An apparatus and method for producing a continuous fiber thermoplastic prepreg tape

Abstract

The application discloses a kind of production equipment and method of continuous fiber thermoplastic prepreg tape, including yarn separating mechanism, yarn spreading mechanism, impregnation mechanism and composite setting mechanism connected in sequence, yarn spreading mechanism includes airflow spreading device and mechanical spreading device, airflow spreading device includes the airflow box being arranged below fiber prepreg tape, airflow box is cavity structure and is internally equipped with centrifugal fan, impregnation mechanism includes impregnation mould, impregnation mould is formed by upper die body and lower die body, and upper die body and the lower die body are oppositely arranged and form wave-shaped impregnation passage.The yarn spreading mode of airflow spreading as main, mechanical spreading as auxiliary solves the problem that the mechanical spreading method of current domestic mainstream yarn spreading technology is greater, and the yarn spreading effect is not ideal;Impregnation mould has wave-shaped impregnation passage, increases the impregnation area of prepreg tape, makes hot-melt resin more evenly dispersed on continuous fiber tape, can be fully impregnated, avoid the problem of uneven impregnation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite material production, in particular to a production equipment and method of continuous fiber thermoplastic prepreg tape. BACKGROUND

[0002] Fiber Reinforced Plastics (FRP) is made of high-performance fibers and resins, which has high specific strength and specific stiffness, and has many advantages such as light weight, corrosion resistance compared with traditional materials such as metals, and has been widely used in aerospace, petrochemical industry and other fields. FRP can be divided into thermoplastic composite materials (Fiber Reinforced Thermoplastics, FRTP) and thermoset composite materials according to the type of matrix. The traditional thermoset composite material has good mechanical properties, but the interlaminar fracture toughness is generally poor, the molding period is long, the storage conditions of prepreg are harsh and it cannot be recycled for secondary molding, which greatly limits the application of thermoset composite materials. FRTP has incomparable advantages such as good toughness, low cost, short production cycle, repeated processing and recycling compared with thermoset composite materials, so its output and application fields are expanding, and it has become one of the important development directions of composite materials.

[0003] Continuous fiber reinforced thermoplastic resin prepreg tape is composed of continuous fibers and thermoplastic resin, and has solution impregnation method, melt impregnation method and powder impregnation, reaction impregnation process, etc. Among them, the melt impregnation method is widely used in industrial production due to its low production cost and high efficiency.

[0004] The dispersion and forming process of high-performance fibers is the difficulty of the preparation of continuous fiber reinforced thermoplastic resin prepreg tape. On the one hand, the viscosity of thermoplastic resin after melting is very high, reaching hundreds of Pa·S, so it is difficult for general processing equipment and process conditions to combine with continuous fibers, which is easy to produce pores and the impregnation effect is not ideal. On the other hand, in order to ensure the performance of the product, fully impregnate the resin, reduce the thickness of the prepreg and increase the fiber content, it is necessary to expand and thin the high-performance fibers before impregnation to expand the gap between the fibers.

[0005] To solve the above problems, the Chinese patent with application number CN201911335610.6 discloses a continuous fiber spreading device and a spreading method, which includes a spreading roller group that spreads the fibers and arranges them in a plane, and a spreading assembly for conveying fibers to the spreading roller group; wherein the spreading assembly includes a blowing mechanism for blowing air to the fibers and a supporting mechanism for supporting the fibers; the blowing mechanism is arranged above the supporting mechanism to apply air pressure to the fibers on the supporting mechanism, so that the fibers move in the width direction and spread out. The present application adopts a composite spreading technology, that is, a spreading assembly for blowing air to the fibers is installed at the front end of the mechanical roller spreading device. The spreading assembly has the advantage of low damage to glass fibers, but pure air blowing spreading can disorder the arrangement of glass fibers, and the composite spreading of the spreading assembly and the spreading roller group can improve the spreading width, reduce fuzz, improve stability, and improve the parallel spreading property of the fiber bundle after spreading. However, air flow spreading can disorder the arrangement of glass fibers, which can easily lead to uneven distribution of resin in the composite fiber yarn, poor stability, and poor product quality.

