Far infrared physiotherapy card and preparation method thereof

Abstract

This invention discloses a far-infrared therapy card and its manufacturing method, comprising a far-infrared ceramic sheet and an encapsulation layer covering the outside of the far-infrared ceramic sheet; the encapsulation layer is made of thermoplastic elastomer, and the surface of the encapsulation layer has multiple mesh openings; the far-infrared ceramic sheet is made of the following raw materials by weight percentage: 30%~40% aluminum oxide, 25%~30% silicon dioxide, 5%~15% zinc oxide, 5%~15% titanium dioxide, 2%~8% zirconium dioxide, 1%~3% graphene oxide, 2%~5% borate sintering aid, and 5%~15% high-hardness ceramic additive; the high-hardness ceramic additive is selected from one or more of silicon carbide micro powder, boron nitride fiber, and hydroxyapatite, which solves the problems of easy cracking, low density, and poor far-infrared emission performance of existing far-infrared ceramic sheets.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular relates to a far-infrared physiotherapy card and its preparation method. Background Technology

[0002] Far-infrared therapy relies on the thermal and non-thermal effects of far-infrared rays on the human body to promote local blood circulation, accelerate cell metabolism, and aid in soft tissue repair. It is currently a widely used physical therapy method. The conventional method for commercially available far-infrared therapy cards involves simply mixing powders of silicon dioxide, aluminum oxide, zinc oxide, titanium dioxide, and zirconium dioxide, unidirectionally pressing them into shape, and then sintering them in a resistance furnace at 1200-1300℃ for 4 hours to prepare a ceramic sheet. Finally, the sheet is encapsulated within PVC material.

[0003] Existing technologies have several inherent drawbacks: First, the high proportion of glass phase in the ceramic formula results in brittle materials with low compressive strength and numerous micropores after sintering, making them prone to cracking and splitting. Second, traditional resistance furnaces use external heating, leading to slow heating, long holding times, high sintering temperatures, and extremely high energy consumption, resulting in low production efficiency. Third, unidirectional pressing causes uneven pressure distribution and significant density differences in the green body, easily generating internal stress after sintering and further increasing the risk of breakage. Fourth, the green body is only simply dried without fully removing moisture and organic binders, making it prone to forming pores and cracks during high-temperature sintering. Fifth, the ceramic composition is not optimized for the optimal absorption band of 4-14μm for the human body, resulting in a low effective far-infrared emissivity. Finally, the PVC encapsulation material is hard, has poor breathability, and prolonged close contact with the skin can easily cause redness and itching; its sharp edges also pose a risk of scratching, resulting in insufficient comfort and safety.

[0004] Therefore, there is an urgent need to design a far-infrared therapy card and its preparation method to solve the problems mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide a far-infrared therapy card and its preparation method, which solves the problems of existing far-infrared ceramic sheets being prone to cracking, having low density, and poor far-infrared emission performance.

[0006] To achieve the above objectives, the specific technical solution of the far-infrared therapy card and its preparation method of the present invention is as follows: A far-infrared therapy card includes: a far-infrared ceramic sheet; and an encapsulation layer covering the outside of the far-infrared ceramic sheet; the encapsulation layer is made of thermoplastic elastomer, and the surface of the encapsulation layer has multiple mesh openings; the far-infrared ceramic sheet is made of the following raw materials in weight percentages: 30%~40% aluminum oxide, 25%~30% silicon dioxide, 5%~15% zinc oxide, 5%~15% titanium dioxide, 2%~8% zirconium dioxide, 1%~3% graphene oxide, 2%~5% borate sintering aid, and 5%~15% high-hardness ceramic additive; the high-hardness ceramic additive is selected from one or more of silicon carbide micro powder, boron nitride fiber, and hydroxyapatite.

[0007] Furthermore, the high-hardness ceramic additive is silicon carbide micro powder, the particle size of which is 50~100nm and the weight percentage is 8%.

[0008] Furthermore, the borate sintering aid is zinc borate or borax.

