DE102016111074A1 - Gas guide arrangement and method for the vacuum-assisted processing of a semi-finished fiber product - Google Patents

Abstract

A gas guide assembly (106) for use in a method of vacuum assisted processing of a semifinished fiber product (100) in an evacuable mold cavity (114), said gas guide assembly (106) being intrinsically rigid and dimensionally stable, and methods of vacuum assisted processing of a semifinished fiber product (100) in an evacuable mold cavity (114), wherein for evacuating the mold space (114) at least one such gas guide arrangement (106) is used.

Description

The invention relates to a gas guide arrangement for use in a method for the vacuum-assisted processing of a semifinished fiber product in an evacuable mold space. Moreover, the invention relates to a method for the vacuum-assisted processing of a semifinished fiber product in an evacuable mold space.

From the DE 100 13 409 C1 a method is known for the production of fiber-reinforced plastic components from dry fiber composite semi-finished products by means of an injection method for injection of matrix material with the steps: arranging the fiber composite semifinished product on a tool, wherein on a surface of the semifinished product a flow aid is arranged, formation a first space by means of a gas-permeable and matrixmaterialundurchlässigen membrane around at least on one side of the semifinished product, wherein in the first space matrix material is insertable, forming a second space adjacent to the first space from the environment by means of a gas and matrixmaterialundurchlässigen, with respect to the tool Sealed air is drawn from the second space, whereby matrix material from the reservoir is sucked into the evacuated first space and the flow aid is a distribution of the matrix material on the surface of the semifinished product facing this and penetration d The same effects vertically in the semifinished product.

From the DE 201 02 569 U1 An arrangement is known for producing a component from a fiber-reinforced material by means of resin impregnation of a semi-finished fiber product, comprising a mold; a vacuum film, by means of which a vacuum space can be produced, in which the semi-finished fiber can be positioned on the mold, wherein the vacuum space can be acted upon by negative pressure and a supply device for liquid resin to the semifinished fiber, in the negative pressure and temperature in the resin impregnation so controllable and / or can be regulated that, based on the liquid resin, the boiling point curve is not exceeded.

From the DE 10 2014 111 358 A1 is a multi-part vacuum hood known for covering fiber material in the manufacture of a fiber composite component, wherein the vacuum hood is made of a flexible material or has a flexible material and a plurality of separate vacuum hood segments, which together form the multi-part vacuum hood to cover the fiber material, wherein the vacuum hood segments for releasably connecting in provided on the vacuum hood segments connecting portions to form the composite, multi-part vacuum hood are formed.

From the DE 10 2014 116 848 A1 For example, a method is known for automated production of a vacuum structure for the manufacture of a fiber composite component which is made by curing a matrix material infused into a fibrous material using a vacuum structure, wherein a plurality of unconsolidated material layers for vacuum buildup are provided by a material supply device, wherein the material layers are automated be assembled in layers by a joining device to a prefabricated vacuum structure, wherein before, during or after assembly, the material layers are assembled by a cutting device in dependence on predetermined geometry data.

From the DE 40 19 744 A1 a method is known for repairing components made of plastic, in particular fiber composite materials, in which one removes material at the defect or defect in the component to form a recess material and fills the depression with existing resin and fiber material repair material, wherein in the recess fiber mats , Fiber fabric, fibrous fabric od. Like. Inserted in the form of the size and shape of the recess adapted blanks, the blanks were either soaked before loading with resin or instead the depression is then filled with resin, and wherein the shape and Determines the size of the recess to be produced to a few standard sizes and wherein prefabricated and provided for each individual standard size associated blanks, each of which at least substantially fit exactly fit into the well associated shape and size.

From the DE 10 2011 076 463 A1 a repair method is known for a molding made of a plastic material, wherein a repair element of the plastic material is applied to a damaged portion of the molded part and bonded by the action of heat, wherein the heat is generated by means of a passive heating element made of an electrically conductive material in that the heating element is subjected to an alternating magnetic field.

The invention has for its object to improve an initially mentioned gas guide assembly structurally and / or functionally. In addition, the invention has for its object to improve a method mentioned above.

The object is achieved with a gas guide arrangement having the features of claim 1.

The semi-finished fiber may comprise organic fibers such as aramid fibers, carbon fibers, polyester fibers, nylon fibers, polyethylene fibers, Plexiglas fibers, and / or inorganic fibers such as basalt fibers, boron fibers, glass fibers, ceramic fibers, silica fibers. The fibers may have filaments. The filaments can be combined into rovings. The fibers may be in the form of woven, knitted, knitted, braided or stitchbonded threads. The fibers can be present as textile. The semi-finished fiber may have one or more layers.

