DE10012378C2 - Process for the adhesion of fiber-reinforced thermoplastic tapes on a tool platform - Google Patents

Process for the adhesion of fiber-reinforced thermoplastic tapes on a tool platform

Info

Publication number
DE10012378C2
DE10012378C2 DE2000112378 DE10012378A DE10012378C2 DE 10012378 C2 DE10012378 C2 DE 10012378C2 DE 2000112378 DE2000112378 DE 2000112378 DE 10012378 A DE10012378 A DE 10012378A DE 10012378 C2 DE10012378 C2 DE 10012378C2
Authority
DE
Germany
Prior art keywords
tool
fiber
thermoplastic
tapes
tape
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
DE2000112378
Other languages
German (de)
Other versions
DE10012378A1 (en
Inventor
Jochen Korn
Jens Lichtner
Guido Beresheim
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institut fuer Verbundwerkstoffe GmbH
Original Assignee
Institut fuer Verbundwerkstoffe GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institut fuer Verbundwerkstoffe GmbH filed Critical Institut fuer Verbundwerkstoffe GmbH
Priority to DE2000112378 priority Critical patent/DE10012378C2/en
Publication of DE10012378A1 publication Critical patent/DE10012378A1/en
Application granted granted Critical
Publication of DE10012378C2 publication Critical patent/DE10012378C2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/04Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
    • B29C70/28Shaping operations therefor
    • B29C70/30Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
    • B29C70/38Automated lay-up, e.g. using robots, laying filaments according to predetermined patterns
    • B29C70/386Automated tape laying [ATL]

Abstract

When placing thermoplastic tapes, there is insufficient adhesion between the tool and the material surface. The application of a first cover layer is essential for the production of molded parts. The resulting detachment phenomena during the application process prevent further layers from being deposited on the first layer and thus the production of components or, in particular, of concave contours. So far, attempts have been made to keep the fiber-reinforced thermoplastic tapes on the tool surface using double-sided adhesive tape or negative pressure. DOLLAR A By applying a DC voltage (1) between a tool platform (3) provided with an insulating layer (8) and the carbon fibers (12) located in a thermoplastic tape (10), an electrostatic field is generated which prevents the thermoplastic tape from adhering to the tool surface enables. DOLLAR A With the new process, fiber-reinforced thermoplastic tapes can be automatically deposited on a tool surface using the tape laying process.

Description

The invention relates to a method for depositing fiber-reinforced thermoplastic tapes a tool platform using the tape laying process according to the generic term of the first Claim.

With the term tape laying, or in English tape / tow placement or fiber placement the automated storage of unidirectional fiber-reinforced, regardless of direction and position Plastic tapes on flat or curved flat structures. Tape laying enables fiber orientation and positioning in the component to meet the requirements. The Ribbon can be of different width or thickness either individually or several be filed at the same time.

A multi-axis portal system or an articulated arm robot 13 is used to position and orient the tape laying head (TLK) ( FIG. 2) 5 on large structures. Both the coil for ribbon semi-finished products 7 and the tape laying head 5 together with the heating device 11 are mounted on this. In addition to the heating device, the essential components of the TLK are the pressing device 6 , the cutting mechanism and the tape feed unit. The ribbon 10 is transported to the pressing device 6 with the aid of an integrated feed unit. The TLK is placed on a rotatably mounted tool platform 3 . The ribbon is then heated to the melting temperature during the laying process and placed on the tool surface or the laminate that has already been deposited while applying the consolidation pressure. At the end of a path, the ribbon is cut by a cutting unit and the TLK is removed from the tool platform after the storage has been completed.

