Pressure-bearing foam material preparation process, shock-absorbing energy storage component and shoe sole

Abstract

The application discloses a kind of pressure-bearing foamed material preparation process, comprising the following steps: S1, the material to be foamed is placed into reaction kettle, and gas is introduced into the reaction kettle, temperature and pressure are raised, so that the gas reaches supercritical state to impregnate the material to be foamed, and reaches saturation state;S2, quickly depressurize to set pressure state, the material to be foamed is foamed into intermediate stage foamed material, and a film material is added to coat the intermediate stage foamed material to form a closed film on its outer surface;The gas pressure of the set pressure state is greater than atmospheric pressure;S3, continue to depressurize until the gas pressure in the reaction kettle is the same as atmospheric pressure, and the foamed material is shaped, to obtain a pressure-bearing foamed material.The pressure-bearing foamed material prepared has high compression and rebound performance, good cushioning and shock absorption effect and good energy return effect.Based on this, the application further discloses a cushioning and energy storage component and a sole, both of which have excellent rebound performance, good cushioning and shock absorption effect and good energy return effect.

Description

Technical Field

[0001] The present invention relates to the technical field of soles, and in particular to a preparation process of a pressure-bearing foam material, a shock-absorbing energy storage component and a sole. Background Art

[0002] Polymer foam refers to a microporous material based on a polymer (plastic, rubber, elastomer, or natural polymer) containing countless bubbles. It can also be considered a composite material with a gas filler. The combination of bubbles and the polymer matrix gives polymer foam advantages such as lightweight, thermal insulation, and energy absorption, making it widely used in various fields such as construction, cushioning packaging, furniture, transportation, and shoemaking.

[0003] Taking the field of sole technology as an example, many existing soles use polymer foam materials. As an important component that provides cushioning protection during human movement, the sole can deform when the human foot lands to absorb the impact of the ground, preventing the human body from being subjected to excessive impact and causing sports injuries. At the same time, the sole will also convert the human body's kinetic energy into the elastic potential energy of the material during deformation. When the foot pushes off the ground, the elastic potential energy stored in the material is returned to the human body through the rebound of the material, thereby saving energy consumption during human movement and improving the human body's athletic ability. Influenced by the characteristics of polymer foam materials, soles made of polymer foam materials have good rebound performance and have a good energy return effect when subjected to force. However, this type of sole lacks additional energy-absorbing structure, and the rebound performance and energy return effect still need to be improved.

[0004] In addition, when polymer foam materials are applied to the soles in the form of particles (such as popcorn soles), there is usually a certain amount of space between the particles. When compressed, the force is easily transmitted from the space and cannot be stored, which also affects the rebound performance of the soles. Summary of the Invention

[0005] The purpose of the present invention is to provide a process for preparing a pressure-bearing foam material to prepare a pressure-bearing foam material with better rebound performance, and also to provide a shock-absorbing energy storage component and a sole, which use the aforementioned pressure-bearing foam material, have excellent rebound performance, and better energy return effect when subjected to force.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A process for preparing a pressure-bearing foam material comprises the following steps:

[0008] S1. Place the material to be foamed into a reactor, introduce gas into the reactor, increase the temperature and pressure, so that the gas reaches a supercritical state to impregnate the material to be foamed and reach a saturated state;

[0009] S2, rapidly releasing the pressure to a set pressure state, the material to be foamed is foamed into an intermediate-stage foaming material, and a coating material is added to coat the intermediate-stage foaming material to form a closed film on its outer surface; the pressure of the set pressure state is greater than atmospheric pressure;

[0010] S3. Continue to release the pressure until the air pressure in the reactor is the same as the atmospheric pressure, foam and shape, and obtain a pressure-bearing foam material.

[0011] Furthermore, in step S2: the air pressure of the set pressure state is 1.2MPa-2MPa.

[0012] Furthermore, in step S2: the coating material is coated on the outer surface of the intermediate stage foaming material by dipping, spraying or brushing.

[0013] Furthermore, the reactor is provided with a liquid inlet, the coating material is heated to a molten state and introduced into the reactor from the liquid inlet to form a coating impregnation liquid, and the intermediate stage foaming material is immersed in the coating impregnation liquid, so that the coating impregnation liquid is evenly coated on the surface of the intermediate stage foaming material.

