METHOD FOR APPLYING A COATING TO AN INTERDENTAL CLEANER AND INTERDENTAL CLEANER WITH A COATING

Description

[0001] The invention relates to an interdental cleaner with a rod-shaped carrier made of plastic, which has a cleaning part made of a soft-elastic plastic in an axial end region, wherein the cleaning part is provided with a coating on its outer surface in a coating area.

[0002] Furthermore, the invention relates to a method and a device for applying a coating to an interdental cleaner.

[0003] Interdental cleaners are used to clean the spaces between teeth. A typical interdental cleaner has a rod-shaped plastic handle with a grip section at its rear axial end. A cleaning element made of a soft, elastic plastic is attached to the axial end of the rod-shaped handle opposite the grip section. This cleaning element can be sleeve-shaped and surround the front end of the rod-shaped handle, or it can be injection-molded onto it. Alternatively, the cleaning element may extend beyond the front axial end of the handle.

[0004] To increase consumer acceptance and provide added value, it can be beneficial to introduce substances and / or flavorings known from the field of oral hygiene into the oral cavity, and especially into the interdental spaces. This can be achieved, for example, by coating the cleaning part of the interdental cleaner with a suitable coating agent. Various methods exist for applying such a coating. One option is to dip the cleaning part into a liquid reservoir of the coating agent and then withdraw it. However, this method has the disadvantage that droplets often form, which are aesthetically and functionally detrimental and also result in an excessive amount of coating agent being applied to the interdental cleaner.

[0005] Alternatively, the coating agent can be sprayed onto the part being cleaned. This method has the disadvantage of significant losses of the sprayed medium and requires encapsulation of the spray chamber to capture the spray mist. Furthermore, filters must be used to prevent the spray mist from escaping into the production environment or the surrounding environment. In addition, a defined quantity of coating agent cannot be applied to the part being cleaned, and there is a risk of the very fine nozzles clogging during prolonged use, requiring cleaning before production of the interdental cleaners can resume.

[0006] In principle, every known application of a coating material has the disadvantage that the cleaning part is completely covered with an encapsulating coating that hardens upon drying and increases the flexural rigidity of the cleaning part and its elements, such as bristles, lamellae, fingers, or so-called pins. This results in a lack of softness for the user. This is only remedied when the user inserts the interdental cleaner into the interdental space and the coating is softened again by saliva.

[0007] US 2016 / 135932 A1, JP 2016 087362 A and US 2008 / 313834 A1 are cited as relevant prior art.

[0008] The invention is based on the objective of creating an interdental cleaner of the type mentioned above, which carries a defined amount of coating material and whose flexural stiffness is not affected by the coating material or only to a very small extent.

[0009] Furthermore, a method for applying a coating to an interdental cleaner is to be created, which allows the coating material to be applied to the cleaning part of the interdental cleaner in a simple manner and in precise quantity.

[0010] Furthermore, a device for applying a coating to an interdental cleaner is to be created, with which the process can be carried out in a simple manner.

[0011] With regard to the interdental cleaner, the aforementioned problem is solved by an interdental cleaner with the features of claim 1. It is provided that the coating area comprises only a partial region of the outer surface of the cleaning element. Thus, the cleaning element of the interdental cleaner carries the applied coating material only on a partial region of its outer surface. The other regions of the outer surface do not carry any coating material. Since, in the embodiment according to the invention, the cleaning element is not completely surrounded or encased by a coating, but rather the coating is applied only to a partial region, the coating practically does not impair the flexural stiffness of the interdental cleaner. The size of the partial region is preferably less than 50% and particularly less than 20% of the total outer surface of the cleaning element.

[0012] In a preferred embodiment, the coated area or partial area of ​​the outer surface of the cleaning part extends in the longitudinal direction of the carrier. This is the case, for example, when the coating is applied to the cleaning part in a strip-shaped configuration. Such a strip-shaped coating area can extend either axially, i.e., in the longitudinal direction of the interdental cleaner, or it can be provided that a corresponding strip-shaped partial area spirals around the cleaning part.