[0006] Therefore, in order to solve the two process difficulties mentioned above, it is necessary to provide a production equipment and method for continuous fiber reinforced thermoplastic resin prepreg tape, to solve the problems of large fiber wear, unsatisfactory spreading effect of the current domestic mainstream mechanical spreading method, disordering of glass fiber arrangement by air flow spreading, and uneven distribution of resin in the composite fiber yarn during subsequent hot melt resin impregnation, to improve the molding efficiency and increase the plasticity. SUMMARY

[0007] To overcome the problems in the prior art, the present application provides a production equipment and method for continuous fiber thermoplastic prepreg tape, which solves the problem of uneven distribution of resin in the composite fiber yarn during hot melt resin impregnation, improves the molding efficiency and increases the plasticity.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0009] The present application provides a production equipment for continuous fiber thermoplastic prepreg tape, which includes a yarn separating mechanism, a spreading mechanism, an impregnation mechanism and a composite shaping mechanism connected in sequence,

[0010] The spreading mechanism includes an air flow spreading device and a mechanical spreading device, the air flow spreading device includes an air flow box arranged below the fiber prepreg tape, the air flow box is a hollow structure and internally mounted with a centrifugal fan, and the suction direction of the centrifugal fan is perpendicular to the surface of the fiber prepreg tape;

[0011] The impregnation mechanism includes an impregnation mold, the impregnation mold is composed of an upper mold body and a lower mold body, the upper mold body and the lower mold body are oppositely arranged and form a wave-shaped impregnation channel.

[0012] Preferably, the airflow box is a cavity structure penetrating from top to bottom, comprising an upper shell and a lower shell, the fiber prepreg tape passing through the gap between the upper shell and the lower shell, and the centrifugal fan being suspended at the center of the inside of the lower shell.

[0013] Preferably, the width of the airflow box ranges from 30 cm to 100 cm, the length ranges from 20 cm to 40 cm, the inclination angle of the upper shell side plate ranges from 10° to 20°, and the airflow velocity ranges from 10 m / s to 16 m / s.

[0014] Preferably, the wave height of the impregnation channel ranges from 2 cm to 3 cm, and the diameter ranges from 5 cm to 7 cm, and the number of wave crests of the impregnation channel is 2-20.

[0015] Preferably, the impregnation channel is connected to the screw extruder.

[0016] Preferably, the mechanical yarn spreading device comprises at least 5 yarn spreading steel rollers, which are arranged in parallel and staggered, and the fiber prepreg tape passes above the airflow yarn spreading device and is wound on the yarn spreading steel rollers in sequence.

[0017] Preferably, the composite sizing mechanism comprises at least two groups of sizing mold groups arranged on the same plane, and each sizing mold group comprises an upper rubber-covered roller and a lower roller arranged in a vertical manner.

[0018] Preferably, the yarn separating mechanism is provided with a mountain reed and a yarn separating roller, the mountain reed is provided with equidistant separating teeth, and the number of the yarn separating rollers is at least 5.

[0019] Preferably, the composite sizing mechanism is connected to the edge cutting mechanism, and the edge cutting mechanism comprises a cutting device and a waste edge winding device.

[0020] The application also provides a production method of continuous fiber thermoplastic prepreg tape, which uses the production equipment of any one of the above-mentioned continuous fiber thermoplastic prepreg tape to produce, and the specific steps are as follows:

[0021] The fiber material is selected, and the fiber material is at least one of carbon fiber, glass fiber and aramid fiber;

[0022] The type of impregnating resin is selected, and the impregnating resin is at least one of PPS, PEEK and PEKK;

[0023] The different working areas of the production equipment are preheated, the preheating time lasts for 2-3 h, and then the production is carried out.

[0024] The fiber is placed on a creel, the drawing speed is adjusted, the fiber sequentially passes through airflow spreading and mechanical spreading, and is subjected to melt impregnation in an impregnation die; after the fiber is spread evenly, the main machine and the feeding are started, the impregnation mechanism is closed, and the die outlet gap is adjusted to 0.2-0.4 mm; after being shaped by a composite shaping mechanism, the edge is cut and the winding is performed.

[0025] Preferably, the drawing speed adjustment range is 1.0-3.0 m / min.

[0026] Preferably, the preheating temperature range is 260-395 DEG C.

