Gasket and washing machine including same

Abstract

This washing machine comprises: a main body including an opening through which laundry can be loaded into the main body; a door configured to open or close the opening; a tub positioned in the main body; a drum positioned in the tub and configured to be rotatable; and a gasket connecting the main body to the tub, wherein the gasket is brought into close contact with at least a portion of the door when the opening is closed by the door, and the gasket comprises a thermoplastic elastomer (TPE), the TPE comprising: a styrene-ethylene-butylene-styrene block copolymer (SEBS), a polypropylene (PP) copolymer, and 0.1 to 5 wt % of a thermoplastic polyolefin (TPO) relative to the total weight of the TPE, and the TPE has a hardness of 31 to 33 Shore A.

Description

Gaskets and washing machines containing them

[0001] One embodiment disclosed in this document relates to a gasket, and more particularly, to a gasket applicable to a washing machine.

[0002] Typically, washing machines use electricity to wash items like clothing or bedding. Washing machines remove dirt from laundry through the interaction of water, detergent, and a rotating drum.

[0003] A washing machine may include a main body having an opening for loading laundry, a door for opening and closing the opening, a tub positioned within the main body to store water, and a drum rotatably installed within the tub. The washing machine may perform washing by causing laundry within the drum to rise and then fall along the inner wall of the drum when the drum rotates.

[0004] A washing machine may include a gasket positioned between a drum and a door, and sealing the space between the drum and the door when the opening is closed by the door. The gasket may be composed of a thermoplastic elastomer (TPE) and may have properties such as elasticity, heat resistance, high-temperature resilience, and chemical resistance. The gasket may be manufactured by injection molding using the composition, and the gasket may reduce vibration and noise generated by the washing machine by preventing vibration generated by the rotation of the drum from being transmitted to the main body.

[0005] Meanwhile, for gaskets to effectively reduce vibration and noise, the hardness of the material forming the gasket must be below a certain level. Furthermore, to maintain a smooth surface during the injection molding process, the flowability of the composition flowing within the injection mold must be above a certain level.

[0006] The above information may be provided as background art to aid in understanding the present disclosure. No claim or determination is made as to whether any of the above-described matters constitute prior art related to the present disclosure.

[0007] A washing machine according to one embodiment of the present disclosure may include a gasket composed of a composition having a hardness and fluidity below a predetermined level.

[0008] Aspects of embodiments of the present disclosure will be set forth in part in the description that follows, and in part will be apparent from the description or may be learned by practice of the embodiments presented.

[0009] According to one embodiment of the present disclosure, a washing machine comprises: a body including an opening configured to load laundry into the body; a door configured to open or close the opening; a tub in the body; a drum in the tub and configured to be rotatable; and a gasket connecting the body and the tub, the gasket being in close contact with at least a portion of the door when the opening is closed by the door, the gasket comprising a thermoplastic elastomer (TPE), wherein the TPE comprises: a styrene-ethylene-butylene-styrene block copolymer (SEBS), a polypropylene (PP) copolymer, and 0.1 to 5 wt% of a thermoplastic polyolefin (TPO) based on the total weight of the TPE, and the TPE may have a hardness of 31 to 33 Shore A.

[0010] According to one embodiment of the present disclosure, the TPO may be present in an amount of 0.1 to 2 wt% relative to the total weight of the thermoplastic elastomer.

[0011] According to one embodiment of the present disclosure, the TPO may be present in an amount of 1 to 2 wt% relative to the total weight of the TPE.

[0012] According to one embodiment of the present disclosure, the TPO may be present in an amount of 0.025 to 0.05 wt% relative to the weight of the SEBS block copolymer.

[0013] According to one embodiment of the present disclosure, the TPO may be a composition formed by copolymerization of PP and alpha-olefin (α-olephin).

[0014] According to one embodiment of the present disclosure, the PP copolymer may include a random type PP copolymer.

[0015] According to one embodiment of the present disclosure, the random type PP copolymer may be composed of a compound of PP and at least one of ethylene, butene, butadiene, and synthetic rubber.

[0016] According to one embodiment of the present disclosure, the melt flow index (MFI) of the TPE may be 0.5 to 2.5 g / 10 min.

[0017] According to one embodiment of the present disclosure, the melt flow index (MFI) of the TPE may be 1.5 to 2.1 g / 10 min.

[0018] According to one embodiment of the present disclosure, the TPE may further include modified polyphenylene ether (mPPE). The mPPE may be present in an amount of 1 to 5 wt% relative to the total weight of the TPE.

[0019] According to one embodiment of the present disclosure, the specific gravity of the TPE may be from 0.96 to 1.

[0020] According to one embodiment of the present disclosure, a gasket configured to connect a main body and a tub included in a washing machine and configured to be in close contact with at least a portion of a door of the washing machine, wherein the gasket is a thermoplastic elastomer (TPE), wherein the thermoplastic elastomer (TPE) includes a styrene-ethylene-butylene-styrene (SEBS) block polymer, a polypropylene (PP) copolymer, and 0.1 to 5 wt% of a thermoplastic polyolefin (TPO) based on the total weight of the TPE, and the TPE may have a hardness of 31 to 33 Shore A.

[0021] According to one embodiment of the present disclosure, the TPO may be present in an amount of 0.1 to 2 wt% relative to the total weight of the TPE.

[0022] According to one embodiment of the present disclosure, the TPO may be present in an amount of 1 to 2 wt% relative to the total weight of the TPE.

[0023] According to one embodiment of the present disclosure, the TPO may be present in an amount of 0.025 to 0.05% by weight relative to the weight of the SEBS block copolymer.