[0009] Furthermore, the thermoplastic elastomer is polyester rubber.

[0010] Furthermore, the mesh is a through hole, the diameter of the through hole is 1~3mm, the spacing between the through holes is 5~8mm, and the total area of ​​the mesh accounts for 30%~40% of the surface area of ​​the encapsulation layer.

[0011] A method for preparing a far-infrared therapy card includes the following steps: S1. Weigh out aluminum oxide, silicon dioxide, zinc oxide, titanium dioxide, zirconium dioxide, graphene oxide, borate sintering aid and high-hardness ceramic additive by weight percentage and mix them evenly to obtain a mixed powder. S2. The mixed powder is subjected to isostatic pressing to obtain a ceramic green body; S3. The ceramic green body is subjected to microwave drying and low-temperature pre-firing to obtain a pre-treated ceramic green body. S4. Microwave sinter the pretreated ceramic green body to obtain far-infrared ceramic sheets. S5: Place the far-infrared ceramic sheet in an injection mold, inject thermoplastic elastomer for insert injection molding, and obtain a far-infrared therapy card with a mesh surface.

[0012] Furthermore, in step S2, the isostatic pressing is a bidirectional isostatic pressing, and the molding pressure of the bidirectional isostatic pressing is 200~300MPa.

[0013] Furthermore, in step S3, the microwave drying temperature is 50~70℃ and the time is 20~40 minutes; the low-temperature preheating temperature is 250~350℃ and the time is 0.5~1.5 hours.

[0014] Furthermore, in step S4, the sintering temperature of the microwave sintering is 950~1050℃, and the sintering time is 40~60 minutes.

[0015] Furthermore, in step S4, the microwave sintering employs a segmented sintering process: Heating section: The temperature is increased to the sintering temperature at a rate of 3~8℃ / min; Insulation section: Hold at the sintering temperature for 40-60 minutes; Cooling section: Cool to room temperature at a rate of 2~5℃ / min.

[0016] The far-infrared therapy card and its preparation method of the present invention have the following advantages: The present invention reduces the brittleness of ceramics from the source by increasing the proportion of alumina corundum phase and reducing the content of silica glass phase; combined with graphene oxide, the far-infrared emission band is precisely controlled to the 4~14μm range that is easily absorbed by the human body, which greatly improves the effective emissivity; the introduction of high-hardness ceramic additives such as silicon carbide can fill the micropores inside the ceramic, significantly improve the density and compressive strength of the ceramic sheet, and completely eliminate the problems of cracking and breakage. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the front structure of the far-infrared therapy card of the present invention; Figure 2 This is a schematic diagram of the reverse side structure of the far-infrared therapy card of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0020] The following is a reference to the appendix. Figure 1 To be continued Figure 2 This invention describes a far-infrared physiotherapy card and its preparation method.

[0021] like Figure 1 and Figure 2 As shown, a far-infrared therapy card includes: a far-infrared ceramic sheet; and an encapsulation layer, the encapsulation layer covering the outside of the far-infrared ceramic sheet; the encapsulation layer is made of thermoplastic elastomer, and the surface of the encapsulation layer has multiple mesh openings; the far-infrared ceramic sheet is made of the following raw materials in weight percentages: 30%~40% aluminum oxide, 25%~30% silicon dioxide, 5%~15% zinc oxide, 5%~15% titanium dioxide, 2%~8% zirconium dioxide, 1%~3% graphene oxide, 2%~5% borate sintering aid, and 5%~15% high-hardness ceramic additive; the high-hardness ceramic additive is selected from one or more of silicon carbide micro powder, boron nitride fiber, and hydroxyapatite.

[0022] In this embodiment, by increasing the proportion of alumina corundum phase and reducing the content of silica glass phase, the brittleness of ceramics is reduced from the root. By combining graphene oxide, the far-infrared emission band is precisely controlled to the 4~14μm range that is easily absorbed by the human body, which greatly improves the effective emissivity. The introduction of high-hardness ceramic additives such as silicon carbide can fill the micropores inside the ceramic, significantly improve the density and compressive strength of the ceramic sheet, and completely eliminate the problems of cracking and breakage.

