Method for manufacturing an oral care tool

Abstract

The present disclosure relates to a method for manufacturing an oral care implement comprising a handle, a connector and a head, the head being repeatedly attachable to and detachable from the handle via the connector, the method comprising the steps of: injection molding at least a portion of the handle, the handle part is provided with a far-side end part and a near-side end part opposite to the far-side end part, and the near-side end part comprises a hollow part; -injection-moulding at least a portion of the connector, the connector having an outer side surface and a groove therein, the groove forming a cavity within the connector,-injection-moulding at least a portion of the head,-inserting the connector into the hollow portion of the handle and securing the connector preferably by gluing, welding and / or press-fitting.

Description

[0001] This application is a divisional application of PCT patent application PCT / US2019 / 016216 (international application date February 1, 2019, priority date February 9, 2018, Chinese patent application number 201980012447.1, entitled "Method for Manufacturing Oral Care Tools"), which entered the Chinese national phase on August 7, 2020. Technical Field

[0002] This disclosure relates to a method for manufacturing an oral care tool, the oral care tool including a handle, a connector, and a head, the head being reusable to and detachable from the handle via the connector. Background Technology

[0003] The head and handle of oral care tools, such as manual toothbrushes, are well known in the art. Generally, bristle tufts or other cleaning elements for cleaning teeth and soft tissues in the mouth are attached to a bristle carrier or mounting surface designed for insertion into the user's mouth. The handle is typically attached to the head and is held by the user during brushing. Typically, the head of a manual toothbrush is permanently attached to the handle, for example, by injection molding the bristle carrier, handle, and neck connecting the head and handle in a single injection molding step. After the normal lifespan of the toothbrush, approximately three months of use, it is discarded. To provide an environmentally friendly / sustainable manual toothbrush that generates less waste when discarded, manual toothbrushes are known to include replaceable (i.e., repeatedly attached to and detachable from the handle) heads or head replacements. Consumers can reuse the handle and only purchase new head replacements instead of buying a brand new toothbrush. Such replacements are typically cheaper than conventional manual toothbrushes and generate less waste.

[0004] For example, a known manual toothbrush includes a handle to which a replaceable head is attached. The handle has a cavity into which the head can be inserted. To provide a sufficiently strong connection between the head and the handle, the brush head is formed with a neck having a coupling anchor having multiple grooves in a complementary engagement mechanism for engaging within a bushing in the handle.

[0005] However, this anchoring / engaging mechanism has a relatively complex external geometry that makes it difficult to clean after toothbrush use. Toothpaste and slurry can accumulate in the grooves of the anchoring / engaging mechanism and may prevent the brush head from attaching precisely to the handle. Furthermore, this handle and head construction is not easy to manufacture in a cost-effective manner.

[0006] Furthermore, connector solutions characterized by small plastic hooks that interact with corresponding holes are known. However, these plastic hooks loosen over time, and the user needs to actively push the hooks back parallel to pull the replacement to remove the brush head from the handle. This connector solution is neither intuitive nor convenient for consumers. Moreover, this connector is difficult to clean. Additionally, the engagement parts located within the brush replacement are necessary, leading to additional manufacturing costs and complexity.

[0007] The purpose of this disclosure is to provide a method for manufacturing oral care tools in a cost-effective and easy manner, specifically a method for manufacturing a manual toothbrush comprising a handle and a head, the head being reusable to and detachable from the handle. Summary of the Invention

[0008] According to one aspect, a method for manufacturing an oral care tool is provided, the tool including a handle, a connector, and a head, the head being reusable to and detachable from the handle via the connector, the method comprising the following steps:

[0009] - Injection mold at least a portion of the handle, the handle having a distal end and a proximal end opposite to the distal end, the proximal end including a hollow portion;

[0010] - Injection mold at least a portion of the connector, the connector having an outer surface and a groove therein, the groove forming a cavity within the connector.

[0011] - Injection mold at least a portion of the head,

[0012] - Insert the connector into the hollow portion of the shank, and preferably secure the connector by gluing, welding and / or press fitting. Attached Figure Description

[0013] The invention is described in more detail below with reference to various embodiments and accompanying drawings, wherein:

[0014] Figure 1 A perspective view of an exemplary embodiment of a manual oral care tool according to the present disclosure is shown, the oral care tool including a head, a handle, and a connector;

[0015] Figure 2 It shows Figure 1 A perspective view of the handle with the connector;

[0016] Figure 3 It shows according to Figure 2 A schematic side view of the handle with a connector;

[0017] Figure 4 It shows according to Figure 2A schematic front view of the handle with a connector;

[0018] Figure 5 It shows according to Figure 2 A schematic top view of the handle with a connector;

[0019] Figure 6 A front view of an exemplary embodiment of the connector according to this disclosure is shown;

[0020] Figure 7 It shows Figure 6 Side view of the connector;

[0021] Figure 8 It shows Figure 2 A longitudinal sectional view of the handle with the connector;

[0022] Figure 9 A sectional view along line AA is shown;

[0023] Figure 10 A sectional view along line BB is shown;

[0024] Figure 11 It shows Figure 1 A schematic perspective view of the head of a manual oral care tool;

[0025] Figure 12 It shows Figure 11 Bottom view of the head;

[0026] Figure 13 It shows the manufacture of including Figure 1 A flowchart of the handle of the connector for an oral care tool; and

[0027] Figure 14 Average results for heat transfer and flow distance are shown for several different formulations / material compositions. Detailed Implementation

[0028] The method for manufacturing oral care tools according to this disclosure may include the following steps:

[0029] - Injection mold at least a portion of the handle, the handle having a distal end and a proximal end opposite to the distal end, the proximal end including a hollow portion;

[0030] - Injection mold at least a portion of the connector, the connector having an outer surface and a groove therein, the groove forming a cavity within the connector.

[0031] - Injection mold at least a portion of the head,

[0032] - Insert the connector into the hollow portion of the shank, and preferably secure the connector by gluing, welding and / or press fitting.

