TW201930057A - Carbon fiber workpiece core shaft air bag integral forming technology - Google Patents

Abstract

The invention relates to the technical field of carbon fiber formation and particularly discloses carbon fiber workpiece core shaft air bag integral forming technology which comprises the following steps of providing a hollow core shaft; covering the outer side of the core shaft with carbon fibers in an attaching manner; putting the core shaft, on which the carbon fibers are covered in the attaching manner, in a die cavity of a workpiece die, and then blowing air into the core shaft to enable the carbon fibers to be formed; and taking out the core shaft. The invention provides the carbon fiberworkpiece core shaft air bag integral forming technology, in which by arranging the core shaft with certain thermoplasticity to replace original inner core and air bag, the technology is simplified,and the rate of finished products can be increased.

Description

 Method for integrally forming carbon fiber part mandrel air bag  

The invention relates to the technical field of carbon fiber forming, in particular to a method for integrally forming a core fiber bag of a carbon fiber part.

With the improvement of people's living standards, the market demand for bicycles is also getting higher and higher. Many bicycle frames have adopted carbon fiber as the main material. The traditional carbon fiber frame mainly adopts the following production method: firstly, the inner core is made according to the shape of the frame, and then the carbon fiber is wrapped on the surface of the inner core, and after the required number of carbon fiber layers are laid, the mandrel is extracted and simultaneously The nylon air duct is inserted into the carbon fiber tube, placed in the mold cavity, and the mold cavity is heated while blowing the nylon air bag to apply pressure to the carbon fiber, so that it is applied to the surface of the mold cavity, and is to be in the carbon fiber. After the resin is cured, a carbon fiber frame or product of the desired shape is obtained.

The traditional hollow composite shaped tube method mainly comprises a combination of a shell inner core and an air bag, and a combination of a Polylon inner core and a latex air bag. Among them, the role of the inner core includes: carbon fiber shaping, positioning, control of product size and shape. The role of the air bag includes: providing a source of pressure during the heat conversion of the carbon fiber to ensure the adhesion between the carbon fiber layers.

The disadvantages of the traditional method are: 1. The method is complicated, the material positioning operation is difficult; 2. The production operation process is complicated, and it is easy to cause the operation to be discarded; 3. The structural design accuracy of the inner core is not easy to control; 4. The hollow opening of various structures The tube cannot be directly produced, and it is necessary to obtain the required hollow open tubular shape by subsequent processing; 5. The air bag is easy to break in the forming process, resulting in poor bonding between the product layers and being scrapped.

The traditional method of production is complicated and cumbersome, and the labor cost is high. In the forming process, the air bag is easily broken and the product is scrapped.

The object of the present invention is to provide a method for integrally forming a carbon fiber component mandrel air bag, which is simple in method and high in yield.

To this end, the present invention provides a method for integrally forming a carbon fiber component mandrel air bag, comprising the steps of: providing a hollow mandrel; attaching carbon fiber to the outside of the mandrel; and mandrel with carbon fiber The mold is placed in the cavity of the part mold, and then blown into the mandrel to heat-solidify the carbon fiber; the mandrel is taken out.

As an ideal embodiment, the aforementioned mandrel is a soft plastic.

As a preferred embodiment, the aforementioned mandrel is polypropylene.

As an ideal embodiment, the foregoing steps provide a hollow mandrel, specifically: a mandrel having an air inlet is formed by a blow molding method.

As an ideal embodiment, the foregoing steps: manufacturing a mandrel having an air inlet by a blow molding method, comprising the steps of: melting a raw material colloid, extruding a round tube; using a blow needle The inner core mold is closed, so that part of the round tube is located in the cavity after the inner core mold is closed; the circular tube in the cavity of the inner core mold is blown, and the round tube is attached to the inner wall of the inner core mold to form Mandrel.

As an ideal embodiment, when the inner core mold is clamped, one end of the circular tube in the cavity of the inner core mold is closed, and the other end has an air inlet.

