or easily slip out of the user's hand, for example. Therefore, such handles may pose a safety risk or make working with the power tool uncomfortable or unpleasant. Summary of the Invention [Problem to be solved by the invention]

[0003] The object underlying the present invention is to overcome the above-mentioned drawbacks and disadvantages of the prior art and to present an improved material for use in the field of power tools, which is particularly safe, pleasant to the touch and easy to use. [Means for solving the problem]

[0004] This object is achieved by the subject matter of the independent claims. Advantageous embodiments related to the subject matter of the independent claims can be found in the dependent claims.

[0005] According to the present invention, a material is provided, comprising a thermoplastic elastomer. This material is characterized in that the texture depth of the material is in the range of 250 to 400 μm. In a preferred embodiment of the present invention, the texture depth of the material can be in the range of 300 to 380 μm. Even more preferably, the texture depth of the material is approximately 325 μm. For purposes of the present invention, the proposed material is preferably produced by injection molding, and in particular, a laser-structured injection mold can be used. For the production of the proposed material, preferably, an injection mold is used in which the hills have a height of, for example, 225 μm or the valleys have a depth of 225 μm. These injection molds advantageously produce a material with a texture depth of approximately 325 μm. For purposes of the present invention, the height difference or distance between the hills and valleys of the injection mold is preferably approximately 450 μm. The roughness depth of the injection mold can be in the range of 400 to 500 μm, preferably in the range of 425 to 475 μm, and more preferably 450 μm.

[0006] For the purposes of the present invention, the depth of the texture of the resulting material is preferably smaller than the height of the hills and / or valleys of the injection mold used to produce the material. Tests have shown that materials with the described texture can be demolded surprisingly well, thus ensuring that the production method is easy to carry out and, in particular, that little unusable waste material is generated. For the purposes of the present invention, it is preferred that the hills of the injection mold form valleys on the surface of the object produced by the method, while the valleys of the injection mold form hills on the surface of the object produced by the method. In this case, the microstructures (hills and valleys) on the surface of the produced object are preferably about 55-90% of the height or depth of the structures of the injection mold. The injection mold is preferably produced by laser structuring. For the purposes of the present invention, this preferably means that the hills and valleys in the injection mold, which later form the microstructures on the surface of the produced object, are produced by laser structuring. For the purposes of the present invention, it is also preferred that the injection mold be referred to as a "tool."

[0007] It was surprising that an injection-molded object could be successfully removed from an injection mold without causing damage to the object. This is because the peaks and valleys of the injection-molded object protrude, for example, by up to 200 μm from one plane of the material. The hills and valleys on the produced object, which may be, for example, a power tool handle, preferably form a microstructure whose highest point protrudes by up to 200 μm from the center plane of the object. In particular, it was surprising that the microstructure produced by the injection molding method could be removed from the injection mold in a direction transverse to the bump-off direction, and surprisingly, almost no damage or scratch marks were observed on the produced object. In other words, it was quite surprising that the bump-off of the produced object could be performed in such a damage-free manner, even though individual components of the microstructure of the produced object protrude by up to 200 μm from the material. It is an important advantage of the present invention that the combination of the depth of the texture of the microstructure according to the present invention with the thermoplastic elastomer used as the base material can enable such damage-free and uncomplicated bump-off of the injection-molded object produced, which has a microstructure, particularly transverse to the demolding direction, that allows these microstructures to be removed from the injection mold in a particularly damage-free manner.

[0008] For the purposes of the present invention, it is preferred that the ratio between the texture depth T of the microstructure, which may also be referred to as the roughness depth Rz of the microstructure (as will be explained further below), and the distance between the hills and valleys of the injection mold be in the range of 0.55 to 0.90, preferably in the range of 0.65 to 0.85, and particularly preferably 0.72. In other words, for the purposes of the present invention, it is preferred that the roughness depth Rz or texture depth T of the microstructure be smaller than the roughness depth of the tool, i.e., the injection mold. It has been found that objects having a microstructure according to the present invention with such a ratio of the roughness or texture depth to the roughness depth of the injection mold can be particularly easily demolded, i.e., released from the mold. As a result, the proposed manufacturing method can be implemented in a surprisingly simple manner and can be operated in a particularly resource-saving manner.