[0013] In a further development of the invention, it can be provided that the front tip section of the cleaning part, facing away from the handle, is not coated over a length of at least 0.5 mm, and particularly in the range of 0.5 mm to 1.5 mm. This ensures that the tip section of the cleaning part remains soft and flexible, so as not to negatively affect the user's experience when inserting the interdental cleaner into the interdental space. Keeping the tip section free from the coating material can be achieved either by making the transfer body so short that it does not come into contact with the tip section of the cleaning part, or alternatively, by providing recesses in the transfer body, whereby the tip section of the cleaning part is positioned in the area of ​​the recesses when the transfer body is in contact with it, and thus does not come into contact with the transfer body.

[0014] An interdental cleaner typically features a cleaning element with numerous radially outward-projecting cleaning elements. These elements can be, for example, fingers made of the same soft, elastic plastic as the cleaning element, such as a thermoplastic elastomer, and integrally bonded to it. The fingers might have a circular, conical shape that tapers radially outward. Alternatively or additionally, the cleaning element can have cleaning elements in the form of radially outward-projecting bristles. Bristles are segments of a monofilament or multifilament cut to a predetermined length.The bristles can be processed as individual bristles and / or as bristle bundles and are preferably arranged in such a way that they penetrate the cleaning part and also the rod-shaped carrier, protrude axially from both sides of the cleaning part and are embedded in and held in the material of the cleaning part and in the material of the carrier.

[0015] In the following, it is assumed by way of example that the cleaning elements are the aforementioned one-piece molded fingers, but the invention is not limited to this.

[0016] The cleaning elements or fingers can be arranged on the outer surface of the cleaning part such that they form several rows of cleaning elements or fingers extending longitudinally along the carrier. In a further development of the invention, the coating area can be arranged between two adjacent rows of cleaning elements or fingers. It can be provided that only one of the spaces formed between two adjacent rows of cleaning elements or fingers is coated, while all other corresponding spaces remain uncoated. Alternatively, however, it is possible that every second or every third space around the circumference of the interdental cleaner is coated accordingly.

[0017] The coating area can extend over the entire axial length of the cleaning part. Preferably, the coating area extends over at least 50% of the axial length of the cleaning part, and in particular over at least 80% of the axial length of the cleaning part.

[0018] The cleaning element preferably has a sleeve-shaped coating made of a soft, elastic plastic material, for example a thermoplastic elastomer, arranged on the carrier and, in particular, injection-molded onto the carrier. The cleaning elements in the form of fingers and / or lamellae can also be formed during the injection molding process.

[0019] The coating agent forming the coating may be an antimicrobial substance, for example CHX chlorhexidine or CPC cetylpyridinium chloride, and / or essential oils, and / or remineralizing substances, for example fluorides or isomalt, and / or flavorings, and / or anti-inflammatory substances, which include, for example, chamomile, ginger, aloe vera, and / or desensitizing substances, for example potassium nitrate, and / or probiotics, for example Lactobacillos reuteri, and / or dentin-strengthening substances, for example hesperidin, or mixtures of the aforementioned and other substances known in oral hygiene, for example zinc fluoride.

[0020] Regarding the method, the aforementioned problem is solved by coating a transfer body, at least on its outer surface and at least partially, with a coating agent, whereupon the transfer body is brought into contact with the outer surface of the part being cleaned to form the coating. The size of the contact area between the transfer body and the outer surface of the part being cleaned can be very precisely controlled.The amount of coating material applied can be flexibly adjusted by the user by setting parameters such as the speed of the transfer body, the geometry of the cleaning part of the interdental cleaner, the geometry of the transfer body itself, the surface structure of the transfer body, and, in particular, the size of the contact area between the transfer body and the cleaning part of the interdental cleaner. It has been shown that the amount of coating material applied to the outer surface of the cleaning part by the transfer body can be kept within narrow, predefined limits.

[0021] The cleaning part can be coated with the coating agent along its entire length, but it is also possible to coat only a portion of the length of the cleaning part, for example only the rear area facing the handle section or only the front area facing away from the handle section.

