Method and apparatus for manufacturing a member made of a plastic material, and a member made of a plastic material

Abstract

The embodiments described herein relate to a method and apparatus for manufacturing a component (10) made of a plastic material suitable for use as a container, a housing for a household appliance, or a receptacle. The component comprises a first layer and a second layer covering at least a portion of the first layer. The method for manufacturing a component (10) made of a plastic material suitable for forming a container or a housing for a household appliance (50) or a receptacle includes a first step of injecting a first plastic material into a first molding volume (V1) defined between a punch (29) and a first receiving die (30) to produce a first layer (11), and a second step of injecting a second plastic material into a second molding volume (V2) defined between the first layer (11) obtained in the first injection step and a second receiving die (34) to produce a second layer (12). and a second step of forming the second layer (12) with a three-dimensional finish on its outer surface having alternating protrusions (17) and recesses (18), characterized in that in the first injection step, passages or filling cavities (19) are formed in the first layer (11) corresponding to the shape and position of the recesses (18) of the second layer (12) suitable for compensating for thickness differences between the protrusions (17) and the recesses (18) to make the filling flow of the second material substantially uniform in the second injection step.

Description

Technical Field

[0001] Embodiments described in the present application relate to a method and an apparatus for manufacturing a member having a body formed by laminating two layers of plastic material.

[0002] Such a member is particularly suitable for use as a receptacle or as a housing for household appliances such as kettles, toasters, vacuum cleaners, coffee machines, blenders, or irons.

[0003] The present invention further relates to a household appliance or receptacle provided with the above member.

Background Art

[0004] In the field of household appliances, it is known to manufacture a member or an object with a finish having two or more layers of plastic material that at least partially overlap each other in order to provide a decisive aesthetic appearance. Such a member can be used, for example, to form the external structure of household appliances or articles or objects such as carafes, bowls, etc., but the specific examples of the above articles or objects are not limited to an enumerated list.

[0005] It is also known that attention to aesthetic research to satisfy consumer preferences in the design and manufacture of household appliances has become even stronger in order to provide an attractive and recognizable aesthetic appearance and stand out from similar solutions on the market.

[0006] For example, a member that serves as a receptacle for a kettle, comprising a first layer of a transparent plastic material and a second layer of a metallic material, and a plurality of through-holes are formed in the second layer, and the first layer and thus the inside of the kettle itself are visible through the through-holes, is known.

[0007] However, this solution requires separately manufacturing the first layer and the second layer and then joining and connecting them to each other, which causes problems in the connection and sealing between them.

[0008] The above aesthetic research also led to the manufacture of household appliances having an external structure made of a plastic material formed by overmolding two layers superimposed and integrated.

[0009] A method of manufacturing a member of a household appliance, in which a plastic material of a second layer is injected after injecting a plastic material of a first layer, is also known. For example, the first injection layer can be made of a transparent material, and the second layer can be made of a colored and / or opaque material.

[0010] In particular, the material of the second layer can be injected only partially over the entire outer surface of the member to be manufactured, whereby at least a part of the first injection layer can be kept visible in order to obtain a satisfactory aesthetic appearance of the final product. Alternatively, the injection material of the first layer can be made colored and / or opaque, while the second layer is made of a transparent or translucent material, making the injection material of the underlying layer visible.

[0011] Alternatively, the materials used have mechanical and / or thermal and / or aesthetic types of technical characteristics that are unsuitable for contact with food and thus cannot be used for the first layer.

[0012] Articles such as bowls or cutlery handles are also known, which have the entire first layer of material covered by the second layer of material. The first layer of this article is thicker than the second layer and serves as a structural member, while the second layer serves as an aesthetic surface finish.

[0013] Overmolding the material of the second layer onto the material of the first layer can be problematic. In fact, when overmolding the second layer onto the first layer, a "washing-away" phenomenon of the first layer may occur, leading to aesthetic problems. This problem is particularly noticeable when at least a part of the outer layer is transparent.

[0014] In known solutions, when it is desired to manufacture a member having a substantially three-dimensional surface finish portion with alternately large-thickness convex portions and small-thickness concave portions instead of a substantially constant thickness for the outer layer, overmolding of the material can become even more complicated.

[0015] Due to such a thickness variation, when actually injecting the second material between the first layer and the receiving mold of the mold to form the second layer, the advancing speed of the material in the mold is different, so the filling speed of the material is different, and thus a weld line can be formed.

[0016] Furthermore, since the advancing speed of the material is different, the flow becomes non-uniform and non-homogeneous, and a difference in cooling speed may occur in a plurality of different portions with different thicknesses, resulting in non-uniform cooling. This non-uniform cooling of the second layer of the material may cause the formation of structural and aesthetic defects such as weld lines on the surface of the second layer, or may cause deformation.

[0017] Furthermore, it may also cause unwanted melting of the material of the previously injected layer below it at a site where the cooling speed is low.

[0018] Moreover, as another drawback of the prior art, the above-mentioned non-uniform and non-homogeneous filling may also lead to the formation of air bubbles inside the volume of the second layer, which is non-aesthetic and may also endanger the firmness of the molded member.

[0019] U.S. Patent Application Publication No. 2018 / 0290419 describes a panel for manufacturing a seating surface of a chair. The panel has a base layer having a first surface and a second surface, and the base layer is confined between an outer first layer and an outer second layer. Each surface of the base layer has a portion that protrudes outward, and the portion penetrates through each corresponding opening provided in the outer first layer and the second layer.