[0024] According to one embodiment of the present disclosure, the TPO may be a composition formed by copolymerization of PP and alpha-olefin.

[0025] According to one embodiment of the present disclosure, the PP copolymer may include a random type PP copolymer.

[0026] According to one embodiment of the present disclosure, the random type PP copolymer may be composed of a compound of PP and at least one of ethylene, butene, butadiene, and synthetic rubber.

[0027] According to one embodiment of the present disclosure, the melt flow index (MFI) of the TPE may be 0.5 to 2.5 g / 10 min.

[0028] According to one embodiment of the present disclosure, the melt flow index (MFI) of the TPE may be 1.5 to 2.1 g / 10 min.

[0029] The above and other aspects, features, and advantages of specific embodiments of the present disclosure will become more apparent through the following description taken in conjunction with the accompanying drawings, wherein:

[0030] FIG. 1 is a cutaway view of a portion of a washing machine according to one embodiment of the present disclosure;

[0031] FIG. 2 is a side cross-sectional view of a washing machine according to one embodiment of the present disclosure;

[0032] FIG. 3 is a perspective view of a gasket included in a washing machine according to one embodiment of the present disclosure;

[0033] FIG. 4a illustrates the morphology of a TPO produced by a copolymerization method according to one embodiment of the present disclosure;

[0034] FIG. 4b illustrates the morphology when TPO is manufactured by a simple blending type according to one embodiment of the present disclosure; and

[0035] FIG. 5 illustrates a portion of a surface of a gasket according to one embodiment of the present disclosure.

[0036] The embodiments of this document and the terminology used herein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly indicates otherwise. In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can include any one of the items listed together in the corresponding phrase among those phrases, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0037] Hereinafter, in this document, “front-back direction”, “left-right direction”, and “up-down direction” may be used based on the drawings shown, and the shape and position of each component are not limited thereby.

[0038] According to some embodiments, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the multiple entities may be separately disposed in other components.

[0039] The washing machine described below (e.g., the washing machine (1) of FIG. 1) may be understood as an example to aid understanding of the present disclosure, and may be implemented in various modified forms. Furthermore, some of the attached drawings are not drawn to scale, and the dimensions of some components may be exaggerated to aid understanding of the present disclosure.

[0040] FIG. 1 is a cross-sectional view of a portion of a washing machine (1) according to one embodiment of the present disclosure.

[0041] Figure 2 is a side cross-sectional view of a washing machine (1) according to one embodiment of the present disclosure.

[0042] Referring to FIGS. 1 and 2, a washing machine (1) may include a main body (10) forming an exterior, a tub (30) installed inside the main body (10) to store water, a drum (40) rotatably arranged inside the tub (30), and a driving device (60) that drives the drum (40).

[0043] According to one embodiment, the body (10) may include a body. The body (10) may have an overall hexahedral shape. The body (10) may include an opening formed on one surface. Two or more surfaces of the body (10) may be formed integrally. Each surface of the body (10) may be manufactured separately and assembled. The body (10) may be formed, for example, by press molding from a sheet metal material or by injection molding from a resin material.

[0044] According to one embodiment, an opening (10a) may be formed in the front frame (11) of the main body (10). The opening (10a) of the front frame (11) may be opened and closed by a door (20) installed in the front frame (11).

[0045] According to one embodiment, a door (20) that opens and closes the opening may be arranged in a portion corresponding to the opening of the main body (10). The door (20) may be rotatably coupled to a hinge fixed to one surface of the main body (10). For example, at least a portion of the door (20) may be provided to be transparent or translucent so that the inside may be visible. A user may open and close the door (20) to load laundry into the drum (40) located inside the main body (10) or to take laundry out of the drum (40). The door (20) may be locked, for example, by a locking device (not shown) so as not to be opened while the washing machine (1) is in operation. In one example, the door (20) may include a door frame (21) and a glass member (22). The glass member (22) may be formed of, for example, a transparent tempered glass material so that the inside of the main body (10) may be visible, but the present document is not limited thereto.

[0046] According to one embodiment, the washing machine (1) may include a tub (30) fixedly arranged inside the main body (10). The tub (30) may have a roughly cylindrical shape with one side open. A tub opening (30a) may be provided at a position corresponding to the opening of the main body (10) on the front of the tub (30). The tub (30) may store washing water. A drain hole (32) for draining washing water may be provided at the bottom of the tub (30). The drain hole (32) may be connected to, for example, a drainage device (80).

[0047] According to one embodiment, the washing machine (1) may include a damper (12). The damper (12) may be provided to connect the main body (10) and the tub (30). One side of the damper (12) may be fixed to the inner surface of the main body (10) and the other side may be fixed to the tub (30). The damper (12) may be provided to absorb vibration energy transmitted to the tub (30) and / or the main body (10) when the drum (40) rotates, thereby attenuating the vibration.

[0048] According to one embodiment, the washing machine (1) may include a drum (40) provided inside a tub (30). The drum (40) may have a generally cylindrical shape with one side open. A front plate (43) and a rear plate (44) may be arranged on the front and rear sides of the drum (40), respectively. A drum opening may be provided in the front plate (43) at a position corresponding to the opening of the main body (10) and the tub opening (31) of the tub (30). The drum (40) may accommodate laundry. The drum (40) may be arranged to be rotatable within the tub (30) by receiving rotational power from a driving device (60). The drum (40) may perform washing, rinsing, and / or dehydration while rotating within the tub (30).

