Injection molding method of massage roller

Abstract

The invention provides an injection molding method of a massage roller. The injection molding method comprises the following steps: providing a hollow shaft tube; placing the hollow shaft tube in a mold of an injection molding device, wherein a molding space is formed between the hollow shaft tube and the mold; and a forming material is injected towards the forming space in the direction perpendicular to the axis of the hollow shaft tube, so that a coating layer is formed on the outer periphery of the hollow shaft tube, and the massage roller is manufactured. By means of the method, surface bonding lines and burrs of a finished product can be reduced.

Description

Technical Field

[0001] This invention relates to an injection molding method, and more particularly to an injection molding method for a massage roller. Background Technology

[0002] Moderate massage can temporarily stimulate the muscles and fascia, thereby achieving the effects of soothing, relaxing, and promoting blood circulation. To further enhance the effects of massage, rollers are often used as an auxiliary tool to effectively remove lactic acid buildup after exercise and relax and relieve body soreness.

[0003] like Figure 1 The diagram shows a schematic of an existing injection molding method for massage rollers. Before molding, the massage roller is first placed in a mold 2 with a hollow tube 1. Then, the plastic raw material is injected into the gate 2a of the mold 2 through the injection gun 3 of the injection machine, so that the surface layer 4 is injected out from the outer periphery of the hollow tube 1, so that the surface layer 4 covers the hollow tube 1, thereby completing the production of the massage roller.

[0004] However, in the prior art, the gate 2a is located at one axial end of the hollow tube 1. When the plastic raw material enters the mold cavity through the gate 2a, the part closer to the gate 2a cools and solidifies first, while the part farther away from the gate 2a solidifies later. This uneven cooling rate easily produces obvious weld lines or burrs on the surface of the surface layer 4, affecting the appearance of the product. More seriously, such defects may cause stress concentration inside the massage roller, reducing the strength of the product. Summary of the Invention

[0005] To address the aforementioned issues, this invention discloses an injection molding method for a massage roller. This method employs injection molding perpendicular to the axis of the hollow shaft tube, enabling the molding material to completely cover the outer periphery of the hollow shaft tube. This effectively reduces common seam lines and burrs on the surface of the massage roller, improving the product's appearance quality and service life.

[0006] To achieve the above objectives, this invention provides an injection molding method for a massage roller, comprising the following steps: providing a hollow shaft tube; placing the hollow shaft tube in a mold of an injection molding apparatus, wherein a molding space exists between the hollow shaft tube and the mold; and injecting a molding material into the molding space along an axis perpendicular to the hollow shaft tube, thereby forming a coating layer on the outer periphery of the hollow shaft tube to produce a massage roller.

[0007] In another embodiment of the present invention, the injection molding apparatus has a first mold base, a second mold base, a stripper plate and a fixed plate. The mold is disposed between the first mold base and the second mold base, the fixed plate is away from the second mold base, and the stripper plate is disposed between the second mold base and the fixed plate. The fixed plate has a gate, the second mold base has an injection runner connected to the gate, the mold has two guide runners parallel to the axial direction, the two guide runners each have an inlet and an outlet, the two inlets are connected to the injection runners, and the two outlets are respectively located on both sides of the hollow shaft tube, and the two outlets are perpendicular to the axial direction and connected to the molding space.

[0008] In another embodiment of the present invention, the gate is connected to the sprue through a runner. The sprue has a main runner and two runners. The main runner is vertically connected to the runner, and the two runners are respectively connected to the two ends of the main runner and the two inlets.

[0009] In another embodiment of the present invention, after the massage roller is formed, the injection gating and the two guide gating systems form a cold material. The cold material includes a first cold material portion and a second cold material portion. The first cold material portion is located in the injection gating system, and the second cold material portion is located in the guide gating system. When the stripper plate separates from the second mold base, the first cold material portion is cut off, so that the first cold material portion and the second cold material portion are separated. In another embodiment of the present invention, when the first mold base and the second mold base separate, and the mold is opened, the second cold material portion is separated from the massage roller so that the massage roller can be removed.

[0010] In another embodiment of the present invention, the hardness of the hollow shaft tube is greater than the hardness of the coating layer.