[0033] This oral care tool includes a handle and a head to which at least one tooth and / or tissue cleaning element (e.g., bristle tufts and / or elastomer element) is attached. The head is reusable to and detachable from the handle. The oral care tool may be a manual toothbrush, or alternatively an inter-proximal pick, plaque scraper, or tissue / tongue cleaner. Because the connector is fixed in the handle and forms part of the handle, the connector (representing a relatively expensive part of the entire oral care tool) can be used for an extended / longer period of time. Compared to the handle including the connector, the head, with its relatively simple structure and relatively low cost, can be replaced after normal use (e.g., every three months). New head replacements can be purchased at a relatively low cost. Although replaceable brush heads according to the prior art consist of components of multiple parts or include at least one additional insert, frequently replaceable brush heads for oral care tools according to this disclosure can be produced at a lower cost.

[0034] Method steps for manufacturing the handle of an oral care tool may include:

[0035] -Provide amorphous thermoplastic resins,

[0036] - Available in alumina, boron nitride, or aluminum silicate.

[0037] - Provides iron oxide,

[0038] - The amorphous thermoplastic resin, alumina, boron nitride or aluminum silicate and iron oxide are mixed to form a magnetic and / or ferromagnetic molding material.

[0039] - Heating the molding material mixture into a flowable molding material, and

[0040] - The flowable molding compound is molded into a handle or a portion thereof.

[0041] The amorphous thermoplastic resin may include styrene-acrylonitrile, polybutylene terephthalate, and polyethylene terephthalate, wherein polybutylene terephthalate and polyethylene terephthalate may be premixed with glass fibers. The content of the amorphous thermoplastic resin may range from about 13% by weight to about 30% by weight; the content of alumina, boron nitride, or aluminum silicate may range from about 3% by weight to about 25% by weight; and the content of iron oxide may range from about 45% by weight to about 67% by weight.

[0042] The magnetic and / or ferromagnetic material may contain about 17% by weight of styrene-acrylonitrile; about 10.5% by weight of a composition comprising polybutylene terephthalate and polyethylene terephthalate; about 4.5% by weight of glass fiber; about 17% by weight of alumina; and about 51% by weight of iron oxide.

[0043] The material composition can be prepared by blending an amorphous thermoplastic resin with alumina powder, boron nitride powder, or aluminum silicate powder, and with iron oxide powder. Increasing the amount of iron oxide in the material composition also has the advantage of providing a lower-cost molding material, as iron oxide powder is cheaper than other fillers. The amorphous thermoplastic resin, glass fiber, alumina / boron nitride or aluminum silicate powder, and iron oxide powder can be blended using a uniaxial extruder, biaxial extruder, kneader, Banbury mixer, roller, or other such extruders. After blending, the material is heated to become flowable. The flowable material can then be injection molded into a stem or part of a stem.

[0044] The method for manufacturing oral care tools may also include the following steps:

[0045] - Provides a spring-loaded ball latching element, which includes a ball and a spring that applies a radial force to the ball.

[0046] - Insert the spring-loaded ball snap-fit ​​element into the cavity of the connector and preferably fix the connector by press fit, such that the spring applies a radial force to the ball in the direction toward the outer surface of the connector.

[0047] By providing a spring-loaded ball-locking element in the connector, the head of the oral care tool can be attached to the handle via a snap-fit ​​locking mechanism to ensure a sufficiently strong connection and stability between the head and the handle. This spring-loaded ball-locking element includes a ball and a spring that applies a radial force to the ball in a direction toward the outer surface of the connector. Hereinafter, the radial force is defined by a force applied in a direction substantially perpendicular to the longitudinal length extension of the connector. In other words, the spring applies force to the ball and pushes the ball outward, causing the ball to extend slightly beyond the outer surface of the connector. When the head is attached to the handle, the ball engages with a groove provided in the hollow portion of the head. Once the head snaps into the connector, the head is axially secured to the handle / connector. In other words, the connector and the oral care tool including such a connector allow for easy attachment and removal of the head from the handle, respectively. The user can attach the brush head to the handle with a simple linear movement. Furthermore, the ball-locking provides precise retention of the brush head and gives the user clear tactile feedback that the head is securely locked. In other words, the user recognizes the brush head once it engages with the groove set in the inner wall of the hollow part of the head. The brush head can be easily removed without requiring synchronization with other components / unlocking mechanisms.

[0048] The brush head can be secured to the handle until a specific / predetermined pull-out force is applied. The connection between the brush head and the connector is strong enough to allow for well-coordinated brushing techniques. The brush head will not detach from the handle or twist to the side during brushing.

[0049] The ball and / or spring of a spring-loaded ball element can be made of stainless steel. While typical snap-fit ​​elements include spring elements made of plastic that exhibit relaxation and aging effects over time, stainless steel springs exhibit constant spring stiffness over time, even under prolonged use conditions (e.g., temperature). A spring-loaded ball element made of stainless steel provides a durable and reliable hold of the head on the connector / shank. Furthermore, if the spring-loaded ball snap-fit ​​element is made entirely of stainless steel, electrical contact from the shank to the replacement can be easily provided. To provide a closed circuit, a conductive ring at the proximal end of the shank can be attached as a second contact. Electrical contact from the shank to the replacement allows for various additional functions, such as lamps for diagnostic or therapeutic purposes (e.g., for iontophoresis).

[0050] Spring-loaded ball elements can be fixed in the cavity through press-fitting, welding, and / or gluing, which represents a simple and cost-effective method.

[0051] In an additional step, the handle or a portion thereof may be electroplated to enhance its appearance and aesthetic appeal. For example, through the electroplating step, the handle or a portion thereof may be provided with a metallic layer or coating, such as chromium, silver, or gold, to further improve the appearance of the handle.