[0027] In summary, the beneficial effects of the above technical solutions of the present application are as follows:

[0028] The spreading mechanism comprises airflow spreading devices and mechanical spreading devices, and the airflow spreading is mainly used, and the mechanical spreading is auxiliary, so as to solve the problems of the current mainstream spreading technology, i.e., the mechanical spreading method has large fiber abrasion and unsatisfactory spreading effect; meanwhile, the impregnation die has a wave-shaped impregnation channel, and the fiber prepreg after airflow spreading and mechanical spreading passes through the wave-shaped impregnation channel, so as to increase the impregnation area of the prepreg, make the hot-melt resin on the continuous fiber band be more evenly distributed, and achieve sufficient impregnation and avoid uneven impregnation.

[0029] The present application also provides a production method of continuous fiber thermoplastic prepreg, which uses standard polymers from PP to PEEK as raw materials, can be applied to thermoplastic resins with a processing temperature of 200-400 DEG C, and forms a commercial composite material production line for producing high-grade thermoplastic prepreg in an industrial scale. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed for the embodiment description will be briefly introduced as follows, and obviously, the drawings in the following description can also be used to obtain other drawings without creative labor for those skilled in the art.

[0031] Figure 1 A structure schematic view of a production equipment of a continuous fiber thermoplastic prepreg provided by the present application is shown in the figure.

[0032] Figure 2 A flow schematic view of a production method of a continuous fiber thermoplastic prepreg provided by the present application is shown in the figure.

[0033] In the drawings, the component list represented by each number is as follows:

[0034] 1-screw extruder; 2-yarn rack; 3-yarn drum; 4-yarn separating mechanism; 5-preheating mechanism; 6-yarn spreading mechanism;

[0035] 7-air flow yarn spreading device; 8-mechanical yarn spreading device; 9-dipping mechanism; 10-composite setting mechanism;

[0036] 11-edge cutting mechanism; 12-rolling mechanism; 13-guillotine; 14-yarn separating roller; 15-coating top pressure roller;

[0037] 16-lower roller; 17-edge cutting device; 18-waste edge rolling device. DETAILED DESCRIPTION

[0038] In order to make the person skilled in the art better understand the technical solutions of the present application, the technical solutions of the present application will be described clearly and completely below in combination with the drawings of the present application. Based on the embodiments in the present application, other similar embodiments obtained by the person skilled in the art without making creative efforts shall fall within the scope of protection of the present application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc. are only the directions of the drawings, therefore, the directional words used are used for illustration but not for limiting the present application.

[0039] As shown in Figures 1-2 The present application provides a production equipment of continuous fiber thermoplastic prepreg tape, which comprises, in sequence according to the production process, a yarn rack 2, a yarn separating mechanism 4, a preheating mechanism 5, a yarn spreading mechanism 6, a dipping mechanism 9, a composite setting mechanism 10 and an edge cutting mechanism 11.

[0040] The yarn rack 2 is provided with a plurality of yarn drums 3 of 46-92 spindles, which are used to provide fiber raw materials. The fibers drawn from the yarn rack 2 enter the yarn spreading mechanism 6 through the yarn separating mechanism 4. The yarn separating mechanism 4 is provided with a guillotine and a yarn separating roller 14. The guillotine is provided with equidistant separating teeth, which can preliminarily comb the fibers, so as to facilitate subsequent yarn spreading. The number of the yarn separating roller 14 is at least 5. The preheating mechanism 5 provides preheating for the fiber raw materials. The preheating is to remove sizing agent on the surface of the fibers, so as to facilitate subsequent yarn spreading and dipping.

[0041] The yarn spreading mechanism 6 includes an airflow yarn spreading device 7 and a mechanical yarn spreading device 8. The airflow yarn spreading device 7 includes an airflow box arranged below the fiber prepreg tape, which is a hollow structure and internally mounted with a centrifugal fan. The airflow box is a hollow structure penetrating from top to bottom, including an upper shell and a lower shell. The fiber prepreg tape passes through the gap between the upper shell and the lower shell. The centrifugal fan is suspended at the center of the lower shell. The suction direction of the centrifugal fan is perpendicular to the surface of the fiber prepreg tape. The width of the airflow box ranges from 30cm to 100cm, and the length ranges from 20cm to 40cm. When the fiber passes through the gap between the upper shell and the lower shell, the fiber is spread and a fiber prepreg tape is preliminarily formed due to the narrow gap between the upper shell and the lower shell. The centrifugal fan in the airflow box generates a strong airflow below the fiber prepreg tape, which sucks and compresses the air downward. The fiber prepreg tape is in a loose state under the suction of the strong airflow, and is further spread and thinned. Then the mechanical yarn spreading device 8 is used.