Although the current state of development of the laying process itself would enable component production, today fiber-reinforced, thermoplastic components cannot yet be manufactured economically using tape laying technology. The reason for this is the solution to the first layer problem that has not yet been suitable for series production: The connection or adhesion of the thermoplastic tapes to one another is ensured by heating and consolidating during the process. However, a first layer of thermoplastic tapes must first be applied for the continuous process. The first layer problem thus consists of the reversible connection of fiber-reinforced thermoplastic tapes on a contoured tool surface, provided that the finished component can in turn be removed from the tool surface without any problems. For this reason, solutions are ruled out that adversely affect the material properties and surface of the component due to chemical processes, contamination, damage, etc. B. Application of adhesives, adhesive tapes etc. [Steiner, Karl: Use of a robot-controlled system for depositing tapes of thermoplastic composites, dissertation, Newark, 1995]. Furthermore, both process engineering and economic suitability for series production, in particular for very large components such as are used for the aerospace industry, must be ensured. Therefore, solutions such as B. a pressurized tool platform made of sintered aluminum (z. B. Metapor) or tools provided with suction holes [Kim, HJ; Lee, W. I; Sihn, SW; Tsai, SW: Flow and heat transfer analyzes during tape lay-up process of thermoplastic composite, I. Crivelli Visconti, ECCM-8, vol. 2, Cambridge 1998 , pp. 631-636]. The first layer problem is therefore not yet suitable for series production and is not dealt with in almost all publications [Ahrens, Markus; Mallik, Vishal: Automated manufacturing of carbon fiber reinforced thermoplastic, in: Advanced Composites Bulletin, August 1998, pp. 7-8 / Ahrens, M .; Mallick, V .; Parfrey, K .: Robots insert thermoplastic fibers in composite materials; in: ABB technology 2/1998, Dornbirn 1998, p 27-34 / Ahrens, Mark: Fiber placement offers cheaper composites; in: Reinforced Plastics, vol. 42 No. 6, Oxford 1998 , p. 25 / Maison, Serge et. al .: Technical developments in thermoplastic composite fuselages; in: Sampe Journal, Vol. 34, No. 5, September / October 1998 , pp. 33-39 / Johnston, NJ et. al .: Automated Fabrication of high performance composites: An overview of research at the Langley Research Center; in: International conference on composite Materials, Gold Coast, Australia, July 14-18 , 1997 / NN: Automated Fiber Placement Technology, FirmenprospektfHauber, David E .; Hardtmann, Dirk J .; Bubeck, Kenneth B .: Recent advances in thermoplastic composite fabrication using rows; in: 35th International SAMPE Symposium, April 2- 5, 1990 / NN: Fiber Placement Equipment from Automated Dynamics, http://www.global2000.net/ adc / fiber.htm, 9.4.1999 / Heider, Dirk; Piovoso MJ; Gillespie, JW Jr .: Intelligent Control of the Thermplastic Composite Tow-Placement Process; in: Journal of Theroplastic Composite Materials, Vol. 11-Nov. 1998 / Don, Roderic C .; Holmes, Scott T .; Steiner, Karl V .; Gillespie, JW Jr .: Integrated process models for control of thermoplastic tow placement with on line consolidation; in: 25th international SAMPE technical conference, Oct. 26-28, 1993 / Zender, H .: Use of industrial robots for the production of fiber composite components in the winding and tape laying process, dissertation, VDI progress reports, series 2 : Manufacturing technology, VDI-Verlag, Düsseldorf 1992 / Schmidt, Ralph: Development of innovative manufacturing techniques for processing continuously fiber-reinforced thermoplastics in the winding process, dissertation, VDI progress reports, series 2 : Manufacturing engineering, VDI-Verlag, Düsseldorf 1994 / Maison, Serge et. al .: Technical developments in thermoplastic composite fuselages; in: Sampe Journal, Vol. 34, No. 5, September / October 1998 , pp. 33-39 / NN: Dassault-Aviation's know-how for composite materials; in: Composites, No. 31 Jan./Feb. 1999 / Du Pont, patent, US 5447586, September 5, 1995 / Weck, M .; Michaeli, W .; Collaborative Research Center SFB 332 , report 1997 , subproject 4 , pp. 175-184 / Weck, M .; vor der Esche, R .: New ways of processing fiber composite materials; in: Industrial application of fiber composite technology III, conference on 5th / 6th October 1998 at RWTH Aachen University, pp. 125-128 / in front of Esche, R .: laser scanner to optimize the heating process, trade fair sheet, 1998 / in front of Esche, R .: processing method for fiber-reinforced thermoplastics, Messeblatt, 1998 / Johnston, NJ: Thermoplastic Composite Fabrication by Automated Robot Heated Head Technology; in: http://larcpubs.larc.nasa.gov/randt/1995/SectionB1.fm514.htm, 11.3.1999 / Johnston NJ; Towell TW; Machello JM; Grenoble RW: Automated fabrication of high preforms composites: an overview of research at the Langley Research Center; in: International Conference on Composite Materials, Gold Coast, Australia, July 14th-18th 1997 / Shuart MJ; Johnston NJ; Dexter HB; Marchello JM; Grenoble RW: Automated fabrication technologies for high performance polymer composites; in: AGARD spring '98 Workshop on Intelligent Processing of high performance Materials, Brussels, Belgium, May 11th-15th 1998, p. 14-1-14-11 / Grenoble, Ray W .; Messier, Bernadette C .; Marchello, Joseph M; Belvin, Harry L .; Johnston, Norman J .: Adhesive Bonding of composite ribbon during automated tow placement; in: Sampe Journal, Vol. 34, No. 3, May / June 1998 , pp. 56-61 / published application DE 196 26 662 A1, Johnson, Bruce]. In the field of the production of thermoset, short fiber reinforced prepregs, the use of electrostatic forces for targeted fiber orientation and deposition on an electrically insulated surface (carrier layer) is known. [Patent DE 31 27 017 C2]. However, short fibers are deposited there in several layers according to a predetermined load. In contrast, in the claim filed by the applicant, thermoplastic tapes are caused to adhere to a tool surface during electrostatic charging when they are deposited automatically.

