MXPA98002004A - Pigs with structured surface, process to produce the pigs and a brush or interdental device manufactured with the ceres - Google Patents

Abstract

The present invention relates to a method for manufacturing a bristle material with a structured surface from a plastic by means of monofilament extrusion. Before or during extrusion, a granular material is mixed with the first plastic material that melts thermally, which forms the main component of the monofilament. The granular material comprises a second plastic material which has a higher thermal force compared to the first plastic material. The particle size of the granular material is such that the monofilament, during the subsequent stretching is subjected to a greater transverse contraction, in its cross sections where there is little or no granular material, compared to the cross sections containing granular material. The invention also relates to a bristle with a surface structure of a first plastic material forming a main component and in which a granular material of a second plastic material is embedded in a substantially complete covered manner, the granular material forms a structured on the surface of the sow The invention also relates to a brush, particularly a toothbrush or an interdental cleaner, with a plurality of bristles that optionally are combined with groups and in which at least some bristles have the aforementioned structure.

Description

PIGS WITH STRUCTURED SURFACE. PRO ^ AT ^ A. PRODUCE TAS CERDA.? AND A BRUSH OR INTERDENTAL DEVICE MANUFACTURED WITH THE PIGS.

DESCRIPTION OF THE INVENTION The invention relates to bristles with a surface structure, and to a method for the manufacture of bristle material or with a structured surface from a plurality of extruded monofilaments. The invention also relates to a brush, particularly an interdental toothbrush or cleanser, which is provided, at least partially, with bristles with a structured surface. Although the invention is described below in relation to bristles and bristle material, it specifically covers monofilaments, which can be processed into fabrics, mats, filters, etc. The invention can also be used in cases of brushes for painting, pads for polishing or for abrasion, or cleaning, application or polishing or for abrasion devices. The plastic bristles which are extruded normally have a regular surface due to the manufacturing process. In the case of brushes of a random nature, such bristles exert their brushing action REF: 26894 initially and mainly through the free ends of the bristles, which transport the dirty surface and remove the residues by scraping and scraping. In the case of stronger pressure, the bristles are curved and act with their circumferential surface. Then they slide in an incident way and with sliding on the surface, with a softer action. Furthermore, when painting and the like are applied by means of a brush, the bristles are bent or curved, so that they make contact with the surface to be treated not only with the free ends of the bristle, but also with its circumferential surface . For a long time consideration has been given to the use of the circumferential surface of the bristles for surface treatment purposes when structuring or profiling them. The East German patent 32963 and the US patent 2 642 705 describe the application of abrasive particles to the circumferential surface of bristles or a bristle material by embedding the same in a bristle material on the surface. Such a procedure is not only very complicated, but it has also been found that the external abrasive particles are loosened in particular due to the curvature action that occurs when the bristles are used. In addition, such bristles are so abrasive and therefore so aggressive that it is not possible to use them in all cases of dental and human body care. It is known from US Pat. No. 2 642 705, British Patent 1 327 329 and in particular DE-OS 20 37 674 to incorporate mixed abrasive particles into plastic materials of the bristles. According to DE-OS 20 37 674, inorganic abrasive particles of aluminum oxide, glass fibers in small fragments, asbestos particles or ceramic material or also diamond particles, which have a much greater hardness than plastic material, are used. surrounding, so that they have a very pronounced abrasive action, which in many cases is not desirable. Frequently, abrasive particles incorporate such a high percentage that they make contact or penetrate the surface of the sow. Experience has also shown that the embedded abrasive particles, over a period of time, are exposed as a result of the wear of the surfaces of the bristles, so that the abrasive capacity of the bristles can be significantly increased, so that such bristles do not They can be used for dental or human body care, because it would lead to considerable risks of damage to the skin, teeth or mucous membranes of a user. In order to, for example, remove tartar from teeth or debris from floors or roads, it is not much of a matter of obtaining an abrasive action by an abrasive material, but instead, what is called reaming action, which can be obtained by a surface structure or topography. By mixing the abrasive particles such a surface structure can be obtained only when relatively large particles are used. Admitting that the reaming characteristics of such bristles are suitable, but that the large abrasive particles project onto the surface, this leads simultaneously to a high abrasiveness. The bristles are also greatly weakened by the incorporation of large abrasive particles, so that the bristles have only inadequate resistance. The process of mechanically wrinkling the surface of the bristles in which the flanks of the bristles are structured with a tool is also known.

