TW202102161A - Method for producing a brush, and bristle carrier and magazine for carrying out the method - Google Patents

Abstract

The invention relates to a method for producing a brush, according to which a one-piece, injection-molded bristle carrier (10) has sleeve-like tuft seats (22) that are coupled to a central support structure (18) via a thin connecting piece (20). This bristle carrier is over molded with a soft plastic material (26). Once the bristle tufts (24) are inserted, the tuft seats (22) are narrowed at the front end by applying heat and pressure. The invention also relates to an over molded bristle carrier and to a magazine for carrying out the method.

Description

Method of manufacturing brush, bristle carrier and magazine for carrying out the method

The invention relates to a method of manufacturing a brush, a bristle carrier and a magazine.

In the process of manufacturing brushes, especially toothbrushes, the use of anchors to fix the bristle bundles and the use of anchors to fix the bristle bundles are implemented in actual operations. The present invention is only about fixing without anchors. Therefore, a pre-injection molded bristle carrier opens openings for the bristle carrier during the injection molding process, and inserts the bristle bundle into the openings. Before inserting the bristle bundle into the opening, the rear ends of the bristles of the bristle bundle are fused together via heat. This produces a material expansion phenomenon similar to mushrooms. The melting of individual bristles is achieved by means of hot air or a printing head.

A method is known from DE 10 2016 107 759 A1, which relates to a new way of fixing bristle bundles to a bristle carrier. In this regard, after inserting the bristles into the so-called anchoring hole, the front of the bristle carrier is heated and pressure is applied. Therefore, the wall surrounding the receiving hole is deformed and narrowed toward the front at the entrance area of the wall, and the bristle bundle expands The end is fixed in the anchor hole. The front part of the bristle carrier is heated to a certain temperature, which is lower than the melting temperature of the bristle material and/or bristle carrier material, especially in °C, the highest is 85% of the melting temperature. The heat acting on the bristle carrier is introduced through the tool part (called a magazine or a perforated plate). There are openings in the magazine or the perforated plate, and the openings contain the bristle bundles, and the bristle bundles are pressed into the anchor holes from the openings. The advantage of this method is that the bristle bundles are held in the bristle carrier in a state of being extremely resistant to pulling out, without the need for additional anchoring members. In addition, the anchoring hole is narrowed around each bristle bundle, so that no impurities can settle at the transition into the anchoring hole.

The present invention uses the method described in DE 10 2016 107 759 A1 and the temperature and pressure described therein to manufacture a brush whose bristle tufts have high flexibility relative to other bristle tufts.

For many applications, there is an increasing need for the mobility of individual bristle bundles relative to the bristle carrier. In this regard, WO 2006/131397 A1 shows a bristle carrier plate, which is mounted on the bristle carrier and can be moved in all directions via hinged feet. A single bristle bundle is inserted into a sleeve-shaped, highly elastic receiving groove, which in principle is softer than the bristle carrier. The receiving grooves should allow the bristles to deviate.

WO 97/20484 A1 describes a similar method, in which the bristle bundles are also received by a soft elastic block, which has a sleeve-like extension and is accommodated in a hard brush carrier.

The purpose of the present invention is to introduce a method for manufacturing a brush, and the implementation of the method is simple and safe, so the quality of the brush is high, and the elasticity and mobility of the bristle bundle relative to the bristle carrier are ensured.

This is solved in the method according to the invention through the following steps: A one-piece, injection-molded bristle carrier is provided, the bristle carrier is provided with a sleeve-shaped, open-front bristle bundle receiving groove, each of the bristle bundle receiving grooves is connected to a central support body via at least one connecting piece, The bristle carrier is overmolded with a softer plastic, that is, a plastic softer than the plastic of the bristle carrier is used to embed the bristle bundle accommodating groove and fill the gap between the bristle bundle accommodating grooves and the bristle bundle accommodating groove. The gap between the supports, Insert the bristle bundle into the bristle bundle receiving groove, and The bristle bundle accommodating groove is deformed at the front edge of the bristle bundle accommodating groove through heating and pressurization, thereby fixing the bristle bundle in the bristle bundle accommodating groove.