[0023] Preferably, the composition is 35% aluminum oxide, 28% silicon dioxide, 10% zinc oxide, 10% titanium dioxide, 5% zirconium dioxide, 2% graphene oxide, 3% zinc borate, and 7% silicon carbide micropowder; the particle size of the silicon carbide micropowder is controlled at 50~100nm. Alumina, as the main source of the corundum phase, provides a high-hardness and high-strength structural framework; silica is controlled within the preferred range of 25%~30% to avoid excessive glass phase leading to increased brittleness; graphene oxide achieves far-infrared emission wavelengths precisely concentrated in the range of 4~14μm, increasing emissivity to 0.92; it also improves thermal conductivity uniformity; zinc borate, as a sintering aid, forms a low-melting-point liquid phase during sintering, promoting particle rearrangement and densification, thus lowering the sintering temperature to below 1000℃; silicon carbide micropowder, as a high-hardness nano-agent, has unique mechanisms of action including: pore-filling effect (filling the micropores between corundum phase particles), strength-enhancing effect (silicon carbide has a Mohs hardness of 9.5 and is distributed in the ceramic matrix as a reinforcing phase), and thermal conductivity synergistic effect (synergistically improving temperature distribution uniformity with graphene oxide); the above raw materials are placed in a ball mill for wet ball milling with anhydrous ethanol as the milling medium for 12 hours to ensure thorough and uniform mixing of the components, resulting in a mixed slurry with uniform particle size. The slurry is dried and sieved (400 mesh) to obtain ceramic powder with uniform particle size.

[0024] Furthermore, the high-hardness ceramic additive is silicon carbide micro powder, the particle size of which is 50~100nm and the weight percentage is 8%.

[0025] Furthermore, the borate sintering aid is zinc borate or borax.

[0026] Furthermore, the thermoplastic elastomer is polyester rubber.

[0027] In this embodiment, traditional rigid PVC materials are abandoned, and a polyester rubber thermoplastic elastomer is used as the encapsulation layer, which is soft and skin-friendly. With a large proportion of through-hole mesh structure, it has excellent breathability and can quickly wick away sweat and moisture. There are no skin redness or itching problems even after long-term wear. With the conventional rounded corner design, the risk of scratches is eliminated, making it suitable for all-day close-fitting physical therapy use.

[0028] Furthermore, the mesh is a through hole, the diameter of the through hole is 1~3mm, the spacing between the through holes is 5~8mm, and the total area of ​​the mesh accounts for 30%~40% of the surface area of ​​the encapsulation layer.

[0029] Preferably, the encapsulation layer is made of polyester rubber, with circular through-holes on the surface. The hole diameter is 2mm, the hole spacing is 6mm, and the total area of ​​the mesh accounts for 35% of the surface area of ​​the encapsulation layer.

[0030] A method for preparing a far-infrared therapy card includes the following steps: S1. Weigh out aluminum oxide, silicon dioxide, zinc oxide, titanium dioxide, zirconium dioxide, graphene oxide, borate sintering aid, and high-hardness ceramic additive by weight percentage and mix them evenly to obtain a mixed powder. Specifically, wet ball milling can be used to assist dispersion to ensure uniform distribution of nano-sized silicon carbide powder and graphene oxide. S2. The mixed powder is subjected to isostatic pressing to obtain a ceramic green body; S3. The ceramic green body is subjected to microwave drying and low-temperature pre-firing to obtain a pre-treated ceramic green body. S4. Microwave sinter the pretreated ceramic green body to obtain far-infrared ceramic sheets. S5: Place the far-infrared ceramic sheet in an injection mold, inject thermoplastic elastomer for insert injection molding, and obtain a far-infrared therapy card with a mesh surface.

[0031] Specifically, the rough edges of the far-infrared therapy card are trimmed, and the appearance inspection and far-infrared emission performance inspection are completed. If the inspection is qualified, it is a finished product.