[0022] The coating material can be applied to the transfer body by brushing or spraying. However, it is preferred that the coating material be applied by immersion, by immersing the transfer body in a coating material bath.

[0023] The transfer body can have a cylindrical shape, particularly a circular cylindrical shape, or a conical shape, particularly a circular conical shape. Different transfer bodies can be used depending on the viscosity of the coating material to be applied. In particular, the transfer body can have a flattened, and especially a flat, surface area. This can be achieved, for example, by a cylinder with a polygonal cross-section, particularly a triangular, square, or hexagonal cross-section. By forming flat surfaces, a defined contact area between the transfer body and the part being cleaned can be achieved, and it is possible to ensure that the coating material can run off the transfer body regardless of its viscosity.

[0024] If the cleaning part has a plurality of radially outwardly projecting cleaning elements, for example, fingers of the type mentioned, arranged in at least two rows extending longitudinally along the carrier, a further development of the method may provide that the transfer body is inserted into a space formed between two adjacent rows. In this way, the coating material located on the outside of the transfer body is applied to the surface areas of the cleaning part that form the bottom of the space.

[0025] Preferably, the transfer body is also brought into contact with the side surfaces of the cleaning elements or fingers facing the gap, so that these side surfaces are also coated with the coating material. It can be provided that the cleaning elements or fingers are elastically deformed by the transfer body when it is inserted into the gap formed between two adjacent rows. This ensures that the cleaning elements or fingers are held against the surface of the transfer body from the outside and pick up a sufficient amount of coating material.

[0026] To improve the absorption of the coating agent on the outer surface of the part being cleaned, the part, especially if it is made of a thermoplastic elastomer, can be subjected to surface treatment, at least in sections and particularly in the coating area, before the coating is applied. This surface treatment can involve roughening and / or heating and / or corona treatment and / or plasma treatment.

[0027] The coating process described above can be applied to individual interdental cleaners. However, from an economic standpoint, it is more efficient to apply the partial coating to several interdental cleaners simultaneously. For this purpose, several interdental cleaners can be grouped together and connected, in particular, by means of bridges. A group can, for example, consist of eight or more interdental cleaners arranged side by side.

[0028] A device according to the invention for applying a coating to an interdental cleaner of the type mentioned is characterized by a transfer body which is adjustable relative to the interdental cleaner between a receiving position, in which it can be brought into contact with the coating agent at least partially and at least on the outside, and a delivery position, in which the transfer body carrying the coating agent is in contact with the outer surface of the cleaning part.

[0029] A coating bath can be provided to receive the coating material, comprising a basin filled with the coating material into which the transfer body can be immersed. The transfer body is preferably attached to a holder, for example, a vertically adjustable holder, the adjustment of which preferably allows the transfer body to be completely immersed in the coating bath.

[0030] The interdental cleaner can be positioned with its cleaning part above the coating bath, so that the transfer body can be lifted out of the coating bath by a purely vertical translational movement and brought into contact with the outer surface of the cleaning part in its delivery position.

[0031] The transfer body can be made of a plastic, and in particular of a porous material, for example of an open-cell or closed-cell plastic foam. Preferably, however, the transfer body is made of metal, and in particular preferably of stainless steel.

[0032] The outer surface of the transfer body can be pretreated to improve the uniform absorption of the coating material across the entire surface. This pretreatment can consist of external corona treatment and / or external roughening of the transfer body. Such roughening is preferably achieved through mechanical processing, for example, by sandblasting, grinding, etching, or electrical discharge machining (EDM).

[0033] The device can be designed such that only one interdental cleaner can be coated at a time. Preferably, however, at least one group of interdental cleaners, consisting of several, is coated accordingly. Each interdental cleaner can have its own transfer body, so that the transfer bodies are also arranged in a corresponding transfer body group. In a further embodiment of the device, it is provided that several groups of interdental cleaners are coated simultaneously in one step. For this purpose, several transfer body groups are preferably provided, whose movements are coupled, i.e., preferably immerse themselves in the coating bath simultaneously and also preferably reach their discharge position simultaneously, in which they are in contact with the outer surface of the respective assigned cleaning element.