[0009] What is even more surprising is that the material used for injection molding preferably so well reproduces the hills and valleys introduced into the laser-structured injection mold, even though individual components of the microstructure of the laser-structured injection mold protrude into the material of the injection mold by up to 200 μm, thereby forming valleys of up to 200 μm in the microstructure. Deep valleys of, for example, 225 μm in the injection mold then preferably generate hills having a height of up to 200 μm on the surface of the object produced by this method. Those skilled in the art have previously assumed that such deep structures in the injection mold form a termination for trapped air and therefore for the injection molding material used. Therefore, it was surprising that this is not the case in the present invention due to the thermoplastic elastomer material and the injection mold depth of, for example, 225 μm, and that the material fills and reproduces the hills and valleys of the injection mold particularly well. For example, a ratio may be formed between the height or depth of the individual microstructures produced in the thermoplastic material by the proposed manufacturing method and the tool, i.e., injection mold, which may be, for example, 72%. For the purposes of the present invention, this preferably means that 72% of the thermoplastic elastomer material penetrates into the injection mold and fills the laser-structured structures of the injection mold.

[0010] The microstructures produced by this manufacturing method preferably have a grain size in the range of 100-140 μm. In other words, this manufacturing method allows for the production of hills and valleys that can be described in a plan view of the material by a diameter in the range of 100-140 μm. Those skilled in the art will understand that, although this is not a diameter for describing a mathematically precise circle, the grains that can be produced by this manufacturing method are objects that can be well described in a plan view by a structure similar to a circle, and are therefore best characterized by a diameter.

[0011] For the purposes of the present invention, the material preferably comprises a base material, which may include the plastic materials polyolefin, polyamide, styrene copolymer, polyester, and polyurethane. For the purposes of the present invention, the base material of the proposed material preferably comprises a TPE material, i.e., a thermoplastic elastomer. For example, the base material may also include polyurethane, and mixtures of different types of plastics are particularly preferred to provide the base material. For the purposes of the present invention, it may be very particularly preferred to use a soft injection material, i.e., a plastic material that can be used for injection molding.

[0012] The proposed material has a surface texture whose properties are determined, in particular, by the difference in height between the highest and lowest regions of the material. For the purposes of the present invention, the distance between these highest and lowest regions of the material is preferably referred to as the "depth of the texture." In other words, the material may include "hills" as the highest points and "valleys" as the lowest points, with the difference in height between the highest and lowest points being in the range of 250 to 400 μm, preferably in the range of 300 to 380 μm, and more preferably 325 μm. For the purposes of the present invention, the difference in height between the hills and valleys of the material is preferably referred to as the "depth of the texture." The height of each hill and valley relative to the imaginary central plane of the material is preferably in the range of 125 to 200 μm, preferably in the range of 150 to 190 μm, and more preferably in the range of 160 to 165 μm.

[0013] For the purposes of the present invention, the hills and valleys of the proposed material are preferably produced in a laser-targeted manner on the tool or injection mold, resulting in a material texture depth of approximately 325 μm in combination with the injection molding method. The manufactured object can be obtained in particular by injection molding, and the injection mold used in this method or its structuring can be obtained by laser structuring. As a result, a manufactured object that can be, for example, a power tool handle is advantageously produced by a combination of the "injection molding" manufacturing method and laser structuring of the injection mold used for this purpose.

[0014] Materials with a texture depth in the range of 250-400 μm, which can be produced by the manufacturing method described below, feel surprisingly soft and conform well to the user's hand. Tests have shown that despite the harsh environment and normal working conditions at construction sites, the proposed fine material feels comfortable to hold, and therefore power tools made with this material feel particularly high-quality and comfortable to handle. Furthermore, the proposed material has been found to be surprisingly slip-resistant. This latter property improves the user's grip when holding a power tool and may represent an important safety feature for power tools coated with the proposed material. The risk of losing control of a power tool can be significantly reduced by using the proposed material, and operational safety can thus be greatly increased.

[0015] In a second aspect, the present invention relates to the use of the proposed material as a surface material for a power tool. For the purposes of the present invention, the material is preferably used as a surface material for, for example, the handle of a power tool. For the manufacture of the handle, also referred to as an "object" for the purposes of the present invention, a hollow part, preferably made of steel, is used as an injection mold, which is laser-structured. This means, in other words, that the valleys and peaks of the manufactured material are subsequently formed, or that the hills and valleys in the injection mold on the surface of the manufactured object are introduced into the injection mold by laser structuring.