Contrary to the prior art, the method according to the present invention provides that the bristle bundle is inserted into a bristle bundle containing groove made of hard plastic, that is, a plastic that is harder than the covering material. The plastic is deformed by temperature and heat so as to compress and narrow the entrance of the bristle bundle receiving groove. The sleeve-shaped bristle bundle receiving groove is connected with the central support body only via at least one thin connecting piece, thereby realizing the flexibility of the individual bristle bundles with respect to each other and the single bristle bundle relative to the bristle carrier. However, the connecting piece cannot maintain the stability of the bristle carrier during use. By overmolding the bristle carrier with softer plastic, the entire complete bristle carrier becomes more stable as a whole, and has a smooth and closed outer surface, but the hard bristle bundle receiving groove can still be in the soft plastic mobile.

The deformation of the bristle bundle receiving groove is achieved through pressurization and heating, as mentioned in the aforementioned DE 10 2016 107 759 A1 in this respect.

Preferably, especially after the bristle carrier is overmolded with a softer plastic, the bristle bundle receiving groove is heated to a certain temperature, the temperature is in °C, and the maximum is 85% of the melting temperature of the bristle carrier material.

For example, heating is achieved through a heated magazine, the bristle bundle is accommodated in the magazine, and the bristle bundle is pushed from the magazine into the bristle bundle receiving groove in the bristle carrier. The magazine presses against the bristle bundle receiving groove, and while deforming at the front edge, heats the bristle bundle receiving groove, where "front" refers to the front of the brush, and the bristle bundle extends from the front, and the back is the reverse side of the brush. , Usually without a brush.

The back surface of the overmolded bristle carrier is actively cooled by a cooling device, preferably a fluid cooling or even a water cooling device, during the deformation and heating process.

The bristle carrier may have at least one exposed part to the adjacent soft plastic after overmolding, the exposed part being especially the support body.

The exposed part can be supported during the deformation process of the overmolded bristle carrier on the one hand, and cooled on the other hand. Preferably, there is a complementary receiving groove on the tool side, and the overmolded bristle carrier will be placed in the receiving groove, and be supported and cooled in the receiving groove.

After closing the tool and deforming and reshaping the sleeve-shaped bristle bundle receiving groove, the tool preferably stays in this position for a few seconds, which represents a predetermined stay time. Before the tool is opened, the dwell time should be at least 1 second, especially at least 1.5 seconds and/or at most 3 seconds.

In addition to the dwell time, there is also a time period during which the tool will first move to the closed position once, and at the closed position heat has been introduced to the bristle carrier and pressure is applied to the bristle carrier. The entire time period from the first contact between the magazine and the bristle carrier to the separation of the magazine and the bristle carrier is called the action time, and the residence time becomes a sub-period. The action time is preferably at least 4 seconds, especially at least 5 seconds.

In order to maintain the flexibility of the bristle bundle receiving groove as much as possible, and at the same time to keep the resulting brush head smooth, it is stipulated that the connecting pieces on the back and the sides are completely surrounded and covered by softer plastic. In addition, at the front, the connecting piece is also completely covered by the soft plastic, but the bristle bundle accommodating groove protrudes from the soft plastic in the front, so here, the plastic will not be close to the bristle bundle accommodating groove in the entire depth, and The bristle bundle receiving grooves are stabilized over the entire depth.

The bristle bundle receiving groove can be exposed on the back facing the soft plastic, such as a dot type, in order to provide support during the deformation process. Therefore, it can be considered that a thin pin protrudes from the back of the bristle bundle receiving groove, and the pin is relatively exposed to the soft plastic in the front.

The present invention also relates to an overmolded brush carrier for manufacturing bristles using the method according to the present invention. The brush carrier is composed of an injection-molded brush carrier with a plurality of sleeve-shaped, open-front bristle bundle accommodating grooves, each of the bristle bundle accommodating grooves preferably only passes through a unique The connecting piece is connected to the central support body, wherein the brush carrier is overmolded by soft plastic, and the bristle bundle containing groove is embedded in the soft plastic, and the front ends of the bristle bundle containing grooves are open. The plastic completely fills the gaps between the bristle bundle accommodating grooves and the gap between the bristle bundle accommodating grooves and the supporting body.

The back of the supporting body is preferably exposed to the adjacent soft plastic, so that it can be supported on the harder supporting body during the production process.