[0049] In one embodiment, the drum (40) may include a lifter (41) and / or a plurality of holes (42). The lifter (41) may, for example, lift laundry while the drum (40) rotates, thereby causing the laundry to repeatedly rise and fall, thereby evenly washing multiple surfaces of the laundry. The holes (42) may, for example, be passages formed so that washing water contained in the tub (30) may flow into the interior of the drum (40), or washing water inside the drum (40) may be discharged to the exterior. In one embodiment, the lifter (41) or the holes (42) may be omitted.

[0050] According to one embodiment, a tub opening (30a) and a drum opening (40a) may be formed in the front part of the tub (30) and the front part of the drum (40), respectively, corresponding to the opening (10a) of the front frame (11) so that laundry can be fed into the interior of the drum (40).

[0051] According to one embodiment, the washing machine (1) may include a driving device (60) for rotating the drum (40). The driving device (60) may include a driving motor (61) and a driving shaft (62) for transmitting driving force generated by the driving motor (61) to the drum (40). The driving motor (61) may be configured with a fixed stator (61a) and a rotor (61b) that rotates by electromagnetic interaction with the stator (61a), thereby converting electrical power into mechanical rotational power. The rotational power generated by the driving motor (61) may be transmitted to the drum (40) through the driving shaft (62). The driving shaft (62) may be, for example, provided to be press-fitted into the rotor (61b) of the driving motor (61) and to rotate together with the rotor (61b). The driving shaft (62) may, for example, have a portion that penetrates the rear wall of the tub (30) to connect the drum (40) and the driving motor (61). The driving device (60) can rotate the drum (40) forward or backward to perform washing, rinsing, and / or dehydration operations.

[0052] According to one embodiment, the washing machine (1) may include a water supply device (70) for supplying washing water to the drum (40) and / or the tub (30). The water supply device (70) may include at least one water supply pipe (71) and at least one water supply valve (72). At least one water supply pipe (71) may be provided to supply washing water into the interior of the tub (30) using an external water source. One of the at least one water supply pipe (71) may be connected to a detergent supply device (13) provided in the main body (10). Here, the detergent supply device (13) may have an interior divided into a plurality of spaces, and detergent or rinsing agent may be provided in each space. Washing water passing through the detergent supply device (13) may be supplied to the tub (30) together with detergent (or rinsing agent) through a detergent supply pipe (14). At least one of the water supply pipes (71) may be directly connected to the tub (30). For example, washing water supplied through the water supply pipe (71) directly connected to the tub (30) may be supplied directly to the tub (30) without passing through an intermediate component such as a detergent supply device (13).

[0053] According to one embodiment, the washing machine (1) may include a drainage device (80) for draining the washing water contained in the drum (40) and / or the tub (30). The drainage device (80) may include a drain valve (81), a first drainage pipe (82), a second drainage pipe (83), or a pump room (84). The drainage device (80) may be arranged, for example, at the bottom of the tub (30) to drain the washing water discharged from the tub (30) to the outside of the washing machine (1).

[0054] According to one embodiment, the drain valve (81) may be arranged to open and close the drain port (32). When the drain valve (81) is opened, the washing water contained in the tub (30) may flow through the drain port (32) to the drain device (80).

[0055] According to one embodiment, the first drain pipe (82) and the second drain pipe (83) may form a path that guides the washing water to be discharged to the outside. For convenience of explanation, the upstream side with respect to the pump room (84) is referred to as the first drain pipe (82) and the downstream side is referred to as the second drain pipe (83). The first drain pipe (82) and the second drain pipe (83) may be formed integrally. For example, one end of the first drain pipe (82) may be connected to the drain port (32) and the other end may be connected to the pump room (84). The washing water may move into the pump room (84) along the first drain pipe (82). The second drain pipe (83) may, for example, one end may be connected to the pump room (84) and the other end may be connected to the outside of the washing machine (1). Therefore, the washing water passing through the pump room (84) may be discharged to the outside of the washing machine (1) along the second drain pipe (83).

[0056] According to one embodiment, a pump room (84) may be provided at the bottom of the tub (30) to store the washing water drained from the tub (30). For example, a drain pump (85) may be provided inside the pump room (84) to discharge the stored washing water to the outside. The washing water pumped by the drain pump (85) may be guided to the outside of the main body (10) through the second drain pipe (83).

[0057] According to one embodiment, a gasket (100) may be disposed between the tub (30) and the door (20). The gasket (100) may also be referred to as a “diaphragm.” The gasket (100) may be disposed between the opening (10a) of the front frame (11) and the opening (30a) of the tub (30) to form a passage from the opening (10a) of the front frame (11) to the opening (30a) of the drum (30). The gasket (100) may reduce vibration transmitted toward the front frame (10a) when the drum (30) rotates.

[0058] According to one embodiment, a portion of the gasket (100) may be placed between the door (20) and the front frame (11) to prevent water collected in the tub (30) from leaking out of the main body (10).

[0059] According to one embodiment, the gasket (100) may be formed of an injection molded thermoplastic elastomer (TPE). Since the thermoplastic elastomer has a certain elasticity at room temperature, the gasket formed of the thermoplastic elastomer can effectively dampen vibrations transmitted from the tub (20) to the front frame (11) of the main body (10), thereby reducing vibrations and noise generated when the drum (40) rotates.

[0060] According to one embodiment, in order to effectively dampen vibrations generated by the rotation of the drum (40), the gasket (100) may be composed of a thermoplastic elastomer having a hardness of a predetermined level or less. For example, the gasket (100) may have a hardness of 31 to 33 Shore A.