As an ideal embodiment, the foregoing steps: placing a mandrel coated with carbon fiber into a cavity of a part mold, and then blowing air into the mandrel to heat-solidify the carbon fiber, specifically: carbon fiber is attached The mandrel is placed in the cavity of the part mold, so that the temperature in the cavity rises and the air is blown into the mandrel to generate pressure, so that the carbon fiber is attached to the inner wall of the part mold for a certain time, the shape of the carbon fiber is solidified to form carbon fiber. Components.

As an ideal embodiment, the foregoing steps: taking out the mandrel is specifically: after the carbon fiber parts are formed and solidified, the blowing is stopped and the part mold is cooled, and after the temperature of the cavity of the part mold is lowered, the carbon fiber parts are taken out, and then the carbon fiber parts are placed. The oven is heated, and after the hardness of the mandrel is lowered, the carbon fiber parts are taken out of the oven and the softened mandrel is immediately taken out.

The invention has the effect of providing a method for integrally forming a carbon fiber part mandrel air bag, which is provided by replacing the original inner core and the air bag with a mandrel having a certain thermoplasticity, thereby simplifying the method and improving the yield.

1‧‧‧ mandrel

2‧‧‧carbon fiber

3‧‧‧Part mould

4‧‧‧Carbon bicycle rack

5‧‧‧ Frame mandrel

[Fig. 1] Schematic diagram of the mandrel

[Fig. 2] Schematic diagram of carbon fiber parts

[Fig. 3] Schematic diagram of the mold clamping of the part mold

[Fig. 4] Schematic diagram of a carbon fiber bicycle frame

[Fig. 5] A schematic view of a frame mandrel.

The technical means of the present invention will be further described below in conjunction with the drawings and by way of specific embodiments.

The present embodiment provides a method of forming a carbon fiber component 2 (a method of integrally forming a carbon fiber component core airbag), comprising the following steps S10 to S40: S10: providing a hollow mandrel 1.

Specifically, the mandrel 1 is a hollow structure and has good thermoplasticity or ductility. Ideally, a soft plastic can be used as the material of the mandrel 1. Further, the soft plastic generally refers to a thermoplastic plastic, and the plastic that can be processed again after being formed by injection molding is called a soft plastic. In general, soft plastic is made of plastic and is relatively durable. The main soft plastics are polyethylene (PE), polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA, commonly known as plexiglass), polyvinyl chloride (PVC), nylon (Nylon), Polycarbonate (PC), polyurethane (PU), polytetrafluoroethylene (PTFE, PTFE), polyethylene terephthalate (PET, PETE), and the like. A large number of experiments have shown that when polypropylene (PP) is used as the mandrel 1, the yield is high, the cost is low, and the processing is easy, which has a great advantage. Ethylene hydrocarbon (CH2-CH2)n is a thermoplastic material. It is glassy at room temperature and has stable rigidity. It can support composite materials such as carbon fiber for lamination operation, meet various structural design requirements, and enter rubber state at high temperature. It has high plasticity to meet the needs of any complex mold cavity deformation, and complete the processing conditions of uniform pressure of the full cavity. The non-polar characteristics of ethylene itself and the polar characteristics of the epoxy of the composite material cause natural incompatibility. After the composite material is formed, it is easily peeled off and taken out, and the inner surface is smooth and high quality.

Ideally, the plastic may not be used, but the material satisfies the following requirements: the mandrel 1 is in a glassy state at 25 ° C and a rubbery state at 70 ° C or more. It has been experimentally shown that only materials satisfying this requirement can be used as the raw material of the mandrel 1 in the present embodiment. Specifically, the glass state is not a state of matter, but its structure. Solid matter is divided into crystals and amorphous, and the atoms (or ions or molecules) constituting the crystal have a certain spatial structure (ie, a crystal lattice), the crystal has a certain crystal shape, and a fixed melting point, and is not isotropic. The glass state is an amorphous, and the amorphous is a solid other than crystals in the solid. It has no fixed shape and a fixed melting point and is isotropic. They gradually soften as the temperature rises and finally melt. When softened, it can be processed into various shapes. In the rubber state, as the temperature rises to a certain temperature, the motion of the segment is excited, but the entire molecular chain is still in a frozen state. When subjected to an external force, the amorphous polymer exhibits a large deformation, and after the external force is released, The deformation can be recovered. This state is called rubbery state, high elastic state or crystalline state.