[0020] U.S. Patent Application Publication No. 2001 / 027140 describes a golf ball provided with an outer layer and at least one inner layer in contact with the outer layer. Convex portions and concave portions are provided on the surfaces of both layers. The thickness of the inner layer is thicker than that of the outer layer, and the depths of the convex portions and concave portions of the two layers are substantially the same. These convex portions and concave portions are intended to ensure better retention between the two layers.

[0021] Therefore, it is necessary to develop a method and an apparatus for manufacturing a member made of a plastic material suitable for forming a housing of a container or a household appliance that can eliminate at least one of the drawbacks of the prior art.

[0022] Another object is to provide a method and an apparatus for manufacturing a member made of a plastic material that can achieve high productivity and efficiency at high speed.

[0023] Still another object is to complete a method and an apparatus that can manufacture a member having a three-dimensional surface finish while preventing the formation of a joining line between portions having different thicknesses.

[0024] Another object of the present invention is to develop a method for manufacturing a member that can provide a portion having a variable thickness and a satisfactory aesthetic effect on the outer surface of a finished product.

[0025] Another object is to obtain a fully transparent area such as a window and / or a lens in order to make the inside of the product or the inside of the operating tool visible while ensuring sealing to prevent leakage of liquid, vapor, and dust.

[0026] The applicant of the present application has conducted research and tests to eliminate the drawbacks of the prior art and achieve the above and other objects and advantages, thus realizing the present invention.

Summary of the Invention

[0027] The present invention is described in the independent claims, and its features are set forth therein. The dependent claims describe other features of the present invention or modifications of its main inventive concept.

[0028] In accordance with the above object, the present invention relates to a method and an apparatus for manufacturing a member made of a plastic material suitable for constituting a receptacle, a housing of a household appliance, an outer shell, an external structure and / or an external body, or at least a part thereof.

[0029] Examples of the application of the member of the present invention may include household appliances such as a kettle, a toaster, a vacuum cleaner, an electric brush, a blender, a microwave oven, an electric oven, a fryer, a teapot, a coffee machine, an ice cream maker, a kneader, and a hair dryer.

[0030] The member of the present invention has a variable-thickness portion on its outer surface that gives a three-dimensional appearance with high aesthetic and recognition values.

[0031] The member of the present invention has a plastic body comprising a first layer inside a first material and a second layer outside a second material covering at least a part of the inside first layer.

[0032] In some embodiments, the second layer covers the entire first layer.

[0033] In one aspect of the present invention, a three-dimensional finishing portion having convex and concave portions alternately is provided on the outer surface of the second layer.

[0034] In one aspect of the present invention, the first layer has a passage or a filling cavity suitable for at least partially compensating for the difference in thickness between the convex portion and the concave portion, and the passage or the filling cavity corresponding to the shape and position of the concave portion of the second layer is formed in the thickness of the first layer.

[0035] By providing such a passage or a filling cavity, the second layer has a substantially uniform thickness, or the deviation from the nominal average value is reduced, thereby obtaining a satisfactory final aesthetic effect.

[0036] In some embodiments, the first layer forms the inner surface of the member.

[0037] In some embodiments, the inner surface described above can have a smooth and uniform transition without unevenness.

[0038] In some embodiments, the member has a cylindrical shape, and the cylindrical shape has a circular, polygonal, or elliptical cross-section, or has a circumference combining a straight section and a curved section. Further, the cross-section of the member can be invariant or variable along the axial transition, and can have a concave portion or a convex portion.

[0039] In some embodiments, the first material can be opaque, or single-color, or multi-color, and the second material can be at least partially transparent, thereby making the opaque first layer visible through the second material. Thereby, a partially convex three-dimensional appearance can be given to the final member.

[0040] In other embodiments, the transparent second layer protrudes at least axially from the edge of the opaque first layer. According to such an embodiment, the member has a transparent peripheral strip, thereby achieving the effects of transparency and brightness.

[0041] In some embodiments, the outer surface of the member can have a surface finish portion having vertical or inclined ribs or a spiral transition.

[0042] In an alternative embodiment, the outer surface can have a bubble or diamond surface finish, or other geometric or non-geometric shapes, such as a flower shape, etc., and can have other surface finishes.

[0043] The present invention also relates to a method for manufacturing a member made of a plastic material, the method comprising: - a first step of injecting a first plastic material into a first forming volume defined between a punch and a first receiving mold to produce a first layer; - a second step of injecting a second plastic material into a second forming volume defined between the first layer obtained in the first step and a second receiving mold to produce a second layer having a three-dimensional surface finish with alternating convex and concave portions on the outer surface; and having.

[0044] In one aspect of the present invention, in the first injection step, a passage or filling cavity suitable for compensating for the thickness difference between the convex and concave portions in the first layer and making the filling flow of the second material substantially uniform in the second injection step is produced corresponding to the shape and position of the concave portions of the second layer.

[0045] In particular, due to the filling cavity obtained during the production of the first layer, in the second injection step, a forming volume with a substantially constant width, or at least fluctuating but with a small deviation from the constant average value, can be obtained.

[0046] In some embodiments, the method produces the outer second layer having a greater thickness than the inner first layer. Such an embodiment can reduce the resistance to the filling flow of the second material, thereby reducing the so-called shear stress phenomenon of the material, and preventing the formation of possible aesthetic defects caused by mechanical friction of the second material due to rubbing against the walls of the mold or the material of the first layer.

