Method for manufacturing a carbon fibre composite ladder

Abstract

The present application relates to a kind of preparation methods of carbon fiber composite material ladder stand, belong to ladder stand production field.Use auxiliary core mold to lay one 0 ° carbon fiber unidirectional prepreg on outer surface, then lay one 90 ° carbon fiber unidirectional prepreg, become column carbon fiber preform after laying, lay one glass fiber fabric prepreg on the surface of column carbon fiber preform;Lay one 0 ° carbon fiber prepreg on the core material of film laying, then lay one 90 ° carbon fiber unidirectional prepreg, become beam carbon fiber preform after laying, lay one glass fiber fabric prepreg on the surface of beam carbon fiber preform;Column preform is taken off from auxiliary core mold, together with beam preform is placed in the corresponding position of ladder stand forming mould, and upper and lower mould are positioned together by guide column and are placed in hot press to cure, mould temperature is cooled to after, and demoulding is carried out, mechanical processing, surface treatment.

Description

Technical Field

[0001] This invention relates to the field of ladder frame production, and more specifically to a method for preparing a carbon fiber composite ladder frame. Background Technology

[0002] As we all know, with the development of the composite materials industry and the increasing demand for lightweight products, more and more protective equipment is made of lightweight and high-strength composite materials. Traditional ladders are mainly made of metal, which are heavy, prone to rust and corrosion, and are cold in winter and hot in summer, resulting in poor comfort. Therefore, high-strength, wear-resistant, corrosion-resistant and comfortable ladders can better meet the needs.

[0003] Although some carbon fiber composite ladder frames can meet the requirements of lightweight function, the crossbeams and columns are molded separately, and the crossbeams are fixed to the columns by plugging and riveting. Both plugging and riveting require grooving and drilling in the composite material, which damages the integrity of the composite material and leads to a decrease in mechanical properties. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a method for preparing carbon fiber composite ladder frames, which solves the problem that carbon fiber composite ladder frames require the destruction of the complete structure to achieve structural fixation, while achieving a lightweight and high-strength ladder frame structure.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for preparing a carbon fiber composite ladder frame, comprising the manufacture of two carbon fiber composite columns and multiple carbon fiber composite beams, characterized by the following steps: S1: Laying the columns a. Use an auxiliary mandrel for application. First, apply a layer of 0° carbon fiber unidirectional prepreg to the outer surface of the auxiliary mandrel, and then apply a layer of 90° carbon fiber unidirectional prepreg on top of the 0° carbon fiber unidirectional prepreg. b. Repeat step S1 to lay 3 sets of layers. After laying, it becomes a carbon fiber precast column. c. Lay a layer of glass fiber fabric prepreg on the surface of the carbon fiber preform of the column; d. The precast columns are formed using an internal expansion bag molding process; S2: Laying the beams a. Apply a layer of adhesive film to the entire surface of the core material; b. Lay a layer of 0° carbon fiber prepreg on the core material after the adhesive film has been laid, and then lay a layer of 90° carbon fiber unidirectional prepreg on the 0° carbon fiber unidirectional prepreg to ensure that every side of the core material is covered by carbon fiber unidirectional prepreg. c. Repeat step S3, lay 3 sets of layers, and after laying, it becomes a crossbeam carbon fiber precast body; d. Lay a layer of glass fiber fabric prepreg on the surface of the carbon fiber precast beam; e. The precast beam is formed using a compression molding process; S3: Ladder frame curing and molding a. Remove the column preform from the auxiliary core mold, put the inner expansion bag into the column cavity, and place it together with the crossbeam preform into the corresponding position in the ladder frame forming mold. The upper and lower molds are joined together by the positioning of the guide column and placed into the hot press. b. Set the hot press temperature to 125±5℃, place the mold in the hot press, and start pressurizing when the mold temperature reaches 65±5℃ at a rate of 0~10℃ / min, with a pressure of 9±1MPa; then perform intermittent inflation and deflation until the inflation pressure reaches 0.8~1.0MPa; after the mold temperature reaches 125±5℃ at a rate of 0~10℃ / min, hold it at that temperature for 120±5min, and after the holding time is completed, release the inflation pressure and press pressure, and allow the mold to leave the press and cool naturally to below 60℃; S4: The ladder frame undergoes a topcoat spraying process. a. Demolding should be performed after the mold temperature has cooled to below 60℃, removing any excess material. b. Machining, processing the product to a fixed length according to the drawings; c. After processing, perform surface treatment; d. After the surface treatment is completed, it is transferred to the spray booth for spray painting, and then the paint surface is cured.

[0006] The core material is a foam core material.