[0032] Furthermore, in step S2, the isostatic pressing is a bidirectional isostatic pressing, and the molding pressure of the bidirectional isostatic pressing is 200~300MPa.

[0033] Preferably, the mixed powder is loaded into a flexible mold and formed by bidirectional isostatic pressing at 250MPa. After pressure holding and shaping, a ceramic green body with uniform density is obtained. In this embodiment, bidirectional isostatic pressing is used to ensure uniform stress in all directions of the blank and good density consistency. Combined with microwave drying and low-temperature pre-firing pretreatment, residual moisture and organic impurities in the blank are completely removed, avoiding the generation of pores and cracks during sintering and improving product yield.

[0034] Specifically, in bidirectional isostatic pressing, the prepared ceramic powder is loaded into a flexible mold and placed inside an isostatic pressing machine. The pressing pressure is set to 280 MPa, a bidirectional pressing method is used, and the holding time is 60 seconds. Isostatic pressing ensures that the powder is subjected to uniform pressure in all directions, resulting in a ceramic green body with uniform density and isotropic properties, effectively avoiding the density gradient problem caused by uneven pressure distribution in traditional unidirectional pressing.

[0035] Furthermore, in step S3, the microwave drying temperature is 50~70℃ and the time is 20~40 minutes; the low-temperature preheating temperature is 250~350℃ and the time is 0.5~1.5 hours.

[0036] Preferably, the ceramic green body is pretreated by microwave drying at 60°C for 30 minutes to remove free moisture; then pre-fired at 300°C for 1 hour to completely remove organic binder and crystal water, thus obtaining the pretreated ceramic green body.

[0037] Specifically, the formed green body is placed in a microwave drying oven and microwave-dried at 60°C for 30 minutes to remove free moisture. Then, the dried green body is placed in a resistance furnace and pre-fired at 300°C with a heating rate of 2°C / min for 1 hour to thoroughly remove organic binders and water of crystallization. This pretreatment step effectively avoids porosity and cracks caused by the rapid evaporation of moisture and organic matter during subsequent high-temperature sintering.

[0038] Furthermore, in step S4, the sintering temperature of the microwave sintering is 950~1050℃, and the sintering time is 40~60 minutes.

[0039] In this embodiment, by relying on borate sintering aid in conjunction with microwave internal heating sintering, the traditional high temperature of 1200~1300℃ is reduced to 950~1050℃, and the sintering time is reduced from 4 hours to 40~60 minutes, which greatly reduces production energy consumption, improves production efficiency, and meets the needs of green manufacturing.

[0040] Furthermore, in step S4, the microwave sintering employs a segmented sintering process: Heating section: The temperature is increased to the sintering temperature at a rate of 3~8℃ / min; Insulation section: Hold at the sintering temperature for 40-60 minutes; Cooling section: Cool to room temperature at a rate of 2~5℃ / min.

[0041] Preferably, microwave segmented sintering is used: the temperature is increased to 1000℃ at a rate of 5℃ / min and held for 50min to fully densify the ceramic; then the temperature is slowly reduced to room temperature at a rate of 3℃ / min. After cooling, a high-density, high-strength far-infrared ceramic sheet is obtained, avoiding internal stress cracking caused by rapid cooling.

[0042] Specifically, microwaves cause the ceramic component molecules to resonate and heat up through "internal heating," avoiding the heat conduction losses of traditional "external heating." Rapid heating reduces grain growth and increases the density of the ceramic. Zinc borate sintering aid forms a low-melting-point liquid phase during sintering, promoting particle rearrangement and densification, and working synergistically with microwave sintering to achieve low-temperature rapid densification. Silicon carbide nanoparticles migrate to the micropores between corundum phase particles through capillary action during sintering, and form a strong interfacial bond in the later stage of sintering, effectively filling the pores and further increasing the density. The slow heating and cooling rates in the segmented sintering process effectively control thermal stress and prevent cracking.