[0052] Thermoplastic elastomers are also well-suited for electroplating because they allow for the selective creation of hard and soft composite components to be electroplated in a single operation. Therefore, additionally or alternatively, the handle can be electroplated with any additional material (e.g., polyethylene or thermoplastic elastomer) to create a soft area, such as a thumb rest. The soft area / thumb rest improves the comfort and feel of the handle. This thumb rest can provide improved handling characteristics to the handle of oral care tools, such as providing anti-slip properties to improve the maneuverability of the oral care tool under wet conditions (e.g., when the user is brushing their teeth). The thumb rest can be made of a thermoplastic elastomer having a Shore A hardness of about 30 to about 60, or about 40, to prevent the oral care tool from becoming too slippery when used under wet conditions. At least a portion of the thumb rest can have a concave shape with an angle α of about 20° to about 25° or about 24° relative to the rest of the thumb rest. The thumb rest or gripping area can be attached to the front surface of the handle in the area near the proximal end (i.e., closest to the head). The thumb rest may include multiple ribs extending substantially perpendicular to the longitudinal axis of the oral care tool. These ribs allow the user / consumer to use the oral care tool with even greater control. The user / consumer can better grip and manipulate the handle of the oral care tool during brushing. This handle can provide further improved control and greater comfort during brushing, especially in wet conditions.

[0053] The handle may be made of at least two or at least three different materials, each forming a different part of the handle. For example, a first material (e.g., a magnetic and / or ferromagnetic material) may be injection molded into a first component of the handle, thereby forming the underlying base structure of the oral care tool. A second component, such as a polypropylene material, may be injection molded over the first component, and / or a third component, such as a thermoplastic elastomer material, may be injection molded over the first component and / or the second component.

[0054] The third component, made of thermoplastic elastomer material, can form a thumb rest on the front surface of the oral care tool and / or a palm grip on the rear surface opposite the front surface, for the user / consumer's fingers and thumb to grip. This handle configuration can further resist slippage during use. The thermoplastic elastomer material can extend through holes provided in the second component of the underlying base structure and / or the handle.

[0055] The method for manufacturing oral care tools may also include the following steps:

[0056] -Provide a ring,

[0057] The ring is preferably attached to the proximal end of the handle by gluing, welding, and / or press fitting. For example, the ring may be a metal layer surrounding the outer circumference of the handle. Such a ring can be used as an identification device.

[0058] The handle can be injection molded such that the proximal end of the handle has at least a partially beveled upper surface, and this beveled upper surface and a cross-sectional area extending substantially perpendicular to the longitudinal axis of the handle define an angle α of about 15° to about 30°, or about 18° to about 28°, or about 25°. Surprisingly, this angled / beveled surface has been found to provide anti-torsional protection during brushing. In other words, if a lateral force is applied to the brush head during brushing, the head is less likely to twist to the side. Furthermore, the angled / beveled surface allows fluids such as toothpaste slurry and saliva to drain after use of the oral care tool, preventing such fluids from accumulating over time. The entire oral care tool remains clean for an extended period of time, making the tool more hygienic.

[0059] Corresponding to the handle, the head can be manufactured and formed in such a way that the proximal end of the head is opposite to the distal end and is closest to the handle when the head is attached to it. The proximal end of the head also has a beveled upper surface. This beveled upper surface and the cross-sectional area of ​​the head, substantially perpendicular to its longitudinal axis, can define an angle β of approximately 15° to approximately 30°, or approximately 18° to approximately 28°, or approximately 25°. This configuration allows the head to be precisely adjusted and fitted onto the handle. The user can attach the head to the handle with a simple linear movement. Utilizing the beveled surface of the handle and the corresponding beveled surface of the head, the head automatically rotates to the correct orientation during the attachment movement.

[0060] The connector can be injection molded in such a way that at least a first substantially cylindrical segment, a second substantially cylindrical segment, and at least a partially tapered segment connecting the first cylindrical segment and the second cylindrical segment are formed, the first substantially cylindrical segment, the at least partially tapered segment, and the second substantially cylindrical segment are arranged in a continuous sequence along a longitudinal length extension, and the first substantially cylindrical segment and the second substantially cylindrical segment are positioned off-center relative to the longitudinal length extension.

[0061] In the following text, the substantially cylindrical section is defined by a three-dimensional body having a longitudinal length extension and a cross-sectional area extending substantially perpendicular to that longitudinal length extension. This cross-sectional area has a substantially constant shape along the longitudinal length extension. Since the connector can be manufactured using an injection molding process, the substantially cylindrical section also includes a section / body having a small draft angle of at most 2° or at most 1°. In other words, the substantially cylindrical section also includes a section / body that tapers slightly at most 2° or at most 1° towards the proximal end closest to the head once the head is attached to the connector.

[0062] The cross-sectional region can have any shape, such as substantially circular, elliptical, rectangular, semi-circular, circular with a flat portion, convex, or concave. The cross-sectional region can also have a polygonal shape, such as a square or triangle. The portion extending along the length of the cylinder around the outer surface of the cylinder can be defined as consisting of straight lines substantially parallel to the longitudinal length of the cylinder.

[0063] The proximal end of the head may include a hollow portion for receiving a portion of the connector (e.g., a second substantially cylindrical segment, at least a partially tapered segment, and a portion of a first substantially cylindrical segment). The hollow portion of the head may be formed with an inner wall having a geometry / profile corresponding to the external geometry / profile of the portion of the connector to be inserted into the hollow portion of the head. The eccentric / off-center arrangement of the substantially cylindrical segments of the connector allows for precise positioning of the brush head onto the handle. The geometry of the head is clearly defined. Because the handle includes the connector at the proximal end closest to the head, the eccentric / off-center arrangement of the two substantially cylindrical segments can act as a guiding element when the user attaches the head to the handle. In other words, these two substantially cylindrical segments allow for precise engagement between the head and the handle. Furthermore, for example, if a lateral force is applied to the head, the eccentric / off-center arrangement of the two substantially cylindrical segments can provide anti-torsional protection for the head on the handle during brushing.

[0064] The first substantially cylindrical segment and the second substantially cylindrical segment may have a length extension and a cross-sectional area extending substantially perpendicular to the length extension, and the cross-sectional area of ​​the first substantially cylindrical segment and / or the second substantially cylindrical segment may be substantially circular. This geometry provides a robust and simple structure that is easy to clean after use with oral care tools. Furthermore, due to the relatively simple external geometry, this connector can be manufactured in a cost-effective manner.