The semi-finished fiber may be a dry semi-finished fiber. The semifinished fiber product can be infiltratable with a matrix material. The semi-finished fiber can be limp. The semifinished fiber product may be a semi-finished fiber product preimpregnated with a matrix material. The semi-finished fiber may be a prepreg. The semi-finished fiber may be inherently stiff. The semi-finished fiber can be made up. Fabrication can include cutting, assembly and / or joining, such as gluing, welding and / or sewing.

The matrix material may be thermoplastic. The matrix material may include polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polysulfone (PSU), polyetherimide (PEI) and / or polytetrafluoroethene (PTFE). The matrix material may be thermosetting. The matrix material may include epoxy resin (EP), unsaturated polyester resin (UP), vinyl ester resin (VE), phenol-formaldehyde resin (PF), diallyl phthalate resin (DAP), methacrylate resin (MMA), polyurethane (PUR) and / or amino resins such as melamine resin (MF / MP) or urea resin (UF). The matrix material may have benzoxazines.

The semi-finished fiber can be processed to produce a fiber composite component. The semi-finished fiber can be processed to repair a fiber composite component. The fiber composite component may be a vehicle component. The vehicle may be a land vehicle, motor vehicle, aircraft, watercraft or spacecraft. The fiber composite component may be a large-area component. The fiber composite component may be a body portion of an aircraft. The fiber composite component may be a wing portion of an aircraft.

The mold cavity can be formed by means of an open mold and a cover layer. The mold may have a molding surface. The mold can be inherently rigid. The top layer can be limp. The cover layer can be gas-tight. The cover layer may be matrix material-tight. The cover layer may be tightly connected to the mold. The mold space can be evacuated by applying a negative pressure. "Evacuation" can mean "sucking off". A gas may in particular be air and / or a reaction gas. The semi-finished fiber can be arranged in the mold space. The gas guide assembly may serve for gas flow guidance during evacuation of the mold cavity.

The gas guide arrangement may have a predetermined shape. The gas guide arrangement can be handled while maintaining its predetermined shape. The gas guide arrangement can be dimensionally stable in such a way that it does not deform significantly under the action of underpressure-induced forces. The gas guide arrangement can be elastically deformable. The gas guide arrangement can be dimensionally stable in such a way that it elastically deforms under the action of particularly forces due to negative pressure and, after discharge, assumes its original form again.

The gas guide arrangement may be made of a fabric. The gas guide assembly may be made of a wire. The gas guide assembly may be made of a stranded wire. The gas guide arrangement may be made of a metal. The gas guide assembly may be made of iron or a steel. The gas guide assembly may be made of a stainless steel. The gas guide assembly may be made of a non-ferrous metal such as copper, brass, bronze, nickel or titanium. The gas guide assembly may be made of a refined, for example rolled, heat treated, sintered, pickled, electropolished, coated and / or cleaned material.

The gas guide arrangement may have a sheet-like shape. The gas guide arrangement can have a flat shape. The gas guide arrangement may have a planar shape. The gas guide arrangement may have a single or multiple curved shape.

The gas guide arrangement may have a frame-like shape. The gas guide arrangement may have at least one edge section. The gas guide arrangement may have at least one recess exhibit. The at least one recess can serve to receive a semi-finished fiber product. The at least one recess may have a shape adapted to a male semi-finished fiber product. The gas guide arrangement may have a height adapted to a male semi-finished fiber product. The at least one recess may be angular. The at least one recess may be polygonal. The at least one recess may be quadrangular, in particular rectangular. The at least one recess may be round. The at least one recess may at least partially have a straight contour. The at least one recess may have a curved contour at least in sections. The at least one recess may, at least in sections, have a multiply curved contour.

The gas guide arrangement can be multi-layered, in particular three-layered. The gas guide arrangement can have a plurality of individual layers. The gas guide arrangement can have folded layers.

In addition, the object underlying the invention is achieved with a method having the features of claim 6.

The method may comprise at least one of the following steps: arranging the semifinished fiber product on a molding surface of an open mold and / or on the gas guide arrangement; Arranging the gas guide arrangement on a molding surface of an open mold and / or on the semifinished fiber product; Covering the semifinished fiber product and the gas guide assembly with a cover layer; tightly joining the cover sheet and the mold to form an evacuable mold space; Heating the semifinished fiber product; Evacuate the mold space.