The invention is intended to provide a method for the automated production of thin-walled, load-optimized fiber composite molded parts which are constructed from thermoplastic, continuously fiber-reinforced strips, and the method is to be carried out by a fully automated process using the tape laying method on a temperature-controlled or temperature-controlled tool platform can. The method with the features of claim 1 is based on the adhesive mechanisms of electrostatics. The two necessary conductors are provided by the metallic tool platform and a conductive fiber or a conductive polymer ( Fig. 1). The thermoplastic itself can serve as an insulating medium between the two conductors. On the other hand, the tool platform is coated with a heat-resistant insulator, e.g. As ceramics, Teflon etc., since in the case of carbon fibers, which are usually also on the surface of the ribbon, or conductive polymers, a short circuit would occur.

According to today's knowledge of the structure of matter, the atoms consist of electrical charged and electrically neutral particles. The atom represents a simple model positive nucleus made up of positively charged particles (protons) and neutral particles (neutrons) consists of around which the negatively charged electrons revolve. The atom appears to the outside neutral if the sum of the positive charges is equal to the total negative charge of the orbiting electrons. If such charged particles are separated, they occur as a positive or negative charge. Outweigh the positive or negative on a body Charges, this is called electrically positively or negatively charged.

The field theory assumes that the existence of an electrical charge Field that exists in their environment. Is located around the body Secondly, a force is exerted on it, which results from the interactions between the charge of the second body and the field of the first. The charges rest, the one generate an electric field, it is an electrostatic field.

However, for a complete description of the electric field, it is not sufficient if the Direction of the lines of force is given. There must also be the amount of force for each point can be specified that the field exerts on a test specimen with the charge Q. The power that acts on a test charge in the electric field is proportional to its charge. However, it is  Unsuitable for clearly describing the strength of a field, as it depends on the size of the charge depends. By arranging electrodes parallel to one another, one obtains without consideration the border areas a homogeneous field.

In contrast to electrical conductors, the electrons in insulators cannot move freely. If there is an insulator (dielectric) in an electrostatic field, this will also be tightened, although a free movement of the load is not possible. Those in the atom or Molecule-bound charges align under the influence of the field. To the External surfaces are thus created, on which the field exerts a force. This The process is called electrical polarization. Since this is just a Polarization through the acting field forces, the insulator remains electrical as a whole neutral.

The following analogy to the plate capacitor results for the tape laying process. One of the Electrodes are formed by the metallic tool platform. By the high Volume fraction of electrically conductive carbon fibers can serve as the counter electrode of the Plate capacitor are used. The applied electrode voltage leads to Formation of an electrical field between the plates.