[0065] The first substantially cylindrical segment may have a cross-sectional area that is larger than the cross-sectional area of ​​the second substantially cylindrical segment. For example, the first substantially cylindrical segment in the hollow portion at the proximal end of the insertable handle may have a substantially circular cross-sectional area with a diameter of about 8 mm to about 10 mm, preferably about 9 mm, while the second substantially cylindrical segment in the hollow portion at the proximal end of the insertable head may have a substantially circular cross-sectional area with a diameter of about 4 mm to about 6 mm, preferably about 5 mm.

[0066] The first substantially cylindrical segment and the second substantially cylindrical segment may each have a first longitudinal central axis and a second longitudinal central axis, defined as axes of symmetry of the first substantially cylindrical segment and the second substantially cylindrical segment, respectively. The first substantially cylindrical segment and the second substantially cylindrical segment may be formed relative to each other such that the second longitudinal central axis of the second cylindrical segment is positioned relative to the first longitudinal central axis of the first cylindrical segment by approximately 1 mm to approximately 2.5 mm, or approximately 1.5 mm to approximately 2 mm, or approximately 1.65 mm off-center. This connector can be easily manufactured by injection molding and provides sufficient torsional stability for the oral care tool if a lateral force is applied to the brush head.

[0067] The first substantially cylindrical section and / or the second substantially cylindrical section may be formed with a flat portion extending along the length of the first substantially cylindrical section and / or the second substantially cylindrical section. For example, if a lateral force is applied to the head, this flat portion can provide additional anti-torsional protection to the head of the toothbrush connected to the handle during brushing.

[0068] The first substantially cylindrical segment and the second substantially cylindrical segment each have a first outer surface and a second outer surface, and the first substantially cylindrical segment and the second substantially cylindrical segment can be formed relative to each other such that a portion of the first outer surface and a portion of the second outer surface are substantially linearly aligned. Optionally, a flat portion including a spring-loaded ball element can be arranged opposite to the substantially linearly aligned first and second outer surfaces. This connector has an external geometry that is easy to clean. The connector is robust, easy to use, and can be manufactured in a cost-effective manner.

[0069] The connector and the oral care tool incorporating such a connector allow for easy attachment and removal of the head from the handle, respectively. The user attaches the head to the handle with a simple linear motion. Utilizing a specific design of an off-center, substantially cylindrical segment and the beveled surface of the handle, the head automatically rotates to the correct orientation (within tolerances) during the attachment motion. Therefore, the consumer is not forced to precisely position the head on the handle before snapping it onto it. Furthermore, the ball-and-socket design provides precise retention of the brush head and offers the consumer clear tactile feedback that the head is securely locked. The brush head can be easily removed without any synchronized action with other components (unlocking mechanisms). Additionally, the connector is easy to clean. This specific design of the connector eliminates any grooves that could accumulate dirt, toothpaste, and / or saliva. The connector also avoids any fragile structures by including only substantially rounded edges, preventing easy breakage or damage to the surface.

[0070] To allow for a sufficiently good fit between the brush head and the connector in the event of manufacturing tolerances, the inner wall of the hollow portion of the head may be formed with at least one slit or two slits opposite to each other for precise adjustment of the head on the connector / handle. Furthermore, the at least one slit prevents air compression within the hollow portion of the head, which could act as a spring or provide additional resistance when the head is snapped onto the connector / handle.

[0071] At least a portion of the head (e.g., the neck / axis and bristle carrier) may be at least partially composed of a material with a density of about 0.5 g / cm³. 3 Approximately 1.2 g / cm³ 3 or approximately 0.7 g / cm³ 3 To approximately 1.0 g / cm 3 or approximately 0.9 g / cm³ 3 The head can be made of materials such as thermoplastic polymers (e.g., those with a density of about 0.9 g / cm³). 3 The stem is injection molded from polypropylene. In contrast to the head, the stem may be at least partially made of a material with a significantly higher density (i.e., a density of approximately 2.1 g / cm³). 3 Approximately 3.1 g / cm³ 3 or approximately 2.3 g / cm³ 3 Approximately 2.8 g / cm³ 3 or approximately 2.5 g / cm³ 3 Approximately 2.7 g / cm³ 3 Made of materials.

[0072] The handle material can be relatively heavy to provide users with a high-quality perception and comfortable feel during the use of the oral care tool. Users typically prefer products (especially in the personal care field) with a certain weight to ensure high quality and provide comfort during use. Therefore, this oral care tool offers this superior perception of product quality.

[0073] Furthermore, because the handle material can have a higher density than the head material, the center of gravity / weight is located within the handle (even when the brush head is loaded with toothpaste). This allows the user to perform well-coordinated brushing techniques and has an improved sensory experience during brushing. The center of gravity, located in the center of the handle, provides an oral care tool with better balance and prevents it from tipping over / loading the head once toothpaste is applied. The oral care tool according to this disclosure has the advantage of having its center of gravity at or very close to the wrist joint pivot point when the user applies different grips / brushing techniques. A balanced toothbrush is easier to control in the mouth, allowing for more precise and accurate brushing movements, which results in better cleaning.

[0074] Compared to a regular manual toothbrush that is discarded after about three months of use, while the high quality and relatively expensive handle of an oral care tool are suitable for use over a longer period, the brush head can be replaced periodically, for example, after about three months, with a relatively inexpensive replacement brush. This provides a cost-effective and environmentally sustainable high-quality oral care tool with improved disposal characteristics.

[0075] In the past, it has been observed that users typically store damp brushes in toothbrush cups to dry after brushing. However, in typical toothbrush cups, the expelled fluid is collected and accumulates at the bottom of the cup, and the fluid remains in contact with the toothbrush for an extended period. Because the cup is only open on one side, the toothbrush dries relatively slowly. Bacteria living in damp conditions / environments can grow rapidly, contaminating the toothbrush and ultimately making it unhygienic. Therefore, a solution is needed for the hygienic storage and drying of manual toothbrushes, allowing residual water, toothpaste slurry, and saliva to drain from the brush. The brush should dry quickly to inhibit bacterial growth.