[0047] The present invention further relates to an apparatus for manufacturing a member made of a plastic material as described above. The apparatus includes a first molding assembly having a punch, a first receiving mold, and a first injection device, and a second molding assembly having a second receiving mold and a second injection device. The first receiving mold is suitable for defining a first molding volume between the punch and the first receiving mold. The first injection device is configured to inject a first plastic material into the first molding volume to obtain a first layer. The second receiving mold has a second molding surface with alternating concave and convex portions, which is a negative mold of the shape of the outer surface of the member and is suitable for defining a second molding volume in combination with the first layer of the material. The second injection device is configured to inject a second plastic material into the second molding volume to obtain a second layer.

[0048] In one aspect of the present invention, the first receiving mold has a molding surface provided with at least a convex relief in part. The relief projects into the first molding volume during use and is configured to define a filling passage or cavity in the first layer of the material corresponding to the shape and position of the recesses in the second layer.

[0049] By forming the molding cavity as a negative mold of the shape of the recesses on the outer surface of the second layer of the member, a second molding volume with a substantially uniform width can be obtained, which can promote the progress of the second layer of the material and prevent the formation of possible weld lines.

[0050] By reading the following description of some embodiments with reference to the accompanying drawings, the above and other aspects, features, and advantages of the present invention will become apparent. These some embodiments are illustrative rather than limiting.

Brief Description of the Drawings

[0051]

Figure 1

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Figure 4a

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Figure 7

Figure 8

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Figure 12

Embodiments for Carrying out the Invention

[0052] Here, possible embodiments of the present invention will be described in detail. Each of the accompanying drawings shows one or more examples of these embodiments. Each example is provided as an illustration of the present invention and should not be construed as limiting the present invention.

[0053] Before describing these embodiments, it should be made clear that the application of the present invention is not limited to the detailed structure and arrangement of the members described in the following description with reference to each of the attached drawings. The following description can also provide other embodiments and can be produced or implemented in various other ways. Further, it should be made clear that the language and terms used in this application are for illustrative purposes only and should not be considered as limiting the present invention.

[0054] Using each of the attached drawings, embodiments of a member 10 made of a plastic material suitable for constructing a container, a housing of a household appliance 50, an outer shell, an external structure and / or an external body, or at least a part thereof, or other objects such as a bowl, a carafe, a thermos, etc. will be described.

[0055] In the following description, household appliances such as a kettle 50A and a toaster 50B will be taken as examples for description. However, it is understood that the member 10 of the present invention can be the housing of a container or other types of household appliances such as a vacuum cleaner, an electric brush, a blender, a microwave oven, an electric oven, a fryer, a teapot, a coffee machine, an ice cream maker, a kneader, a hair dryer, an iron, etc.

[0056] The member 10 of the present invention includes an inner first layer 11 and a second outer layer 12 that at least partially overlaps the inner first layer 11.

[0057] In some embodiments, the member 10 includes only the first layer 11 and the second layer 12.

[0058] In a preferred embodiment, the first layer 11 and the second layer 12 can be made of a plastic material such as a heat-resistant polymer material.

[0059] In a possible embodiment, the first layer 11 and the second layer 12 can be made of materials having similar properties and characteristics.

[0060] In a possible embodiment, the first layer 11 and the second layer 12 can be made of a material having non-uniform properties or characteristics.

[0061] For example, in some embodiments applicable to household appliances for food processing, etc., the first layer 11 and the second layer 12 can be made of a resin such as polypropylene suitable for applications in the food field.

[0062] In a possible embodiment, only the first layer 11 is suitable for applications in the food field, while the second layer 12 is not suitable for such applications.

[0063] In other embodiments, depending on the application, the first layer 11 and / or the second layer 12 can be made of thermoplastic resins with different properties.

[0064] In some embodiments, by making the first layer 11 of an opaque first material, or in a single color or multiple colors, and making the second layer 12 of a second material that is at least partially transparent, the opaque first layer 11 inside can be made visible through the second material.

[0065] When a layer is transparent or translucent, it means that light radiation can pass through the entire thickness of the layer and an object located on the other side of the layer can be visible.

[0066] Thereby, a three-dimensional appearance with a partially convex shape can be given to the final member 10.

[0067] In some embodiments, the second layer 12 consists of a substantially uncolored or unpigmented completely transparent layer, thereby giving the member 10 an aesthetic appearance with a sense of lightness.

[0068] In some embodiments, the first layer 11 and the second layer 12 can be made by a bi-injection process.

[0069] The first layer 11 has a first surface 13, and the first surface 13 becomes the inner surface of the member 10 and faces the inside of the household appliance 50 during use.

[0070] The first layer 11 also has a second surface 14 on the side opposite to the first surface 13, and the outer second layer 12 is disposed in contact with the second surface 14.

[0071] In some embodiments, the inner surface 13 can have a smooth and uniform transition without irregularities.

[0072] The second layer 12 has an outer surface 15 on the side opposite to the inner surface 13, and the outer surface 15 becomes the outer surface of the member 10 during use, and thus the outer surface of the household appliance 50 to which the member 10 is applied.

[0073] In some embodiments, the outer surface 15 has a three-dimensional finish and at least a portion where a plurality of aesthetic reliefs 16 protrude, and the reliefs 16 are suitable for giving the member 10 a satisfactory aesthetic appearance.

