THERMAL EXPANSION COMPOUND FOR HANDLE MOLDING, PREPARATION METHOD AND APPLICATION TECHNOLOGY THEREOF

Abstract

The disclosure discloses a thermal expansion compound for handles, a preparation method, and applications thereof. The thermal expansion compound for handles is prepared by 20-80 wt of thermosetting resin, 5-50 wt of foaming agent, 5-50 wt of stuffing, and 0-60 wt of diluent. The thermal expansion compound for handles applies to the preparation of various sports instruments such as tennis rackets, badminton rackets, squash rackets, PK rackets, beach rackets, flexible rackets, ball bats and clubs. Handles prepared from the thermal expansion compound have an elegant appearance and a good hand feel, avoid secondary expansion during 100-160 C. post-heating treatment, and have a hardness of SHORE D 60-95.

Claims

1. A thermal expansion compound for handles, wherein thermal expansion compound for handles is prepared from the following ingredients by weight part: thermosetting resin: 20-80; foaming agent: 5-50; stuffing: 5-50; diluent: 0-60.

2. The thermal expansion compound for handles according to claim 1, wherein the thermal expansion compound for handles is prepared from the following ingredients by weight part: thermosetting resin: 30-50; foaming agent: 20-40; stuffing: 10-30; diluent: 0-30.

3. The thermal expansion compound for handles according to claim 1, wherein the thermosetting resin is high-Tg thermosetting resin at a temperature within the range of 120-350 C.

4. The thermal expansion compound for handles according to claim 1, wherein an expansion temperature of the foaming agent is within the range of 50-180 C.

5. The thermal expansion compound for handles according to claim 1, wherein the stuffing is carbon fiber powder, graphite powder, carbon nano-tube, aluminum oxide, magnesium oxide, calcium carbonate, or talcum powder.

6. The thermal expansion compound for handles according to claim 1, wherein the diluent is a reaction-type diluent or non-reaction-type diluent; preferably, the reaction-type diluent is butyl glycidyl ether, phenyl glycidyl ether, C12-14 aliphatic polyalcohol glycidyl ether, or 1,4-butanediol diglycidyl ether; and the non-reaction-type diluent is acetone, butanone, xylene, ethyl acetate, or butyl acetate.

7. The thermal expansion compound for handles according to claim 1, wherein the thickness of the thermal expansion compound for handles is 0.4-10 mm, preferably 2-5 mm.

8. The thermal expansion compound for handles according to claim 1, wherein a preparation method comprises the following steps: adding the thermosetting resin into the diluent, blending the mixed materials, adding the foaming agent and the stuffing in turn to obtain a mixture, stirring the mixture well, coating the mixture on a backing material; or heating the thermosetting resin until the temperature exceeds a softening temperature, adding the foaming agent and the stuffing to obtain a mixture, stirring the mixture well, and coating the mixture on a backing material; wherein a proper drying method is adopted according to the existence of a solvent, and cutting dimensions depend on the actual situations; preferably, the backing material is non-woven fabric, glass fiber felt, pearl cotton or cotton cloth.

9. Applications of the thermal expansion compound for handles according to claim 1, wherein handles are preferably handles of tennis rackets, badminton rackets, squash rackets, PK rackets, beach rackets, flexible rackets, ball bats and clubs.

10. Applications according to claim 9, wherein a process adopted for preparing handles comprises the following procedures: designing specifications and dimensions according to respective structures of sports instruments, cutting a piece of fiber composite fabric and the thermal expansion compound for handles, sorting the cut pieces for later use; coiling: coiling a fiber composite fabric according to the structure of a specific sports instrument; pre-molding: placing the coiled fabric on a heating platform at a temperature within the range of room temperature 80 C., pre-heating the coiled fabric for 3-60 min, extruding the coiled fabric to remove gases among layers as much as possible, flattening the coiled fabric, cutting the thermal expansion compound to an appropriate size and wrapping cut pieces around a handle of the instrument, then placing the wrapped product in a pre-forming die, and pre-forming the wrapped product into a pre-designed shape of the pre-forming die; molding: placing the pre-formed product into a pre-heating oven, pre-heating the pre-formed product to a temperature of 35-75 C. for 3-60 min, then taking out the preheated product, placing the preheated product into a molding die, closing a die cover; sending the die into a hot pressing molding platform, heating the thermal expansion compound for handles by the effect of a heating program such that the thermal expansion compound expands and then handle molding is completed, wherein preferably, the heating program includes the following parameters: 80-180 C. heating temperature, 10-120 min heating time, 80-120 kg/cm.sup.2 external pressure and 5-15 kg/cm.sup.2 internal pressure; cooling and de-molding: sending the die into a cooling platform after molding, cooling the molding die, sending the cooled molding die into a de-molding platform, opening the die and taking out the finished product, wherein preferably, the cooling program includes the following parameters: 15-45 C. cooling temperature, 3-10 min cooling time, 70-105 kg/cm.sup.2 and external cooling pressure.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0051] The sole FIGURE is a flowchart of a process for preparing a thermal expansion compound for handles of the disclosure into racket handles.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0052] The embodiments of the disclosure are described in detail below. Examples of the embodiments are shown in the sole FIGURE, where the same or similar marks always represent the same or similar elements or elements with the same or similar functions. The Embodiments depicted by the attached drawings are exemplary, used to explain the disclosure only, and cannot be regarded as limits to the disclosure. Unspecified technologies or conditions in the embodiments are subject to the technologies or conditions as described in the literature in the prior art or product manuals. All reagents or instruments without markings from manufacturers are all commercially available conventional products.