[0014] Furthermore, a spray port is provided in the reactor, and the coating material is heated to a molten state and enters the reactor through the spray port and is evenly sprayed onto the surface of the foaming material in the intermediate stage.

[0015] Furthermore, in step S2: the coating material is polyamide, polypropylene or polyurethane.

[0016] Preferably, the coating material is thermoplastic polyurethane.

[0017] Furthermore, the gas in step S1 is carbon dioxide. The specific process of step S1 is: placing the material to be foamed into a reactor, and heating the reactor to 110°C-130°C, then introducing carbon dioxide into the reactor until the pressure in the reactor reaches 25MPa-35MPa, and then allowing the carbon dioxide to circulate in the reactor. During the circulation process, the pressure in the reactor is maintained at 25MPa-35MPa. The circulating flow of carbon dioxide allows the material to be foamed to fully contact with the carbon dioxide, and then the internal temperature of the reactor is maintained at 50°C-100°C, the pressure is maintained at 18MPa-23MPa, and the pressure-maintaining penetration is ≤4h.

[0018] Furthermore, the material to be foamed is in the form of particles or sheets.

[0019] Furthermore, the material to be foamed is modified nylon particles, which include the following components by mass: 50-70 parts of polyamide; 20-40 parts of polyester rubber; 4-6 parts of branching agent; 1-2 parts of oxidant; and 5-8 parts of plasticizer.

[0020] A shock-absorbing energy storage component is formed by connecting pressure-bearing foam materials into one body or dispersing them in the same closed cavity. The pressure-bearing foam materials are prepared by the above-mentioned pressure-bearing foam material preparation process.

[0021] Furthermore, it also includes an airbag, and the pressure-bearing foam material is filled inside the airbag.

[0022] A sole comprises a sole body, wherein the sole body has the above-mentioned shock-absorbing and energy-storage component.

[0023] Furthermore, the shock-absorbing and energy-storage components are arranged at the forefoot and / or heel of the sole body, or the shock-absorbing and energy-storage components are evenly arranged on the entire sole body.

[0024] Furthermore, when the pressure-bearing foam material is connected into one body and the side is exposed outside the sole body, an outer membrane layer is provided at the side wall of the sole body, and the outer membrane layer seals the outside of the shock-absorbing and energy-storage component.

[0025] The present invention has the following beneficial effects:

[0026] 1. The present invention provides a process for preparing a pressure-bearing foam material, which uses a supercritical fluid as a physical foaming agent to impregnate the material to be foamed, allowing it to penetrate into the interior of the material to be foamed and reach a saturated state. The pressure is then quickly released to a set pressure state, and the material to be foamed is foamed into an intermediate-stage foam material, and a film is applied to seal the gas. After coating, the pressure is continuously released and foaming is continued until the air pressure in the reactor is the same as the atmospheric pressure. After foaming, the pressure-bearing foam material is shaped to obtain a pressure-bearing foam material. The prepared pressure-bearing foam material has a closed film on the outside, through which the air pressure inside the pressure-bearing foam material can be made greater than the external air pressure, and the wrapping property of the pressure-bearing foam material itself is enhanced, which can effectively improve the compression rebound performance of the pressure-bearing foam material and enhance its cushioning, shock absorption and energy return effects.

[0027] 2. The present invention provides a process for preparing a pressure-bearing foam material. Due to the effect of a closed membrane, the individual pressure-bearing foam materials prepared by this process can be better integrated into one under certain working conditions (temperature, pressure), which is beneficial to the implementation of the processing process.

[0028] 3. The present invention provides a shock-absorbing energy storage component, which is formed by connecting a pressure-bearing foam material into one body or dispersing it in the same closed cavity. It has excellent rebound performance and better energy return effect when subjected to force.

[0029] 4. The present invention provides a sole that uses the above-mentioned shock-absorbing energy storage component, has excellent rebound performance, and has a better energy return effect when subjected to force. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic structural diagram of the pressure-bearing foam material of the present invention.

[0031] Figure 2 This is a schematic structural diagram of the energy storage elastic member of the present invention.

[0032] Figure 3 This is a side view of the sole structure of the present invention (1).

[0033] Figure 4 This is the side view (2) of the sole structure of the present invention.