[0074] For example, the aesthetic reliefs 16 in examples of possible embodiments shown in FIGS. 1, 2, 3, 4, 4a and 4b, etc. can include a plurality of parallel rib-shaped, bubble-shaped, hemispherical, diamond-shaped processed parts, or other aesthetic reliefs 16 of geometric or non-geometric shapes.

[0075] In particular, the outer surface 15 has convex portions 17 and concave portions 18 alternately, whereby the member 10 is given a three-dimensional appearance and the household appliance 50 as a whole is given a three-dimensional appearance.

[0076] In some embodiments, the convex portions 17 and the concave portions 18 respectively correspond to portions of different thicknesses on the inner surface 13 of the member 10.

[0077] In a possible embodiment, the convex portions 17 are formed as vertical ribs adjacent to each other substantially parallel to each other.

[0078] In possible deformation forms, ribs arranged horizontally or obliquely, or convex portions or reliefs of spiral or spiral-like transitions can be provided.

[0079] In another embodiment shown in FIG. 4a, the convex portion 17 can be formed as adjacent hemispherical or bubble portions distributed in an equal or desired arrangement.

[0080] In another embodiment shown in FIG. 4b, the convex portion 17 can be formed in a pyramid shape with a polygonal base, and in the case of the rectangular type of this specific example, it can be formed adjacent to each other.

[0081] In other deformation forms (not shown), the relief 16 can have other shapes, and can also have non-geometric shapes such as a flower shape or a heart shape.

[0082] In some embodiments, the member 10 can have a cylindrical shape.

[0083] Its cross-section can be circular, polygonal, elliptical according to requirements or applications, or can have a perimeter combining straight line sections and curved line sections.

[0084] Furthermore, the cross-section of the member 10 can be invariant or variable along the axial transition, and can have concave or convex portions.

[0085] In other embodiments, the member 10 can be in an open curve shape and be configured to be connected to other similar members 10 to form a housing of a container or a household appliance 50, or be configured to be connected to different members to form a container or a housing.

[0086] In some embodiments, the outer second layer 12 covers all of the inner first layer 11.

[0087] In other possible embodiments, the second layer 12 has an outer edge 23, and this outer edge 23 protrudes from the inner edge 24 of the first layer 11 in the axial direction X.

[0088] Specifically, in the present embodiment, a part of the second layer 12 actually protrudes from the first layer 11 in the axial direction.

[0089] In this way, the member 10 has a single-layer peripheral strip 25 made of a second material, and this peripheral strip 25 is particularly of a transparent type. This transparent peripheral strip 25 gives the member 10 a bright three-dimensional appearance.

[0090] In other embodiments, the second layer 12 can extend with respect to the main body of the member 10 in other parts such as the spout 51 or the handle 52 of the kettle 50A, etc., thereby giving a further sense of lightness.

[0091] In some embodiments, the inner first layer 11 has a passage or a filling cavity 19 formed in its thickness.

[0092] The shape and position of the passage or the filling cavity 19 correspond to the shape and position of the recess 18 on the outer surface 15.

[0093] In particular, the filling cavity 19 can be made corresponding to the second surface 14 in the thickness of the first layer 11 so as to follow the shape of the outer surface 15 of the second layer 12 formed by the aesthetic relief 16, that is, the shape of the outer surface 15 of the second layer 12 in which the convex portions 17 and the recesses 18 are arranged alternately.

[0094] In other words, the second surface 14 of the first layer 11 has flat portions 19a sandwiching the filling cavity 19, and its shape and position respectively coincide with the shape and position of the convex portions 17 and the recesses 18 of the second layer 12.

[0095] Advantageously, the filling cavity 19 can compensate for at least a part of the difference in thickness between the convex portion 17 and the recess 18.

[0096] In other words, except for a slight deviation of, for example, about 10 to 20% with respect to the average value, the outer second layer 12 has a substantially constant thickness along the lateral dimension of the member 10, or in any case a substantially constant average thickness.

[0097] The average thickness of the inner first layer 11 varies in the lateral direction of the member 10.

[0098] In some embodiments, the transition site 20 sandwiched between the portion of the second surface 14 provided with the filling cavity 19 and the portion of the second surface 14 not provided with the filling cavity 19 can be formed in a bevel shape as shown in FIG. 3 and the like.

[0099] Advantageously, the beveled transition site 20 can prevent or at least suppress the concentration of heat during the step of injecting the second material to form the second layer 12, and thus can prevent or at least suppress the undesired remelting of the first material for forming the first layer 11.

[0100] In this way, erosion due to mechanical rubbing caused by the flow of the second material is also reduced.

[0101] In some embodiments, the second thickness S2 of the outer layer 12 is greater than the first thickness S1 of the inner layer 11.

[0102] Advantageously, the ratio of the second thickness S2 of the outer layer 12 to the first thickness S1 of the inner layer 11 can be in the range of 1.05 to 2.5, more preferably in the range of 1.1 to 2.

[0103] The first thickness S1 has a minimum value S1 corresponding to the filling cavity 19 hitting the recess 17 min and a maximum value S1 corresponding to the flat portion 19a hitting the convex portion 18 of the second layer 12. max and has.

[0104] In the case of the cylindrical member 10, each filling cavity 19 will hit the corresponding recess in the radial direction.

[0105] Depending on the shape and size of the relief 16, the first thickness S1 can vary directly between a minimum value S1 min and a maximum value S1 max or can take on intermediate values.