[0016] For purposes of the present invention, the injection mold preferably has a roughness depth of approximately 450 μm. For purposes of the present invention, this preferably means that the valleys in the injection mold have a depth of, for example, up to 225 μm. An object or handle is then preferably produced using the laser-structured injection mold. They comprise at least one thermoplastic elastomer material, and the produced object has a texture depth in the range of 250-400 μm. The surface of the produced object is formed by a microstructure that may have valleys and hills. For purposes of the present invention, the term "power tool" should be broadly understood. In particular, this term refers to conventional power tools, such as, but not limited to, screwdrivers, cut-off or cutting devices, grinders, saws, chisels, core drills, and simple drilling and / or setting tools. However, the term "power tool" preferably also encompasses auxiliary devices, such as, but not limited to, vacuum cleaners, water management or recycling devices, supply devices, or external control devices. Furthermore, the handle may have any conceivable shape, i.e., C-shaped, T-shaped, or D-shaped. Of course, the handle at least partially covered with the proposed material may also be rod-shaped and / or protrude from the housing of the power tool.

[0017] For purposes of the present invention, it is also preferable to be able to assign a roughness depth to the microstructure. For example, the microstructure may essentially comprise alternating, i.e., adjacent, high plateaus and low-lying regions, which for purposes of the present invention are preferably referred to as "hills" and "valleys." These high plateaus and low-lying regions may represent the circular structures described above, which may be characterized by a diameter and have a grain size of 100 to 140 μm. In a cross-sectional representation of the microstructure, the high plateaus and low-lying regions may be visualized as alternating hills and valleys. The roughness depth of the microstructure may then be designated by the letter combination "Rz" and may be defined, for example, as the average hill / valley distance in a sequence of hills and valleys. For example, if five consecutive regions, each containing hills and valleys, are considered in a cross-sectional representation of the microstructure, the distance between the hills and valleys in each region may be determined, for example, for each of the five regions. The distances determined in this way may be averaged, and the distance between the hills and valleys averaged over, for example, five regions, is referred to as the (average) microstructural roughness depth Rz. In another formulation, this averaged distance between the hills and valleys may be referred to as the "average hill / valley distance in a sequence of hills and valleys." Thus, the microstructural roughness depth Rz preferably represents the maximum height of the microstructural profile, and the microstructural roughness depth Rz is preferably determined as the average value of the differences in height of the hills and valleys in, for example, five consecutive regions of a cross-sectional representation of the microstructure. The differences in height of the hills and valleys in a number "i" consecutive regions are referred to as Rz_i, where the index "i" represents a first, second, or further region, and the microstructural roughness depth Rz can be obtained as the average value of the values ​​Rz_i. For example, if the height difference of five consecutive hills and valleys is used to determine the microstructural roughness depth Rz, an average value of the values ​​Rz_1 to Rz_5 can be formed, which then advantageously gives the microstructural roughness depth Rz.

[0018] For the purposes of the present invention, it is preferred that the texture depth T of the microstructure can be equal to the roughness depth Rz of the microstructure, with the texture depth T and / or roughness depth Rz of the material or microstructure being in the range of 250 to 400 μm. For the purposes of the present invention, it is very particularly preferred that the texture depth T and / or roughness depth Rz of the material or microstructure be in the range of 300 to 380 μm. Particularly preferred is a value for the texture depth T and / or roughness depth Rz of the material or microstructure of approximately 325 μm.

[0019] The proposed material, which can be manufactured from a base material containing at least one thermoplastic elastomer and has a texture depth in the range of 250 to 400 μm, is surprisingly abrasion-resistant and robust, making it particularly advantageous for use in the power tool field, especially in the handle area. Even under heavy use, the proposed material remains intact and maintains its user-friendly and skin-friendly properties. Application tests have shown that the proposed material is particularly allergy-neutral and is also available with antistatic properties. As a result, power tool components coated with the proposed material do not or are less likely to acquire static electricity, significantly reducing unwanted discharges that can be unpleasant for users. In addition, the proposed material is easy to clean, particularly because any contamination can be surprisingly easily removed from the material's particularly deep valleys and particularly high hills. Contrary to the expectations of those skilled in the art, particularly deep valleys are very easily accessible, allowing dust and other dirt to be particularly easily removed from the material's surface.

[0020] A further advantage of the use of the proposed material in the power tool field is that it is particularly light and therefore it is possible to provide relatively light power tools comprising said material.

[0021] In another aspect, the present invention relates to a method for manufacturing an object having a microstructure, the method comprising: a) providing a base material for manufacturing an object, the base material comprising at least one thermoplastic elastomer; b) providing an injection mould for producing an object, the injection mould having a reverse structure to the microstructure of the object; c) the method step of injection molding an object, the microstructure of the object being produced by the inverse structure of the injection mold, The present invention is characterized by having the following.