[0042] The impregnation mechanism 9 includes an impregnation mold composed of an upper mold body and a lower mold body arranged opposite to each other and coupled to each other to form a wave-shaped impregnation channel therebetween. The wave height of the impregnation channel ranges from 2cm to 3cm, the diameter ranges from 5cm to 7cm, and the number of wave crests ranges from 2 to 20. The impregnation channel is connected to the screw extruder 1. The molten resin extruded by the screw extruder 1 can enter the impregnation channel through the flow channel. After the fiber prepreg tape passes through the yarn spreading mechanism 6, it enters the impregnation channel of the impregnation mold. Since the impregnation channel is wave-shaped and filled with molten resin, the contact interface between the fiber prepreg tape and the molten resin is larger during impregnation. At the same time, the fiber prepreg tape can be further spread into a planar arrangement under the guidance of the wave crests and troughs, preventing uneven impregnation caused by fiber overlap. The wave-shaped arrangement ensures that the frictional tension on each part of the fiber prepreg tape is the same, and the hot melt resin is evenly distributed on the fiber prepreg tape, allowing for sufficient impregnation.

[0043] The fiber prepreg tape after sufficient impregnation is drawn out of the impregnation mold into the composite shaping mechanism 10 for cooling and shaping, the composite shaping mechanism 10 comprises at least two groups of shaping mold sets arranged on the same plane, the shaping mold set comprises an upper rubber-coated compression roller 15 and a lower roller 16 arranged in an upper and lower manner, the fiber prepreg tape passes through the gap between the upper rubber-coated compression roller 15 and the lower roller 16, and finally the low thickness and high impregnation of the prepreg tape can be realized due to the extremely small gap, preferably 0.2 mm, and the molten resin after cooling returns to solid state and fully intermingles with the fiber.

[0044] The composite shaping mechanism 10 is connected with the edge cutting mechanism 11, and the edge cutting mechanism 11 comprises an edge cutting device 17 and a waste edge winding device 18. The fiber prepreg tape after cooling and shaping has certain strength, hardness and toughness and does not appear to be bonded, and after edge cutting and winding, the fiber prepreg tape product is obtained.

[0045] The application also provides a production method of continuous fiber thermoplastic prepreg tape, and the specific steps are as follows:

[0046] The fiber material is selected, and the fiber material is at least one of carbon fiber, glass fiber and aramid fiber;

[0047] The impregnation resin type is selected, and the impregnation resin is at least one of PPS, PEEK and PEKK, and the preferred resin type is a thermoplastic resin with a processing temperature of 200-400 DEG C.

[0048] The production equipment is preheated, and the specific added areas include but are not limited to the threaded base, the runner and the impregnation mold, the preheating time lasts for 2-3 h, and then the production is carried out; wherein the preheating temperature is determined according to the type of the impregnation resin, and the specific temperature is selected as shown in the following table:

[0049] Table 1 preheating parameter selection

[0050] Resin species Pre-heat temperature Barrel 1 Barrel 2 Barrel 3 Flow channel Impregnation mould PPS 100-150 260 280 280 300 310 PEEK 100-150 360 385 390 390 395 PEKK 100-150 310 330 330 330 330

[0051] The fiber material is placed on the creel 2, and the drawing speed is adjusted, and the drawing speed adjustment range is 1.0-3.0 m / min; the fiber passes through airflow spreading and mechanical spreading in sequence, and after the fiber is spread evenly, the main machine and the feeding are started, the feeding is carried out by using granular standard polymer, which greatly simplifies and shortens the process without affecting the quality and performance of the final product. The fiber enters the impregnation mold for molten impregnation; after impregnation, the impregnation mechanism 9 is closed, the mold outlet gap is adjusted to 0.2-0.4 mm; and the edge cutting and winding are carried out after the composite shaping mechanism 10.