[0106] In some embodiments, the maximum value S1 max can be 20 to 50% greater than the minimum value S1 min .

[0107] The first thickness S1 and the second thickness S2 can be defined as the maximum thickness of each layer. In some embodiments, the member 10 can include a transparent window 22 that is suitable for a user to view through to the other side.

[0108] For example, in the case of the kettle 50A, the transparent window 22 allows the user to check the liquid level height of the water contained in the container formed by the member 10.

[0109] In other applications, the window 22 can be configured so that the user can view other possible features of the household appliance, such as the thermostat or timer of the toaster 50B, etc.

[0110] In other applications, the window 22 can be for the user to view possible internal parts of the household appliance 50 and / or to make the product being cooked visible, or to view the accumulation state of dust in the dust collection container of the vacuum cleaner.

[0111] In some embodiments, the window 22 can be directly fabricated by an outer transparent second layer 12.

[0112] In particular, the first layer 11 can have an opening 21 or slot that is substantially the same shape as the shape of the window 22 to be fabricated.

[0113] In contrast to the first layer 11, the second layer 12 that actually covers the first layer 11 can be produced continuously with the outer surface 15 so as to completely cover the opening 21 or the slot.

[0114] In a possible solution, the member 10 can be provided with different surface finishes, such as a substantially flat and smooth finish, etc., on the second layer 12 according to the window 22 so as to be more visible through the window 22.

[0115] The window 22 produced as described above has the advantage that it does not require any specific assembly or any packing or other device to guarantee its airtight seal. In fact, the window 22 produced as described above guarantees maximum sealing, preventing any possible liquid, vapor or dust inside the household appliance from leaking out to the outside, and conversely, preventing it from entering from the external environment into the internal environment.

[0116] The embodiment described with reference to FIGS. 5 to 12 here also relates to an apparatus 26 for manufacturing the member 10.

[0117] The apparatus 26 includes a first molding assembly 27 configured to produce the first layer 11 and a second molding assembly 28 configured to produce the second layer 12.

[0118] In one embodiment of the apparatus 26, the first molding assembly 27 is adjacent and disposed close to the second molding assembly 28.

[0119] In some embodiments, the first molding assembly 27 and the second molding assembly 28 can be arranged continuously in front and back and configured to operate directly in sequence in time to produce the finished member 10 in one step.

[0120] In some embodiments, the first molding assembly 27 includes a punch 29, a first molding die 30, and a first injection unit 31. The punch 29 and the first molding die 30 are adapted to cooperate to define a first molding volume V1 therebetween, and the first injection unit 31 is configured to inject a first plastic material into the first molding volume V1.

[0121] In some embodiments, the first molding volume V1 has a first maximum width W1 that coincides with the first thickness S1 of the first layer 11 of the member 10. max It has.

[0122] In some embodiments, the first injection unit 31 includes first heating means 53 configured to heat the first plastic material to a first injection temperature T1.

[0123] In some embodiments, the punch 29 has a contrast surface 32 configured to be a negative mold of the shape of the inner surface 13 of the first layer 11 of the member 10.

[0124] In some embodiments, the contrast surface 32 can be substantially uniform and smooth.

[0125] For example, when the member 10 is suitable for manufacturing the kettle 50A, the punch 29 can be substantially frustoconical, and when the member 10 is suitable for manufacturing the toaster 50B, the punch 29 can have the shape of a parallelepiped with a square cross section.

[0126] The first mold 30 includes a first molding surface 33 that is a negative mold of the shape of the second surface 14 of the first layer 11.

[0127] In some embodiments, the first molding die 30 can include one or more first molding side portions 37, which are configured to be positioned adjacent to each other in use to form one first molding surface 33 of the first molding die 30.

[0128] In some embodiments, at least a portion of the first molding surface 33 has a first molding ridge 38 that protrudes into the interior of the first molding volume V1 during use.

[0129] The first molding ridge 38 serves as a negative mold of the shape of the filling cavity 19 formed in the first layer 11.

[0130] In some embodiments, the second molding assembly 28 includes a second molding receptacle 34 having a second molding surface 35 suitable for serving as a negative mold of the shape of the outer surface 15 of the member 10.

[0131] The second molding receptacle 34 is suitable for cooperating with the second surface 14 of the first layer 11 of material during use to define a second molding volume V2 between the second molding receptacle 34 and the second surface 14.

[0132] In some embodiments, the second molding volume V2 has a second width W2 that corresponds to the second thickness S2 of the second layer 12 max and the second width W2 max is larger than the first width W1 max .

[0133] In some embodiments, the ratio of the second width W2 max to the first width W1 max is between 1.05 and 2.5, preferably between 1.1 and 2.

[0134] The second molding assembly 28 further includes a second injection unit 36 configured to inject a second plastic material into the second molding volume V2.

[0135] In some embodiments, the second injection unit 36 includes second heating means 54 configured to heat the second plastic material to a second injection temperature T2.

[0136] In some embodiments, the first heating means 53 and the second heating means 54 can be operated and adjusted independently of each other.

[0137] In some embodiments, the second molding receptacle 34 includes one or more second molding side portions 39.

[0138] In particular, the second molding side portions 39 are configured to be positioned adjacent to each other in use to form one second molding surface 35 of the second molding receptacle 34.

[0139] In some embodiments, a plurality of cavities 40a are formed in at least a portion of the second molding surface 35 such that they alternate with each molding relief 40b.