[0053] In the following embodiments, thermosetting resin is bismaleimide modified epoxy resin.

[0054] A foaming agent is an azoic compound, a sulfonyl hydrazine compound, a nitroso compound, calcium carbonate, magnesium carbonate or sodium hydrogen carbonate.

[0055] Stuffing is carbon fiber powder, graphite powder, carbon nano-tube, aluminum oxide, magnesium oxide, calcium carbonate or talcum powder.

[0056] A diluent is a reaction-type diluent or non-reaction-type diluent; the reaction-type diluent is butyl glycidyl ether, phenyl glycidyl ether, C12-14 aliphatic polyalcohol glycidyl ether, or 1,4-butanediol diglycidyl ether; and the non-reaction-type diluent is acetone, butanone, xylene, ethyl acetate, or butyl acetate.

TABLE-US-00001 TABLE 1 Ingredients (weight part) in embodiments 1-6 Embodiment Embodiment Embodiment Embodiment Embodiment Embodiment 1 2 3 4 5 6 Thermosetting 20 30 80 60 50 45 resin Foaming 8 5 50 40 30 20 agent Stuffing 5 10 30 50 20 40 Diluent 0 20 60 30 15 40

Embodiment 1: Preparation of a Thermal Expansion Compound for Handles

[0057] Raw materials: See table 1

[0058] Preparation method: Bismaleimide modified epoxy resin is heated to a softening temperature; then the foaming agent and the stuffing are added to obtain a mixture; the mixture is stirred well, and coated on the non-woven fabric with a thickness of 0.4 mm, where the weight is 500 g/m.sup.2, the generated power is 0-20, and the generated pressure is 0-3 kg/cm.sup.2. Then, a subsequent heating treatment is carried out at a temperature 100 C. for 60 min; secondary expansion is avoided; the product size remains stable, and the expansion volume power (the ratio of the volume after expansion to the volume before expansion) is smaller than 0.1%.

Embodiment 2: Preparation of a Thermal Expansion Compound for Handles

[0059] Raw materials: See table 1

[0060] Preparation method: The thermosetting resin is added into the diluent, stirred and dissolved; then the foaming agent and the stuffing are added in turn to obtain a mixture; the mixture is stirred well and coated on a glass fiber felt with a thickness of 2 mm. The mixture is coated on the non-woven fabric with a thickness of 2 mm; the weight is 600 g/m.sup.2; the generated power is 0-20 times, and the generated pressure is 0-2 kg/cm.sup.2. Then, a subsequent heating treatment is carried out at a temperature 160 C. for 10 min; secondary expansion is avoided; the product size remains stable, and the expansion volume power (the ratio of the volume after expansion to the volume before expansion) is smaller than 0.1%.

Embodiment 3: Preparation of a Thermal Expansion Compound for Handles

[0061] Raw materials: See table 1

[0062] Preparation method: Identical with embodiment 2. A mixture is obtained; a part of the mixture is coated on the glass fiber felt with a thickness of 4 mm; a part of the mixture is coated on the non-woven fabric with a thickness of 4 mm; where, the weight is 200 g/m.sup.2; the generated power is 0-20 times, and the generated pressure is 0-12 kg/cm.sup.2. Then, a subsequent heating treatment is carried out at a temperature 120 C. for 40 min; secondary expansion is avoided; the product size remains stable, and the expansion volume power (the ratio of the volume after expansion to the volume before expansion) is smaller than 0.1%.

Embodiment 4: Preparation of a Thermal Expansion Compound for Handles

[0063] Raw materials: See table 1

[0064] Preparation method: Identical with embodiment 2. A mixture is obtained; a part of the mixture is coated on the glass fiber felt with a thickness of 3.5 mm; a part of the mixture is coated on the non-woven fabric with a thickness of 3.5 mm; where, the weight is 1,000 g/m.sup.2; the generated power is 0-20 times, and the generated pressure is 0-10 kg/cm.sup.2. Then, a subsequent heating treatment is carried out at a temperature 140 C. for 20 min; secondary expansion is avoided; the product size remains stable, and the expansion volume power (the ratio of the volume after expansion to the volume before expansion) is smaller than 0.1%.