[0052] The above merely describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-described embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, several improvements and refinements without departing from the principles of the present application shall also be considered as falling within the protection scope of the present application.

Claims

1. A production equipment for continuous fiber thermoplastic prepreg tape, characterized in that: It includes a yarn separating mechanism, a yarn spreading mechanism, an impregnation mechanism, and a composite setting mechanism connected in sequence. The yarn spreading mechanism includes an airflow yarn spreading device and a mechanical yarn spreading device. The airflow yarn spreading device includes an airflow box located below the fiber prepreg belt. The airflow box has a cavity structure and a centrifugal fan is installed inside. The suction direction of the centrifugal fan is perpendicular to the surface of the fiber prepreg belt. The airflow box is a hollow pot-shaped structure that is narrow at the top and wide at the bottom, including an upper shell and a lower shell. The fiber prepreg tape passes through the gap between the upper shell and the lower shell. The centrifugal fan is suspended in the center of the lower shell. The side plate of the upper shell has an inclination angle of 10-20°. The impregnation mechanism includes a flow channel and an impregnation mold. The impregnation mold is composed of an upper mold body and a lower mold body, which are arranged opposite to each other and form a wave-shaped impregnation channel.

2. The production equipment for continuous fiber thermoplastic prepreg tape according to claim 1, characterized in that: The width of the airflow box ranges from 30cm to 100cm, and the length ranges from 20cm to 40cm.

3. The production equipment for continuous fiber thermoplastic prepreg tape according to claim 1, characterized in that: The wave height of the impregnation channel ranges from 2cm to 3cm, the diameter ranges from 5cm to 7cm, and the number of wave peaks in the impregnation channel ranges from 2 to 20.

4. The production equipment for continuous fiber thermoplastic prepreg tape according to claim 1, characterized in that: The impregnation channel is connected to the screw extruder.

5. The production equipment for continuous fiber thermoplastic prepreg tape according to claim 1, characterized in that: The mechanical yarn spreading device includes at least 5 yarn spreading steel rollers, which are parallel to each other and staggered. The fiber prepreg tape passes above the airflow yarn spreading device and is wound around the yarn spreading steel rollers in sequence.

6. The production equipment for continuous fiber thermoplastic prepreg tape according to claim 1, characterized in that: The composite shaping mechanism includes at least two shaping modules arranged on the same plane, and the shaping module includes a rubber-coated pressure roller and a lower roller arranged vertically.

7. The production equipment for continuous fiber thermoplastic prepreg tape according to claim 1, characterized in that: The yarn separating mechanism is provided with a mountain-shaped reed and yarn separating rollers. The mountain-shaped reed is provided with equally spaced combing teeth, and the number of yarn separating rollers is at least 5.

8. The production equipment for continuous fiber thermoplastic prepreg tape according to claim 1, characterized in that: The composite shaping mechanism is connected to the edge trimming mechanism, which includes an edge cutting device and a waste edge winding device.

9. A method for producing a continuous fiber thermoplastic prepreg tape, characterized in that: The production process is carried out using the production equipment for continuous fiber thermoplastic prepreg tape as described in any one of claims 1-8, and the specific steps are as follows: The fiber material is selected from at least one of carbon fiber, glass fiber, and aramid fiber. The impregnation resin is selected, and the impregnation resin is at least one of PPS, PEEK and PEKK; The different working areas of the production equipment are preheated, including at least the screw extruder, the flow channel and the die. The preheating time lasts for 2-3 hours before production begins. The fibers are placed on a yarn rack, the traction speed is adjusted, and the fibers are sequentially spread by airflow and mechanical yarn, and then enter the impregnation mold for melt impregnation. After the fibers are spread evenly, start the screw extruder and adjust the die exit gap to 0.2-0.4mm; after being shaped by the composite shaping mechanism, trim the edges and rewind.

10. The method for producing a continuous fiber thermoplastic prepreg tape according to claim 9, characterized in that: The traction speed adjustment range is 1.0-3.0 m / min.

11. The method for producing a continuous fiber thermoplastic prepreg tape according to claim 9, characterized in that: The airflow velocity range for airflow yarn spreading is 10m / s-16m / s.

12. The method for producing a continuous fiber thermoplastic prepreg tape according to claim 9, characterized in that: The temperature range for the heating and preheating is 260℃-395℃.

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