[0140] In particular, the cavities 40a and the molding reliefs 40b can be made to be a negative mold of the shape of the aesthetic reliefs 16 provided on the outer surface 15.

[0141] Therefore, the shape and size of the cavities 40a and the molding reliefs 40b correspond to the shape and final size of the convex portions 17 and the concave portions 18 of the outer surface 15.

[0142] The cavities 40a and the molding reliefs 40b correspond to the molding ridges 38 of the first molding receptacle 30.

[0143] In other words, the shape, size, and position of the cavities 40a and the molding reliefs 40b of the second molding receptacle 34 are aligned with the shape, size, and position of the molding ridges 38 of the first molding receptacle 30.

[0144] In particular, the molding reliefs 40b are arranged at positions corresponding to the positions of the molding ridges 38 in use.

[0145] In some embodiments, the first molding side portion 37 and the second molding side portion 39 are interchangeable so that members 10 having different aesthetic shapes can be manufactured by the same apparatus 26.

[0146] For example, according to the final appearance to be applied to the member 10, a plurality of sets of a first molded side portion 37 and a second molded side portion 39 each having a different surface finishing portion can be provided.

[0147] In another embodiment, the first molding assembly 26 has at least one coupling protrusion 41 that forms an opening 21 or a slot or a void portion without the first material in the first layer 11 and at the same time maintains the punch 29 and the first receiving mold 30 separated from each other.

[0148] In some embodiments, at least one coupling protrusion 41 is provided on one of the first molded side portions 37.

[0149] In particular, the coupling protrusion 41 is formed to cooperate with the punch 29 to confine and limit a part of the first molding volume V1 and prevent access to the first material therein.

[0150] In some embodiments, in order to preserve the finishing portion and gloss of the contrast surface 32 of the punch 29, the coupling protrusion 41 is formed such that the coupling contact with the punch 29 is minimized.

[0151] In some embodiments described with reference to FIG. 8 and the like, for example, the coupling protrusion 41 has at least one protrusion contact portion 42, which is positioned in contact with the contrast surface 32 of the punch 29 and is suitable for forming a free space or cavity 43 between the punch 29 and the corresponding first molding surface 33.

[0152] In other embodiments, the coupling protrusion 41 can be provided on the punch 29, and in that case, a cavity 43 may be formed between the punch 29 and the first receiving mold 30 of the punch 29, more specifically along the contrast surface 32.

[0153] In some embodiments described with reference to FIG. 10 and the like, for example, the coupling protrusion 41 can include a pair of contact portions 42 or an annular contact portion suitable for isolating and defining the cavity 43 from the first molding volume V1.

[0154] When the abutting portion 42 abuts against the surface 32 of the punch 29 during use and stretches, it is configured to ensure an airtight seal of the cavity 43.

[0155] In this way, the first forming volume V1 is limited to the corresponding portion where the opening 21 in the first layer 11 is provided.

[0156] In some embodiments, the cavity 43 has a height defined as the distance between the opposing surfaces of the punch 29 and the first receiving mold 30, and the height is several tens of micrometers to several hundreds of micrometers.

[0157] In some embodiments, the width of the abutting portion 42 is several hundreds of micrometers, for example, 0.2 to 1.5 millimeters, etc.

[0158] With a width value of 0.2 to 0.9 mm, the contact between the punch 29 and the receiving mold 30 can be minimized, and a cavity 43 with a larger area can be obtained.

[0159] For example, if the width value is slightly increased, such as 0.9 to 1.5 mm, etc., there is a drawback that the area of the cavity 43 is slightly reduced, but that's all. Even when the closing force is relatively small or the required processing accuracy is low, an airtight seal between the punch 29 and the receiving mold 30 can be ensured.

[0160] In some embodiments, one or more coupling protrusions 41 can be provided according to the shape and size of the opening 21 to be formed. When there are a plurality of coupling protrusions 41, they have the same or different shapes from each other.

[0161] For example, in the case of the member 10 applied to the kettle 50A, a first coupling protrusion 41 (FIG. 10) suitable for forming a window 22 for checking the water level, a second coupling protrusion 41 for forming a spout, and a third coupling protrusion 41 (FIG. 10) for forming a transparent peripheral strip 25 can be provided.

[0162] In one embodiment, the abutting portion 42 can have a shape corresponding to the shape of the window 22 to be formed in the member 10.

[0163] In other embodiments, the abutting portion 42 can have a shape that defines the shape of the edge 24 of the first layer 11.

[0164] The cavity 43 existing between the punch 29 and the first forming die 30 has the advantage that the finish and gloss of the contrast surface 32 of the punch 29 can be preserved even after several forming cycles.

[0165] In one embodiment, the first injection unit 31 and the second injection unit 36 each include at least one injection device 44 and at least one injection passage 45, and the injection passage 45 can fluidly connect each injection device 44 to either the first injection volume V1 or the second injection volume V2.

[0166] In one embodiment, it is also possible to provide a plurality of injection devices 44 for each injection unit 31, 36.

[0167] In one embodiment, at least one injection passage 45 is formed in at least one of the first forming side portions 37 and at least one of the second forming side portions 39.

[0168] In one embodiment, the device 26 can include a first cooling circuit 46 and a second cooling circuit 47 for each forming assembly 27, 28 respectively.

[0169] The first cooling circuit 46 includes one or more cooling passages 48 in a known form not shown in the drawings, and a unit for pumping the refrigerant, or a heat exchanger with a cooling circulation path.