A sheet-shaped gas guide arrangement can be arranged between a molding surface of a molding tool and a semi-finished fiber product. A sheet-like gas guide arrangement can be arranged between a semi-finished fiber product and a cover layer.

A frame-shaped gas guide arrangement can be arranged on a molding surface of a molding tool. A semi-finished fiber product can be arranged on a frame-shaped gas guide arrangement. The frame-shaped gas guide arrangement can be used for positioning a semifinished fiber product. The gas guide arrangement can be reused.

In the method, a molding element can be used which is at least partially transparent to heat radiation at least in part. The shaped element may have a low attenuation constant for parts of the infrared spectrum. The molding element can be at least partially transparent to heat radiation at least in a section which serves to abut a semifinished fiber product. The mold element may have a very low thermal conductivity compared to metal. The molded element may have a thermal conductivity of about 1.3 W / (m · K) to about 1.6 W / (m · K), in particular of about 1.46 W / (m · K). The mold element may have a very low heat capacity compared to metal. The mold element may have a very low thermal expansion coefficient compared to metal. The shaped element can be produced at least in sections from glass ceramic.

The mold element may have a plate-like shape. The mold element may have a flat shape. The mold element may have a planar shape. The mold element may have a single or multiple curved shape. The mold element can serve as a pressure element. The mold element or pressure element can be used for pressing a semi-finished fiber product. The mold element or pressure element can be used to press a semifinished fiber product on a mold. The mold element can serve as a mold. The molding element may form at least a portion of a molding tool.

The method may comprise at least one of the following steps: arranging the semi-finished fiber product on a molding element and / or on a gas guide arrangement; Arranging a gas guide arrangement on a molding element or molding tool and / or on the semifinished fiber product; Arranging a molding element or pressure element on the semifinished fiber product in order to press the semifinished fiber product; Covering the semifinished fiber product, the gas guide arrangement and the molding element or pressure element with a cover layer; tightly joining the cover sheet and the mold to form an evacuable mold space; Heating the semifinished fiber product by means of thermal radiation; Evacuate the mold space.

The heat radiation can be applied by means of an infrared radiator. The semifinished fiber product can be acted upon by the molding element or molding tool and / or by the molding element or pressure element through with a thermal radiation.

The semi-finished fiber can be arranged in one or more layers. The semi-finished fiber can be stacked. The semi-finished fiber can be arranged directly on the mold element or mold. A decoupling layer can be arranged between the mold element or molding tool and the semi-finished fiber product. The cover layer can be arranged directly on the semifinished fiber product. Between the cover layer and the semifinished fiber product, a decoupling layer can be arranged. The cover layer may be at least partially transparent to heat radiation. The cover layer may be at least partially transparent to heat radiation at least in sections. For sealing the cover layer and the molding element or mold a sealing tape can be used. The evacuable mold space can have at least one vacuum connection. The at least one Vacuum connection may have a membrane-like cover. The membrane-like cover may be gas permeable and matrix material impermeable. The at least one vacuum connection can be arranged on the cover layer. The at least one vacuum connection can be arranged on the molding tool. The method can be carried out automatically or semi-automatically.

In summary and in other words, the invention thus provides, inter alia, a method for processing plastics by means of vacuum bag methods for the production of thermoplastic organic sheets and components as well as for repairing articles made of plastics.

The gas guide assembly may also be referred to as a breather. As a gas guide arrangement, a three-layer metallic wire mesh can be used. The wire mesh can only be attached laterally to one edge around the laminate. The shape of the laminate can be cut out of the wire mesh in advance. The laminate can be inserted accurately into the wire mesh. A vacuum port can be placed above or below the wire mesh to prevent airflow obstruction.

The wire mesh may have a rigid structure. The wire mesh can be used as often as required and does not need to be replaced regularly. The metallic wire mesh screen can hold a constant height at negative pressure.

It can be used for heat radiation transparent pressure element, for example, a glass ceramic plate made of Ceran ^® . A component can be heated directly.

Glass ceramics can be used on both sides of the component to be consolidated as an upper and lower tool. The component can be heated with infrared radiation from both sides.

By "may" in particular optional features of the invention are referred to. Accordingly, there is an embodiment of the invention each having the respective feature or features.

