Process skin for autoclave forming of composite product and preparation method of process skin

A technology of autoclave molding and composite materials, which is applied in the field of structural composite materials, and can solve the problems of difficult application of parts, low manufacturing efficiency, and long time for hot press equipment

Inactive Publication Date: 2019-05-03
AVIC BASIC TECH RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Autoclave forming, vacuum diversion forming and vacuum bag forming are single-sided molds, the lower surface is attached to the mold, and the shape accuracy is high, while the upper surface needs to be laid with auxiliary materials such as isolation film and release cloth, and there is no mold guarantee. Poor shape accuracy
Especially for composite materials with variable thickness, large thickness, and multiple curvatures with complex shapes, it is more difficult to guarantee the shape accuracy when single-sided molds are used.
To solve this problem, compression molding with closed mold molding can be used. The problem is that the manufacturing efficiency is low, it takes a long time for the hot press equipment, it is difficult to meet the requirements of large-scale mass production, and the internal quality of composite parts molded by compression molding is relatively low. Low, poor quality stability, difficult to apply to parts with higher quality requirements
RTM closed mold molding is a liquid molding process. The fiber volume fraction of composite materials is lower than that of compression molding and autoclave molding, which is difficult to meet for composite parts with high design requirements and harsh operating conditions.

Method used

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  • Process skin for autoclave forming of composite product and preparation method of process skin
  • Process skin for autoclave forming of composite product and preparation method of process skin

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preparation example Construction

[0026] see figure 1 The second aspect of the embodiment of the present application shows a method for preparing a process skin for autoclave molding of a composite material product, the method comprising the following steps:

[0027] S101 According to the digital model of the composite material part, the same metal surface as the digital model of the composite material part is manufactured by mechanical processing;

[0028] S102 Spread a release agent evenly on the surface of the metal mold and dry it naturally, lay a layer of rubber sheet, lay a composite of resin and fiber on the upper surface of the film, and lay a layer of rubber sheet;

[0029] It is worth noting that the technical solution shown in the embodiment of the present application adds two rubber sheets, which are the bottom layer and the top layer respectively.

[0030]The process skin proposed in this application is mainly to improve the surface precision and internal quality of composite material parts. The ...

Embodiment 1

[0036] According to the digital model of the composite material part, the 45# steel is machined into the same profile as the upper surface of the composite material part, which is used as the preparation mold for the process skin. Spread the release agent evenly on the surface of the mold, and after natural drying, lay a layer of silicone rubber sheet with a thickness of 1mm. Lay a layer of carbon fiber and epoxy resin composite on the silicone rubber sheet by hand lay-up process, and place a layer of silicone rubber sheet with a thickness of 1mm on top of the composite. Lay isolation film, release cloth, air felt and other auxiliary materials on the upper surface of the rubber sheet in turn, use vacuum bags to package, place in an autoclave, and follow the curing process of the resin and rubber sheet and the vulcanization process of the rubber sheet Carry out curing molding. After the curing is completed, the temperature is naturally lowered to below 60°C and taken out to ob...

Embodiment 2

[0038] According to the digital model of the composite material part, the 45# steel is machined into the same profile as the upper surface of the composite material part, which is used as the preparation mold for the process skin. Spread the release agent evenly on the mold surface, after natural drying, lay a layer of silicon rubber sheet with a thickness of 1.5mm, and lay a layer of carbon fiber / epoxy resin prepreg with a mass of 200 grams per unit area on top of it Material and a layer of silicon rubber sheet with a thickness of 1.5mm. Lay isolation film, release cloth, air felt and other auxiliary materials on the upper surface of the rubber sheet in turn, use vacuum bags to package, place in an autoclave, and follow the curing process of the resin and rubber sheet and the vulcanization process of the rubber sheet Carry out curing molding. After the curing is completed, the temperature is naturally lowered to below 60°C and taken out to obtain a technical skin for composi...

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Abstract

The embodiment of the invention discloses a process skin for autoclave forming of a composite product and a preparation method of the process skin. In the autoclave forming process, the process skin is put on the upper surface of the composite product, an auxiliary material is put on the upper surface of the process skin, under the pressure applied by an autoclave, a prepreg preform is overall pressed downwards, the internal quality is improved, and wrinkles, caused by the weak deformation capacity of the auxiliary material, generated on the surface of the composite product are avoided. Meanwhile, a molded surface consistent with the upper surface of the composite product is arranged on the process skin, so that the appearance precision of the composite product is well guaranteed. The process skin can be widely applied to autoclave forming of composite products with complex shapes, and the appearance precision and the internal quality of the products are greatly improved.

Description

technical field [0001] The invention belongs to the technical field of structural composite materials, and relates to a process skin for forming composite material parts in autoclave and a preparation method thereof. Background technique [0002] Advanced composite materials reinforced by continuous fibers such as carbon fibers have outstanding advantages such as high specific strength, specific modulus, low density, good corrosion resistance, fatigue resistance, and strong designability, and are more widely used in aerospace and other fields and in-depth. In the field of advanced manufacturing, more and more metal parts with complex shapes are replaced by composite parts. However, limited by the molding process characteristics of composite material parts, the high-precision molding of corresponding composite material parts has become a manufacturing difficulty. In addition, composite parts have undergone a transformation from non-load-bearing members to secondary load-bea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B29C70/34C08L63/00C08L79/08C08L77/00C08K7/06C08K7/14
Inventor 高军鹏邓华任永哲李斌太
Owner AVIC BASIC TECH RES INST
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