[0034] Explanation of the main component symbols: 1. Closed membrane; 2. Pressure-bearing foam material; 3. Closed cavity; 4. Airbag; 5. Sole body; 6. Shock-absorbing energy storage component; 7. Outer membrane layer. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] The present invention discloses a process for preparing a pressure-bearing foam material, comprising the following steps:

[0038] S1. Put the material to be foamed into a reactor, introduce gas into the reactor, increase the temperature and pressure, so that the gas reaches a supercritical state to impregnate the material to be foamed and reach a saturated state.

[0039] The foaming material is modified nylon particles, which comprise the following components, by weight: 50-70 parts polyamide, 20-40 parts polyester rubber, 4-6 parts branching agent, 1-2 parts oxidant, and 5-8 parts plasticizer. The foaming material is in the form of particles or sheets. The gas is carbon dioxide or nitrogen.

[0040] Taking the case of introducing carbon dioxide as an example, the specific process of step S1 is as follows:

[0041] S11. Place the material to be foamed into a reactor, heat the reactor to 110°C-130°C, and then introduce carbon dioxide into the reactor until the pressure inside the reactor reaches 25MPa-35MPa. As the temperature and pressure inside the reactor increase, the introduced carbon dioxide gas reaches a supercritical state and impregnates the foamed material.

[0042] S12. Circulate the carbon dioxide in the reactor, maintaining the pressure in the reactor at 25 MPa-35 MPa during the circulation process. The circulation allows the carbon dioxide to fully contact the material to be foamed and fully infiltrate the material to be foamed.

[0043] S13. Maintain the internal temperature of the reactor at 50°C-100°C and the pressure at 18MPa-23MPa, and maintain the pressure penetration for ≤4h to reach saturation.

[0044] S2. After the pressure is quickly released to a set pressure state, the foaming material is foamed into an intermediate stage foaming material. At this time, a coating material is added to coat the intermediate stage foaming material to form a closed film 1 on its outer surface.

[0045] The pressure in the set pressure state is greater than atmospheric pressure. Preferably, the pressure in the reactor is 1.2 MPa to 2 MPa. The coating material can be applied to the outer surface of the intermediate foaming material by dipping, spraying, or brushing.

[0046] Compared with dipping or spraying methods, brushing is more suitable for sheet-like intermediate-stage foaming materials. During lamination, a brush or roller can be used to apply the coating evenly.

[0047] When the coating is performed by dipping, the reactor is provided with a liquid inlet. The coating material is heated to a molten state and introduced into the reactor through the liquid inlet to form a coating impregnation liquid. The intermediate-stage foaming material is immersed in the coating impregnation liquid, which can be evenly coated on the surface of the intermediate-stage foaming material to form a closed film 1.

[0048] When spray coating is performed, a spray nozzle is provided in the reactor. The coating material is heated to a molten state and enters the reactor through the spray nozzle. The coating material entering the reactor is sprayed in a mist form and evenly sprinkled onto the surface of the intermediate foaming material, forming a closed film 1. By adjusting or replacing the spray nozzle, the spray volume and spray droplet size can be controlled to obtain a closed film 1 of a corresponding thickness.

[0049] The coating material is a polymer material with good adhesion and chemical stability, such as polyamide, polypropylene or polyurethane. Preferably, thermoplastic polyurethane is used, which has excellent elasticity and wear resistance.

[0050] S3. After the lamination is completed, the pressure in the reactor is continuously released until it is the same as the atmospheric pressure. During the process of continuous pressure release, the foaming material can continue to foam in the intermediate stage. After the foaming is completed, the foaming material can be formed into a solid shape. Figure 1 The pressure-bearing foam material 2 is shown.

[0051] The resulting pressure-bearing foam material 2 exhibits a fully decompressed appearance, with the majority of its internal cells being closed. The closed film 1 formed under these special coating conditions not only enhances the wrapping properties of the pressure-bearing foam material 2 itself but also creates a closed space within it, allowing the internal pressure of the pressure-bearing foam material 2 to exceed the external atmospheric pressure. Due to this high internal pressure, the pressure-bearing foam material 2 exhibits enhanced compression deformation, resulting in improved shock absorption and energy return when subjected to stress.

[0052] In addition, since the pressure-bearing foam material 2 is provided with a closed film 1 on the outside, under certain working conditions (temperature, pressure), the closed film 1 can promote the pressure-bearing foam material 2 to fuse together into one, which is beneficial to the implementation of the fusion process.