[0034] Further details and features of the invention will become apparent from the following description of an exemplary embodiment with reference to the drawing. The drawing shows: Fig. 1 a schematic perspective view of an interdental cleaner, Fig. 2 the cleaning part of the interdental cleaner according to Fig. 1 In enlarged view, Fig. 3 shows a schematic sectional view of a device for applying a coating to an interdental cleaner, with the transfer body in its receiving position, Fig. 4 shows a Fig. 3 corresponding representation, with the transfer body in its delivery position, Fig. 5 section VV in Fig. 4 , Fig. 6 a schematic perspective view of a device for the simultaneous application of a coating to several interdental cleaners, Fig. 7 a top view of the transfer body and the cleaning part during the coating and Fig. 8 a special embodiment of the transfer body.

[0035] Fig. 1 Figure 1 shows a perspective view of an interdental cleaner 10, which has a rod-shaped carrier 11 made of a dimensionally stable plastic. A plate-shaped handle section 12 is integrally molded onto the carrier at its axially rear end. At the opposite front axial end, a cleaning section 13 is formed on the carrier 11. The cleaning section 13 has a sleeve-shaped covering 14 of the carrier 11, which extends at the front end of the carrier 11 over approximately one-third of the length of the interdental cleaner 10. The sleeve-shaped covering 14 is made of a soft-elastic material, for example, a thermoplastic elastomer, and has radially outwardly projecting cleaning elements 15 on its outer surface in the form of integrally molded, conical fingers.

[0036] How especially Fig. 2 As shown, the cleaning elements 15 are arranged in the form of several rows R1, R2, R3, R4 extending longitudinally along the carrier 11, with a strip-shaped gap 17 extending longitudinally along the interdental cleaner 10 between each pair of adjacent rows. One of the gaps 17 is used to form a coating area 18. The coating area 18 comprises the bottom of the gap 17, i.e., the outer surface of the cleaning element arranged between the two adjacent rows R1, R2, and also partially the surface areas of the cleaning elements 15 facing the gap 17.

[0037] In coating area 18, a coating 16, for example from a dental care product, is applied.

[0038] A device for applying the coating 16 to the interdental cleaner 10 is shown in Fig. 3 schematically represented. The device comprises a housing 20 in which a basin 21 is formed, which is open at the top and in which a coating agent bath 19 with a liquid coating agent 22 is located.

[0039] A holder 23 is vertically adjustable, as indicated by the double arrow V, and carries a transfer body 24, which in the illustrated case is designed as a circular cylinder attached to the holder 23 at its rear end and spherically rounded at the opposite front end. The transfer body 24 can be made of metal, and in particular steel, and its surface can be treated to improve the absorption or wetting of the coating agent 22.

[0040] Above the housing 20 is a holding device 25 in which an interdental cleaner 10 is clamped and held by its rear handle section 12. The front cleaning part 13 of the interdental cleaner 10 is freely cantilevered above the coating agent bath 19.

[0041] According to Fig. 3 The transfer body 24 is in its receiving position, in which it is fully immersed in the coating medium 22 of the coating medium bath 19. The holder 23 is then moved vertically upwards until the transfer body 24 comes into contact with the outer surface of the cleaning part 13. This discharge position is in Fig. 4 depicted.

[0042] As can be seen from the sectional view according to Fig. 5 The transfer body 24 engages in the space 17 formed between two adjacent rows R 1 , R 2 of the cleaning elements 15 and elastically deforms the cleaning elements 15 and pushes them laterally outwards, so that the surfaces of the cleaning elements 15 facing the space 17 and the bottom of the space 17 come into contact with the surface of the transfer body 24 over a large area, thereby transferring the coating agent 22.

[0043] Fig. 6 Figure 1 shows a schematic and partially simplified representation of a device 26 for simultaneously coating a plurality of interdental cleaners 10. According to the illustrated embodiment, four interdental cleaner groups 27, each consisting of 8 interdental cleaners 10, are provided. The interdental cleaners 10 of each interdental cleaner group 27 are connected to one another and each clamped in a holding device 25.