In a plan view of the opening side of the bristle bundle accommodating groove, the connecting piece preferably has a smaller height and/or width than the bristle bundle accommodating groove itself, that is, the cross section of the bristle bundle accommodating groove. This ensures that the bristle tuft receiving groove itself is stable, but the bristle tuft receiving groove is movable relative to the support body and furthermore relative to the brush handle.

The supporting body can be integrally connected to the brush neck and (or) the brush handle, that is to say, it becomes a part of the brush neck and (or) the brush handle.

Generally, an elongated structure can be provided as a support, which extends in the center and passes through the brush head.

As mentioned above, the bristle bundle receiving groove can protrude from the soft plastic at the front and/or be exposed to the plastic at the back without protruding.

The present invention also relates to a magazine, also called a perforated plate, in which a bristle bundle is inserted, and the back of the bristle bundle has a welding end, wherein the deformation of the bristle bundle receiving groove is realized through the magazine. The magazine according to the present invention has holes for accommodating bristle bundles, and the holes have an enlarged cross-section at the end of the holes that is close to the bristle bundle accommodating groove, so as to form a single recess into which the bristle bundle accommodating groove extends The recesses are equal and supported from the side during the deformation process, wherein the recesses are transformed into reduced cross-sections through the steps, and the recesses are terminated at the conical step.

Through the recesses, the sleeve-shaped bristle bundle receiving groove can be supported laterally during the deformation process. In particular, the deformation is completed by means of the tapered section steps on the front end of the bristle bundle receiving groove. The bristle bundle accommodating groove itself may have a corresponding tapered shape at the free end of the bristle bundle accommodating groove in an undeformed state. Therefore, when pressure is applied, the sleeve-shaped bristle bundle receiving groove bulges outward due to the pressure of the front end surface and receives an unpredictable geometric shape.

In addition, the magazine can have an integrated heating device.

FIG. 1 shows a toothbrush with a bristle carrier 10 made of thermoplastic. The bristle carrier 10 in this case has a part that extends into the brush head 12 and includes a brush neck 16 and a brush handle 14.

The bristle carrier 10 is shown in detail in FIG. 2. The neck 16 is integrally connected to a central elongated support 18 forming an extension of the neck 16, and this elongated support 18 is a part of the brush head 12. The supporting body 18 is an integral part which is located in the middle, i.e., is arranged on the longitudinal axis of the toothbrush.

The side connecting piece 20 protrudes from the supporting body 18 and is integrally connected to the supporting body 18, and the connecting piece 20 extends to the sleeve-shaped bristle bundle receiving groove and is integrally connected to the bristle bundle receiving groove 22.

The bristle bundle receiving grooves 22 are open on the front and closed on the back (see FIG. 1), that is, they have the shape of a basin.

The connecting piece 20 is smaller than the corresponding bristle bundle receiving groove 22 not only in the width of the connecting piece 20 (the width is visible in FIG. 2), but also in the height of the connecting piece 20 (the height is partially visible in FIG. 4), Thereby, the connecting piece 20 forms a kind of flexible bridge between the bristle bundle accommodating groove 22 and the support body 18, so the bristle bundle accommodating groove 22 is flexibly attached to the support body 18 in all directions.

The bristle carrier 10 is overmolded with a soft plastic 26 before being filled with the bristle bundle 24 and is in the area of the brush head 12. In FIG. 2, the outline of the soft plastic 26 is shown by dotted lines. "Soft" means that it is softer than the plastic of the bristle carrier 10.

The soft plastic 26 is completely filled in the gaps between the adjacent bristle bundle accommodating grooves 22 and the connecting pieces 20 of the bristle bundle accommodating grooves 22 and the gap between the bristle bundle accommodating groove 22 and the support 18.

The soft plastic 26 also covers the back (see FIG. 3) and the side as well as the connecting piece 20, so that the connecting piece 20 cannot be touched from the back.

Optionally, the bristle bundle accommodating groove 22 may be exposed on the back in a dot-like manner. However, the side of the bristle bundle receiving groove is completely covered with soft plastic.

The central support 18 is not covered by the soft plastic 26 on the back, so it is exposed on the back.