[0053] Example 2

[0054] The present invention also discloses a shock-absorbing and energy-storage component 6, which is formed by connecting a pressure-bearing foam material 2 into a single body or distributing the same closed cavity 3. The pressure-bearing foam material 2 is prepared using the aforementioned pressure-bearing foam material 2 preparation process, and the closed cavity 3 is elastically deformable. This shock-absorbing and energy-storage component 6 utilizes the aforementioned pressure-bearing foam material 2 and exhibits excellent resilience, making it suitable for use in a variety of applications requiring shock absorption, such as shoe soles in the shoemaking industry.

[0055] When the pressure-bearing foam material 2 is in sheet form, the shock-absorbing energy storage component 6 can be made of a single pressure-bearing foam material 2. When the pressure-bearing foam material 2 is dispersed, the shock-absorbing energy storage component 6 can also be provided with an external airbag 4, and the internal space of the airbag 4 is used as a closed cavity 3, and the pressure-bearing foam material 2 is filled inside the airbag 4. The external airbag 4 not only limits the range of movement of the pressure-bearing foam material 2, but also has compression rebound performance, and has a certain buffering and shock-absorbing effect. Of course, if Figure 2 As shown, when the pressure-bearing foam material 2 is connected into one, an external airbag 4 can also be installed to improve performance. At the same time, the airbag 4 can protect the internal pressure-bearing foam material 2, improve the problem of easy cracking of the foam material, and extend the service life of the shock-absorbing energy storage component 6.

[0056] Example 3

[0057] The present invention further discloses a sole, comprising a sole body 5 , on which the above-mentioned shock-absorbing and energy-storing component 6 is provided, and which has the excellent properties thereof.

[0058] According to the needs, the shock absorbing and energy storage component 6 can be set up on the whole palm and evenly distributed on the entire sole body 5 to support the entire sole, cushion and reduce shock, etc. Figure 3 As shown, it is partially arranged at the forefoot and / or heel position of the sole body 5 to provide targeted support, cushioning and shock absorption, etc.

[0059] Since the sole adopts the above-mentioned shock-absorbing energy storage component 6, the interior of the sole has high air pressure. When worn, the closed membrane 1 and the air bag 4 structure inside the sole can provide additional support force, so that the sole has excellent compression rebound performance, thereby achieving a better energy return effect, reducing energy loss caused by poor material rebound performance, and achieving the effect of energy saving and auxiliary exercise.

[0060] The same principle applies to setting up airbag 4. Figure 4 As shown, taking the full-length arrangement of the shock-absorbing and energy-storage component 6 as an example, when the pressure-bearing foam material 2 is connected as a whole and leaks out of the sole body 5 at the side, an outer film layer 7 is provided at the side wall of the sole body 5. This outer film layer 7 can also be provided by dipping, spraying, brushing, etc. This outer film layer 7 can seal the outside of the shock-absorbing and energy-storage component 6, that is, it can seal the space between the pressure-bearing foam materials 2 within the shock-absorbing and energy-storage component 6, preventing the force from being transmitted from these spaces and not being stored when the sole is compressed. Therefore, this outer film layer 7 can also improve the support performance of the sole, enhancing the cushioning and shock absorption and energy return effects of the sole.

[0061] Impact tests were conducted on shoe soles with different thicknesses of the closure membrane 1. The test results are as follows:

[0062]

[0063] Note: The sole thickness is 20mm, the impact mass is 8.5kg, the impact height is 50mm, and the impact is repeated 15 times. The average value of the 5th to 10th impact is taken.

[0064] Material energy return ratio (HER) calculation formula: HER=UF / UM×100%

[0065] Where UF is the energy value returned by the shock absorption system, which is calculated by integrating under curve BC and occurs when the material recovers its maximum deformation. The unit is J. UM is the energy value applied by the impact test system, which is calculated by integrating under curve AC and occurs when the material experiences maximum deformation (displacement). The unit is J.

[0066] According to the test results, it can be seen that the use of the above-mentioned pressure-bearing foam material 2 to make the shock-absorbing energy storage component 6 and applying it to the sole can significantly improve the compression rebound performance of the sole, so that the sole has excellent cushioning, shock absorption and energy return effects.