[0061] According to one embodiment, during the process of injection molding the gasket (100), the surface of the injected gasket (100) can be smoothly processed in response to the flowability (or fluidity) of the thermoplastic elastomer, which is the injection material.

[0062] According to one embodiment, in order to smooth the surface of the gasket (100), it is required to increase the flowability of the thermoplastic elastomer used as the injection material, thereby reducing the amount of gas generated from the injection material during the molding process or permeated during the injection process.

[0063] For example, if the flowability of a thermoplastic elastomer is high, the amount of gas generated within the thermoplastic elastomer, which is an injection material, before flowing into the mold device may be reduced. For example, if the flowability of a thermoplastic elastomer is high, the amount of gas penetrating into the injection material when the thermoplastic elastomer, which is an injection material, flows into the mold device may be reduced.

[0064] According to one embodiment, the gasket (100) has a surface that is smoothly processed to come into close contact with each opening (10a, 30a, 40a) formed in the main body (10), the tub (30), and / or the drum (40), so that the sealing force between the gasket (100) and the door (20) can be increased when the door (20) closes each opening (10a, 30a, 40a). As a result, vibration generated when the drum (40) rotates can be effectively reduced.

[0065] Hereinafter, in the present disclosure, a thermoplastic elastomer, which is a constituent material for effectively reducing vibration and noise generated when a drum (40) rotates, will be described, while maintaining the hardness of the gasket (100) at a predetermined level, by reinforcing the sealing force between the opening (10a) formed in the front frame (11), the tub opening (30a) formed in the tub (30), and the drum opening (40a) formed in the drum (40) and the door (20).

[0066] FIG. 3 is a perspective view of a gasket (100) (e.g., the gasket (100) of FIG. 2) according to one embodiment of the present disclosure.

[0067] The embodiment of FIG. 3 can be optionally combined with FIG. 1 and FIG. 2.

[0068] Referring to FIG. 3, a gasket (100) may be placed between a tub (30) (e.g., tub (30) of FIG. 2) and a door (20) (e.g., door (20) of FIG. 1). For example, one side of the gasket (100) may be placed to surround the inner circumferential surface of a tub opening (30a) and a drum opening (40a) formed in the tub (30) and the drum (e.g., drum (40) of FIG. 1), respectively. For example, the other side of the gasket (100) may be placed to surround the inner surface of the door (20).

[0069] According to one embodiment, the gasket (100) forms a passage leading to an opening (10a) formed in a front frame (11) of a main body (e.g., main body (10) of FIG. 1) and a tub opening (30a) formed in a tub (30), and can reduce vibration transmitted to the main body (10) when the drum (40) rotates.

[0070] According to one embodiment, a portion of the gasket (100) may be disposed between the door (20) and the body (10) to prevent water in the tub (30) from leaking out of the body (10).

[0071] According to one embodiment, the gasket (100) may include a body (101) formed in an overall cylindrical shape, a door coupling portion (102) connected to one end of the body (101) and connected to a door (20), and a drum coupling portion (103) connected to the other end of the body (101) and connected to a drum (40).

[0072] According to one embodiment, the gasket (100) can be manufactured by injection molding using a molding device. For example, a thermoplastic elastomer, which is an injection material for forming the gasket (100), can be injected into a cavity having a shape corresponding to the gasket (100) using a molding device, and the gasket (100) can be formed as the thermoplastic elastomer solidifies.

[0073] In one embodiment, the gasket (100) may have a hardness of a predetermined level. For example, the gasket (100) may have a hardness (Shore hardness) of 31 to 33 SHORE A. The Shore hardness may be measured, for example, using a standardized test procedure according to ISO 7619-1 or ASTM D2240 according to the Shore test method, and may be tested by measuring the indentation depth using an indenter equipped with a spring made of a cemented carbide to indent a material and / or a specimen. The gasket (100) may have a relatively soft hardness of a predetermined level, thereby damping vibrations generated when the drum (40) rotates.

[0074] According to one embodiment, the thermoplastic elastomer constituting the gasket (100) may have a predetermined level of flowability (or fluidity) during the molding process. For example, the thermoplastic elastomer constituting the injection material may be a material having a melt flow index (MFI or MI) of 0.5 to 2.5 g / 10 min, and preferably, a material having a melt flow index of 1.5 to 2.1 g / 10 min. The melt flow index may be measured according to a standard test method such as ASTM D1238, for example, and may be defined as the weight of a material discharged through an orifice in a molten state under temperature and load conditions defined in the standard for 10 minutes.

[0075] According to one embodiment, the thermoplastic elastomer constituting the gasket (100) may include a styrene block copolymer, a polypropylene (PP) copolymer, and a thermoplastic polyolefin (TPO).

[0076] In one embodiment, the styrene-based block copolymer may include styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-ethylene-propylene-styrene block copolymer (SEPS), crosslinked styrene-ethylene-propylene-styrene block copolymer (SEPS-V), but styrene-ethylene-butylene-styrene block copolymer (SEBS) is preferred.

[0077] In one embodiment, the thermoplastic elastomer may include a polypropylene copolymer having thermoplastic properties, preferably random type polypropylene (random type PP). In addition, the thermoplastic elastomer may further include a polyvinyl chloride resin, a polystyrene resin, a polyethylene resin, an acrylic resin, or a nylon resin having thermoplastic properties.

[0078] In one embodiment, the thermoplastic elastomer may comprise a thermoplastic polyolefin. The thermoplastic polyolefin may allow the thermoplastic elastomer of the present disclosure to maintain a desired level of hardness and provide a desired level of flowability to the thermoplastic elastomer in a molten state.