[0076] The head material can be made of non-magnetic or non-ferromagnetic material, while the handle material can be made of magnetic and / or ferromagnetic material. Magnetic / ferromagnetic materials not only have a relatively high density but also a relatively heavy weight, which provides the aforementioned benefits for oral care tools, but also allow the oral care tool to be magnetically attached to a magnetic retainer. The magnetic / ferromagnetic material of the handle allows for hygienic storage of the oral care tool. If the oral care tool is magnetically attached to a magnetic retainer, residual water, toothpaste paste, and saliva can be expelled from the brush. The oral care tool can dry relatively quickly. Therefore, bacterial growth is significantly reduced, making the oral care tool more hygienic. Compared to a regular toothbrush stored in a toothbrush cup, where the expelled fluid is collected and accumulates at the bottom of the cup, the brush according to this disclosure is exposed to moist conditions for a significantly shorter period.

[0077] For example, a magnetic retainer can take the form of a flat disc that can be attached to a wall. This flat disc represents an easy-to-clean surface. Furthermore, the user simply needs to bring the oral care tool close to the magnetic retainer, and the tool automatically attaches. Precise positioning or threading is not required as in a regular toothbrush retainer. Because magnetism is provided only in the handle, not the head, the head portion cannot accidentally attach to the magnetic retainer, thus reducing the risk of the retainer getting dirty.

[0078] The magnetic and / or ferromagnetic material forming at least a portion of the handle may comprise an amorphous thermoplastic resin. The magnetic and / or ferromagnetic material may also comprise alumina, boron nitride, or aluminum silicate. Furthermore, the magnetic and / or ferromagnetic material may additionally or alternatively comprise iron oxide. The magnetic and / or ferromagnetic material may also comprise glass fiber that can be premixed with at least a portion of the amorphous thermoplastic resin. This handle material allows for control of the handle's weight at any location, for example, through variations in filler. Due to the relatively high weight of the handle, control of the entire toothbrush is necessary. It is now possible to use the mass / weight distribution of the material to accommodate the inertial torque of the finished toothbrush.

[0079] The magnetic and / or ferromagnetic material may comprise about 13% to about 30% by weight of an amorphous thermoplastic resin; about 3% to about 25% by weight of alumina, boron nitride, or aluminum silicate; and about 45% to about 67% by weight of iron oxide. This composition provides a material density approximately three times that of standard plastic materials used in toothbrushes (e.g., polypropylene). This material, particularly when combined with an electroplated coating, drives perceived value due to its higher weight and higher thermal conductivity. Such a coating may be made from a real metal. The electroplated coating may be applied in a selective electroplating process. During this coating process for multi-component plastic parts, the metal layer is deposited only on the rigid material, while the additional overmolded soft components remain unaffected.

[0080] Magnetic and / or ferromagnetic materials may contain about 27.5% by weight of amorphous thermoplastic resin, about 17% by weight of alumina, about 51% by weight of iron oxide and about 4.5% by weight of glass fiber.

[0081] Amorphous thermoplastic resins may include styrene resins, such as styrene-acrylonitrile "SAN". Amorphous thermoplastic resins may be selected from acrylonitrile-butadiene-styrene, polystyrene, and styrene-acrylonitrile.

[0082] The amorphous thermoplastic resin may contain about 17% by weight of styrene-acrylonitrile and 10.5% by weight of a mixture comprising polybutylene terephthalate and polyethylene terephthalate.

[0083] Surprisingly, the composition has been found to provide a high-density molding material suitable for injection molding or extrusion. It provides a high-density molding material with high surface hardness, excellent coating properties, and excellent thermal conductivity.

[0084] The use of molding materials with relatively high specific gravity is known. Such molding materials typically contain polymer resins and high-density fillers such as iron oxide. However, the amount of iron oxide that can be included in such molding materials is limited due to their relatively poor thermal conductivity. Therefore, on the one hand, the lower thermal conductivity results in relatively long cycle times during manufacturing to allow the molding material to cool after molding. On the other hand, if the heavy polymer material is filled with highly thermally conductive additives, such as metal powders or fibers, the addition of these materials results in a tight process window in the molding process because the molten material solidifies immediately upon contact with the cold wall of the tool. This rapid solidification leads to high injection speeds and a low flow length to wall thickness ratio at the produced part.

[0085] It has now been surprisingly discovered that the molding materials according to this disclosure possess high specific gravity and optimally controlled thermal conductivity, thereby reducing or extending the time required for cooling of the molding material during or after injection molding. Surprisingly, it has been found that a relatively high percentage of iron oxide can be maintained in the molding material while simultaneously improving its thermal conductivity. The addition of alumina, boron nitride, or aluminum silicate provides improved thermal conductivity to the molding material compared to materials containing only styrene resin and iron oxide. This improved thermal conductivity results in lower cycle times because the molding material requires less time to cool after molding.

[0086] Another benefit of adding alumina, boron nitride, or aluminum silicate to materials is the ability to increase the total amount of iron oxide in molding materials compared to materials containing iron oxide and resin in the past. The improved properties of molding materials result from the addition of relatively small amounts of alumina, boron nitride, or aluminum silicate. Material compositions containing a relatively high percentage (i.e., from about 45% to about 67% by weight, preferably about 51% by weight) of iron oxide (magnetite) provide good magnetic properties and a relatively heavy total material weight.

[0087] Styrene-acrylonitrile (SAN) offers high heat resistance. The acrylonitrile units in the chain give SAN a glass transition temperature greater than 100°C. The properties of SAN allow for reduced cycle times due to its relatively early and faster transition temperature. Amorphous polymers are suitable for the heavy resin composites of this disclosure because amorphous polymers reversibly transition from a viscous or rubbery state to a hard state at a glass transition temperature (Tg). Through injection molding of the heavy resin materials of this disclosure, the temperature of the melt is above the Tg region (viscous or rubbery state). During cooling, the composite reaches a high Tg temperature early and achieves dimensional stability (glassy state). Due to the high Tg of the material, the material maintains dimensional stability, thus enabling overmolding of the heavy resin materials.