With the invention, an effort, such as time, cost, energy consumption and / or cost of materials is reduced. Requirements for temperature resistance can be reduced. A coating can be omitted. A need for consumables can be reduced. Repair possibilities for fiber composite components are extended. A litigation is simplified. Resource efficiency is increased. A waste quantity is reduced. Reproducibility is increased. Process reliability is increased. A mobile application can be enabled. Flow guidance during evacuation is improved. An evacuation is facilitated. Manual work shares can be reduced. A complexity is reduced.

Hereinafter, embodiments of the invention will be described with reference to figures. From this description, further features and advantages. Concrete features of these embodiments may represent general features of the invention. Features associated with other features of these embodiments may also constitute individual features of the invention.

They show schematically and by way of example:

1 an arrangement for the vacuum assisted processing of a semifinished fiber product with a wire guide fabricated gas guide assembly, a glass ceramic plate as a pressure element and overhead vacuum connection,

2 Pressure curves as a function of a distance to a vacuum connection,

3 an arrangement for the vacuum assisted processing of a semifinished fiber product with a wire guide fabricated gas guide assembly, a glass ceramic plate as a pressure element and bottom vacuum port,

4 an arrangement for the vacuum-assisted processing of a semifinished fiber product with a glass ceramic plate as a molding tool, a gas guide assembly made of a wire mesh and a glass ceramic plate as a pressure element.

1 shows an arrangement for the vacuum assisted processing of a semi-finished fiber 100 , The arrangement comprises an open mold 102 with a molding surface, a printing element 104 , a gas guide arrangement 106 , a cover layer 108 and an overhead vacuum port 110 ,

The semifinished fiber product 100 is a pre-impregnated with reactive resins textile fiber matrix semifinished product. As a mold 102 serves a metal plate. The pressure element 104 is transparent to heat radiation. The pressure element 104 has a very low thermal conductivity of, for example, about 1.46 W / (m · K) and virtually no thermal expansion. As a pressure element 104 serves a glass ceramic plate. The gas guide arrangement 106 is made of a wire mesh. The gas guide arrangement 106 has a frame-like shape with a cutout. The detail of the gas guide arrangement 106 and the semifinished fiber product 100 have corresponding contours. As a cover layer 108 serves a pliable, gas-impermeable film. The vacuum connection 110 is at the top layer 108 in the field of gas guidance 106 arranged. The vacuum connection 110 is provided with a gas-permeable and matrix-impermeable membrane-like cover.

For processing the semifinished fiber product 100 First, the gas guide arrangement 106 on the mold 102 arranged. The following is the unconsolidated semi-finished fiber product 100 in the recess of the gas guide arrangement 106 inserted. The gas guide arrangement serves this purpose 106 as a positioning frame for the semifinished fiber product 100 , The following is the pressure element 104 on the semifinished fiber product 100 arranged to the semi-finished fiber 100 evenly pressing and subsequently achieving a high-quality component surface. The following are the gas guide arrangement 106 , the semifinished fiber product 100 and the pressure element 104 with the top layer 108 covered and the top layer 108 is done using a band-shaped seal 112 with the mold 102 tightly connected to an evacuable mold space 114 to limit. The semi-finished fiber will be described below 100 heated by heat radiation. For heating the semifinished fiber product 100 An infrared radiator can be used. The heat radiation penetrates the top layer 108 and the pressure element 104 and immediately heats the semifinished fiber product 100 , Adjacent areas are thus exposed only to a reduced thermal load. The following is the shape space 114 evacuated. These are via the vacuum connection 110 and the gas guide assembly 106 Aspirated air and / or reaction gases.

The gas guide arrangement 106 has a high and consistent gas permeability. 2 shows pressure gradients 202 . 204 as a function of a distance to the vacuum connection 110 , In the diagram 200 in 2 is on an x-axis a distance to the vacuum port 110 and applied a pressure on a y-axis. When using a glass fabric as a gas guide arrangement results in a pressure curve 202 , from which it can be seen that a negative pressure applied to the vacuum port rapidly loses its effectiveness with increasing distance from the vacuum port. When using a made of a wire mesh gas guide assembly 106 results in a pressure curve 204 , from which it can be seen that one at the vacuum port 110 Applied negative pressure with increasing distance from the vacuum port 110 remains effective.