Ideally, the mandrel 1 having the air inlet can be produced by a blow molding method, and includes the following steps S101 to S104: S101: after the raw material colloid is melted, the round tube is extruded; and S102: the air blowing needle is used. The inner core mold is clamped so that part of the round tube is located in the cavity after the inner core mold is closed; when the inner core mold is closed, the round tube in the cavity of the inner core mold is closed at one end, and the other end is left. There is an air inlet, as shown in FIG. 1; S103: blowing a circular tube in the cavity of the inner core mold, so that the round tube is attached to the inner wall of the inner core mold to form the mandrel 1.

S104: Open the inner core mold and take out the mandrel 1.

S20: The carbon fiber is attached to the outside of the mandrel 1, as shown in FIG.

Specifically, the shape of the mandrel 1 is similar to that of the part mold 3, but the size is small, and the thickness of the carbon fiber is determined according to the difference in size between the mandrel 1 and the cavity of the part mold 3.

S30: The mandrel 1 coated with the carbon fiber is placed in the cavity of the part mold 3, the temperature in the cavity is raised, and the air is blown into the mandrel 1 to generate pressure, so that the carbon fiber is attached to the inner wall of the part mold 3. After a certain period of time, the shape of the carbon fiber is solidified to form the carbon fiber part 2, as shown in FIG.

Specifically, since the mandrel 1 has a certain thermoplasticity, when the cavity of the part mold 3 is heated, the mandrel 1 is blown, and the shape of the mandrel 1 is changed, which can replace the conventional air bag and assist the carbon fiber wind press forming. By using the mandrel 1 instead of the original inner core and the air bag, the mandrel is not easily broken, which not only simplifies the method but also ensures stable product quality.

S40: After the carbon fiber component 2 is formed and solidified, the blowing is stopped and the part mold 3 is cooled. After the temperature of the cavity of the part mold 3 is lowered, the carbon fiber component 2 is taken out, and then the carbon fiber component 2 is placed in an oven for heating, and the hardness of the mandrel 1 is to be maintained. After dropping to a suitable value, the carbon fiber part 2 was taken out of the oven and the softened mandrel 1 was immediately taken out.

Specifically, since the mandrel 1 has good thermoplasticity, the mandrel 1 is removed after the mandrel 1 is softened under heating.

The forming method provided by this embodiment can be applied to the manufacturing process of all the air-formed carbon fiber parts 2, such as a carbon fiber bicycle frame 4, a carbon fiber badminton racket, a carbon fiber container, a carbon fiber pipe, and the like. For example, the bicycle frame shown in FIG. 4 can be produced by the following steps: by using a PP material, the shape of the carbon fiber bicycle frame 4 shown in FIG. 5 is the same as that of the closed carbon fiber bicycle frame 4, but the size is small. Frame mandrel 5 (because there is still carbon fiber between the frame mandrel 5 and the part mold 3, so the size is small), while ensuring that the frame mandrel 5 has a certain wall thickness, the frame core at normal temperature (25 ° C) The hardness of the shaft 5 is relatively large. After the temperature rises (greater than 70 ° C), the frame mandrel 5 begins to soften and has a certain deformability; 2) the carbon fiber is wrapped and wrapped on the frame mandrel 5, and the carbon fiber is not required to be wrapped. The frame mandrel 5 is taken out; directly embedded in the carbon fiber, the frame mandrel 5 is used to shape, position and replace the air duct; 3) the carbon fiber and the frame mandrel 5 are placed together in the part mold 3 After heating, the temperature is raised, the wind pressure is applied, the frame mandrel 5 is blown, and the frame mandrel 5 is expanded outward under the wind pressure, thereby applying pressure to the carbon fiber, and the carbon fiber is in the frame mandrel 5 and the part mold 3 Combined with heat forming and curing, the carbon fiber bicycle frame 4 is obtained; 4) heating and blowing for a certain time After the resin in the carbon fiber is solidified, the blowing is stopped and the part mold 3 is cooled, and then the carbon fiber bicycle frame 4 is taken out from the part mold 3 together with the frame mandrel 5 and placed in an oven for heating, and the temperature is raised to a suitable temperature. After the temperature, the frame mandrel 5 becomes soft, and the carbon fiber bicycle frame 4 can be taken out together with the frame mandrel 5 in the oven, and the frame mandrel 5 is still in a softened state, and the frame mandrel 5 is taken from the carbon fiber bicycle. Take out the rack 4.