In the front, the soft plastic 26 covers all the connecting pieces 20. As shown in FIGS. 1 and 4, the bristle bundle receiving groove 22 protrudes forward relative to the soft plastic 26 and extends from the soft plastic 26.

Next, the method of manufacturing the brush will be described in detail.

First, as described above, the bristle carrier 10 is injection molded, and then the bristle carrier 10 is overmolded with the soft plastic 26 in the area of the brush head 12.

Then, the overmolded bristle carrier 10 is placed in a tool, which is shown in FIGS. 4 and 5. The tool has a lower tool half 30 with a receptacle corresponding to the shape of the overmolded bristle carrier 10 in the area of the brush head 12 and, if necessary, to the area of the neck 16, And designed to complement it. Therefore, the back surface of the overmolded bristle carrier 10 rests on the entire surface of the lower tool half 30 with the support 18 and the similar soft plastic 26.

If the bristle bundle accommodating grooves 22 are exposed to the plastic on the back side (without protruding), the bristle bundle accommodating grooves 22 are also directly supported on the mold half 30 on the back side.

A bundle of bristles 24 is inserted into a so-called magazine 32 which is also called a perforated plate. One end of the bristle bundle 24 is provided with a thickened portion 34 formed by fusing the bristles of the bristle bundle 24 with each other. After the bristle bundle 24 is inserted into the magazine 32, this fusion can be performed if necessary.

The bristle bundle 24 is inserted into the sleeve-shaped bristle bundle accommodating groove 22 that is open at the front with the thickened portion 34 in the front, if necessary, by means of a push rod or compressed air. This is indicated by the corresponding arrow in Figure 4. The magazine 32 is preferably made of metal or ceramic, and has a heating device 36, such as an electric heater or a hot water heating device. Alternatively, the heater is connected to the magazine 32 before the molding process.

The magazine 32 has holes 33 for accommodating the bristle bundles 24, and the holes 33 have enlarged cross-sections at the ends of the holes 33 that are close to the bristle bundle accommodating groove 22, so as to form a single recess 35, the bristle bundle accommodating groove 22 extends into the recesses 35 and is supported from the side during the deformation process, wherein the recesses 35 are transformed into reduced cross-sections through the tapered section step 37, and the recesses 35 terminate at the tapered section step 37.

As shown in the figure, this stage can be conical or dome-shaped.

The bristle bundle receiving groove 22 may have a tapered front edge 39 on the outer side, and the front edge 39 may be formed opposite to the recess 35 and the step 37 optionally but not necessarily. It can even be seen in FIG. 6 that the bristle bundle accommodating groove 22 has a conical shape at the edge when it is not deformed, but the step 37 is dome-shaped and the bristle bundle accommodating groove 22 is thus dome-shaped.

Via the recess 35, the sleeve-shaped bristle bundle receiving groove 22 can be supported from the side when deformed (see FIG. 5).

In particular, the deformation is completed at the front end of the bristle bundle receiving groove 22 by means of the tapered section step 37. This prevents the sleeve-shaped bristle bundle receiving groove 22 from bulging outward due to the pressure on the front end surface and receiving an unpredictable geometric figure during the deformation process.

When the bottom of the magazine 32 is forward, the magazine 32 moves toward the bristle carrier 10 and therefore hits the upper part of the bristle bundle receiving groove 22 (see FIG. 5). The magazine 32 is heated at the front, and as a result, the plastic of the bristle bundle accommodating groove 22 becomes soft at the front end, but remains lower than the melting temperature of the plastic. Preferably, the front portion of the bristle bundle receiving groove 22 is heated to a certain temperature, the temperature is in °C, and the maximum temperature is 85% of the melting temperature of the bristle carrier 10. More preferably, when in contact with the bristle carrier 10, the temperature of the magazine 32 rises to 60°C to 200°C, especially over 80°C, preferably lower than 150°C.

The magazine 32 moves toward the lower tool half 30, so that the front portion of the bristle bundle accommodating groove 22 is deformed and reshaped inward, as shown in FIG. 6 according to the bristle bundle accommodating groove 22 on the left, the opening of the bristle bundle accommodating groove 22 The cross-section is therefore significantly reduced in the end region, and as shown symbolically in FIG. 6, the resulting narrowed opening is significantly smaller than the thickened portion 34.