When evacuating the top layer 108 under pressure in the direction of the mold 102 pulled, wherein the semi-finished fiber 100 subjected to a compressive force and the semi-finished fiber 100 is consolidated under pressure and heat. The gas guide assembly made of a wire mesh 106 is not compacted, so that even when evacuating a uniform evacuation flow with increased throughput and reduced flow resistance is guaranteed. The gas guide assembly made of a wire mesh 106 can be reused for processing further semi-finished fiber products.

In another embodiment, a layered gas guide arrangement made of a wire mesh can alternatively or additionally lie in the form of a layer between the molding tool 102 and the semifinished fiber product 100 and / or between the semifinished fiber product 100 and the top layer 108 to be ordered.

3 shows an arrangement for the vacuum assisted processing of a semi-finished fiber 300 with a gas guide made of a wire mesh 302 , a glass ceramic plate as a pressure element 304 and bottom vacuum connection 306 , The vacuum connection 306 is in the field of gas guidance 302 in the mold 308 arranged. Incidentally, in addition to particular 1 and 2 and the associated description.

4 shows an arrangement for the vacuum assisted processing of a semi-finished fiber 400 with a glass ceramic plate as a molding tool 402 a gas guide assembly made of wire mesh 404 and a glass ceramic plate as a pressure element 406 ,

The semifinished fiber product 100 can thus from the top through the top layer 408 and the pressure element 406 and / or from below through the mold 402 to be heated. Incidentally, in addition to particular 1 and 2 and the associated description.

LIST OF REFERENCE NUMBERS

100

Semi-finished fiber

102

Mold element, mold

104

Form element, pressure element

106

Gas guide assembly

108

topsheet

110

Vacuum port

112

poetry

114

cavity

200

diagram

202

pressure curve

204

pressure curve

300

Semi-finished fiber

302

Gas guide assembly

304

Form element, pressure element

306

Vacuum port

308

Mold element, mold

400

Semi-finished fiber

402

Mold element, mold

404

Gas guide assembly

406

Form element, pressure element

408

topsheet

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10013409 C1 [0002]
• DE 20102569 U1 [0003]
• DE 102014111358 A1 [0004]
• DE 102014116848 A1 [0005]
• DE 4019744 A1 [0006]
• DE 102011076463 A1 [0007]

Claims (9)

Gas guiding arrangement ( 106 . 302 . 404 ) for use in a process for the vacuum assisted processing of a semifinished fiber product ( 100 . 300 . 400 ) in an evacuable mold space ( 114 ), characterized in that the gas guiding arrangement ( 106 . 302 . 404 ) is inherently rigid and dimensionally stable. Gas guiding arrangement ( 106 . 302 . 404 ) according to claim 1, characterized in that the gas guide arrangement ( 106 . 302 . 404 ) is made of a wire mesh. Gas guiding arrangement ( 106 . 302 . 404 ) according to at least one of the preceding claims, characterized in that the gas guide arrangement ( 106 . 302 . 404 ) has a sheet-like shape. Gas guiding arrangement ( 106 . 302 . 404 ) according to at least one of the preceding claims, characterized in that the gas guide arrangement ( 106 . 302 . 404 ) has a frame-like shape. Gas guiding arrangement ( 106 . 302 . 404 ) according to at least one of the preceding claims, characterized in that the gas guide arrangement ( 106 . 302 . 404 ) is multi-layered, in particular three-ply. Process for the vacuum assisted processing of a semi-finished fiber product ( 100 . 300 . 400 ) in an evacuable mold space ( 114 ), characterized in that for evacuating the mold space ( 114 ) at least one gas guide arrangement ( 106 . 302 . 404 ) is used according to at least one of the preceding claims. A method according to claim 6, characterized in that a sheet-like gas guide arrangement ( 106 . 302 . 404 ) between a molding surface of a mold ( 102 . 308 . 402 ) and a semi-finished fiber product ( 100 . 300 . 400 ) and / or between a semi-finished fiber product ( 100 . 300 . 400 ) and a cover layer ( 108 . 408 ) is arranged. Method according to at least one of claims 6 to 7, characterized in that a frame-shaped gas guide arrangement ( 106 . 302 . 404 ) on a molding surface of a molding tool ( 102 . 308 . 402 ) and / or a semi-finished fiber product ( 100 . 300 . 400 ) on a frame-shaped gas guide arrangement ( 106 . 302 . 404 ) is arranged. Method according to at least one of claims 6 to 8, characterized in that the gas guide arrangement ( 106 . 302 . 404 ) is reused.

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