(North American patents 3 325 845 and 3 229 347). The creping process of the flanks of the bristles can be carried out by means of an abrasion or grinding device or also by sandblasting. However, this leads to the disadvantage that the longitudinally oriented molecules in the bristles are rotated and opened, and consequently the bristles are weakened. This procedure is also very complicated. After working the surfaces become fibrous and brittle, which leads to the risk that parts of them are released from the bristle material. It has been found that it is not possible to obtain a clearly defined surface topography in this way. EP 360 938 A1 proposes to embed a blowing agent in the bristle material and to carry out a surface corrugation process by foaming the blowing agent. However, the chambers or cavities that are formed through the bristle strand lead to a significant reduction in the stiffness of the bristle. In addition, due to the open cavities, the surface of the bristle is not uniform and does not clearly define the structural depth or topography, which is necessary for an effective reaming. The problem of the invention is to provide a bristle or bristle material which has a predetermined surface topography with a predetermined or only slight abrasivity, but with an increased reaming action. In addition, a method is provided for the manufacture of the bristle material with which the corresponding bristles can be easily fabricated. With respect to the method, this problem is solved by a thermal fusion of the first plastic material forming the main component of the extruded monofilament having a granular material of a second plastic material with a superior thermal resistance compared to the first plastic material, which is Mix with the last before or during extrusion. When a thermoplastic material is used as the second plastic material, the latter has a higher melting point. Alternatively, if other plastic materials are used, it must be ensured that the latter do not liquefy or that they do not liquefy before the first plastic material. The particle size of the granular material must be such that the monofilament during a subsequent extraction or stretching is located in cross sections in which there is little or no granular material and is subjected to a greater cross-sectional reduction or a transverse shrinkage compared to the cross sections with a large amount of granular material. The granular material does not serve as abrasive particles, but only as a shape or body of resistance in order to locally avoid transverse shrinkage. In the method according to the invention, the first plastic material, which can be, in a known manner, polyamide, polyester, polyolefin, etc., is heated in an extruder and subsequently becomes fluid. Then, during or before extrusion, the granular material of the second plastic material is mixed in an amount of preferably 5 to 30% of the total weight of the bristle material. The dimensions of the particles of the granular material and their shape depend on the desired surface structure. The dimensions may fluctuate, but they will not be too small. In a preferred development of the invention, the particle size of granular material is between 10 and 50% of the diameter of the bristle material. To the extent that the second plastic material of the granular material has a higher thermal resistance or a higher melting point compared to the first plastic material forming the main component, it can be obtained that, as a result of heating the first material plastic, the surface does not melt or lightly, so that the particles of granular material during extrusion are contained as solid inclusions in the first fluid plastic material. According to the invention, the granular material is also formed by a plastic material. This provides the advantage that the granular material can be produced in a simple manner for example, when an extruded monofilament is produced it can be cut to length in the desired manner. It has been found to be advantageous to choose the particle length of granular material either identical or larger than the diameter of the monofilament. Alternatively, however, it is also possible to produce the granular material by crushed plastic. In order to obtain a relatively uniform particle size, the granular material can be classified in the conventional manner by a sieving process. It has been shown that it is advantageous to deburr the granular material. Particularly in the case of granular materials produced by cutting to the length of a monofilament, relatively sharp edges are presented which can pass to the outside in the event of a wear of the bristle. These cutting edges are removed by the deburring process, which can be carried out thermally and / or mechanically. In the case of thermal deburring, the granular material undergoes pre-melting of the surface, so that the cutting edges flow. Alternatively, it is possible to work the surface in drums, the granular material before mixing it with the first plastic material and subsequently the edges are removed. It has been found that, for the granular material, it is also possible to use more thermally stable plastics which, as a result of their molecular structure, can not be used up to now for the manufacture of bristles, because the technical values of the manufactured bristle material of the invention not only depend to a limited extent on the nature of the granular material.