[0088] Polybutylene terephthalate (PBT) and / or polyethylene terephthalate (PET) provide high-quality surface properties for the handle, including improved optical properties and high impact strength. Upon heating, the mixture of PBT and PET represents a high-temperature melt with low viscosity and a high melt flow index (MFI). Therefore, the processability of the magnetic / ferromagnetic material is improved during molding.

[0089] It is well known that heavy resin materials tend to exhibit high shrinkage effects for products with thick walls / sizes. However, it has been surprisingly found that glass fibers added to magnetic / ferromagnetic materials provide improved stability and low shrinkage effects to the material composition.

[0090] The material disclosed herein is an alternative to metal / zinc die-casting materials. The material disclosed herein offers an attractive solution relative to the manufacturing methods, prices, and environment of the materials disclosed herein. This alternative allows the handle to have the appearance and feel of a metal product in its final state. Simultaneously, the material disclosed herein should be easily processable by injection molding and should save assembly work. For example, the method of the disclosed invention requires three basic steps: (1) injection molding of the handle 12; (2) two-component injection molding of a hard material and / or a soft material, for example, to form a thumb rest 16; and (3) electroplating of the handle, for example, to form a metal layer in the form of a ring 18. In contrast, when using zinc die-casting materials, five steps are required: (1) manufacturing of the zinc die-casting master component; (2) deburring of the master component; (3) electroplating of the master component; (4) separate production of the soft material component; and (5) assembling the master component with the separately produced soft material component. Lubricants may also be added to the material to improve the flowability of the molding process.

[0091] Table 1 shows the flowability and heat transfer results for several different formulations / material compositions.

[0092] Table 1: Flowability and Heat Transfer

[0093]

[0094] It can be seen that different fillers and different filler concentrations control the thermal conductivity or heat transfer and flowability of the material.

[0095] Test results show that using boron nitride or aluminum silicate exhibits the same characteristics as in Table 1 above. Figure 14 The results for alumina shown are very similar.

[0096] Thermal and shear heating affect the flowability of heavy resin materials, thereby allowing precise control of the process window for effective injection molding. Furthermore, since the materials disclosed herein can fill any available cavity within the mold, it is possible to use the mass / weight distribution of the material to accommodate the inertial moment of the finished product.

[0097] Several advantages exist related to the materials of this disclosure: handles manufactured using the materials of this disclosure have the appearance and feel of heavy metal handles and are corrosion resistant. Compared to metal inserts or die-cast handles and products with assembled components, this material also offers manufacturing and cost savings due to its heat transfer properties, and has a fast cycle time. Compared to zinc die-cast products, the materials of this disclosure require less energy and other necessary resources for manufacturing.

[0098] Compared to material compositions with highly loaded fillers, the magnetic / ferromagnetic materials of this disclosure exhibit optimized mechanical properties due to improved melt viscosity and glass transition temperature, particularly dimensional stability under thermal and shock strength.

[0099] The materials disclosed herein have the ability to adhere to other components / materials (e.g., substrates and resins), which is important for multi-component injection molding, such as for molding shanks comprising two or three different materials.

[0100] Dental cleaning elements of oral care tools, such as bundles of filaments forming one or more clusters, can be attached to a head via a thermal tufting process. A method of manufacturing a head having a filament cluster embedded in the head may include the following steps: In a first step, forming a cluster by providing a desired amount of filaments. In a second step, placing the cluster in a mold cavity such that the ends of the filaments to be attached to the head extend into the cavity. The opposite ends of the filaments not extending into the cavity may be end-rounded or not end-rounded. For example, in the case where the filaments are tapered filaments with sharp tips, the filaments may be not end-rounded. In a third step, the head is formed around the ends of the filaments extending into the mold cavity by an injection molding process, thereby anchoring the cluster in the head. Alternatively, the cluster may be anchored by forming a first portion of the head (a so-called "sealing plate") around the ends of the filaments extending into the mold cavity using an injection molding process before forming the rest of the oral care tool. Before initiating the injection molding process, the ends of the clusters extending into the mold cavity can optionally be melted or fused together to join the filaments together in the melt or molten ball, such that the melt or molten ball is located within the cavity. The clusters can be held in the mold cavity by a molding bar with blind holes corresponding to the desired location of the clusters on the finished head of the oral care tool. In other words, clusters attached to the head by the thermal tufting process do not overlap along their middle portion and are installed in the head without the use of anchors / pins. A tufting process without anchors can be used to attach the clusters to the head.

[0101] Alternatively, the head of the oral care tool may be provided with a bristle carrier having at least one tufting hole (e.g., a blind-end hole). A tuft comprising multiple filaments can be secured / anchored in the tufting hole by a binding process / anchoring tufting method. This means that the filaments of the tuft are bent / folded in a substantially U-shape around an anchor, for example, made of metal, such as an anchor cable or anchor plate. The filaments are pushed into the tufting hole together with the anchor, such that the anchor penetrates the opposite sidewall of the tufting hole, thereby anchoring / secured / fastening the filaments to the bristle carrier. The anchor can be secured in the opposite sidewall by positive friction engagement. In the case of a blind-end hole, the anchor holds the filament against the bottom of the hole. In other words, the anchor can be positioned substantially vertically above the U-shaped bend. Because the filaments of the tuft are bent in a substantially U-shaped configuration around the anchor, the first and second branches of each filament extend from the bristle carrier along the filament direction. The type of filament that can be used / suited for use in binding processes is also known as "double-sided filament". Heads for oral care tools manufactured using binding processes can be provided in a relatively low-cost and time-efficient manner.

[0102] The following is a non-limiting discussion of exemplary embodiments of oral care tools and components thereof according to the present disclosure, with reference to the accompanying drawings.

[0103] Figure 1 A manual oral care tool 10 is shown, in this specific embodiment being a manual toothbrush 10. The manual toothbrush 10 includes a handle 12 with a connector 14 attached and a brush head 16. The brush head 16 can be repeatedly attached to and detached from the handle 12 via the connector 14.