[0079] According to one embodiment, the thermoplastic polyolefin can be produced by a simple blending method, a crosslinking method in which partial or complete crosslinking is performed by dynamic vulcanization treatment on a synthetic rubber such as a dual-synthetic rubber (ethylene-propylene diene monomer, EPDM), and a copolymerization method of polypropylene and alpha olefin (α-olefin), but preferably, the thermoplastic polyolefin can be produced by a copolymerization method.

[0080] In one embodiment, when producing thermoplastic polyolefin by copolymerization, the polypropylene may be Homo-type polypropylene (Homo-PP). For example, the thermoplastic polyolefin may have EPDM dispersed in a domain form within a matrix of Homo-PP. The morphology of EPDM dispersed in a domain form within a matrix of Homo-PP will be described with reference to FIGS. 4a and 4b.

[0081] According to one embodiment, by adding a certain level of thermoplastic polyolefin, the dispersibility of PP, EPDM, and SEBS included in the material constituting the thermoplastic elastomer can be improved, and thus, the hardness and flowability of the thermoplastic polyolefin can be improved due to the arrangement structure of Homo-PP and EPDM.

[0082] In one embodiment, the thermoplastic elastomer may further comprise mopped (modified-polyphenylene ether, modified-PPE) to control hardness.

[0083] In one embodiment, the thermoplastic elastomer may further comprise a softening agent, such as silicone oil and mineral oil.

[0084] In one embodiment, the thermoplastic elastomer may further comprise an inorganic filler such as calcium carbonate (CaCO3), clay, diatomaceous earth, talc, barium sulfate (BaSO4), magnesium carbonate (MgCO3), metal oxides, graphite, aluminum hydroxide (Al(OH)3), with calcium carbonate being preferred.

[0085] According to one embodiment, the thermoplastic elastomer may be composed of a styrene block copolymer, a polypropylene copolymer, a thermoplastic polyolefin, m-PPE, and an inorganic filler in a predetermined ratio. Table 1 below shows the composition ratios of each composition in examples (e.g., examples 1 and 2) representing the thermoplastic elastomer of the present disclosure and comparative examples for comparison with the examples, and the unit is weight %.

[0086] Comparative examples of constituent materials Example 1 Example 2 PP copolymer 10 to 15 10 to 15 10 to 15 SEBS 25 to 40 25 to 39 25 to 38 Oil 35 to 50 35 to 50 35 to 50 Calcium carbonate 3 to 10 3 to 10 3 to 10 TPO-0.5 to 11 to 2 m-PPE 1 to 51 to 5 1 to 5

[0087] Referring to , Examples 1 and 2 differ from the comparative example in the presence or absence of thermoplastic polyolefin (hereinafter referred to as TPO), and Examples 1 and 2 differ in the composition ratio of TPO and SEBS. According to one embodiment, the thermoplastic elastomer of the present disclosure may include TPO constituting a weight % of 0.5 to 5% of the total weight. For example, in Example 1, the composition ratio of TPO may constitute 0.5 to 1 weight % of the total weight of the thermoplastic elastomer. For example, in Example 2, the composition ratio of TPO may constitute 1 to 2 weight % of the total weight of the thermoplastic elastomer.

[0088] According to one embodiment, the thermoplastic elastomer of the present disclosure includes a thermoplastic polyolefin, thereby maintaining the hardness of an injection-molded article made of the thermoplastic elastomer at a predetermined level (e.g., 31 to 33 SHORE A) and improving flowability in a molten state. Hereinafter, in , the properties of Example 1 (e.g., Example 1 of Table 1) and Example 2 (e.g., Example 2 of Table 1) are shown in a table with respect to a comparative example (e.g., Comparative Example of Table 1).

[0089] Comparative examples of physical properties Example 1 Example 2 Flowability [g / 10 min] 0.1 0.7 2.1 Hardness [Shore A] 333231

[0090] Referring to , it can be confirmed that the flowability of Examples 1 and 2 is increased and the hardness is decreased compared to the comparative example. Therefore, it can be confirmed that the thermoplastic elastomer of the present disclosure has improved flowability and hardness by including a thermoplastic polyolefin in a predetermined ratio. According to one embodiment, when Example 1 and Example 2 are compared, it can be confirmed that the degree of improvement in flowability and hardness of Example 2, which includes a higher ratio of thermoplastic polyolefin, is higher.

[0091] According to one embodiment, it can be confirmed that the flowability and hardness of the thermoplastic elastomer (Example 2) including the thermoplastic polyolefin constituting 1 to 2 wt% of the total weight of the thermoplastic elastomer are improved compared to the thermoplastic elastomer (Example 1) including the thermoplastic polyolefin constituting 0.1 to 1 wt% of the total weight of the thermoplastic elastomer. For example, Example 2 has a hardness reduced by about 0.32% compared to Example 1, so that vibrations generated by the rotation of the drum (40) can be further attenuated. For example, Example 2 has a flowability increased by about three times compared to Example 1, so that appearance defects due to gas can occur less during the molding process.

[0092] According to one embodiment, since the thermoplastic elastomer of the present disclosure includes a thermoplastic polyolefin at a predetermined ratio, the injection-molded gasket (100) can maintain a low level of hardness to dampen vibrations caused by the rotation of the drum (40) and reduce noise. In addition, since the thermoplastic elastomer of the present disclosure includes a thermoplastic polyolefin at a predetermined ratio, the flowability is improved, so that the surface can be smoothly processed during injection molding. Accordingly, when the door (20) closes the opening (10a), the gasket (100) molded from the thermoplastic elastomer can increase the adhesion between the door (20) and the main body (10), and can prevent the washing water (or rinsing water) stored in the tub (30) from leaking out of the main body (10).