[0043] The sintered far-infrared ceramic sheet is placed into a thermoplastic elastomer (polyester rubber) injection mold. Medical-grade thermoplastic polyester elastomer is used as the injection material, as it possesses excellent flexibility, aging resistance, and biocompatibility. After injection molding, the ceramic sheet is completely encapsulated within the card, contacting the human body only through the thermoplastic elastomer.

[0044] The card features rounded corners and a thickness of 2.5mm. Multiple through-hole oval or circular mesh openings are created on both sides of the card using a mold design. The major axis of each mesh opening is 3mm, the minor axis is 2mm, and the spacing between the openings is 6mm. The total area of ​​the mesh openings accounts for 30% to 40% of the card's surface area, ensuring free airflow and effectively wicking away sweat and moisture.

[0045] The present invention will be further illustrated by specific embodiments below, but these embodiments do not limit the scope of protection of the present invention.

[0046] Example Far-infrared ceramic raw materials (containing graphene oxide, borate sintering aid, and high-hardness ceramic additives) were weighed according to the optimized ratio, mixed, ball-milled, dried, and sieved to obtain uniform powder. A biaxial isostatic pressing process of 200-300 MPa was used to obtain a green body with uniform density. The green body was microwave-dried at 60℃ for 30 minutes and pre-fired at 300℃ for 1 hour to remove moisture and organic binders. The green body was placed in a 2.45 GHz microwave sintering furnace and sintered using a segmented process (heating 5℃ / min → holding for 40-50 minutes → cooling 3℃ / min) at a sintering temperature of 950-1050℃ to obtain ceramic sheets with high density (≥98%) and high strength (≥220 N). The ceramic sheets were then placed as inserts into an injection mold, and thermoplastic elastomer was injected to form a mesh-like therapeutic card. The rough edges were trimmed, and the appearance and far-infrared emission performance were tested. After passing the tests, the card was packaged and stored.

[0047] Comparative Example Cut plastic cards to a length of 80mm, a width of 54mm, and a thickness of 0.78mm. Ensure the card edges are burr-free and both sides are smooth. Set aside. Weigh out 300g of silicon dioxide, 500g of aluminum oxide, 100g of zinc oxide, and 100g of titanium oxide, mix them, and activate them at a high temperature of 1000-1200℃ for 8 hours. Then grind the mixture into a fine powder with a fineness of 3 microns, and dry it again at 200℃ to make the powder uniform and white, thus creating a bio-far-infrared functional ceramic material. Mix 1000g of this bio-far-infrared functional ceramic material with 4000g of printing pigment. Use screen printing to print the pigment containing the bio-far-infrared functional ceramic material onto the back of the cards, ensuring that each card's printed layer contains between 50g and 80g of far-infrared functional ceramic material. Finally, seal with plastic film to create a card with a bio-far-infrared functional ceramic material layer on one side.

[0048] Performance comparison tests were conducted on the embodiments and comparative examples, and the results are shown in Table 1.

[0049] Table 1 shows the performance comparison test results of the embodiments and comparative examples. As can be seen from the comparative data in Table 1, this invention has achieved significant breakthroughs in three dimensions: material properties, functional effects, and process indicators. Compressive strength increased from 85N to 225N, density increased from 88% to 98.5%, and porosity decreased from 12% to 1.5%, mainly due to the increased proportion of alumina corundum phase and the effective filling of micropores by silicon carbide nanoparticles. Far-infrared emissivity increased from 0.78 to 0.94 (+20.5%), and surface temperature difference decreased from ≥8℃ to ≤1.0℃, attributed to the resonance effect of graphene oxide and its synergistic thermal conductivity with silicon carbide. Sintering temperature decreased from 1250℃ to 1000℃, sintering time was shortened from 4 hours to 45 minutes, and power consumption decreased by 72%, stemming from the synergistic effect of the low-temperature liquid-phase sintering mechanism of borate sintering aid and the microwave "internal heating" process. These data collectively demonstrate that the various technical features of this invention are not simply additive, but rather achieved through the synergistic effect of component optimization and process innovation, resulting in a comprehensive improvement in structural strength, therapeutic performance, and production efficiency.