[0104] Figures 2 to 5 Schematic perspective, side, front, and top views of a handle 12, including a connector 14, are shown. The connector 14 includes a first substantially cylindrical segment 18, a second substantially cylindrical segment 20, and at least partially tapered segment 22 connecting the first cylindrical segment 18 and the second cylindrical segment 20. The first substantially cylindrical segment 18, the at least partially tapered segment 22, and the second substantially cylindrical segment 20 are arranged in a continuous sequence and together define a longitudinal length extension 24 of the connector 14. The first substantially cylindrical segment 18 and the second substantially cylindrical segment 20 are positioned off-center relative to the longitudinal length extension 24 of the connector 14. Figure 7From the side view, it can be seen that the first substantially cylindrical segment 18 and the second substantially cylindrical segment 20 each have a first longitudinal central axis 74 and a second longitudinal central axis 76, which are defined as axes of symmetry of the first substantially cylindrical segment 18 and the second substantially cylindrical segment 20, respectively. The first substantially cylindrical segment 18 and the second substantially cylindrical segment 20 can be placed / arranged relative to each other such that the second longitudinal central axis 76 of the second cylindrical segment 20 is positioned at a distance 78 from the center relative to the first longitudinal central axis 74 of the first cylindrical segment 18, approximately 1 mm to approximately 2.5 mm, or approximately 1.5 mm to approximately 2 mm, or approximately 1.65 mm. In other words, when viewed in the side view (see...), Figure 3 , Figure 7 and Figure 8 When observed in the image, the central axis 76 of the second substantially cylindrical section 20 is offset / eccentrically located from the longitudinal central axis 74 of the first substantially cylindrical section 18 by a distance 78 of approximately 1 mm to approximately 2.5 mm, or approximately 1.5 mm to approximately 2 mm, or approximately 1.65 mm.

[0105] The handle 12 has a distal end 54 and a proximal end 56, the proximal end 56 being closest to the brush head 16 that can be attached to the handle 12. Figures 8 to 10 As shown, the proximal end 56 of the handle 12 includes a hollow portion / groove 58 in which a portion of the first substantially cylindrical section 18 is fixed, for example, by a press-fit process and / or gluing.

[0106] The proximal end 56 of the handle 12 includes a chamfered surface 60. The cross-sectional region 62 extending substantially perpendicular to the longitudinal length extension 64 and the chamfered surface 60 define an angle α of about 15° to about 30°, or about 18° to about 28°, or about 25°.

[0107] Figure 6 and Figure 7 Schematic front and side views of connector 14 are shown. A first substantially cylindrical segment 18 and a second substantially cylindrical segment 20 each have length extensions 26 and 28 and cross-sectional regions 30 and 32 extending substantially perpendicular to the length extensions 26 and 28, respectively. The cross-sectional region 30 of the first substantially cylindrical segment 18 and the second cross-sectional region 32 of the second substantially cylindrical segment 20 are substantially circular. The cross-sectional region 30 of the first substantially cylindrical segment 18 is larger than the cross-sectional region 32 of the second substantially cylindrical segment 20. The first cross-sectional region 30 has a diameter 36 of about 8 mm to about 10 mm, or about 9 mm, while the second cross-sectional region 32 has a diameter 34 of about 4 mm to about 6 mm, or about 5 mm.

[0108] The first substantially cylindrical section 18 includes a flat portion 38 at the outer surface 80 of the connector 14. The flat portion 38 extends along a length extension 26 of the first substantially cylindrical section 18. (As can be seen from...) Figures 8 to 10 Further, the flat portion includes a groove 40 that forms an inner cavity 82 within the connector 14. A spring-loaded ball element 42 is inserted into the cavity 82 and secured therein, for example, by a press-fit process and / or gluing. The spring-loaded ball element 42 is an element with a snap-fit ​​locking mechanism to provide sufficiently strong connection and stability between the head 16 and the handle 12 in the axial direction (i.e., along the longitudinal length extension 24 of the connector and the oral care tool 10). The spring-loaded ball element 42 includes a ball 44 and a spring 46, the spring 46 applying a radial force to the ball 44 toward the outer circumference 48 and outer surface 80 of the connector 14. When the brush head 16 is attached to the handle, the ball 44 extends slightly beyond the outer surface of the first substantially cylindrical section 18 and rests in a corresponding groove 70 provided in the hollow portion (66) of the head shaft (see...). Figure 11 and Figure 12 Both spring 46 and ball 44 can be made of stainless steel.

[0109] The first substantially cylindrical segment 18 and the second substantially cylindrical segment 20 each have a first outer surface 50 and a second outer surface 52, and the first substantially cylindrical segment 18 and the second substantially cylindrical segment 20 are arranged relative to each other such that a portion of the first outer surface 50 and a portion of the second outer surface 52 are substantially linearly aligned. The flat portion 38 is arranged opposite to the substantially linearly aligned first outer surface 50 and second outer surface 52.

[0110] Figure 11 A perspective view of the brush head 16 is shown, and Figure 12 A corresponding bottom view is shown. The head 16 includes a hollow portion 66 for receiving a second generally cylindrical segment 20, at least a partially tapered segment 22, and a portion of a first generally cylindrical segment 18 of the connector 14. The hollow portion 66 has an inner wall 68 that includes a groove 70 for receiving a portion of a ball 44 of a spring-loaded ball element 42. The inner wall 68 of the hollow portion 66 also includes two oppositely arranged slits 72 for precisely adjusting the head 16 on the connector 14.

[0111] Figure 13A flowchart illustrating the steps for manufacturing a handle 12 comprising a connector 14 of an oral care tool 10 according to the present disclosure is shown: In step 1000, a handle 12 having a distal end 54 and a proximal end 56 is injection molded, the proximal end including a hollow portion 58. A soft component forming a thumb rest 102 is injection molded over the handle material. In step 2000, the handle 12 is coated with a metallic coating 104 by electroplating. In step 3000, at least a portion of the connector 14 is injection molded, the connector 14 having an outer surface 80 and a groove therein, the groove forming a cavity 82 within the connector 14. The connector may be injection molded from PBT optionally containing about 30% by weight of glass fiber. In step 4000, a spring-loaded ball-locking element 42 is inserted and secured in the cavity 82 of the connector 14 by press fitting. In step 5000, the connector 14 including the spring-loaded ball-locking element 42 is inserted into the hollow portion 58 at the proximal end 56 of the handle 12. The connector 14 is secured in the hollow portion 58 by gluing or alternatively by welding and / or press-fitting. In step 6000, a ring 100, which may be made of stainless steel, is attached to the proximal end 56 of the handle 12 by press-fitting and gluing. Optionally, a logo or indicator element 106 may be attached to the surface at the distal end 54 of the handle 12, for example by applying heat transfer foil, metallic letters, or metallic markings.