[0007] The auxiliary core mold is a round core.

[0008] The surface treatment includes sanding and isolation, where the isolation is for areas that do not require painting.

[0009] The requirements for temperature and humidity for the laying of crossbeams and laying of columns are as follows: temperature 22℃±4℃, relative humidity ≤65%.

[0010] The beneficial effects of this invention are that carbon fiber composite ladder frames can be successfully prepared using the above method. The ladder frames meet the external dimensional requirements and have a smooth and flat outer surface, making them both aesthetically pleasing and practical. The carbon fiber composite ladder frames are lightweight, meeting the requirements for lightweighting. The use of glass fiber fabric on the surface layer improves their wear resistance and impact resistance, meeting functional requirements and exhibiting good mechanical properties. Attached Figure Description

[0011] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0012] Figure 1 This is a schematic diagram of the ladder frame structure; Figure 2This is a schematic diagram of the column ply structure; Figure 3 This is a schematic diagram of the beam ply; Figure 4 This is a schematic diagram of the core material of the crossbeam; Figure 5 This is a schematic diagram of a ladder frame integrated molding mold; Figure 6 Auxiliary core mold for column installation.

[0013] In the diagram, 1-upright column, 2-beam, 3-inner expansion bag, 4-carbon fiber unidirectional prepreg, 5-glass fiber fabric prepreg, 6-core material, 7-position of upright column in mold, 8-position of beam in mold, 9-inflation port. Detailed Implementation

[0014] This embodiment includes the following steps. Step S1: Selection of raw materials: unidirectional carbon fiber prepreg, epoxy resin with a resin content of 33% and an areal density of 150 g / m³. 2 The outer surface is made of fiberglass fabric prepreg, with epoxy resin as the resin content (34%) and a prepreg areal density of 180 g / m³. 2 .

[0015] Step S2: Mold preparation. Clean the mold surface and apply liquid release agent. Auxiliary mold: Lay an auxiliary core mold on column 1 and wrap a layer of release film around its surface.

[0016] Step S3: Prepare materials. Prepare the raw and auxiliary materials required for making the ladder frame, including raw materials: carbon fiber unidirectional prepreg 4, glass fiber fabric prepreg 5, adhesive film, core material 6, and inner expansion bag 3.

[0017] Step S4: Cutting: According to the cutting procedure, cut the required carbon fiber unidirectional prepreg 4, glass fiber fabric prepreg 5, adhesive film, and core material 6.

[0018] Step S5: Temperature and humidity requirements for installation: temperature 22℃±4℃, relative humidity ≤65%.

[0019] Step S6: Lay the column 1. Use the auxiliary mandrel for laying. First, lay a layer of 0° carbon fiber unidirectional prepreg 4 on the outer surface of the auxiliary mandrel, and then lay a layer of 90° carbon fiber unidirectional prepreg on the 0° carbon fiber unidirectional prepreg.

[0020] Step S7: Repeat step S6 for 3 sets of layup. After the layup is completed, it becomes a carbon fiber preform with a layup thickness that meets the strength requirements. The thickness can be increased or decreased according to the strength requirements. The carbon fiber layup is the guarantee of strength.

[0021] Step S8: Lay a layer of glass fiber fabric prepreg 5 on the surface of the carbon fiber preform, and complete the molding of the column preform by using the inner expansion bag 3 molding process. The function of the glass fiber fabric prepreg is to enhance the surface impact resistance and wear resistance of the ladder plate.

[0022] Step S9: Lay the crossbeam 2, and apply a layer of adhesive film to the core material 6 to increase the interlayer bonding between the carbon fiber unidirectional prepreg 4 and the core material 6, ensuring that there is adhesive film on each side.

[0023] Step S10: Lay a layer of 0° carbon fiber unidirectional prepreg on the core material 6 after the adhesive film has been laid, and then lay a layer of 90° carbon fiber unidirectional prepreg on the 0° carbon fiber unidirectional prepreg to ensure that each side of the core material 6 is covered by carbon fiber unidirectional prepreg 4.

[0024] Step S11: Repeat S10 for 3 sets of layup. After the layup is completed, it becomes a carbon fiber preform with a layup thickness that meets the strength requirements. The thickness can be increased or decreased according to the strength requirements. The carbon fiber layup is the guarantee of strength.

[0025] Step S12: Lay a layer of glass fiber fabric prepreg on the surface of the carbon fiber preform, and use a molding process to complete the forming of the beam preform. The glass fiber fabric prepreg enhances the surface impact resistance and wear resistance of the ladder plate.