[0044] Four transfer body groups 28, each containing eight transfer bodies 24, are provided, with each transfer body 24 being assigned to an interdental cleaner 10 as described above. The transfer body groups 28 are all arranged on the common holder 23 and are thus synchronized in their movement. By lowering the holder 23, all transfer body groups 28 can be simultaneously immersed in the coating agent bath 19 and then simultaneously moved into their respective dispensing positions, in which a transfer body 24 with the cleaning element 13 of the assigned interdental cleaner 10 comes into contact with the coating agent and transfers the coating agent.

[0045] How Fig. 7 As shown, in a specific embodiment of the invention, a pointed section 13a formed at the front end of the cleaning part 13 can be provided in such a way that it does not come into contact with the transfer body 24, and thus the coating material is not applied to the cleaning part 13 in this pointed section 13a. This results in the pointed section 13a remaining soft, elastic, and flexible.

[0046] Fig. 8 Figure 24 shows a special embodiment of the transfer body 24, which has a basically cylindrical shape with a spherical rounding at its front end. On at least one side of the transfer body 24, a flat surface area 24a extending longitudinally is formed, which extends approximately over the entire length of at least the cylindrical part of the transfer body 24.

Claims

1. An interdental cleaner (10) with a rod-like support (11) made of plastic, which has a cleaning part (13) made of a soft-elastic plastic in an axial end region, wherein the cleaning part (13) has a sleeve-like coating (14) arranged on the support (11) and carries a plurality of radially outwardly projecting cleaning elements (15), characterized in that the cleaning part (13) is provided with a coating (16) on its external surface in a coating region (18), and that the coating region (18) comprises only a partial region of the external surface of the cleaning part (13).

2. The interdental cleaner according to claim 1, characterized in that the coating region (18) extends in the longitudinal direction of the support (11).

3. The interdental cleaner according to claim 1 or 2, characterized in that the cleaning elements (15) are arranged in at least two rows (R1, R2, R3, R4) extending in the longitudinal direction of the support (11), and in that the coating region is arranged between two adjacent rows (R1, R2).

4. The interdental cleaner according to any one of claims 1 to 3, characterized in that the coating region (18) extends over at least 50% of the axial length of the cleaning part (13).

5. The interdental cleaner according to any one of claims 1 to 4, characterized in that the coating (16) is formed by an antimicrobial substance and / or by an essential oil and / or by a remineralizing substance and / or by a flavoring substance and / or by an anti-inflammatory substance and / or by a desensitizing substance and / or by probiotics and / or by a dentin-strengthening substance or by mixtures of the specified substances.

6. The interdental cleaner according to any one of claims 1 to 5, characterized in that a front tip portion (13a) of the cleaning part (13) is free of coating.

7. A method for applying a coating (16) to an interdental cleaner (10) for producing an interdental cleaner according to any one of claims 1 to 6, wherein the interdental cleaner (10) has a rod-like support (11) and a cleaning part (13) made of a soft-elastic plastic, wherein a transfer body (24) is provided at least on the outside and at least in portions with a coating agent (22), whereupon the transfer body (24) is brought into contact with the external surface of the cleaning part (13) to form the coating (16).

8. The method according to claim 7, characterized in that the transfer body (24) is immersed in a coating agent bath (19).

9. The method according to claim 7 or 8, characterized in that the cleaning part (13) carries a plurality of radially outwardly projecting cleaning elements (15) arranged in at least two rows (R1, R2, R3, R4) extending in the longitudinal direction of the support (11), and in that the transfer body (24) is inserted into a space (17) formed between two adjacent rows (R1, R2).

10. The method according to any one of claims 7 to 9, characterized in that the cleaning part (13) is corona-treated and / or plasma-treated at least in portions before the coating (16) is applied to its external surface.

11. The method according to any one of claims 7 to 10, characterized in that a front tip portion (13a) of the cleaning part (13) is left free of coating.