[0112] In the context of this disclosure, the term "substantially" refers to an arrangement of elements or features that, while theoretically expected to exhibit precise consistency or behavior, may in practice make something appear somewhat imprecise. Similarly, the term represents the degree to which quantitative values, measurements, or other relevant representations may differ from the reference without causing a change in the fundamental function of the subject matter.

[0113] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified, each such dimension is intended to represent the stated value and a range around which it is functionally equivalent. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

Claims

1. A connector for repeatedly attaching and detaching a head from a handle, the connector comprising: The first is a generally cylindrical section having a cavity with a spring-loaded ball latching element comprising a ball and a spring that applies force to the ball and pushes the ball outward, causing the ball to extend slightly beyond the outer surface of the connector. The second is basically a cylindrical section; as well as At least a partially tapered section connects a first substantially cylindrical section and a second substantially cylindrical section, the first substantially cylindrical section, the second substantially cylindrical section, and the at least partially tapered section defining a longitudinal length extension, wherein the first substantially cylindrical section and the second substantially cylindrical section are off-center relative to the longitudinal length extension, the longitudinal central axis of the second substantially cylindrical section is offset from the longitudinal central axis of the first substantially cylindrical section by a distance of 1 mm to 2.5 mm, the first substantially cylindrical section includes a flat portion extending along the longitudinal length extension, the flat portion having a groove forming the cavity, the first substantially cylindrical section and the second substantially cylindrical section each having a first outer surface and a second outer surface, wherein the first substantially cylindrical section and the second substantially cylindrical section are arranged relative to each other such that a portion of the first outer surface and a portion of the second outer surface are substantially linearly aligned, and the flat portion is arranged opposite to the substantially linearly aligned first and second outer surfaces; The head has a hollow portion sized to receive a portion of a first substantially cylindrical section, at least a partially tapered section, and a second substantially cylindrical section of the connector. The hollow portion has an inner wall with a circular groove sized to receive the ball, such that the head is detachably attached to the second substantially cylindrical section.

2. The connector according to claim 1, characterized in that, The first substantially cylindrical segment has a larger cross-sectional area than the second substantially cylindrical segment.

3. The connector according to claim 1, characterized in that, The inner wall of the hollow portion of the head also includes two slits arranged opposite to each other for adjusting the head on the connector.

4. The connector according to claim 2, characterized in that, The first cross-sectional region has a diameter of 8 mm to 10 mm, and the second cross-sectional region has a diameter of 4 mm to 6 mm.

5. A method for manufacturing a handle, a connector, and a head, the head being reciprocally attachable to and detachable from the handle via the connector, the method comprising the steps of: At least a portion of the handle is injection molded, the handle having a distal end and a proximal end opposite to the distal end, the proximal end including a hollow portion, the handle being at least partially made of a magnetic material, wherein the magnetic material comprises 13% to 30% by weight of an amorphous thermoplastic resin, 3% to 25% by weight of alumina, boron nitride, or aluminum silicate, and 45% to 67% by weight of iron oxide; wherein the magnetic material further comprises glass fiber premixed with at least a portion of the amorphous thermoplastic resin; the amorphous thermoplastic resin comprises styrene-acrylonitrile, polybutylene terephthalate, and polyethylene terephthalate, wherein the polybutylene terephthalate and polyethylene terephthalate are premixed with glass fiber; At least a portion of the connector is injection molded, the connector having an outer surface and a groove therein, the groove forming a cavity within the connector; A spring-loaded ball latching element is provided, the spring-loaded ball latching element comprising a ball and a spring, the spring being configured to apply a radial force to the ball; The spring-loaded ball latching element is inserted into the cavity of the connector and fixed therein, such that the spring applies a force to the ball in the direction toward the outer surface of the connector; Injection molding at least a portion of the head; The connector is inserted into the hollow portion of the handle and secured therein by at least one of gluing, welding and press fitting, wherein a portion of the connector having the spring-loaded ball locking element extends outward from the proximal end of the handle along the longitudinal axis, and wherein the ball extends slightly beyond the outer surface of the connector surrounding the ball.

6. The method according to claim 5, characterized in that, The method further includes the step of electroplating at least a portion of the handle.

7. The method according to claim 5, characterized in that, The handle is injection molded such that the proximal end of the handle has at least a partially beveled upper surface, wherein an angle α of about 15° to about 30° is formed between the beveled upper surface and a cross-sectional region extending substantially perpendicular to the longitudinal axis.

8. The method according to claim 5, characterized in that, The connector is injection molded to form at least a first substantially cylindrical segment, a second substantially cylindrical segment, and at least a partially tapered segment connecting the first and second cylindrical segments, wherein the first substantially cylindrical segment, the at least partially tapered segment, and the second substantially cylindrical segment are arranged in a continuous sequence along the longitudinal axis, and wherein the first substantially cylindrical segment and the second substantially cylindrical segment are positioned off-center relative to the longitudinal axis.

9. The method according to claim 8, characterized in that, The connector is formed such that at least one of the first substantially cylindrical segment and the second substantially cylindrical segment includes a flat portion.

10. The method according to claim 9, characterized in that, The connector is formed such that the flat portion has a groove forming the cavity.

11. The method according to claim 5, characterized in that, The head is formed such that it includes a distal end and a proximal end opposite to the distal end, and the proximal end includes a hollow portion (66) for receiving a portion of the connector when the head is attached to the handle, the hollow portion including an inner wall and the inner wall including a groove for receiving a ball of the spring-loaded ball latching element.

12. The method according to claim 11, characterized in that, The head is formed such that the inner wall of the hollow portion includes two slits arranged opposite to each other.

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