Packaging method of heating pad

Abstract

The invention relates to the technical field of heating products and packaging, and particularly discloses a heating pad packaging method which comprises the following steps: S1, providing a welding mold which comprises a first mold and a second mold, and forming a hollow welding mold cavity when the first mold and the second mold abut against each other; and S2, placing a heating pad wiring structure to be packaged in the welding die cavity, and applying pressure and high frequency to the heating pad wiring structure until the heating pad wiring structure forms a sealing structure. In the heating pad prepared by utilizing the packaging method, after being extruded in a molten state, the wrapping layer can be gathered in the annular groove between the adjacent annular bulges of the welding mold to form a dense ring layer, and then a multi-stage sealing ring structure is formed, so that the sealing property and the firmness of the heating pad are improved.

Description

Technical Field

[0001] The present invention belongs to the technical fields of heating products and encapsulation technology, and particularly relates to a method for encapsulating a heating pad. Background Art

[0002] Heating pads often appear in an ultra-thin form, with a thickness generally of 1 - 5 millimeters. Since the diameter of the wires used in heating pads is much smaller than that of commonly used wires, it is difficult to effectively encapsulate the wiring structure between the heating pad and the wires. As a result, after long-term use in a damp and water-rich place, internal water seepage may occur.

[0003] The wiring structure of the heating pad can be encapsulated through the following solution: punch holes on either side of the upper and lower sides of the heating pad encapsulation film, and fix the wire joints through a plastic snap component, and the snap component is generally made of PE, PP, ABS, etc. This solution attempts to achieve an insulating and sealing effect by tightly fitting two different materials (plastic and rubber, or rigid and flexible), but in fact, it cannot be achieved.

[0004] The wiring structure of the heating pad can also be encapsulated through the following solution: directly lead the cable out from the side of the heating pad, and fuse the packaging layer material and the cable material through equipment such as a high-frequency pressing device. This solution attempts to achieve an insulating and sealing effect by the high-temperature melting combination of the same type of materials (both are polyvinyl chloride rubber). In actual operation, it is often impossible to perfectly fuse within the range of 360 degrees in a circle, and fine cracks will occur during use (such as bending, stretching, etc.), resulting in water seepage.

[0005] In addition, the heating pad often encounters pulling situations during use. Repeated direct stress will damage its structure and exacerbate the water seepage problem. Therefore, the existing heating pads have deficiencies in both waterproof performance and structural firmness, and there is an urgent need to provide a new method for encapsulating heating pads for improvement. Summary of the Invention

[0006] The technical object of the present invention is to provide a method for encapsulating a heating pad that can significantly improve the sealing and firmness of the heating pad, thereby solving the above-mentioned problems in the prior art. Specifically, the present application provides a new type of mold, and seals the wiring structure between the heating pad and the wires by simultaneously applying pressure and high frequency, so that the sealed interface of the heating pad includes a multi-stage sealing ring structure, improving the sealing and firmness of the heating pad. In addition, by providing a wrapping layer with a thickness smaller than that of the encapsulation layer between the wire and the encapsulation layer, when encapsulating, the film of the wrapping layer melts earlier than the film of the encapsulation layer, penetrates into the gaps at all corners of the interlayer, and achieves a perfect sealing effect.

[0007] To solve the above technical problems, the present application provides the following technical solutions.

[0008] In a first aspect, the present application provides a method for encapsulating a heating pad, the heating pad including a heating element, and the method comprising:

[0009] Step S1: Provide a welding mold, the welding mold including a first mold and a second mold, and when the first mold and the second mold are abutted, a hollow welding cavity is formed;

[0010] Step S2: Place the wiring structure of the heating pad to be encapsulated in the welding cavity, apply pressure and high frequency waves to the wiring structure of the heating pad until the wiring structure of the heating pad forms a sealed structure;

[0011] Wherein, the wiring structure of the heating pad includes:

[0012] A cable, one end of the cable is connected to the heating element, and the other end extends a certain distance along the direction away from the heating pad;

[0013] A wrapping layer, the wrapping layer is wound around the outer periphery of the cable, one end of the wrapping layer is close to the heating element, and the other end extends a first length along the direction away from the heating pad;

[0014] An encapsulation layer, the encapsulation layer is wound around the outer periphery of the wrapping layer, one end of the encapsulation layer seals the heating element, and the other end extends a second length along the direction away from the heating pad.