[0022] For purposes of the present invention, it is preferred that the individual elements of the counterstructure of the injection mold be approximately twice as high or deep as the elements of the microstructure of the object. The injection mold may have, for example, a roughness depth of 450 μm, and the height and depth of the hills and valleys of the microstructure of the object may be, for example, 160-165 μm. The term "counterstructure" means that the valleys of the microstructure of the object are formed from the hills of the surface structure of the injection mold, and the hills of the microstructure of the manufactured object are formed from the valleys of the surface structure of the injection mold. For purposes of the present invention, it is preferred that the depth of the texture of the microstructure be in the range of 250-400 μm. For example, the hills and valleys of the surface of the manufactured object may have a height or depth of 160-165 μm.

[0023] For the purposes of the present invention, it is preferred that the surface structure of the injection mold, i.e. the counterstructure, is produced by laser structuring. In other words, the injection mold or injection molding tool can be produced by a method step preferably upstream of the laser structuring. For the purposes of the present invention, this preferably means that in particular the counterstructure of the injection mold is produced using a laser.

[0024] The invention also relates in particular to any object, device and / or device part that can be manufactured by the manufacturing method described.

[0025] Processing of the proposed material in the power tool field has proven particularly advantageous, since, surprisingly, the material can be processed in a particularly material-saving manner without significant losses, even when the handle of a power tool may have a complex external shape. The proposed material meets these specific challenges in a particularly favorable manner. The good processability of the proposed material is due in particular to the surprisingly good elasticity of the material, which is achieved in particular by the material mixture of the underlying base material and a texture depth in the range of 250 to 400 μm.

[0026] The terms, definitions and technical advantages introduced for the materials equally apply to the use of materials and manufacturing methods in the power tool field.

[0027] When the proposed material is used in the area of ​​a power tool handle, it may be preferable for the purpose of the present invention for the power tool handle to have zones with different heights and depths of the material's hills and valleys. In other words, zones with different roughness can be used in areas of the handle to meet different functions or requirements. It has been found that materials with a relatively high roughness, for example, a texture depth of 400 μm, ensure greater friction between the power tool and the user's hand than materials with a lower roughness or texture depth, for example, in the range of 250 μm. Based on this knowledge, it is possible to develop handles for power tools having zones with different roughness or texture depth, with these roughness and / or texture depth of the material adapted to the respective requirements of each handle area.

[0028] For example, if a power tool handle is designed as a C or D handle, the handle may have a zone with particularly high roughness and / or texture depth in its central region. The central region of a power tool handle formed in this manner often extends substantially parallel to an edge or side of the power tool or its main body. The power tool handle is preferably gripped by the user's hand in this central region, and therefore preferably requires high friction in this region. The present invention can provide this high friction by a handle for a power tool having a central region, where the central region of the handle has a roughness and / or texture depth greater than the roughness and / or texture depth of the surrounding regions. For example, the region of the handle that opens into the power tool or its main body may have a roughness and / or texture depth less than the roughness and / or texture depth of the central region of the power tool handle.

[0029] It was surprising enough that the proposed manufacturing method also allows the manufacture of handles in which the roughness and / or texture depth varies within a zone. For example, the roughness and / or texture depth within a zone can increase or decrease substantially continuously, thereby achieving a "fading effect," i.e., a fade-in or fade-out effect. In such a zone, the roughness, roughness depth, and / or texture depth can, for example, pass substantially continuously through the range of 250-400 μm of the texture depth according to the invention. Of course, it is also possible for the increasing or decreasing texture depth to pass only partially through the range of 250-400 μm of the texture depth according to the invention. For example, the roughness and / or texture depth may preferably have a maximum roughness and / or texture depth of about 400 μm in the central region of a power tool handle designed as a C or D handle, while the central region of the handle is bordered by a zone of decreasing roughness and / or texture depth, where the roughness, roughness depth and / or texture depth in the border region relative to the central region is, for example, about 300 μm and at the opposite end of the zone is about 250 μm. For the purposes of the present invention, it is very particularly preferred that the roughness, roughness depth and / or texture depth can be adapted to the intended functionality of the corresponding handle region. In other words, handle regions requiring high friction may have a relatively large roughness and / or texture depth, while other handle regions requiring low friction, for example due to frequent position changes or circumferential grip, have a relatively low roughness and / or texture depth.

[0030] Thus, in the context of the present invention, a handle for a power tool is also disclosed, which may have, for example, a C-shape or a D-shape. The handle may be characterized by having zones with different roughness and / or texture depth. Additionally, in this aspect of the invention, it may be preferred that the roughness and / or texture depth in such zones increases or decreases substantially continuously. These last-mentioned features allow the properties of the handle, in particular its roughness and / or texture depth, to be adapted to the desired functionality of the corresponding region or zone of the handle.

[0031] Further advantages will become apparent from the following description of the figures. The figures, this specification and claims include numerous feature combinations. Those skilled in the art will also consider features individually and combine them as appropriate to form useful additional combinations.