The advantage of this method is: cancel the traditional inner core + nylon air bag or inner core + latex air bag to apply pressure to the product, instead of directly wrapping the carbon fiber on the pre-formed preform (mandrel 1) The mandrel 1 can realize the integration of the inner core and the air bag function, thereby simplifying the method and improving the stability of the product quality.

The words "first", "second", etc. in this article are only for the purpose of distinguishing between descriptions and have no special meaning.

The specific technical features described in the above specific embodiments may be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention does not further explain various possible combinations. .

In addition, any combination of various embodiments of the invention may be made, as long as it does not deviate from the idea of the invention, and should also be regarded as the disclosure of the invention.

Claims (9)

 A method for integrally forming a carbon fiber part mandrel air bag, characterized in that the method comprises the steps of: providing a hollow mandrel; attaching carbon fiber to the outer side of the mandrel; and placing the mandrel coated with carbon fiber into the part mold In the cavity, the air is blown into the mandrel to heat-form the carbon fiber; the mandrel is taken out.    The method for integrally forming a carbon fiber component mandrel air bag according to the first aspect of the invention, wherein the mandrel is in a glass state at 25 ° C and a rubber state at 70 ° C or higher.    The method for integrally forming a carbon fiber component mandrel air bag according to the second aspect of the invention, wherein the mandrel is a soft plastic.    A method for integrally forming a carbon fiber component mandrel air bag according to claim 3, wherein the mandrel is polypropylene.    The method for integrally forming a carbon fiber component mandrel air bag according to the first aspect of the invention, wherein the step of providing a hollow mandrel, specifically: forming a mandrel having an air inlet by a blow molding method.    The method for integrally forming a carbon fiber component mandrel air bag according to claim 5, wherein the step of: forming a mandrel having an air inlet by a blow molding method comprises the following steps: After melting, the round tube is extruded; the inner core mold with the blowing needle is used for clamping, so that part of the round tube is located in the cavity after the inner core mold is closed; the round tube in the cavity of the inner core mold is blown The gas is applied to the inner wall of the inner core mold to form a mandrel.    The method for integrally forming a carbon fiber component mandrel air bag according to claim 6, wherein when the inner core mold is closed, one end of the circular tube in the cavity of the inner core mold is closed, and the other end is left. Air inlet.    The method for integrally forming a carbon fiber component mandrel air bag according to the first aspect of the invention, wherein the step of: placing a mandrel coated with carbon fiber into a cavity of a part mold, and then blowing the air into the mandrel The carbon fiber is formed by heat forming, specifically: the mandrel coated with the carbon fiber is placed in the cavity of the part mold, so that the temperature in the cavity rises and the air is blown into the mandrel to generate pressure, so that the carbon fiber is attached to the part mold. After a certain period of time on the inner wall, the shape of the carbon fiber is solidified to form a carbon fiber part.    The method for integrally forming a carbon fiber component mandrel air bag as described in claim 8 wherein the step of removing the mandrel is specifically: after the carbon fiber component is formed and solidified, the blowing is stopped and the part mold is cooled, and the part mold is to be cooled. After the temperature of the cavity is lowered, the carbon fiber parts are taken out, and then the carbon fiber parts are placed in an oven for heating. After the hardness of the mandrel is lowered, the carbon fiber parts are taken out from the oven and the softened mandrel is immediately taken out.