The insulation layer on the plate prevents charge equalization, causing it to Attraction between the tool platform and the deposited laminate comes. The The tool platform and the tape are considered to be homogeneous conductive plates that pass through the voltage can be charged on the cargo. The achievable force is limited by the Insulation ability of the dielectrics. The voltage at which an insulating layer of electrical Can no longer withstand stress is referred to as dielectric strength. Will this If the limit is exceeded, a charge is exchanged between the platform and the tape and there is a loss of power. Is the distance of the plates by the thickness of the Insulation determined, it corresponds to the distance between the plates. The maximum achievable force between two capacitor plates depends essentially on the dielectric strength, the used dielectric. When using fiber-reinforced thermoplastic tapes usually through the matrix another insulator in the electrical field.

The invention is explained in more detail with reference to the drawings. It shows:

Fig. 1: Adhesion of a fiber-reinforced plastic tape on a tool surface by electrostatic attraction

Fig. 2: Process for automated depositing of the first layer by means of electrostatic attraction in the tape laying process

Fig. 3: Example of voltage transmission to a carbon fiber reinforced ribbon.

Pinching the exposed fibers on the spool core.  

To carry out the invention, the ribbon is transported as far as before to the consolidation device 6 during the process. The negative pole 2 of a DC voltage source 1 is now attached to the tool platform 3 . The positive pole 4 of the voltage source contacts the carbon fibers 12 of the thermoplastic tape. This can be achieved, for example, by processing the end of the ribbon wound on the ribbon spool 7 in such a way that the carbon fibers are exposed and are clamped in the coil core, FIG. 3. The positive pole 4 of the DC voltage source can now be connected to this. Sets the tape laying head 5 for applying the first layer on the tool platform 3, on which the negative terminal of the DC power source 1 is applied, there arises between the tool platform 3 and carbon fibers 12 in the ribbon, an electrostatic field, and thus the connecting normal force effect, Fig. 1. The normal force is is composed of the field effect and the area effect through the polarization. If a non-conductive body, here the thermoplastic ribbon 10 and an insulating tool coating 8 , are brought into an electrical field 15 , this is attracted, although a free displacement of the charge is not possible. In FIG. 2, the method for automatically depositing the first layer of fiber reinforced thermoplastic bands is shown with the tape laying process. A DC voltage source 1 in the kilovolt range is attached with its negative pole 2 to the metallic tool platform 3 and with its positive pole 4 to the tape laying head 5 or the consolidation device 6 or at the end of the carbon fiber reinforced thermoplastic tape in the coil 7 . The electrostatic field between the tool platform and carbon fibers causes the carbon fiber reinforced thermoplastic tape to adhere to the tool surface. The tool surface is to protect against short circuits by carbon fibers located on the belt surface and for easier release of the finished component from the surface with a ceramic 8 z. B. Al 2 O 3 coated. The adhesive effect of the electrostatic field is used even after the first layer has been completed until the laying process is complete in order to hold the component on the tool platform. The same process can also be used for carbon fiber reinforced thermoset tapes.

Claims (7)

1. Process for the automated depositing of reinforced with electrically conductive fibers. Ther moplast tapes with the tape laying process by applying an electrical voltage to the Er Generation of an electrical field between a tool platform and the fiber-reinforced Thermoplastic tapes, which causes the fiber-reinforced plastic tapes to adhere to an elect rically insulated tool surface of the tool platform as a result of the electrostatic field and the electrical polarization is made possible.
2. The method according to claim 1, characterized in that fully impregnated or partially impregnated Thermoplastic tapes are used.
3. The method according to claim 1 or 2, characterized in that the grounding of the fiber-reinforced Plastic straps both over carbon fibers, over the consolidation system, over half tool holder (coil) or via a component of the tape laying head or also omitted len.
4. The method according to claim 1 to 3, characterized in that the tool platform also uncoated with non-conductive thermoplastic with carbon sedimented in the middle is operated.
5. The method according to claim 1 to 4, characterized in that an identical substance or kerami cal, insulating coating of the tool surface is provided.
6. The method according to claim 5, characterized in that the tool insulation in foil form or is applied as a molten powder.
7. The method according to claim 1 to 4, characterized in that the strips are cooled, untempered or stored heated.
DE2000112378 2000-03-09 2000-03-09 Process for the adhesion of fiber-reinforced thermoplastic tapes on a tool platform Expired - Lifetime DE10012378C2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE2000112378 DE10012378C2 (en) 2000-03-09 2000-03-09 Process for the adhesion of fiber-reinforced thermoplastic tapes on a tool platform