Embodiment 5: Preparation of a Thermal Expansion Compound for Handles

[0065] Raw materials: See table 1

[0066] Preparation method: Identical with embodiment 2. A mixture is obtained; a part of the mixture is coated on the glass fiber felt with a thickness of 5 mm; a part of the mixture is coated on the non-woven fabric at a thickness of 5 mm; where, the weight is 550 g/m.sup.2; the generated power is 0-20, and the generated pressure is 0-8 kg/cm.sup.2. Then subsequent heating treatment is carried out at a temperature 150 C. for 20min; secondary expansion is avoided; the product size remains stable, and the expansion volume power (the ratio of the volume after expansion to the volume before expansion) is smaller than 0.1%.

Embodiment 6: Preparation of a Thermal Expansion Compound for Handles

[0067] Raw materials: See table 1

[0068] Preparation method: Identical with embodiment 2. A mixture is obtained; a part of the mixture is coated on the glass fiber felt with a thickness of 10 mm; a part of the mixture is coated on the non-woven fabric with a thickness of 10 mm; where, the weight is 900 g/m.sup.2; the generated power is 0-20, and the generated pressure is 0-5 kg/cm.sup.2. Subsequent heating treatment is carried out at a temperature 110 C. for 50 min; secondary expansion is avoided; the product size remains stable, and the expansion volume power (the ratio of the volume after expansion to the volume before expansion) is smaller than 0.1%.

[0069] For the following embodiments, refer to the process flow of the sole FIGURE.

Embodiment 7: Preparation of Badminton Racket Handles

[0070] Badminton racket products are coiled according to the specifications of a structural design, placed on a 80 C. heating platform, preheated for 3 min and pre-formed, and handles of tennis rackets are wrapped with the 0.4 mm thick thermal expansion compound for handles obtained in Embodiment 1. Then, the pre-formed products are placed in a 75 C. pre-heating oven and pre-heated for 3 min, taken out and placed in a molding die. Next, the die is closed and fastened. The die is sent into a 180 C. hot pressing and molding platform, and then treated for 10 min at an external pressure of 120 kg/cm.sup.2 and an internal pressure of 5 kg/cm.sup.2. Then, the die is cooled on the cooling platform at a temperature of 15 C. for 10min, where the cooling external pressure is 90 kg/cm.sup.2; after forming and de-molding, the appearance is intact; the obtained product is heated at a temperature of 100 C. for 30 min, where the expansion volume power is 0.01%, and the hardness is SHORE D 81.

Embodiment 8: Preparation of Tennis Racket Handles

[0071] Tennis racket products are coiled according to the specifications of a structural design, placed on a 60 C. heating platform, preheated for 10 min and pre-formed, and handles of tennis rackets are wrapped with a 2 mm thick thermal expansion compound for handles obtained in Embodiment 2. Then, the pre-formed products are placed in a 60 C. pre-heating oven and pre-heated for 5 min, taken out and placed in a molding die. Next, the die is closed and fastened. The die is sent into a 150 C. hot pressing and molding platform, and then treated for 17 min at an external pressure of 100 kg/cm.sup.2 and an internal pressure of 10-12 kg/cm.sup.2. Then, the die is cooled at the cooling platform at a temperature of 30 C. for 4 min, where the cooling external pressure is 70 kg/cm.sup.2; after forming and de-molding, the appearance is intact; the obtained product is heated at a temperature of 120 C. for 30 min, where the expansion volume power is 0.09%, and the hardness is SHORE D 90.

Embodiment 9: Preparation of Clubs and Racket Handles

[0072] Tennis racket products are coiled according to the specifications of a structural design, placed on a 25 C. heating platform, preheated for 60 min and pre-formed, and then pre-forming clubs and ball bats are wrapped with a cycle of 5 mm thick thermal expansion compound for handles obtained in Embodiment 5. Then, the pre-formed products are placed in a 35 C. pre-heating oven and pre-heated for 60 min, taken out and placed in a molding die. Next, the die is closed and fastened. The die is sent into an 80 C. hot pressing and molding platform, and then treated for 120 min at an external pressure of 80 kg/cm.sup.2 and an internal pressure of 15 kg/cm.sup.2. Then, the die is cooled at the cooling platform at a temperature of 45 C. for 3min, where the cooling external pressure is 105 kg/cm.sup.2; after forming and de-molding, the appearance is intact; the obtained product is heated at a temperature of 160 C. for 60 min, where the expansion volume power is 0.09%, and the hardness is SHORE D 90.

[0073] The Embodiments of the disclosure are shown and described above, but it should be understood that the above Embodiments are used as examples and cannot be regarded as the limit in the disclosure. Those ordinarily skilled in the art can make changes, amendments, replacement and modifications on the above embodiments within the scope of the disclosure.