[0015] In an implementation manner of the first aspect, the first length is less than or equal to the second length.

[0016] In an implementation manner of the first aspect, the first mold is provided with a first welding groove, and a plurality of uniformly arranged first protrusions are provided in the first welding groove; the second mold is provided with a second welding groove, and a plurality of uniformly arranged second protrusions are provided in the second welding groove; when the first mold and the second mold are abutted, the first protrusions and the second protrusions are joined to form an annular protrusion.

[0017] In an implementation manner of the first aspect, in step S2, the applied pressure is 20 - 100 kg; the high frequency heating time is 3 - 8 seconds, and the cooling and holding time is 10 seconds.

[0018] In an implementation manner of the first aspect, in step S2, high frequency waves are generated by energization, and the energization current range is 5 - 10 A.

[0019] In an implementation manner of the first aspect, the wrapping layer is formed by the following method:

[0020] Stretch the polyvinyl chloride rubber film to more than twice its initial length, and then wind it around the cable for 1 - 3 turns.

[0021] In an embodiment of the first aspect, the encapsulation layer includes a connected first encapsulation layer and a second encapsulation layer. The first encapsulation layer includes a connected first encapsulation portion and a second encapsulation portion, and the cross-section of the second encapsulation portion is arc-shaped.

[0022] The second encapsulation layer includes a connected third encapsulation portion and a fourth encapsulation portion, and the cross-section of the fourth encapsulation portion is arc-shaped. When the second encapsulation portion and the fourth encapsulation portion are hermetically joined, they are used to accommodate a cable with a wrapping layer.

[0023] In an embodiment of the first aspect, the thickness of the wrapping layer is less than the thickness of the second encapsulation portion or the fourth encapsulation portion.

[0024] In an embodiment of the first aspect, the thickness of the wrapping layer is 5%-25% of the smaller one of the thickness of the second encapsulation portion or the fourth encapsulation portion.

[0025] In an embodiment of the first aspect, the thickness of the wrapping layer is 10%-20% of the smaller one of the thickness of the second encapsulation portion or the fourth encapsulation portion.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: The heating pad encapsulation method disclosed in the present invention includes providing a welding mold, placing the heating pad wiring structure to be encapsulated in the mold, and then applying pressure and high frequency simultaneously to complete the encapsulation. In the heating pad after encapsulation, the heating element is sealed in the encapsulation layer, the cable connected to the heating element is wrapped by the wrapping layer, and the wrapping layer is covered by the encapsulation layer. After the wrapping layer is extruded in a molten state, it will gather at the annular groove between adjacent annular protrusions of the welding mold to form a dense layer, thereby forming a multi-stage sealing ring structure, thus improving the sealing performance and firmness of the heating pad. Description of the Drawings

[0027] Figure 1 is a schematic diagram of the overall structure of the heating pad in an embodiment of the present invention;

[0028] Figure 2 is Figure 1 a cross-sectional view taken along line A-A in

[0029] Figure 3 is a schematic diagram of the structure of the protruding portion in an embodiment of the present invention;

[0030] Figure 4 is a schematic diagram of the overall structure of the welding mold in an embodiment of the present invention;

[0031] Figure 5 is a schematic diagram of the structure of the first mold in an embodiment of the present invention;

[0032] Figure 6It is a schematic structural diagram of the second mold in the embodiment of the present invention.

[0033] In the drawings, each reference numeral represents: 1, encapsulation layer; 101, first encapsulation layer; 1011, first encapsulation part; 11, second encapsulation part; 111, first accommodation groove; 112, first protruding part; 102, second encapsulation layer; 1101, encapsulation part; 1021, third encapsulation part; 12, sealing ring; 13, fourth encapsulation part; 131, second accommodation groove; 132, second protruding part; 1102, protruding part; 2, wrapping layer; 3, cable; 4, welding mold; 41, first mold; 411, first welding groove; 412, first protrusion; 42, second mold; 421, second welding groove; 422, second protrusion. Detailed implementation manners

[0034] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0036] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0037] Heating pads often appear in an ultra-thin form, with a thickness generally ranging from 1 to 5 millimeters. Since the diameter of the wires used in heating pads is much smaller than that of commonly used wires, the existing wiring structure encapsulation technology cannot achieve good sealing, resulting in the heating pads being prone to water seepage after long-term use. Moreover, under repeated stress, the firmness between the wires and the encapsulation layer deteriorates.