[0011] Therefore, the method of the present invention can significantly reduce uneven cooling of the material during the flow process by effectively shortening the flow path of the molding material in the mold, thereby reducing the generation of surface bonding lines and burrs, and improving the surface finish of the product. In addition, the uniform cooling process can effectively reduce stress concentration inside the finished product, improving the structural strength and durability of the massage roller. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of an existing injection molding method for massage rollers.

[0013] Figure 2 This is a flowchart of the injection molding method for the massage roller of the present invention.

[0014] Figure 3 This is an external view of the injection molding apparatus used in the injection molding method for the massage roller of the present invention.

[0015] Figure 4 For along Figure 3 The cross-sectional view taken from the AA section line.

[0016] Figure 5This is a schematic diagram of the injection molding process of the massage roller of the present invention.

[0017] Figure 6 This is a schematic diagram of the cutting of the first cold material section in the injection molding method of the massage roller of the present invention.

[0018] Figure 7 This is a schematic diagram of cutting the second cold material section and opening the mold in the injection molding method of the massage roller of the present invention.

[0019] Figure 8 This is a schematic diagram of the appearance of the massage roller of the present invention.

[0020] Explanation of reference numerals in the attached figures 1: Hollow tube.

[0021] 2: Mold.

[0022] 2a: Gate.

[0023] 3: Shooting gun.

[0024] 4: Surface layer.

[0025] 10: Hollow shaft tube.

[0026] 11: Covering layer.

[0027] 12: Protruding rib.

[0028] 13: Groove.

[0029] X: Axis.

[0030] 100: Injection molding device.

[0031] 20: Mold.

[0032] 21: Forming space.

[0033] 22: Flow channel.

[0034] 221: Feed inlet.

[0035] 222: Discharge port.

[0036] 30: First mold base.

[0037] 40: Second mold base.

[0038] 41: Injection channel.

[0039] 411: Main gating system.

[0040] 412: Secondary pouring channel.

[0041] 50: Stripper plate.

[0042] 60: Fixing plate.

[0043] 61: Gate.

[0044] 62: Flow channel.

[0045] 200: Massage roller.

[0046] 300: Cold material.

[0047] 301: First Cold Material Section.

[0048] 302: Second Cold Material Section.

[0049] S1~S3: Steps. Detailed Implementation

[0050] Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings. It is not intended to limit the technical principles of the invention to the specific disclosed embodiments, but rather the scope of the invention is limited only by the scope of the patent, encompassing alternatives, modifications, and equivalents. Furthermore, for the purpose of understanding and reading by those skilled in the art, the structural dimensions and sizes of the various elements presented in the drawings are shown in a schematic manner and are not intended to limit the conditions under which the invention can be practiced.

[0051] Please see Figures 2 to 8 As shown, the present invention provides an injection molding method for a massage roller, comprising the following steps: Step S1: A hollow shaft tube 10 is provided. The outer periphery of the hollow shaft tube 10 is concave-convex along the X-axis.

[0052] Step S2: The hollow shaft tube 10 is placed in a mold 20 of an injection molding device 100, and a forming space 21 is formed between the hollow shaft tube 10 and the mold 20.

[0053] like Figure 3 and Figure 4 In this embodiment of the invention, the injection molding apparatus 100 includes a first mold base 30, a second mold base 40, a stripper plate 50, and a fixing plate 60. The mold 20 is composed of four half-molds, which are disposed between the first mold base 30 and the second mold base 40. The fixing plate 60 is located away from the second mold base 40, and the stripper plate 50 is disposed between the second mold base 40 and the fixing plate 60. The fixing plate 60 has a gate 61 for engaging with the injection gun 3 of the injection machine, and the second mold base 40 has a sprue 41 connected to the gate 61. The gate 61 is connected to the sprue 41 via a runner 62.

[0054] The injection gating system 41 has a main gating system 411 and two secondary gating systems 412 connected to both ends of the main gating system 411. The main gating system 411 is vertically connected to the runner 62. The mold 20 has two guide gating systems 22 parallel to the X-axis. Each guide gating system 22 has an inlet 221 and an outlet 222. The two inlets 221 are connected to the two secondary gating systems 412 of the injection gating system 41. The two outlets 222 are located on both sides of the hollow shaft tube 10 and are perpendicular to the X-axis and connected to the forming space 21.