As shown in FIG. 6, the bristle bundle accommodating groove 22 on the right has not been deformed and the bristle bundle accommodating groove in the middle has not been deformed either, and the bristle bundle 24 has been inserted into the bristle bundle accommodating groove 22 in the middle. Optionally, it is even possible to compress the bristle bundle accommodating grooves 22 so that the bristle bundle accommodating grooves 22 are placed around the thickened portion 34 and the inserted bristles. As an alternative, in the range within the opening 38, that is, in the range within the bristle bundle accommodating groove 22, there is a gap between the bristles and the wall forming the bristle bundle accommodating groove 22. However, the narrowest point of the bristle bundle accommodating groove 22 is preferably (which is not meant to be restrictive) narrow enough to contact the external bristles.

As shown in FIG. 6, the bristle bundle receiving groove 22 is axially shortened by deformation, from the initial height H to the height H', which is shorter by 1-1.3mm, especially 1.2mm.

Preferably, the magazine 32 and the tool half 30 move over the distance and hardly stop (auf Block fahren) (see FIG. 5, where the contact has not been fully reached here), that is, they abut against each other. After a certain residence time and action time, the magazine 32 then moves upward so that the bristle bundles 24 are removed from the opening of the magazine 32.

The lower tool half 30 is cooled during the deformation process because the lower tool half is provided with an active cooling device 40, such as using cooling water introduced by a pipe. However, active gas cooling is also possible. The temperature of the brush carrier 10 on the back of the support 18 is preferably not more than 30°C due to the cooling device 40.

10: bristle carrier 12: Brush head 14: Brush handle 16: brush the neck 18: Support 20: connecting piece 22: bristle bundle holding groove 24: bristle bunch 26: soft plastic 30: Lower tool half 32: hopper 33: Hole 34: Thickening 35: recess 36: heating device 37: Duan Stage 38: opening 39: front edge 40: Cooling device

More features and advantages of the present invention can be derived from the following description and the drawings referred to. In the scheme:

Fig. 1 illustrates a cross-sectional view of a brush manufactured according to the present invention taken along the line I-I in Fig. 2. The brush is in the form of a toothbrush and has a bristle carrier according to the present invention,

Figure 2 illustrates a plan view of an overmolded bristle carrier according to the present invention, which is shown in Figure 1,

Figure 3 illustrates the back of the brush according to Figure 1,

Fig. 4 shows a cross-sectional view of the tool including the cartridge according to the present invention and the bristle carrier according to the present invention inserted into the tool, taken along the line IV-IV in Fig. 2 before deformation,

Figure 5 illustrates a cross-sectional view of the bristle carrier according to the present invention taken along the line IV-IV in Figure 2 during the deformation process along with the tool including the cartridge according to the present invention and embedded in the tool, and

Figure 6 is a detailed enlarged view of the tool and the deformed and reshaped bristle carrier.

Domestic deposit information (please note in the order of deposit institution, date and number) no Foreign hosting information (please note in the order of hosting country, institution, date and number) no

10: bristle carrier

16: brush the neck

18: Support

20: connecting piece

22: bristle bundle holding groove

24: bristle bunch

26: soft plastic

30: Lower tool half

32: hopper

33: Hole

34: Thickening

35: recess

37: Duan Stage

39: front edge

40: Cooling device

Claims (16)