[0050] Twenty volunteers were recruited. Ten volunteers wore the product of the example embodiment for 8 hours continuously, and ten volunteers wore the product of the comparative embodiment for 8 hours continuously. None of the volunteers using the product of the example embodiment experienced skin redness, itching, or other discomfort; however, eight of the volunteers using the product of the comparative embodiment experienced varying degrees of skin redness and itching. The test results indicate that using a thermoplastic elastomer encapsulation layer and a mesh structure effectively solves the problem of skin discomfort from prolonged wear.

[0051] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A far infrared physiotherapy card, characterized in that, include: Far-infrared ceramic sheet; And an encapsulation layer, which covers the outside of the far-infrared ceramic sheet; The encapsulation layer is made of thermoplastic elastomer, and the surface of the encapsulation layer has multiple mesh openings; The far-infrared ceramic sheet is made from the following raw materials by weight percentage: 30%~40% aluminum oxide, 25%~30% silicon dioxide, 5%~15% zinc oxide, 5%~15% titanium dioxide, 2%~8% zirconium dioxide, 1%~3% graphene oxide, 2%~5% borate sintering aid, and 5%~15% high-hardness ceramic additives; The high-hardness ceramic additive is selected from one or more of silicon carbide micro powder, boron nitride fiber, and hydroxyapatite.

2. The far infrared physiotherapy card according to claim 1, wherein, The high-hardness ceramic additive is silicon carbide micro powder, the particle size of which is 50~100nm and the weight percentage is 8%.

3. The far infrared physiotherapy card according to claim 1, wherein The borate sintering aid is zinc borate or borax.

4. The far-infrared therapy card according to claim 1, characterized in that, The thermoplastic elastomer is polyester rubber.

5. The far-infrared therapy card according to claim 1, characterized in that, The mesh is a through hole with a diameter of 1-3 mm and a spacing of 5-8 mm. The total area of ​​the mesh accounts for 30%-40% of the surface area of ​​the encapsulation layer.

6. A method for preparing a far-infrared therapy card as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Weigh out aluminum oxide, silicon dioxide, zinc oxide, titanium dioxide, zirconium dioxide, graphene oxide, borate sintering aid and high-hardness ceramic additive by weight percentage and mix them evenly to obtain a mixed powder. S2. The mixed powder is subjected to isostatic pressing to obtain a ceramic green body; S3. The ceramic green body is subjected to microwave drying and low-temperature pre-firing to obtain a pre-treated ceramic green body. S4. Microwave sinter the pretreated ceramic green body to obtain far-infrared ceramic sheets. S5: Place the far-infrared ceramic sheet in an injection mold, inject thermoplastic elastomer for insert injection molding, and obtain a far-infrared therapy card with a mesh surface.

7. The method for preparing the far-infrared therapy card according to claim 6, characterized in that, In step S2, the isostatic pressing is a bidirectional isostatic pressing, and the molding pressure of the bidirectional isostatic pressing is 200~300MPa.

8. The method for preparing the far-infrared therapy card according to claim 6, characterized in that, In step S3, the microwave drying temperature is 50~70℃ and the time is 20~40 minutes; the low-temperature preheating temperature is 250~350℃ and the time is 0.5~1.5 hours.

9. The method for preparing the far-infrared therapy card according to claim 6, characterized in that, In step S4, the sintering temperature of the microwave sintering is 950~1050℃, and the sintering time is 40~60 minutes.

10. The method for preparing the far-infrared therapy card according to claim 6 or 9, characterized in that, In step S4, the microwave sintering adopts a segmented sintering process: Heating section: The temperature is increased to the sintering temperature at a rate of 3~8℃ / min; Insulation section: Hold at the sintering temperature for 40-60 minutes; Cooling section: Cool to room temperature at a rate of 2~5℃ / min.

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