If the first plastic material with mixed granular material is forced through a die of an extruder and the supplied monofilament is pulled out at a speed which is greater than the feed rate of the die, a first stretch of the monofilament takes place. However, tension forces act only on the first plastic material, because the particles of granular material are contained in a substantially free, mobile manner therein. As a result of stretching, the coiled molecules of the first plastic material are oriented longitudinally and the diameter of the monofilament is reduced by transverse contraction. The diameter reduction does not take place uniformly over the entire length, instead of this, the particles of granular material prevent transverse contraction, so that in the vicinity of a particle of granular material there is a smaller reduction of the cross section than in areas where there are no particles of granular material. Therefore, the stretching leads to a surface structure of the monofilament. The monofilament, still fluid, with a surface structure is subsequently cooled in a known manner, which leads to solidification. Preferably, the monofilament is then exposed to further stretching, which leads to an elongation with a much greater length and in particular to a further reduction in diameter. The longitudinally oriented molecules of the first plastic material are not destroyed. This can be followed conventionally by stabilizing the monofilament or the bristle material. According to a further development of the invention, if the abrasive capacity of the second plastic material of the granular material is at most the same level as that of the first plastic material, the abrasiveness of the bristle material reliably depends on the place and optionally the extent to which the particles of granular material are located on the circumferential surface of the monofilament to exert its action. Even if the flanks or sides of the bristles or the circumferential surface wear out for a period of time and consequently the particles of granular material touch the circumferential surface, at most, the bristle will have the same abrasiveness as the first plastic material that forms the main component According to a preferred development of the invention, the granular material is embedded in the first plastic material and is covered substantially completely by the latter. This is considered in that the granular material is wetted in this manner by the first plastic material in the extruder, so that as it passes outwardly from the die, it is covered mainly by the plastic material. Therefore, the monofilament has a circumferential surface, which is formed substantially complete by the first plastic material. It has been found that the surface topography that is carried out by the zonally different transverse contraction depends on the shape of the particles of granular material and is in accordance with them. To obtain different topographies, the granular material may be spherical, in the form of a parallelepiped or prism-shaped, or it may contain a mixture of particles with different shapes. As already indicated, the granular material does not need to melt during the extrusion process, so that the particles form a solid, dimensionally stable inclusion in the first plastic material. Alternatively, it is also possible to melt the surface so that it takes place during the extrusion of the granular material formed of plastic, so as to form a solid bond and the surface is welded to the first surrounding plastic material. However, it must be ensured that the granular material does not melt completely, because otherwise it would mix with the first plastic material. Nevertheless, surface melting can perform a deburring. For the first and second plastic materials, preferably combinations of thermoplastic materials are used which can be welded together easily. Particularly, in the case of toothbrushes, it has been shown that it is appropriate to combine with the first plastic material of nylon 6.12 bristles, a granular material of polyphenylene sulfide. The difference in melting point between nylon 6.12 (260 ° C) and polyphenylene sulfide (218 ° C) has proved to be particularly advantageous. Both the first and the second plastic materials of the granular material may or may not be filled with fillers. It has been found that the surface structuring is more visible if a relatively small granular material is mixed with the first plastic material. However, this leads to a decrease in the abrasive capacity due to the small number of protuberances on the surface. In this case, the abrasiveness can be increased again by adding fillers to the first plastic material. This makes it possible to obtain a slightly abrasive filled bristle with a good surface structure.

It may be advantageous in certain applications that the granular material is harder than the first plastic material. In this case, the formation of the surface structure is advantageously supported and maintained in a durable manner. However, alternatively, it is also possible that the granular material is softer than the first plastic material. This leads to a more flexible surface structure, which is particularly appropriate with regard to the treatment of sensitive areas, for example gums or interdental spaces. For this purpose, it is possible that the granular material is made of a rubber-like material. For certain applications, it must be ensured that the user is able to recognize the bristles that provide the reaming action according to the invention and not use them by mistake. According to the invention, this can be carried out insofar as the first plastic material is made transparent or translucent. Therefore, the user can detect the covered granular material, which preferably has a different color to the first plastic material, compared to the latter. For the visualization of any of the types of granular materials in terms of different shape, size and action, they can be embedded in different colors in the first transparent or translucent plastic material.