A method of manufacturing a brush includes the following steps: An injection-molded one-piece bristle carrier (10) is provided. The bristle carrier (10) is provided with a sleeve-shaped, open-front bristle bundle receiving groove (22), and the bristle bundle receiving grooves (22) respectively pass through At least one connecting piece (20) is connected to a central support body (18), While inserting the bristle bundle receiving grooves (22), a soft plastic (26) is used to overmold the bristle carrier (10), and the soft plastic (26) is used to fill the bristle bundle receiving grooves (22) The gap between each other and the gap between the bristle bundle containing grooves (22) and the support body (18), Insert the bristle bundles (24) into the bristle bundle accommodating grooves (22), and The bristle bundle accommodating grooves (22) are deformed at the front edge of the bristle bundle accommodating grooves (22) by heating and pressurizing, thereby fixing the bristle bundles (24) in the bristle bundle accommodating grooves ( twenty two). The method according to claim 1, wherein the bristle bundle accommodating grooves (22) are heated to a certain temperature to deform the bristle bundle accommodating grooves (22), and the temperature is in °C, and the highest is the The material of the bristle bundle holding tank (22) is 85% of the melting temperature. The method according to claim 1 or 2, wherein a heated magazine (32) is pressed against the bristle bundle accommodating grooves (22), and the bristle bundle accommodating grooves (22) are heated, and by Pressure is applied to deform the bristle bundle accommodating grooves (22), the bristle bundles (24) are contained in the magazine (32) and the bristle bundles (24) are pushed into the magazine (32) The bristle bundles contain grooves (22). The method according to claim 1 or 2, wherein during the deformation and the heating, the back surface of the overmolded bristle carrier (10) is actively cooled. The method according to claim 1 or 2, wherein after the bristle carrier (10) is overmolded with the soft plastic (26), the soft plastic (26) adjacent to the back is exposed, especially only in the soft plastic (26) On the support (18). The method according to claim 1 or 2, wherein, during the deformation process, the entire back surface of the overmolded bristle carrier (10) is supported in a complementary receiving groove. The method according to claim 1 or 2, wherein the undeformed bristle bundle receiving grooves (22) have a tapered front edge (39) on the outside. The method of claim 1 or 2 and retrospectively referencing claim 3, wherein the magazine (32) has holes (33) for accommodating the bristle bundles (24), wherein the holes (33) are The ends of the holes (33) close to the bristle bundle receiving grooves (22) have an enlarged cross section that matches the bristle bundle receiving grooves (22) to form a single recess (35), The bristle bundle receiving grooves (22) extend into the recesses (35) and are supported from the side during the deformation process. The recesses (35) are transformed into a hole section through a step (37). The cross section fits the bristle bundle (24). The method according to claim 8, wherein the recesses (35) terminate at a tapered section step (37). An overmolded bristle carrier for manufacturing a brush according to any one of the preceding claims, characterized in that an injection molded bristle carrier (10) is provided, and the bristle carrier (10) is provided with There are a plurality of sleeve-shaped, front-opened bristle bundle receiving grooves (22), wherein each of the bristle bundle receiving grooves (22) is connected to a connecting piece (20) via preferably only one respectively allocated connecting piece (20). The central support body (18), wherein the bristle carrier (10) is overmolded with a plastic (26) that is softer than the material of the bristle carrier (10), and the bristle bundle receiving grooves (22) are embedded The soft plastic (26) and the front are open, wherein the soft plastic (26) fills the gaps between the bristle bundle accommodating grooves (22) and the bristle bundle accommodating grooves (22) and the support The gap between the bodies (18). The bristle carrier (10) according to claim 10, wherein the back surface of the support body (18) and/or the bristle bundle accommodating grooves (22) are respectively exposed relative to the adjacent soft plastic (26), Preferably, the supporting body (18) and (or) the side surfaces of the bristle bundle receiving grooves (22) are completely surrounded by the soft plastic (26), and (or) the back and side surfaces of the connecting pieces (22) It is completely surrounded by the soft plastic (26), and only the front of the connecting pieces (22) is exposed relative to the soft plastic (26). The bristle carrier according to claim 10 or 11, wherein, in a plan view of the opening side of the bristle bundle accommodating grooves (22), the connecting pieces (20) have a comparison with the bristle bundle accommodating grooves (22) Smaller height and/or width. The bristle carrier according to claim 10 or 11, wherein the support body (18) is integrally connected to the brush neck (16) and/or the brush handle (14). The bristle carrier according to claim 10 or 11, wherein the bristle bundle receiving grooves (22) protrude from the soft plastic (26) at the front. A magazine for performing the method according to any one of claims 1 to 9, wherein the magazine (32) has holes (33) for accommodating the bristle bundles (24), wherein the The holes (33) have an enlarged cross-section at one end of the holes (33) and the bristle bundle containing grooves (22) to form a single recess (35) into which the bristle bundle containing grooves (22) extend The recesses (35), and the bristle bundle receiving grooves (22) are supported on the side during the deformation process, wherein the recesses (35) are transformed into a reduced hole section through a step (37), and The recesses (35) terminate at a tapered stage (37). The magazine according to claim 15, wherein the magazine (32) is equipped with a built-in heating device (36).

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