Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
  • B24C1/00—Methods for use of abrasive blasting for producing particular effects; Use of auxiliary equipment in connection with such methods
  • B24C1/06—Methods for use of abrasive blasting for producing particular effects; Use of auxiliary equipment in connection with such methods for producing matt surfaces, e.g. on plastic materials, on glass
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
  • B05D3/12—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by mechanical means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
  • B05D7/02—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to macromolecular substances, e.g. rubber

Definitions

• the invention relates to a method for preparing plastic surfaces, preferably surfaces of carbon fiber reinforced plastics, for further processing to produce supporting structural parts, particularly supporting surfaces of aircraft, by means of abrasive removal of the surface.
• Such prepared surfaces are needed in modern aircraft construction in order to be able to build even lighter structures, by means of processing carbon fiber reinforced plastics.
• the bond surfaces of the upper and lower shell of supporting surfaces must be pretreated carefully, before they are bonded together to produce the finished wing.
• frames and stringers must also be laminated in between the shells.
• a water-break test is performed, which takes advantage of the difference in surface tension of ground and contaminated surfaces, in order to be able to make a statement about the quality of the result of grinding.
• the bond surface is completely wetted using de-ionized water. Subsequently, the surface is set vertically, so that the water can flow off. In the case of a well-cleaned surface, the water flows off evenly. Water beads form at dirty points. Such points must be additionally ground.
• the parts must first be dried in an oven, in order to remove the water, i.e. any residual moisture.
• This task is accomplished, in the case of a method of this type, in that the material removal takes place by means of an abrasive sandblasting agent that is distributed in a gaseous fluid. If the time that is required in order to remove the surface, usually down to the fiber, i.e. to destroy it, is measured, about one-tenth of this time is surprisingly sufficient to achieve a treatment of the surface that is sufficient for the bond. The quality of this surface actually surpasses that of a ground surface. In fracture tests, the components fail not at the bond point, but rather in the basic material, and this significantly increases the ability of the bonded structural parts to withstand stress.
• Contamination of the mechanically cleaned surface with the fluid is advantageously avoided in that the gaseous fluid is dried air from which oil has been removed.
• Particularly durable bonds are achieved if a sharp-edged corundum grain, preferably in a grain size range between 0 and 90 ⁇ m, particularly between 17 and 62 ⁇ m, is used as the sandblasting agent.
• sandblasting agent is applied to the surface to be treated by means of a low-pressure jet, preferably from a pressure boiler at less than 2.5 bar.
• the same purpose is served by the measure of applying the sandblasting agent to the surface to be treated by means of an eddy jet nozzle.
• the rotating jet of the eddy jet nozzle prevents the formation of disadvantageous so-called hot spots.
• An optical inspection of the work result is advantageously sufficient, in order to assure sufficient quality of the surface.
• the treatment with the sandblasting agent takes place as long as necessary in order to achieve an almost cloud-free, matt, treated surface.
• This quality is advantageously defined analogous to DIN EN ISO 12944-4 SA 2.5, by way of the work result. Complicated water-break tests with drying steps in large, complicated ovens can therefore be eliminated.
• the treated surface is blown off with dried and oil-free air, in order to remove the sandblasting agent. Any remaining individual grains of the sandblasting agent that might have penetrated deeper into the surface surprisingly do not have a disadvantageous effect.
• a quality inspection of the treated surface takes place by means of measuring a surface resistance and/or by means of an optical inspection using a comparison sample.
• the reproducibility of the work result is additionally improved if the treatment takes place in an air-conditioned, preferably draft-free environment.
• the surface is vacuum-packed for transport.
• Such packaging is already sufficient to transfer the work process according to the invention from the dust-sensitive component assembly to outside vendors.
• the statistical stability of the work result, with its-qualitative improvements, is further improved if the sandblasting agent is not re-circulated.
• the sandblasting agent that is normally usual in sandblasting technology, it cannot be precluded that removed particles of the basic material remain in the sandblasting agent.
• Treatment by means of magnetic separators is not possible in the case of the plastics to be treated by means of the method according to the invention, since they are not magnetic. They must therefore be treated by means of wind-sifting or flotation. Eliminating such treatment also eliminates these method steps.
• the task is also accomplished by a semi-finished product, preferably made of carbon fiber reinforced plastic, having a plastic surface prepared for further processing to produce supporting structural parts, particularly supporting surfaces of aircraft, wherein the surface is fashioned by means of a treatment according to one or more of the above method claims, by means of a sandblasting agent distributed in a jet of a gaseous fluid.
• prepregs are pretreated in a sandblasting method according to the invention, for bonding with stringers, for example, onto outer skins, deep bonding, ribs, reinforcements, etc.
• the method causes a slight removal of material, without any impairment of the dimensional accuracy of the component. It cleans the surface by means of mechanical removal of the surface, but this removal can be metered precisely, in advantageous manner. There is approximately ten times greater security against damage to fibers of the plastic.
• the sandblasting method is carried out dry, whereby the effect on the component surface is essentially determined by the selection of the sandblasting agent. The surface roughness is primarily determined by the sandblasting agent and the pressure.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Reinforced Plastic Materials (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Polishing Bodies And Polishing Tools (AREA)
• Inorganic Fibers (AREA)
• Ceramic Products (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

Country Status (9)

Cited By (3)

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Citations (14)

Family Cites Families (7)

• 2003
  • 2003-01-22 DE DE10302594A patent/DE10302594A1/de not_active Ceased
  • 2003-11-05 DE DE50313119T patent/DE50313119D1/de not_active Expired - Lifetime
  • 2003-11-05 EP EP03795730A patent/EP1592535B1/de not_active Expired - Lifetime
  • 2003-11-05 DK DK03795730.5T patent/DK1592535T3/da active
  • 2003-11-05 US US10/508,290 patent/US20050130565A1/en not_active Abandoned
  • 2003-11-05 WO PCT/DE2003/003675 patent/WO2004067229A1/de active Application Filing
  • 2003-11-05 SI SI200331877T patent/SI1592535T1/sl unknown
  • 2003-11-05 PT PT03795730T patent/PT1592535E/pt unknown
  • 2003-11-05 AT AT03795730T patent/ATE482054T1/de active
  • 2003-11-05 ES ES03795730T patent/ES2348707T3/es not_active Expired - Lifetime

Patent Citations (14)

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