With regard to the sow, the problem that is established in the foregoing is solved insofar as the sow is made of a first plastic material that forms the main component, in which a granular material of a second plastic material is embedded. in a substantially complete cover manner, the granular material forms a structure on the surface of the bristle. The abrasiveness of the second plastic material of the granular material may correspond, at most, with that of the first plastic material. With such bristles, the desired effects of massage and cleaning are not determined by the filling or by the granular material, but by the surface structures of the bristles resulting from the sizing of the granular material. Additional features and advantages of the corresponding bristles can be obtained from the above description and method. The aforementioned features and advantages can also be presented in a monofilament, such as is used, for example, in certain interdental cleaners. The monofilament bristles may have a random cross-sectional shape, in particular rounded, oval, triangular, box-shaped, star-shaped, etc.

The invention also relates to a brush, particularly a toothbrush or an interdental cleaner having a plurality of bristles optionally combined in groups and in which at least some of the bristles are designed in accordance with the invention. In order to adapt the action of a brush to given working conditions, the bristles according to the invention can also be combined and processed together with bristles having other configurations. Interdental cleaners are also known, which comprise only a single monofilament. The invention is also designed to cover those interdental cleaners in which the monofilament is designed according to the invention. In addition to the brushes mentioned above, the invention can also be used in brushes for painting, to obtain a better capacity for retaining paint, in hair brushes with a good cleaning and degreasing capacity, in massage brushes with a better action of rubbing, in brushes or brushes operated manually and with a machine for a better absorption of residues, in polishing and abrasion pads with a higher efficiency as a result of surface topography, as well as in woven, abrasion or other devices mats, cleaning equipment, applicators, polishing and abrasion devices made of bristles or monofilaments.

The invention can also be impiemented in a filter which, due to its structuring, has an enlarged monofilament surface. The invention is described in more detail below in relation to one embodiment and the appended Figures 1 to 3, in which it is shown: Figure 1 is a monofilament after extrusion in a longitudinal section. Figure 2 is a monofilament after pre-stretching. Figure 3 is the monofilament after additional stretching. As can be seen in figure 1, immediately after passing out of the extruder die, a monofilament 10 has a substantially uniform cross section over its length with a regular circumferential surface 13, several particles 12 of granular material of a second plastic material are unevenly embedded in a first plastic material 11 forming the main component of the monofilament . In this embodiment, the particles 12 of granular material, in part, have a spherical shape and, in part, a parallelepiped shape. The first plastic material 11 is flowable, while the particles 12 of granular material form stable and solid inclusions. After passing out of the extruder die (for example arrows in FIG. 1), the monofilament is prestressed, so that it undergoes a reduction in its cross section due to transverse shrinkage. However, particles 12 of granular material avoid cross-sectional shrinkage, so that these cross-sections, where there is little or no particle or particles of granular material, are subjected to a stronger transverse contraction compared to those cross-sections in which there is a greater amount of particles of granular material. This leads to a variation in the shape and size in the cross section that is not uniform with respect to the length of the monofilament, so that on the outside of the circumferential surface 13 a structured is formed, as can be seen in Figure 2 After cooling the monofilament, it is stretched again (see the arrows in Figure 2) and its previous length is lengthened several times. This leads to a further reduction in its cross section due to the transverse shrinkage, which is once again prevented by the particles of granular material. Figure 3 shows the resulting increased structure of the circumferential surface 13 in the monofilament 10. It can be seen that the topography of the formed surface is independent of the shape of the particles of granular material. When spherical granular materials are used, softer topographic structures are formed in comparison to those formed when granular materials are used in the shape of, for example, parallelepiped. It is noted that in relation to this date, the method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims (29)

1. A method for the manufacture of a bristle material with a structured surface from plastic by extrusion of a monofilament, in which, with a first plastic material that is thermally melted, the main component of the monofilament is formed and mixed, before or during the extrusion, with a granular material of a second plastic material which has a superior thermal resistance compared to the first plastic material, the particle size of the granular material is such that during the subsequent stretching, in cross sections in which there is little or no granular material, the monofilament is subjected to a greater transverse contraction compared to the cross sections with a large amount of granular material.

2. The method according to claim 1, characterized in that the abrasive capacity of the second plastic material of the granular material is, at most, the same as that of the first plastic material.