[0038] Heating pad

[0039] In view of the above technical problems, the present invention first proposes a heating pad.

[0040] Figure 1 Show the overall structural schematic diagram of the heating pad in the embodiment of the present invention, Figure 2 is Figure 1 the cross-sectional view along line A-A in. From the attached Figure 1-2 it can be seen that the heating pad includes a heating element (not marked in the figure), an encapsulation layer 1, a cable 3, and a wrapping layer 2.

[0041] The heating element is the main component for the heating pad to generate heat. Usually, it is in a planar shape. After the heating element is powered on, it can convert electrical energy into heat energy, thereby raising the overall temperature of the heating pad. In some embodiments, the heating element is at least one of an electric heating wire, a metal sheet, and a heating film. The electric heating wire, the metal sheet, and the heating film have good thermal conductivity, and preferably, it is a graphene heating film.

[0042] The encapsulation layer 1 includes a connected first encapsulation layer 101 and a second encapsulation layer 102, and the heating element is sealed between the first encapsulation layer 101 and the second encapsulation layer 102. Place the heating element between the first encapsulation layer 101 and the second encapsulation layer 102, and then seal the peripheries of the first encapsulation layer 101 and the second encapsulation layer 102, then the heating element can be encapsulated in the encapsulation layer 1 to achieve sealing and waterproofing.

[0043] The cable 3 is electrically connected to the heating element. One end of the cable 3 is connected to the heating element, and the other end can be connected to an external power source to supply electrical energy to the heating element. At least part of the cable 3 is located between the first encapsulation layer 101 and the second encapsulation layer 102, that is, part of the cable 3 extends into the encapsulation layer 1 to facilitate connection with the heating element. In this way, the entire heating element is located within the encapsulation layer 1, and the encapsulation layer 1 can be used to provide electrical insulation and mechanical protection for the heating element, etc. In addition, since part of the cable 3 is located between the first encapsulation layer 101 and the second encapsulation layer 102, it can prevent the exposed ends of the cable 3 from causing electric leakage and other situations.

[0044] The wrapping layer 2 wraps around the cable 3 at least once and is hermetically connected to the encapsulation layer 1. The heating element and the cable 3 are sealed with the encapsulation layer 1. Under this sealed condition, the wrapping layer 2 wrapped around the cable 3 is further hermetically connected to the encapsulation layer 1, which can improve the sealing performance of the heating pad. Hermetic connection means that there are no gaps at the connection of two objects. Exemplarily, the encapsulation layer 1 and the wrapping layer 2 will be wrapped by the cable 3. The outer peripheral surface of the wrapping layer 2 is connected to the encapsulation layer 1, and there are no gaps at the connection of the outer peripheral surface of the wrapping layer 2 and the encapsulation layer 1, so that the cable 3 and the heating element are sealed and not in communication or contact with the outside air / water.

[0045] As can be seen from the above embodiments, the heating element of the present invention is sealed within the encapsulation layer 1, and the cable 3 connected to the heating element is wrapped with the wrapping layer 2. The wrapping layer 2 is hermetically connected to the encapsulation layer 1, which can improve the sealing performance of the heating pad, and further improve the waterproof performance of the heating pad, preventing water seepage in the heating pad.

[0046] In some embodiments, the thickness of the wrapping layer 2 is significantly smaller than the thickness of the first encapsulation layer 101 or the second encapsulation layer 102. During the manufacturing process of the heating pad, first, the wrapping layer 2 wraps around the cable 3 at least once. Then, the wrapped cable 3 is placed between the first encapsulation layer 101 and the second encapsulation layer 102. Then, a high-frequency welding die 4 is used to perform high-frequency welding and pressing on the first encapsulation layer 101, the second encapsulation layer 102, and the wrapping layer 2, so that the structure formed by the first encapsulation layer 101, the second encapsulation layer 102, and the wrapping layer 2 performs an all-round double-layer seal on the cable 3, that is, a 360-degree circumferential welding seal on the cable 3. Since the thickness of the wrapping layer 2 is smaller than the thickness of the encapsulation layer 1, during the high-frequency welding process, the wrapping layer 2 melts first and penetrates into every corner and gap between the first encapsulation layer 101 and the second encapsulation layer 102, so that the wrapping layer 2 is hermetically connected to the encapsulation layer 1. After that, the first encapsulation layer 101 and the second encapsulation layer 102 melt, and the first encapsulation layer 101 and the second encapsulation layer 102 are hermetically connected, so as to achieve an all-round double-layer seal of the cable 3 by the structure formed by the first encapsulation layer 101, the second encapsulation layer 102, and the wrapping layer 2.