[0026] Step S13: Mold closing. Remove the precast column from the auxiliary core mold, along with the precast beam, and assemble them according to... Figure 5 The corresponding positions are placed in the mold column placement position 7 and the mold crossbeam placement position 8 in the ladder frame forming mold. The upper and lower molds are joined together by the positioning of the guide pillars and placed into the hot press.

[0027] Step S14: Curing. Hot press temperature setting: 125±5℃. Place the mold in the hot press. When the mold temperature reaches 65±5℃ at a rate of 0-10℃ / min, begin pressurizing through the air inlet 9 to a pressure of 9±1MPa. Then, intermittently inflate and deflate until the inflation pressure reaches 0.8-1.0MPa. After the mold temperature reaches 125±5℃ at a rate of 0-10℃ / min, hold the temperature for 120±5 minutes. After holding, release the inflation pressure and press pressure, and allow the mold to cool naturally to below 60℃ after leaving the press.

[0028] Step S15: Demolding. After the mold temperature has cooled to below 60°C, demold the mold and remove excess material edges and inner bulges.

[0029] Step S16: Machining, the product is cut to length according to the drawings.

[0030] Step S17: After processing, surface treatment is performed, which includes sanding and isolation. Isolation is mainly for parts that do not need to be painted.

[0031] Step S18: After the surface treatment is completed, the paint is sprayed in the spray booth at a pressure of 0.6 MPa. After the paint is sprayed, it is left to stand for 24 hours and then transferred to the curing oven for curing.

Claims

1. A method for manufacturing a carbon fiber composite ladder frame, comprising the manufacture of two carbon fiber composite columns and multiple carbon fiber composite beams, characterized in that, Includes the following steps: S1: Laying the columns a. Use an auxiliary mandrel for application. First, apply a layer of 0° carbon fiber unidirectional prepreg to the outer surface of the auxiliary mandrel, and then apply a layer of 90° carbon fiber unidirectional prepreg on top of the 0° carbon fiber unidirectional prepreg. b. Repeat step S1 to lay 3 sets of layers. After laying, it becomes a carbon fiber precast column. c. Lay a layer of glass fiber fabric prepreg on the surface of the carbon fiber preform of the column; d. The precast columns are formed using an internal expansion bag molding process; S2: Laying the beams a. Apply a layer of adhesive film to the entire surface of the core material; b. Lay a layer of 0° carbon fiber prepreg on the core material after the adhesive film has been laid, and then lay a layer of 90° carbon fiber unidirectional prepreg on the 0° carbon fiber unidirectional prepreg to ensure that every side of the core material is covered by carbon fiber unidirectional prepreg. c. Repeat step S3, lay 3 sets of layers, and after laying, it becomes a crossbeam carbon fiber precast body; d. Lay a layer of glass fiber fabric prepreg on the surface of the carbon fiber precast beam; e. The precast beam is formed using a compression molding process; S3: Ladder frame curing and molding a. Remove the precast column from the auxiliary core mold, and place it together with the precast beam into the corresponding position in the ladder frame forming mold. The upper and lower molds are then joined together by the positioning of the guide column and placed into the hot press. b. Set the hot press temperature to 125±5℃, place the mold in the hot press, and start pressurizing when the mold temperature reaches 65±5℃ at a rate of 0~10℃ / min, with a pressure of 9±1MPa; then perform intermittent inflation and deflation until the inflation pressure reaches 0.8~1.0MPa; after the mold temperature reaches 125±5℃ at a rate of 0~10℃ / min, hold it at that temperature for 120±5min, and after the holding time is completed, release the inflation pressure and press pressure, and allow the mold to leave the press and cool naturally to below 60℃; S4: The ladder frame undergoes a topcoat spraying process. a. Demolding should be performed after the mold temperature has cooled to below 60℃, removing any excess material. b. Machining, processing the product to a fixed length according to the drawings; c. After processing, perform surface treatment; d. After the surface treatment is completed, it is transferred to the spray booth for spray painting, and then the paint surface is cured.

2. The method for preparing the carbon fiber composite ladder frame according to claim 1, characterized in that... The core material is a foam core material.

3. The method for preparing the carbon fiber composite ladder frame according to claim 1, characterized in that... The auxiliary core mold is a round core.

4. The method for preparing the carbon fiber composite ladder frame according to claim 1, characterized in that... The surface treatment includes sanding and isolation, where the isolation is for areas that do not require painting.

5. The method for preparing the carbon fiber composite ladder frame according to claim 1, characterized in that... The requirements for temperature and humidity for the laying of crossbeams and laying of columns are as follows: temperature 22℃±4℃, relative humidity ≤65%.

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