[0067] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A process for preparing a pressure-bearing foam material, characterized in that: The following steps are involved: S1. Place the material to be foamed into a reactor, introduce gas into the reactor, increase the temperature and pressure, so that the gas reaches a supercritical state to impregnate the material to be foamed and reach a saturated state; S2, quickly releasing the pressure to a set pressure state, the material to be foamed is foamed into an intermediate stage foaming material, and a coating material is added to coat the intermediate stage foaming material to form a closed film (1) on its outer surface; the air pressure of the set pressure state is greater than atmospheric pressure; S3, continue to release the pressure until the pressure in the reactor is the same as the atmospheric pressure, foam and shape, and obtain the pressure-bearing foam material (2).

2. A process for preparing a pressure-bearing foam material according to claim 1, characterized in that: In step S2: The air pressure of the set pressure state is 1.2MPa-2MPa.

3. A process for preparing a pressure-bearing foam material according to claim 1, characterized in that: In step S2: The coating material is coated on the outer surface of the intermediate stage foaming material by dipping, spraying or brushing.

4. A process for preparing a pressure-bearing foam material according to claim 3, characterized in that: The reactor is provided with a liquid inlet, the coating material is heated to a molten state and introduced into the reactor from the liquid inlet to form a coating impregnation liquid, the intermediate stage foaming material is immersed in the coating impregnation liquid, so that the coating impregnation liquid is evenly coated on the surface of the intermediate stage foaming material.

5. The process for preparing a pressure-bearing foam material according to claim 3, wherein: The reactor is provided with a spray port, and the coating material is heated to a molten state and enters the reactor through the spray port and is evenly sprayed onto the surface of the foaming material in the intermediate stage.

6. The process for preparing a pressure-bearing foam material according to claim 1, wherein: In step S2: The coating material is polyamide, polypropylene or polyurethane.

7. A process for preparing a pressure-bearing foam material according to claim 6, characterized in that: The coating material is thermoplastic polyurethane.

8. The process for preparing a pressure-bearing foam material according to claim 1, wherein: The gas in step S1 is carbon dioxide, and the specific process of step S1 is: Place the material to be foamed into a reactor, and heat the reactor to 110°C-130°C, then introduce carbon dioxide into the reactor until the pressure in the reactor reaches 25MPa-35MPa, and then circulate the carbon dioxide in the reactor. During the circulation process, the pressure in the reactor is maintained at 25MPa-35MPa. The circulating flow of carbon dioxide allows the material to be foamed to fully contact with the carbon dioxide. Then, maintain the internal temperature of the reactor at 50°C-100°C and the pressure at 18MPa-23MPa, and maintain the pressure penetration for ≤4h.

9. The process for preparing a pressure-bearing foam material according to claim 1, wherein: The material to be foamed is in the form of particles or sheets.

10. The process for preparing a pressure-bearing foam material according to claim 1, wherein: The material to be foamed is modified nylon particles, which include the following components by mass: 50-70 parts of polyamide; 20-40 parts of polyester rubber; and 4-6 parts of branching agent. 1-2 parts of oxidant; 5-8 parts of plasticizer.

11. A shock-absorbing energy storage component, characterized in that: The pressure-bearing foam material (2) is connected into one body or dispersed in the same closed cavity (3), and the pressure-bearing foam material (2) is prepared by a pressure-bearing foam material preparation process according to any one of claims 1 to 10.

12. The shock-absorbing energy storage component according to claim 11, characterized in that: It also includes an air bag (4), and the pressure-bearing foam material (2) is filled inside the air bag (4).

13. A shoe sole, characterized in that: The shoe comprises a sole body (5), wherein the sole body (5) has the shock-absorbing and energy-storing component (6) according to claim 11 or 12.

14. A shoe sole according to claim 13, characterized in that: The shock absorbing and energy storage component (6) is arranged at the forefoot and / or heel position of the sole body (5), or the shock absorbing and energy storage component (6) is evenly arranged on the entire sole body (5).

15. The shoe sole according to claim 13, characterized in that: When the pressure-bearing foam material is connected into one piece and the side edges leak out of the sole body (5), an outer membrane layer (7) is provided at the side wall position of the sole body (5), and the outer membrane layer (7) seals the outside of the shock-absorbing energy storage component (6).

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