[0047] As shown in the Figure 2 accompanying drawings, in some embodiments, the first encapsulation layer 101 includes a connected first encapsulation portion 1011 and a second encapsulation portion 11. The cross-section of the second encapsulation portion 11 is arc-shaped to form a first receiving groove 111, and at least a part of the cable 3 is located in the first receiving groove 111. The shape of the second encapsulation portion 11 is more adapted to the shape of the cable 3. During high-frequency welding, the second encapsulation portion 11 can be in closer contact with the wrapping layer 2 wrapped around the cable 3, so that the welding can be better.

[0048] The second encapsulation layer 102 includes a connected third encapsulation part 1021 and a fourth encapsulation part 13. The cross-section of the third encapsulation part 1021 is arc-shaped to form a second accommodation groove 131, and the cable 3 is at least partially located in the second accommodation groove 131. Similarly, the shape of the fourth encapsulation part 13 is more adapted to the shape of the cable 3. During high-frequency welding, the fourth encapsulation part 13 can be in closer contact with the wrapping layer 2 wrapped around the cable 3, so that the welding can be better.

[0049] When the second encapsulation part 11 and the fourth encapsulation part 13 are hermetically connected, the encapsulation part 1101 formed by the second encapsulation part 11 and the fourth encapsulation part 13 wraps around the cable 3 in a circle, so that the cable 3 is sealed by the encapsulation layer 1, thereby preventing external water from entering between the cable 3 and the encapsulation layer 1. Exemplarily, the first encapsulation part 1011 and the third encapsulation part 1021 are in a flat shape, so that the first encapsulation part 1011 and the second encapsulation part 11 can be welded better during high-frequency welding.

[0050] As shown in the Figure 3 accompanying drawings, in some embodiments, in order to improve the sealing performance of the heating pad, the second encapsulation part 11 includes a first protruding part 112, and the first protruding part 112 is located outside the first encapsulation part 1011. The fourth encapsulation part 13 includes a second protruding part 132, and the second protruding part 132 is located outside the third encapsulation part 1021. The first protruding part 112 and the second protruding part 132 are hermetically connected to form a protruding part 1102, and the protruding part 1102 can seal the part of the cable 3 extending out of the encapsulation layer 1, thereby improving the sealing performance between the encapsulation layer 1 and the cable 3, and further improving the overall sealing performance of the heating pad.

[0051] The cable 3 is led out from the side of the heating pad, and the first protruding part 112, the second protruding part 132, the cable 3, and the wrapping layer 2 wrapping the cable 3 are welded by high-frequency pressing to form a multi-layer sealing structure, improving the sealing and waterproof effect.

[0052] The protruding part 1102 is provided with a plurality of sealing rings 12, and the sealing rings 12 are uniformly arranged along the axial direction of the cable 3 on the protruding part 1102. The sealing rings 12 can further improve the sealing performance of the protruding part 1102 to the cable 3. The welding mold 4 is provided with a plurality of protrusions, and the plurality of protrusions surround the cable 3 for one week, and an annular groove is formed between two adjacent protrusions. When high-frequency welding is performed on the encapsulation layer 1, the welding mold 4 presses the first protruding part 112 and the second protruding part 132, and the protrusions squeeze the protruding part 1102, so that the protruding part 1102 and the wrapping layer 2 at the corresponding position are deformed to form a dense sealing ring 12 in the annular groove, thereby improving the sealing performance of the protruding part 1102 to the cable 3. The protrusions include a first protrusion 412 and a second protrusion 422. The sealing ring 12 makes the connection between the encapsulation layer 1 and the cable 3 more reliable, and the cable 3 is not easy to slide relative to the encapsulation layer 1, improving the firmness of the overall structure of the heating pad; on the other hand, after the wrapping layer 2 wrapped around the cable 3 is extruded in a molten state, it will gather at the sealing ring 12 to form a dense layer, thereby greatly improving the waterproof performance.