[0093] In one embodiment, the specific gravity of the thermoplastic elastomer of the present disclosure may be from 0.95 to 1, preferably from 0.96 to 0.98. The thermoplastic elastomer may have a low level of specific gravity by including materials having relatively low specific gravity.

[0094] According to one embodiment, the thermoplastic elastomer maintains a relatively low level of specific gravity, so that the hardness of the gasket (100) manufactured from the thermoplastic elastomer can be maintained at a level of 31 to 33 Shore A.

[0095] According to one embodiment, when a gasket (100) manufactured from a thermoplastic elastomer of the present disclosure is applied to a washing machine (1), an experimental example related to reducing vibration and noise is shown in .

[0096] Comparative Example Example 1 Noise generation level 53dB 50.7dB Vibration generation level 0.51mm 0.30mm

[0097] can be understood as recording the noise and vibration generation levels when a gasket (100) manufactured from a thermoplastic elastomer containing a predetermined level of thermoplastic polyolefin (e.g., Example 1 of Table 1 and / or Table 2) is applied to a washing machine (1), and the noise and vibration generation levels when a gasket (100) manufactured from a thermoplastic elastomer not containing thermoplastic polyolefin (e.g., Comparative Example of Table 1 and / or Table 2) is applied to a washing machine (1). Referring to , the washing machine (1) used in this experiment is a washing machine (1) capable of accommodating 25 kg of laundry. The noise generation level is recorded as an average by measuring the size of the noise generated every second for a predetermined time. The vibration generation level is the distance traveled (displacement) of the main body (10) when a 700g sample is placed inside the drum (40) and the drum (40) is rotated at 1100 rpm.

[0098] Referring to , it can be confirmed that the noise generation level and the vibration generation level are each reduced in Example 1 for the comparative example. For example, when a gasket (100) made of a thermoplastic elastomer (comparative example) that does not contain thermoplastic polyolefin is applied, the noise generation level of the washing machine (1) is 53 dB and the vibration generation level is 0.51 mm, whereas when a gasket (100) made of a thermoplastic elastomer (example 1) that contains a predetermined level of thermoplastic polyolefin is applied, the noise generation level of the washing machine (1) is 50.7 dB and the vibration generation level is 0.30 mm, so it can be confirmed that the noise and vibration generation levels are reduced.

[0099] FIG. 4a illustrates the morphology of a TPO produced by a copolymerization method according to one embodiment of the present disclosure.

[0100] FIG. 4b illustrates the morphology when TPO is manufactured by a simple blending type according to one embodiment of the present disclosure.

[0101] The embodiments of FIGS. 4a and 4b can be optionally combined with the embodiments of FIGS. 1 to 3.

[0102] According to one embodiment, the thermoplastic polyolefin can be produced by a simple blending method, a crosslinking method in which partial or complete crosslinking is performed by dynamic vulcanization treatment on a synthetic rubber such as a dual-synthetic rubber (ethylene-propylene diene monomer, EPDM), and a copolymerization method of polypropylene and alpha olefin (α-olefin), but preferably, the thermoplastic polyolefin can be produced by a copolymerization method.

[0103] Referring to Fig. 4a, when producing thermoplastic polyolefin in a copolymer type, polypropylene can be used as Homo type polypropylene (Homo-PP). For example, the thermoplastic polyolefin can have EPDM dispersed in a domain form within a matrix of Homo-PP.

[0104] In one embodiment, the Homo-PP constituting the matrix may be a polymer composed solely of propylene monomers. The EPDM constituting the domains may be a polymer composed of propylene monomers and ethylene monomers in a ratio of 4:6 to 6:4.

[0105] In one embodiment, it can be seen that the EPDM domain, indicated by a dark color, exists as a dispersed phase within the Homo-PP matrix, indicated by a light color. By adding a certain level of thermoplastic polyolefin, the dispersion of PP, EPDM, and SEBS, which are materials constituting the thermoplastic elastomer, can be improved, and thus, the hardness and flowability of the thermoplastic polyolefin can be improved due to the arrangement structure of Homo-PP and EPDM.

[0106] Referring to Fig. 4b, when producing thermoplastic polyolefin in a blending type, random type polypropylene (Random-PP) can be used. For example, the thermoplastic polyolefin may have EPDM dispersed in a domain form within a Random-PP matrix.

[0107] In one embodiment, the Random-PP constituting the matrix may be a polymer composed of propylene monomers and ethylene monomers. For example, the composition ratio of the propylene monomer constituting the Random-PP may be 95 to 97 wt%, and the composition ratio of the ethylene monomer constituting the Random-PP may be 3 to 5 wt%. The EPDM constituting the domain may be a polymer composed of propylene monomers and ethylene monomers in a ratio of 4:6 to 6:4.

[0108] According to one embodiment, the EPDM domains indicated by dark colors exist as a dispersed phase within the Homo-PP matrix indicated by light colors, but compared to FIG. 4A, it can be seen in FIG. 4B that the degree of dispersion of the EPDM domains indicated by dark colors within the Random-PP matrix indicated by light colors is low. Therefore, it would be preferable for the thermoplastic polyolefin according to one embodiment of the present disclosure to be manufactured by copolymerization of Homo-PP and EPDM.

[0109] FIG. 5 illustrates a portion of a surface of a gasket (e.g., the gasket (100) of FIGS. 2 and 3) according to one embodiment of the present disclosure.