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2000112378 DE10012378C2 (en) 2000-03-09 2000-03-09 Process for the adhesion of fiber-reinforced thermoplastic tapes on a tool platform

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DE10012378C2 true DE10012378C2 (en) 2001-11-22

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102017122584A1 (en) 2016-09-28 2018-03-29 Engel Austria Gmbh Mold for a molding machine
DE102017215153A1 (en) 2017-08-30 2019-02-28 M & A - Dieterle GmbH Maschinen- und Apparatebau A handguide device and method for manually depositing a fiber reinforced web on a substrate, and using a handrail device to manually lay a fiber reinforced web on a substrate
DE202019104861U1 (en) 2019-09-03 2019-09-17 Markus Brzeski Electrostatic fixing of strips of fiber-plastic composite materials in injection mold as a retrofit

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10129514B4 (en) * 2001-06-11 2007-04-19 Institut Für Verbundwerkstoffe Gmbh Method for adhering thermoplastic strips on a tool platform
DE10329431A1 (en) * 2003-07-01 2005-02-03 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Method and apparatus for producing fiber reinforced composite components
EP2203299A4 (en) * 2007-10-16 2012-11-14 Ingersoll Machine Tools Inc Fiber placement machine platform system having interchangeable head and creel assemblies
DE102009017112A1 (en) 2009-04-15 2010-10-21 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Process for the production of plastic-containing components and apparatus suitable for carrying out the process
DE102011121883A1 (en) * 2011-12-21 2013-06-27 Volkswagen Aktiengesellschaft Method for preparation of molded unit, involves applying polymeric matrix material, and applying positive and negative charge carriers to fiber semi-finished product and electrode in tool respectively for fixing product at tool
WO2014012775A1 (en) 2012-07-18 2014-01-23 Voith Patent Gmbh Device and method for producing fibre-reinforced plastics components
DE102012017595B4 (en) * 2012-09-06 2014-08-21 Premium Aerotec Gmbh Laying head and depositing method for the automated depositing of blanks of a sheet material, in particular for the production of large-area fiber composite components
DE102013107103A1 (en) * 2013-07-05 2015-01-08 Deutsches Zentrum für Luft- und Raumfahrt e.V. Semi-finished fiber-laying head
US20170348874A1 (en) * 2014-12-18 2017-12-07 Deutsches Zentrum für Luft- und Raumfahrt e.V. Semi-finished fiber product lay-up head
DE102015116302A1 (en) 2015-09-25 2017-03-30 Deutsches Zentrum für Luft- und Raumfahrt e.V. Downholder, effector and method for producing a layer structure of sheet-like thermoplastic fiber matrix semi-finished layers
DE102016107920A1 (en) 2016-04-28 2017-11-02 Deutsches Zentrum für Luft- und Raumfahrt e.V. Fiber laying head and method for laying fiber material

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DE3127017C2 (en) * 1981-07-09 1984-08-23 Messerschmitt-Boelkow-Blohm Gmbh, 8000 Muenchen, De

Patent Citations (1)

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DE3127017C2 (en) * 1981-07-09 1984-08-23 Messerschmitt-Boelkow-Blohm Gmbh, 8000 Muenchen, De

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102017122584A1 (en) 2016-09-28 2018-03-29 Engel Austria Gmbh Mold for a molding machine
DE102017122584B4 (en) * 2016-09-28 2020-07-02 Engel Austria Gmbh Molding tool for a molding machine, molding machine and method for manufacturing a molding
DE102017215153A1 (en) 2017-08-30 2019-02-28 M & A - Dieterle GmbH Maschinen- und Apparatebau A handguide device and method for manually depositing a fiber reinforced web on a substrate, and using a handrail device to manually lay a fiber reinforced web on a substrate
DE202019104861U1 (en) 2019-09-03 2019-09-17 Markus Brzeski Electrostatic fixing of strips of fiber-plastic composite materials in injection mold as a retrofit

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Publication number Publication date
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