[0053] In some embodiments, the first encapsulation part 1011 and the second encapsulation part 11 are made of the same material, the third encapsulation part 1021 and the fourth encapsulation part 13 are made of the same material, and the first encapsulation layer 101 and the second encapsulation layer 102 are made of the same material. With such a setting, when the first encapsulation layer 101 is manufactured, the first encapsulation part 1011 and the second encapsulation part 11 can be better connected, especially when the first encapsulation part 1011 and the second encapsulation part 11 are integrally formed. When the second encapsulation layer 102 is manufactured, the third encapsulation part 1021 and the fourth encapsulation part 13 can be better connected, especially when the third encapsulation part 1021 and the fourth encapsulation part 13 are integrally formed. When high-frequency welding is performed, the first encapsulation layer 101 and the second encapsulation layer 102 can be better welded.

[0054] In some embodiments, the first encapsulation part 1011, the second encapsulation part 11, the third encapsulation part 1021, and the fourth encapsulation part 13 are all polyvinyl chloride rubber, which is a thermoplastic elastomer material mainly composed of polyvinyl chloride. It combines the characteristics of plastics and rubbers and exhibits unique physical and chemical properties. Polyvinyl chloride rubber has good elasticity and flexibility, and at the same time has high tensile strength and wear resistance. In addition, it also has excellent weather resistance, chemical corrosion resistance, and waterproofness. The first encapsulation part 1011, the second encapsulation part 11, the third encapsulation part 1021, and the fourth encapsulation part 13 are of the same type of material as the commonly used polyvinyl chloride rubber for the cable 3. The welding of polyvinyl chloride rubber materials is generally achieved by using a high-frequency welding machine, and its principle is: by utilizing the increased polarity of the polyvinyl chloride molecular structure, applying a high-frequency alternating magnetic field to generate heat by internal friction until it melts.

[0055] Exemplarily, due to the possible differences in the manufacturers and formulations of polyvinyl chloride rubber, there are significant differences in its thickness. It often occurs that the polyvinyl chloride rubber material of the encapsulation layer 1 melts, but the polyvinyl chloride rubber material of the cable 3 does not melt. Or, the polyvinyl chloride rubber material of the cable 3 melts, and the polyvinyl chloride rubber material of the encapsulation layer 1 has been scalded and damaged. Therefore, at least one wrapping layer 2 is wrapped between the encapsulation layer 1 and the cable 3 as a transition. The wrapping layer 2 is made of polyvinyl chloride rubber, and the thickness of the polyvinyl chloride rubber of the wrapping layer 2 is lower than that of the polyvinyl chloride rubber of the encapsulation layer 1. When wrapping, pull forcefully to extend the length of the wrapping layer 2 to more than twice the starting length, making the wrapping layer 2 thinner, and then wind it around the cable 3 for 1 - 3 turns to form the wrapping layer 2. In a high-frequency environment, the polyvinyl chloride molecules in the polyvinyl chloride rubber film of the wrapping layer 2 generate intense molecular friction. Under the action of the pre-tension, it melts first and penetrates into the gaps at all corners of the interlayer, achieving a perfect sealing effect. The thickness of the wrapping layer 2 is less than that of the polyvinyl chloride rubber layers of the encapsulation layer 1 and the cable 3. In this way, when the polyvinyl chloride rubber of the wrapping layer 2 penetrates into the gaps at all corners of the interlayer, the polyvinyl chloride rubber materials of the encapsulation layer 1 and the cable 3 will not be scalded and damaged.

[0056] Exemplarily, the encapsulation layer 1 uses a polyvinyl chloride rubber film, and the manufacturer is Changzhou Wujin Baixing Plastic Products Co., Ltd. The model of the encapsulation layer 1 is 580 mm in width, 0.40 mm in thickness, and yellow cloth texture. The material of the encapsulation layer 1 is polyvinyl chloride rubber. The manufacturer of the cable 3 is Ningbo Qiuguan Cable Co., Ltd., and the model of the cable 3 is a 2 * 2.5 square millimeter RVV cable 3. The manufacturer of the wrapping layer 2 is Dongguan Changkai Leather and Plastic Products Co., Ltd. The wrapping layer 2 is a polyvinyl chloride transparent film, and the thickness of the wrapping layer 2 is 0.08 mm; the graphene heating film used by the heating element is a customized graphene heating film produced by Ningbo Xicai Warm Technology Co., Ltd.