[0110] The embodiment of FIG. 5 can be optionally combined with the embodiments of FIGS. 1 to 4.

[0111] Referring to FIG. 5, each surface of a gasket (100) manufactured from a thermoplastic elastomer (e.g., comparative examples in Tables 1, 2, and 3) that does not contain thermoplastic polyolefin is illustrated for comparison with a gasket (100) manufactured from an elastomer (e.g., Example 1 or Example 2 in Tables 1 and 2, Example 1 in Table 3) that contains a predetermined ratio of thermoplastic polyolefin.

[0112] According to one embodiment, it can be confirmed that the surface of the gasket (100) illustrated as a comparative example is rough, whereas the surface of the gasket (100) illustrated as an embodiment is formed smoothly.

[0113] According to one embodiment, the thermoplastic elastomer of the present disclosure can have increased flowability in a molten state while maintaining a predetermined hardness by including a thermoplastic polyolefin at a predetermined ratio. Since the thermoplastic elastomer has high flowability in a molten state, when the thermoplastic elastomer in a molten state, which is a molding material, is introduced during a molding process, the infiltration of gas into the interior of the molding material can be prevented. Accordingly, the occurrence of appearance defects when manufacturing a gasket (100) made of the thermoplastic elastomer can be reduced.

[0114] According to one embodiment, due to the increased flowability of the thermoplastic elastomer of the present disclosure, the gasket (100) can be molded at a relatively low injection temperature of 180°C, and also, when the gasket (100) is molded at a relatively high injection temperature of 200°C or higher, the occurrence of appearance defects due to gas can be reduced.

[0115] According to one embodiment, the thermoplastic elastomer of the present disclosure maintains a predetermined hardness (e.g., 31 to 33 Shore A) while maintaining a predetermined level of flowability (0.7 to 2.1 g / 10 min), so that the gasket (100) manufactured with the thermoplastic elastomer can reduce vibrations generated by the rotation of the drum (40) and noise caused by the vibration. Therefore, the washing machine (1) of the present disclosure can reduce the cost of additional devices for reducing vibration and noise by applying the thermoplastic elastomer as a molding material for the gasket (100).

[0116] A washing machine (1) according to one embodiment of the present disclosure relates to a gasket (100) disposed between an opening (10a) formed in a main body (10) and a door (20), and a thermoplastic elastomer as a material for forming the gasket (100).

[0117] A washing machine (1) according to one embodiment of the present disclosure includes a gasket (100) made of a thermoplastic elastomer that maintains a predetermined level of hardness and flowability, thereby attenuating vibrations generated when a drum (40) rotates and reducing noise generated thereby.

[0118] A washing machine (1) according to one embodiment of the present disclosure includes a gasket (100) made of a thermoplastic elastomer that maintains a predetermined level of hardness and flowability, thereby reducing the cost of electric components required for vibration damping in addition to the gasket (100).

[0119] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0120] A washing machine according to one embodiment of the present disclosure (e.g., the washing machine (1) of FIG. 1) may include a main body (10) including an opening (10a) for loading laundry, a door (20) configured to open or close the opening (10a), a tub (30) disposed inside the main body (10), a drum (40) rotatably disposed inside the tub (30), and a gasket (100) connecting the main body (10) and the tub (30), wherein the gasket (100) is configured to be in close contact with the door (20) when the door (20) is disposed to close the opening (10a). The gasket (100) may include a thermoplastic elastomer (TPE). The thermoplastic elastomer may include a styrene-ethylene-butylene-styrene block copolymer (SEBS), a polypropylene (PP) copolymer, and 0.1 to 5 wt% of a thermoplastic polyolefin (TPO). The thermoplastic elastomer may have a hardness of 31 to 33 Shore A.

[0121] In a washing machine (1) according to one embodiment of the present disclosure, the thermoplastic polyolefin may be present in an amount of 0.1 to 2 wt% relative to the total weight of the thermoplastic elastomer.

[0122] In a washing machine (1) according to one embodiment of the present disclosure, the thermoplastic polyolefin may be present in an amount of 1 to 2 wt% relative to the total weight of the thermoplastic elastomer.

[0123] In a washing machine (1) according to one embodiment of the present disclosure, the thermoplastic polyolefin may be present in an amount of 0.025 to 0.05 wt% relative to the weight of the SEBS.

[0124] In the washing machine (1) according to one embodiment of the present disclosure, the thermoplastic polyolefin may be a composition formed by copolymerization of polypropylene and alpha-olefin.

[0125] In a washing machine (1) according to one embodiment of the present disclosure, the polypropylene copolymer may include a random type polypropylene copolymer (random type PP copolymer).

[0126] In a washing machine (1) according to one embodiment of the present disclosure, the random type polypropylene copolymer may be composed of a compound of polypropylene and at least one of ethylene, butene, butadiene, and synthetic rubber.

[0127] In a washing machine (1) according to one embodiment of the present disclosure, the melt flow index (MFI) of the thermoplastic elastomer may be 0.5 to 2.5 g / 10 min.

[0128] In the washing machine (1) according to one embodiment of the present disclosure, the melt flow index (MFI) of the thermoplastic elastomer may be 1.5 to 2.1 g / 10 min.

[0129] In a washing machine (1) according to one embodiment of the present disclosure, the thermoplastic elastomer may further include mPPE (modified polyphenylene ether). The mPPE may be present in an amount of 1 to 5 wt% relative to the total weight of the thermoplastic elastomer.

[0130] In a washing machine (1) according to one embodiment of the present disclosure, the specific gravity of the thermoplastic elastomer may be 0.96 to 1.