[0032] In the figures, identical and similar components are designated with the same reference numerals. [Brief explanation of the drawings]

[0033] [Figure 1] 1 shows a diagram of a preferred embodiment of a power tool handle comprising the proposed material. [Figure 2] 1 shows a schematic diagram of a preferred embodiment of the surface structure of the material. DETAILED DESCRIPTION OF THE INVENTION

[0034] FIG. 1 shows a preferred embodiment of a handle (10) for a power tool (not shown). The surface of the handle (10) comprises the proposed material (1), and the texture depth (T) of the material (1) is in the range of 250-400 μm, preferably in the range of 300-380 μm, and more preferably substantially 325 μm. The term "substantially" is not an unclear term for those skilled in the art; on the contrary, those skilled in the art will recognize that slight deviations from the exact height or depth of the hills (4) or valleys (5) of the material (1) may arise, for example, from manufacturing conditions. The term "substantially" is intended to include such slight deviations, for example, ±3 μm. The hills (4) or valleys (5) preferably form a microstructure that can form the surface of the power tool handle (10). For purposes of the present invention, it is preferred that the microstructure of the power tool handle (10) has a texture depth (T) in the range of 250-400 μm, preferably in the range of 300-380 μm, and more preferably 325 μm.

[0035] A schematic example of a preferred embodiment of the surface structure (3) of the material (1) is shown in Figure 2. It shows an imaginary central plane (2) from which the heights of the hills (4) and the depths of the valleys (5) of the surface of the material (1) are determined. These heights of the hills (4) and the depths of the valleys (5) preferably determine the texture depth (T) of the proposed material (1). In particular, the texture depth (T) represents the distance or height difference between the peaks of the hills (4) and the lowest points of the valleys (5).

[0036] The imaginary central plane (2) can be considered as the average of all heights and depths, i.e., the average of all surface structures of the material (1). Therefore, the imaginary central plane (2) is preferably located midway between the peaks and pits of the surface of the proposed material (1). Figure 2 is a highly schematic representation of a possible surface structure (3) of the material (1), intended to clarify, in particular, the terms "hills," "valleys," and "texture depth." In particular, the surface shown diagrammatically in Figure 2 may form the surface of a power tool handle (10). It may also form the surface of any object manufactured by the proposed manufacturing method. [Explanation of symbols]

[0037] 1 material 2 Virtual center plane 3 Surface structure 4 Hill area 5 Valley 10 Power tool handles T Texture Depth

Claims

1. 1. A method for manufacturing an object having a microstructure, comprising: a) providing a base material for manufacturing said object, said base material comprising at least one thermoplastic elastomer; b) providing an injection mould for said manufacturing of said object, said injection mould having an inverse structure to said microstructure of said object; c) a method step of injection molding the object, wherein the microstructure of the object is produced by the inverse structure of the injection mold, the depth of the roughness of the microstructure or the depth of the texture of the microstructure is smaller than the depth of the roughness of the injection mould, A method comprising:

2. 2. The method according to claim 1, characterized in that the depth of the roughness of the injection mould is in the range of 400 to 500 μm, preferably in the range of 425 to 475 μm, most preferably 450 μm.

3. 2. The method according to claim 1, characterized in that the inverse structure of the injection mold is obtained by laser structuring.

4. 2. The method of claim 1, wherein the microstructure of the object has a texture depth in the range of 250-400 μm, preferably in the range of 300-380 μm, most preferably 325 μm.

5. 2. The method according to claim 1, characterized in that the ratio between the depth of the texture of the microstructure and the depth of the roughness of the injection mould is in the range of 0.55 to 0.90, preferably in the range of 0.65 to 0.85, most preferably 0.

72.

6. A material (1) that can be produced using the method of claim 1, characterized in that it comprises at least one thermoplastic elastomer and that the texture depth (T) of said material (1) is in the range of 250 to 400 μm.

7. The material (1) according to claim 6, characterized in that the depth (T) of the texture of the material (1) is in the range of 300 to 380 μm.

8. 7. The material (1) according to claim 6, characterized in that the depth (T) of the texture of the material (1) is 325 μm.

9. 7. The material (1) according to claim 6, characterized in that it has a microstructure, the texture depth (T) of which is in the range of 250 to 400 μm, preferably in the range of 300 to 380 μm, particularly preferably 325 μm.

10. Use of the material (1) according to any one of claims 6 to 9 as a surface material for power tools.

11. Use according to claim 10, characterized in that the material (1) is used as a surface material for the handle (10) of a power tool.

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