[0057] In some embodiments, the first encapsulation part 1011 and the second encapsulation part 11 are integrally formed, so that the first encapsulation part 1011 and the second encapsulation part 11 can be tightly connected. The third encapsulation part 1021 and the fourth encapsulation part 13 are integrally formed, so that the third encapsulation part 1021 and the fourth encapsulation part 13 can be tightly connected.

[0058] As shown in the appendix Figures 4-6As shown in the figure, the present invention provides a welding mold 4, which includes a first mold 41 and a second mold 42. The welding mold 4 is used for high-frequency welding of the heating pad described in any one of the above. When performing high-frequency welding on the heating pad, the heating pad is placed on the first mold 41, and the second mold 42 approaches the first mold 41 until the first encapsulation layer 101 and the second encapsulation layer 102 of the heating pad are pre-compressed. Then, the pre-compressed first encapsulation layer 101, second encapsulation layer 102, and the wrapping layer 2 are welded. That is, while the first mold 41 and the second mold 42 apply pressure to the encapsulation layer 1, high-frequency welding is performed to achieve the sealing between the encapsulation layer 1 and the cable 3, thereby improving the overall sealing performance of the heating pad.

[0059] As shown in the Figures 5-6 attached figure, in some embodiments, the first mold 41 is provided with a first welding groove 411, which is used to accommodate the first protruding part 112 of the heating pad, and a plurality of first protrusions 412 are evenly arranged in the first welding groove 411. The second mold 42 is provided with a second welding groove 421, which is used to accommodate the second protruding part 132 of the heating pad, and a plurality of second protrusions 422 are evenly arranged in the second welding groove 421. When the first mold 41 and the second mold 42 are in contact, the first protrusions 412 and the second protrusions 422 are joined to form an annular protrusion. An annular groove (not marked in the figure) is formed between two adjacent annular protrusions. When performing high-frequency welding on the encapsulation layer 1, the welding mold 4 compresses the first protruding part 112 and the second protruding part 132, and the annular protrusion squeezes the protruding part 1102, causing the protruding part 1102 to deform to form a dense sealing ring 12 in the annular groove, thereby improving the sealing performance of the protruding part 1102 to the cable 3.

[0060] Encapsulation method of heating pad

[0061] The present invention also provides a method for encapsulating a heating pad. The detailed structure and features of the heating pad have been described above and will not be elaborated here. Here, the improvements of the encapsulation method described in this article will be mainly described.

[0062] In a specific embodiment, the method for encapsulating the heating pad described in this article includes:

[0063] Step S1: Provide a welding mold 4, where the welding mold 4 includes a first mold 41 and a second mold 42, and a hollow welding cavity is formed when the first mold 41 and the second mold 42 are in contact;

[0064] Step S2: Place the heating pad wiring structure to be encapsulated in the welding cavity, apply pressure and high frequency to the heating pad wiring structure until the heating pad wiring structure forms a sealed structure. In a specific embodiment, the heating pad wiring structure includes: a cable 3, one end of the cable is connected to the heating element, and the other end extends a certain distance along the direction away from the heating pad; a wrapping layer 2, the wrapping layer 2 is wound around the outer periphery of the cable 3, one end of the wrapping layer 2 is close to the heating element, and the other end extends a first length along the direction away from the heating pad; an encapsulation layer 1, the encapsulation layer 1 is wound around the outer periphery of the wrapping layer 2, one end of the encapsulation layer 1 seals the heating element, and the other end extends a second length along the direction away from the heating pad. In a specific embodiment, the first length is less than or equal to the second length.

[0065] In a specific embodiment, in step S2, the applied pressure is 20 - 100 kg; the high frequency heating time is 3 - 8 seconds, and the cooling and holding time is 10 seconds. In this embodiment, the cooling and holding time refers to the time when the welding mold cools down. If the pressure of the welding mold is released at a relatively high temperature, it will cause the adhesion between the welding mold and the PVC film, so it is necessary to wait for the welding mold to cool down before releasing. In addition, in this embodiment, high frequency is generated by energization, and the energization current range is 5 - 10 A.