[0055] Step S3: Inject the molding material along the X direction perpendicular to the axis of the hollow shaft tube 10 toward the molding space 21, so that a coating layer 11 is formed on the outer periphery of the hollow shaft tube 10, to create a product as shown in the figure. Figure 8 Massage rollers 200. (For example) Figure 5 As shown, in this embodiment of the invention, the injection gun 3 of the injection machine is aligned with the gate 61 to inject the molding material, so that the molding material is diverted through the injection gating 41 to the two guide gating 22, and the molding material is injected into the molding space 21 along the direction perpendicular to the axis X, so as to form a coating layer 11 on the outer periphery of the hollow shaft tube 10.

[0056] Next, as Figure 6 As shown, after the massage roller 200 is formed, the injection gating 41 and the two guide gating 22 form a cold material 300. The cold material 300 includes a first cold material section 301 and a second cold material section 302. The first cold material section 301 is located in the injection gating 41, and the second cold material section 302 is located in the guide gating 22. Therefore, when the stripper plate 50 separates from the second mold base 40, the first cold material section 301 is cut off, separating the first cold material section 301 from the second cold material section 302.

[0057] like Figure 7 and cooperate Figure 6 , Figure 8 As shown, after the first cold material section 301 and the second cold material section 302 separate, the first mold base 30 and the second mold base 40 separate, and the mold 20 opens, causing the second cold material section 302 to separate from the massage roller 200, so that the massage roller 200 can be removed. The hardness of the hollow shaft tube 10 of the massage roller 200 is greater than the hardness of the covering layer 11. In addition, multiple ribs 12 and multiple grooves 13 are distributed along the axis X on the outer periphery of the massage roller 200, and the ribs 12 and grooves 13 are alternately arranged.

[0058] In the aforementioned steps, the present invention employs an injection direction perpendicular to the X-axis, which effectively reduces the distance the molding material flows in the mold 20, reduces uneven cooling of the molding material during the flow process, and reduces the generation of surface bonding lines and burrs, thus improving the surface finish of the product. Furthermore, due to uniform cooling, it also reduces stress concentration issues within the finished product, improving the structural strength and durability of the massage roller 200.

[0059] The above description, while illustrating a preferred embodiment, allows those skilled in the art to make various modifications without departing from the spirit and scope of the invention. The foregoing embodiments are merely illustrative and not intended to limit the scope of the invention. All modifications or alterations made without departing from the spirit of the invention are within the scope of the patent.

Claims

1. A method for injection molding a massage roller, characterized in that, Includes the following steps: Provide a hollow shaft tube; The hollow shaft tube is placed inside a mold of an injection molding apparatus, with a molding space between the hollow shaft tube and the mold; and A molding material is injected into the molding space along an axis perpendicular to the hollow shaft tube, so that a coating layer is formed on the outer periphery of the hollow shaft tube to produce the massage roller.

2. The injection molding method for the massage roller as described in claim 1, characterized in that, The injection molding apparatus has a first mold base, a second mold base, a stripper plate, and a fixed plate. The mold is disposed between the first mold base and the second mold base. The fixed plate is away from the second mold base. The stripper plate is disposed between the second mold base and the fixed plate. The fixed plate has a gate. The second mold base has an injection runner connected to the gate. The mold has two guide runners parallel to the axial direction. The two guide runners each have an inlet and an outlet. The two inlets are connected to the injection runners. The two outlets are located on both sides of the hollow shaft tube, and the two outlets are perpendicular to the axial direction and connected to the molding space.

3. The injection molding method for the massage roller as described in claim 2, characterized in that, The gate is connected to the sprue via a runner. The sprue has a main runner and two secondary runners. The main runner is vertically connected to the runner, and the two secondary runners are respectively connected to the two ends of the main runner and the two inlets.

4. The injection molding method for the massage roller as described in claim 3, characterized in that, After the massage roller is formed, the injection gating and the two guide gating forms a cold material. The cold material includes a first cold material part and a second cold material part. The first cold material part is located in the injection gating and the second cold material part is located in the guide gating. When the stripper plate separates from the second mold base, it cuts off the first cold material part, so that the first cold material part and the second cold material part are separated.

5. The injection molding method for the massage roller as described in claim 4, characterized in that, The first mold base and the second mold base are separated, and the mold is opened to separate the second cold material part from the massage roller so that the massage roller can be removed.

6. The injection molding method for the massage roller as described in claim 5, characterized in that, The hardness of the hollow shaft tube is greater than the hardness of the coating layer.

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