3. The method according to claim 1 or 2, characterized in that, after stretching, the monofilament is cooled and then stretched and is further hardened.

4. The method according to one of claims 1 to 3, characterized in that the granular material is mixed in an amount of from 5 to 30% by total weight of the bristle material.

5. The method according to one of claims 1 to 4, characterized in that the particle size of the granular material is between 10 and 50% of the diameter of the bristle material.

6. The method according to one of claims 1 to 5, characterized in that the granular material is embedded in the plastic material and is covered substantially completely by the latter.

7. The method according to one of claims 1 to 6, characterized in that the granular material comprises spherical and / or prismatic particles.

8. The method according to one of claims 1 to 7, characterized in that the granular material is produced by cutting the extruded monofilament at a certain length.

9. The method according to one of claims 1 to 8, characterized in that the granular material is produced by polished plastic.

10. The method according to one of claims 1 to 9, characterized in that the granular material is deburred.

11. The method according to one of claims 1 to 10, characterized in that the deburring takes place thermally and / or mechanically.

12. The method according to one of claims 1 to 11, characterized in that the granular material does not melt during extrusion.

13. The method according to one of claims 1 to 11, characterized in that the granular material melts on its surface during extrusion.

14. The method according to claim 13, characterized in that the granular material is soldered on the surface to the first surrounding plastic material.

15. The method according to one of claims 1 to 14, characterized in that the second plastic material of the granular material is harder than the first plastic material.

16. The method according to one of claims 1 to 14, characterized in that the second plastic material of the granular material is softer than the first plastic material.

17. The method according to one of claims 1 to 16, characterized in that the first plastic material is transparent or translucent.

18. The method according to one of claims 1 to 17, characterized in that the first plastic material and / or the second plastic material is filled with fillers.

19. A bristle with a surface structure of a first plastic material forming the main component, characterized in that the first plastic material is embedded in a granular material of a second plastic material in a substantially complete covering, the second plastic material has a superior thermal resistance that the first plastic material and the granular material form on the surface of the bristle a structure resulting from its transverse contraction.

20. The bristle according to claim 19, characterized in that the abrasiveness of the second plastic material of the granular material, at most, corresponds to that of the first plastic material.

The sow according to claim 19 or 20, characterized in that the granular material is mixed in an amount of 5 to 30% of the total weight of the sow.

22. The sow according to one of claims 19 to 21, characterized in that the particle size of granular material is between 10 and 50% of the diameter of the sow.

23. The bristle according to one of claims 19 to 22, characterized in that the granular material comprises spherical and / or prismatic particles.

24. The bristle according to one of claims 19 to 23, characterized in that the granular material is soldered on the surface to the first plastic material.

25. The bristle according to one of claims 19 to 24, characterized in that the second plastic material of the granular material is harder than the first plastic material.

26. The bristle according to one of claims 19 to 24, characterized in that the second plastic material of the granular material is softer than the first plastic material.

27. The bristle according to one of claims 19 to 26, characterized in that the first plastic material is transparent or translucent.

28. A brush, particularly a toothbrush or interdental cleaner, with a plurality of bristles optionally combined in groups, characterized in that at least part of the bristles are in accordance with one of claims 19 to 27.

29. An interdental cleaner characterized in that it is constituted by a single bristle according to claims 19 to 27. SUMMARY OF THE INVENTION The invention relates to a method for manufacturing a bristle material with a structured surface from a plastic by extrusion of a monofilament. Before or during extrusion, a granular material is mixed with the first plastic material that melts thermally, which forms the main component of the monofilament. The granular material comprises a second plastic material which has a higher thermal force compared to the first plastic material. The particle size of the granular material is such that the monofilament, during the subsequent stretching is subjected to a greater transverse contraction, in its cross sections where there is little or no granular material, as compared to the cross sections containing granular material. The invention also relates to a bristle with a surface structure of a first plastic material forming the main component and in which a granular material of a second plastic material is embedded in a substantially complete cover, the granular material forms a structured over the surface of the sow The invention also relates to a cepiltß-, particularly a toothbrush or interdental cleaner, with a plurality of bristles that optionally are combined into groups and in which at least some bristles have the structure mentioned above.