[0066] Another innovation point of the encapsulation method of the present application is to form the wrapping layer 2 on the cable 3 by the following method: stretch the PVC rubber film to more than twice its initial length, and then wind it around the cable 3 for 1 - 3 turns. The wrapping layer 2 is a very thin PVC film with ductility. After stretching, it is wound on the surface of the inner cable 3, while the first encapsulation layer 101 and the second encapsulation layer 102 are still flat PVC films at this time. The welding cavity of the welding mold 4 for high frequency welding is circular. It will first clamp the first encapsulation layer 101 and the second encapsulation layer 102 up and down to make the encapsulation layer 1 PVC film form a circle, and then energize to generate high frequency, so that the molecules of all PVC materials start to vibrate, generate heat through molecular self-vibration and self-friction, and then melt themselves. Due to the stretching effect, the randomly arranged PVC molecules in the wrapping layer 2 become oriented to a certain extent, will be more affected by high frequency, generate more heat, and because it is thinner itself, it will melt earlier.

[0067] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for packaging a heating pad, the heating pad comprising a heating body, characterized in that: The packaging method of the heating pad comprises: Step S1: providing a welding mold, wherein the welding mold comprises a first mold and a second mold, wherein the first mold and the second mold are abutted to form a hollow welding mold cavity; Step S2: placing the heating pad wiring structure to be packaged in the welding cavity, applying pressure and high frequency to the heating pad wiring structure until the heating pad wiring structure forms a sealing structure; Wherein, the heating pad wiring structure comprises: An electric cable, one end of which is connected to the heating body, and the other end of which extends a certain distance away from the heating pad; A wrapping layer, the wrapping layer is wound around the outer circumference of the cable, one end of the wrapping layer is close to the heating body, and the other end of the wrapping layer extends a first length in a direction away from the heating pad; The encapsulation layer is arranged around the outer periphery of the wrapping layer, one end of the encapsulation layer seals the heating body, and the other end of the encapsulation layer extends a second length in a direction away from the heating pad.

2. The packaging method of the heating pad according to claim 1, characterized in that: The first length is less than or equal to the second length.

3. The packaging method of the heating pad according to claim 1, characterized in that: The first mold is provided with a first welding groove, and a plurality of evenly arranged first protrusions are provided in the first welding groove; The second mold is provided with a second welding groove, and a plurality of evenly arranged second protrusions are provided in the second welding groove; When the first mold abuts against the second mold, the first protrusion and the second protrusion are connected to form an annular protrusion.

4. The packaging method of the heating pad according to any one of claims 1 to 3, characterized in that: In step S2, the applied pressure is 20-100 kg; the high frequency heating time is 3-8 seconds, and the cooling time is 5-20 seconds.

5. The packaging method of the heating pad according to any one of claims 1 to 3, characterized in that: In step S2, a high frequency is generated by energizing, and the energizing current range is 5-10A.

6. The packaging method of the heating pad according to any one of claims 1 to 3, characterized in that: The wrapping layer is formed by the following method: The polyvinyl chloride rubber film is stretched to more than twice its original length and then wrapped around the cable wire for 1 to 3 times.

7. The packaging method of the heating pad according to any one of claims 1 to 3, characterized in that: The encapsulation layer comprises a first encapsulation layer and a second encapsulation layer connected to each other, the first encapsulation layer comprises a first encapsulation portion and a second encapsulation portion connected to each other, and the cross section of the second encapsulation portion is an arc; The second packaging layer includes a third packaging part and a fourth packaging part which are connected. The cross section of the fourth packaging part is arc-shaped. When the second packaging part and the fourth packaging part are sealed and connected, they are used to accommodate the cable with the wrapping layer.

8. The packaging method of the heating pad according to claim 7, characterized in that: The thickness of the wrapping layer is smaller than the thickness of the second encapsulation part or the fourth encapsulation part.

9. The packaging method of the heating pad according to claim 8, characterized in that: The thickness of the wrapping layer is 5% to 25% of the smaller thickness of the second packaging part or the fourth packaging part.

10. The packaging method of the heating pad according to claim 9, characterized in that: The thickness of the wrapping layer is 10% to 20% of the smaller thickness of the second encapsulation part or the fourth encapsulation part.

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