[0131] A gasket (100) configured to connect a main body (10) and a tub (30) included in a washing machine (1) according to one embodiment of the present disclosure and to be in close contact with at least a portion of a door (20) may include a thermoplastic elastomer (TPE). The thermoplastic elastomer may include a styrene-ethylene-butylene-styrene block polymer (SEBS), a polypropylene (PP) copolymer, and 0.1 to 5 wt% of a thermoplastic polyolefin (TPO). The thermoplastic elastomer may have a hardness of 31 to 33 Shore A.

[0132] In a gasket (100) according to one embodiment of the present disclosure, the thermoplastic polyolefin may be present in an amount of 0.1 to 2 wt% relative to the total weight of the thermoplastic elastomer.

[0133] In a gasket (100) according to one embodiment of the present disclosure, the thermoplastic polyolefin may be present in an amount of 1 to 2 wt% relative to the total weight of the thermoplastic elastomer.

[0134] In a gasket (100) according to one embodiment of the present disclosure, the thermoplastic polyolefin may be present in an amount of 0.025 to 0.05% by weight relative to the weight of the SEBS.

[0135] In the gasket (100) according to one embodiment of the present disclosure, the thermoplastic polyolefin may be a composition formed by copolymerization of polypropylene and alpha-olefin (α-olephin).

[0136] In a gasket (100) according to one embodiment of the present disclosure, the polypropylene copolymer may include a random type polypropylene copolymer (random type PP copolymer).

[0137] In a gasket (100) according to one embodiment of the present disclosure, the random type polypropylene copolymer may be composed of a compound of polypropylene and at least one of ethylene, butene, butadiene, and synthetic rubber.

[0138] In a gasket (100) according to one embodiment of the present disclosure, the melt flow index (MFI) of the thermoplastic elastomer may be 0.5 to 2.5 g / 10 min.

[0139] In a gasket (100) according to one embodiment of the present disclosure, the melt flow index (MFI) of the thermoplastic elastomer may be 1.5 to 2.1 g / 10 min.

[0140] In a gasket (100) according to one embodiment of the present disclosure, the thermoplastic elastomer may further include mPPE (modified polyphenylene ether). The mPPE may be present in an amount of 1 to 5 wt% relative to the total weight of the thermoplastic elastomer.

[0141] In a gasket (100) according to one embodiment of the present disclosure, the specific gravity of the thermoplastic elastomer may be 0.96 to 1.

Claims

1. In the washing machine, A body including an opening configured to feed laundry into the body; A door configured to open or close the above opening; A tub in the above body; a drum located in the above tub and configured to be rotatable; and As a gasket connecting the main body and the tub, when the opening is closed by the door, the gasket includes a gasket that is in close contact with at least a part of the door, The above gasket is a thermoplastic elastomer (TPE), wherein the TPE is: Styrene-ethylene-butyrene-styrene block copolymer (SEBS), polypropylene (PP) copolymer, and A thermoplastic elastomer comprising 0.1 to 5 wt% of thermoplastic polyolefin (TPO) based on the total weight of the TPE, The above TPE has a hardness of 31 to 33 Shore A, a washing machine.

2. In paragraph 1, A washing machine, wherein the TPO is present in an amount of 0.1 to 2 wt% relative to the total weight of the thermoplastic elastomer.

3. In paragraph 1, A washing machine, wherein the TPO is present in an amount of 1 to 2 wt% relative to the total weight of the TPE.

4. In any one of paragraphs 1 to 3, A washing machine, wherein the TPO is present in an amount of 0.025 to 0.05 wt% relative to the weight of the SEBS block copolymer.

5. In paragraph 1, The above TPO is a washing machine composition formed by copolymerization of PP and alpha-olefin (α-olephin).

6. In paragraph 1, A washing machine, wherein the above PP copolymer comprises a random type PP copolymer.

7. In paragraph 6, The above random type PP copolymer is a washing machine composed of a compound of PP and at least one of ethylene, butene, butadiene, and synthetic rubber.

8. In paragraph 1, A washing machine, wherein the melt flow index (MFI) of the above TPE is 0.5 to 2.5 g / 10 min.

9. In paragraph 8, A washing machine, wherein the melt flow index (MFI) of the TPE is 1.5 to 2.1 g / 10 min.

10. In paragraph 1, The above TPE further contains mPPE (modified polyphenylene ether), A washing machine, wherein the mPPE is present in an amount of 1 to 5 wt% relative to the total weight of the TPE.

11. In any one of paragraphs 1 to 10, A washing machine having a specific gravity of the above TPE of 0.96 to 1.

12. A gasket configured to connect the main body and the tub included in the washing machine and configured to be in close contact with at least a portion of the door of the washing machine, wherein the gasket: As a thermoplastic elastomer (TPE), the thermoplastic elastomer (TPE) is Styrene-ethylene-butyrene-styrene (SEBS) block polymer, polypropylene (PP) copolymer, and Contains 0.1 to 5 wt% of thermoplastic polyolefin (TPO) based on the total weight of the TPE, The above TPE is a gasket having a hardness of 31 to 33 Shore A.

13. In paragraph 12, A gasket wherein the TPO is present in an amount of 0.1 to 2 wt% relative to the total weight of the TPE.

14. In paragraph 12, A gasket wherein the TPO is present in an amount of 1 to 2 wt% relative to the total weight of the TPE.

15. In any one of paragraphs 12 to 14, A gasket wherein the TPO is present in an amount of 0.025 to 0.05% by weight relative to the weight of the SEBS block copolymer.

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