[0170] The second cooling circuit 47 includes one or more cooling passages 49 in a known form not shown in the drawings, and a unit for pumping the refrigerant, or a heat exchanger with a cooling circulation path.

[0171] In some embodiments, the cooling passages 48, 49 can be formed to penetrate at least one of the first molding side portion 37 and / or the second molding side portion 39 and / or the punch 29.

[0172] In particular, the cooling passages 48, 49 are configured to pass a refrigerant such as, for example, water, emulsion, and / or oil.

[0173] The embodiment described with reference to FIGS. 5 to 12 herein also relates to a method for manufacturing the member 10.

[0174] This method includes a first step of injecting a first plastic material to form a first layer 11, - a second injection step of injecting a second plastic material to form a second layer 12 having a three-dimensional stepped portion with alternating convex portions 17 and concave portions 18 on the outer surface 15.

[0175] In some embodiments, the method positions the punch 29 and the first molding mold 30 relative to each other so as to define a first molding volume V1 between the punch 29 and the first molding mold 30, and injects a first material into the first volume V1 thus defined. The first molding volume V1 is defined between the contrast surface 32 of the punch 29 and the first molding surface 33 as shown in the right hand of FIG. 5 and FIG. 9.

[0176] In some embodiments, the method injects the first material with defined temperature and pressure parameters.

[0177] In some embodiments, the method injects the first material at a first temperature T1 of 150°C to 260°C (at least in the case of polypropylene).

[0178] In other embodiments, the first temperature T1 ranges from 120°C to 240°C, preferably from 160°C to 220°C, and more preferably from 180°C to 200°C.

[0179] In one embodiment, the method injects a first material at a first pressure P1 of 700 kg / cm 2 ~1300 kg / cm 2 .

[0180] In other embodiments, the first pressure P1 can be 750 kg / cm 2 ~1250 kg / cm 2 , more preferably 800 kg / cm 2 ~1200 kg / cm 2 .

[0181] The first injection step enables the first layer 11 inside the member 10 to be obtained (Figs. 6 and 10).

[0182] In some embodiments, the method can include circulating a refrigerant in a first cooling circuit 46 to cool at least one of the first receiving mold 30 and / or the punch 29 in the first injection step.

[0183] In some embodiments, the method uses a refrigerant having a first cooling temperature T3 in the range of 35°C to 55°C, more preferably 40°C to 50°C.

[0184] Subsequently, the method places the punch 29 together with the first layer 11 formed on the surface of the punch 29 into a second molding assembly 28. Here, the second receiving mold 34 is positioned to define a second molding volume V2 in combination with the second surface 14 of the first layer 11.

[0185] The second molding volume V2 is defined, for example, as shown in the right - hand side of Fig. 7 and Fig. 11, between the second surface 14 of the first layer 11 having the filling cavity 19 and the second molding surface 35.

[0186] Subsequently, the method has a second injection step of injecting a second plastic material into the second molding volume V2 at a second temperature T2 and a second pressure P2.

[0187] In one possible embodiment, the second injection step is immediately after the first injection step.

[0188] In one embodiment, the method uses a second temperature T2 that is lower than the first temperature T1.

[0189] In a preferred embodiment, the second temperature T2 ranges from 0.90 to 0.95 times T1. In other words, the second temperature T2 is 5 to 10% lower than the first temperature T1.

[0190] In one embodiment, the second pressure P2 can advantageously be made lower than the first pressure P1.

[0191] In one embodiment, the second pressure P2 can range from 0.70 to 0.90 times P1. In other words, the second pressure P2 is 10 to 30% lower than the first pressure P1.

[0192] The second injection step creates a second layer 12 outside the member 10.

[0193] In some embodiments, the method can include circulating a refrigerant in a second cooling circuit 47 to cool at least one of the second receiving mold 34 and / or the punch 29 to a second cooling temperature T4 during the second injection step.

[0194] In a preferred embodiment, the second cooling temperature T4 can range from 25°C to 45°C, more preferably from 30°C to 40°C.

[0195] In some embodiments, the method creates the second layer 12 with a greater thickness than the first layer 11.

[0196] In some embodiments, by creating the second layer 12 with a different greater thickness relative to the first layer 11, processing parameters of lower temperature and pressure can be used, thereby improving the surface stability and brightness, that is, reducing the deformations that may occur in the post-shrinkage step.

[0197] In other embodiments, the method creates at least one transparent window 22.

[0198] To create the window 22, the method forms an opening 21 or slot in the inner first layer 11 and covers the opening 21 or slot with a second material in a second injection step. This second material is a transparent material in this specific example.

[0199] In some embodiments, the method separates the shaping punch 29 and the second shaping die 35 at the end of the second injection step to remove the member 10.

[0200] It is clear that improvements and / or additions can be made to each part or each step of the member 10, the device 26, and the method described above without departing from the scope of the present invention specified in the claims.

[0201] Also, although the present invention has been described with reference to some specific examples, it is certain that those skilled in the art can achieve many other equivalent forms of the member 10, the device 26, and the method having the features described in the claims. Therefore, it is also clear that all such equivalent forms belong to the protection scope described in the claims.

Claims

1. A method for manufacturing a member (10) made of a plastic material suitable for forming a housing of a container, or a household appliance (50) or a receptacle, comprising: a first injection step of injecting a first plastic material into a first forming volume (V1) defined between a punch (29) and a first receiving mold (30) to produce a first layer (11); a second injection step of injecting a second plastic material into a second forming volume (V2) defined between the first layer (11) obtained in the first injection step and a second receiving mold (34) to produce a second layer (12); In a method having: producing the second layer (12) having an outer surface provided with a three-dimensional ribbed portion having alternating convex portions (17) and concave portions (18); In the first injection step, a passage or filling cavity (19) suitable for compensating for the difference in thickness between the convex portion (17) and the concave portion (18) in the first layer (11) and making the filling flow of the second plastic material substantially uniform in the second injection step is produced corresponding to the shape and position of the concave portion (18) of the second layer (12). A method characterized by the above.

2. Using a first opaque material of a single color or multiple colors and a second material that is at least partially transparent, the opaque first layer (11) can be made visible through the transparent second layer (12). The method according to Claim 1.

3. Producing the first layer (11) having a first thickness (S1) and producing the second layer (12) having a second thickness (S2) greater than the first thickness (S1). The method according to Claim 1 or 2.

4. Performing the second injection step immediately after the end of the first injection step. The method according to any one of Claims 1 to 3.

5. An apparatus for manufacturing a member (10) made of a plastic material having a first layer (11) and a second layer (12), comprising: a first molding assembly (27) comprising a punch (29), a first receiving mold (30) and a first injection unit (31); and a second molding assembly (28) comprising a second receiving mold (34) and a second injection unit (36), The first receiving mold (30) has a first molding surface (33) suitable for defining a first forming volume (V1) between the punch (29) and the first receiving mold (30). The first injection unit (31) is configured to inject a first plastic material into the first forming volume (V1) to obtain a first layer (11), The second receiving mold (34) has a second forming surface (35) suitable for defining a second forming volume (V2) in combination with the first layer (11) of the member (10), In an apparatus in which the second injection unit (36) is configured to inject a second plastic material into the second forming volume (V2) to obtain a second layer (12), A molding cavity (40a) and a molding ridge (40b) that can be a negative mold of the shape of the outer surface (15) of the member (10) having convex portions (17) and concave portions (18) alternately are alternately formed on at least a part of the second forming surface (35), A molding relief (38) is formed on at least a part of the first forming surface (33), and the molding relief (38) protrudes into the first forming volume (V1) during use and defines a filling passage or cavity in the first layer (11) corresponding to the shape and position of the molding ridge (40b) of the second forming surface (35), The filling passage or cavity is suitable for compensating for the difference in thickness between the convex portion (17) and the concave portion (18) to make the filling flow of the second plastic material substantially uniform characterized apparatus.

6. The molding ridge (40b) of the second receiving mold (34) has a shape corresponding to the shape of the molding relief (38) of the first receiving mold (30), The apparatus according to claim 5.

7. The first receiving mold (30) has a first molding side portion (37), and the second receiving mold (34) has a second molding side portion (39), The first molding side portion (37) and the second molding side portion (39) are interchangeable to form a plurality of three-dimensional finishing portions, The apparatus according to claim 5 or 6.

8. A member made of a plastic material suitable for forming a container, or a housing of a household appliance (50) or a receptacle, An inner first layer (11) made of a first plastic material, An outer second layer (12) made of a second plastic material covering at least a part of the first layer (11), A member comprising: The second layer (12) has a three-dimensional finishing portion having convex portions (17) and concave portions (18) alternately on the outer surface (15), A passage or filling cavity (19) suitable for at least partially compensating for the difference in thickness between the convex portion (17) and the concave portion (18), wherein a passage or filling cavity (19) corresponding to the shape and position of the concave portion (18) of the second layer (12) is provided in the first layer (11) by being formed in the thickness of the first layer (11). The passage or cavity is suitable for compensating for the difference in thickness between the convex portion (17) and the concave portion (18) to substantially equalize the filling flow of the second plastic material. The first layer (11) has a first surface (13) that is the inner surface of the member (10) and faces the inside of the household appliance (50) during use, and a second surface (14) opposite to the first surface (13), where the second layer (12) is arranged in contact. The second layer (12) has an outer surface (15) on the side opposite to the inner surface. The outer surface (15) becomes the outer surface of the member (10) during use and the outer surface of the household appliance (50) to which the member (10) is applied. A member characterized by the above.

9. The first layer (11) has a first thickness that varies between a minimum value (S1 ｍｉｎ ) corresponding to the passage or filling cavity (19) in the lateral direction of the member, and a maximum thickness (S1 ｍａｘ ) corresponding to the flat portion (19a) provided across the filling cavity or passage (19). The second layer (12) has a second thickness (S2) that is substantially invariant in the transverse direction. The member according to claim 8.

10. The second thickness (S2) of the outer second layer (12) is greater than the first thickness (S1) of the inner first layer (11). The member according to claim 9.

11. The inner first layer (11) is made of a first opaque material, and the outer second layer (12) is made of a second material that is at least partially transparent, through which the inner opaque first layer (11) can be visually recognized. The member according to any one of claims 8 to 10.

12. The outer second layer (12) protrudes at least in the axial direction (X) from the edge (24) of the inner first layer (11). The member according to any one of claims 8 to 11.

13. The convex portion (17) is formed as adjacent vertical ribs arranged substantially parallel to each other. The member according to any one of claims 8 to 12.

14. Having a cylindrical shape. The member according to any one of claims 8 to 13.

15. A household appliance, comprising a container or a housing at least partially formed by the member (10) according to any one of Claims 8 to 13. Characterized in that it is a household appliance.

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