DE102012008046A1 - Preparing laminated body, preferably components for air- or boat models, comprises coating a final layer or solvent-based contact binding agent on a pre-dried blank treated with low viscosity solvent free, acrylic-based binding agent - Google Patents

Abstract

Preparing a laminated body, comprises: (a) employing a pre-dried blank or a core material based on X-ray photoelectron spectroscopy (XPS) for the body to be manufactured; (b) treating the blank or the XPS material with a low viscosity, solvent free, acrylic-based binding agent that penetrates into the structure of the XPS material, and seals; and (c) coating a final layer to be applied or a solvent-based contact binding agent on the core and on the inner side of the XPS hard foam panel.

Description

A method of producing a laminated body wherein at least one layer affects the bonding during the laminating process.

• 2.1 The present invention describes a method which can be used in a variety of ways (stage design, rapid prototyping for large-volume light bodies of any shape) but is particularly suitable for producing components for aircraft, ship and car models. The further description thus relates to the main field of application using the example of the fuselage and wing for a remote-controlled model aircraft.
• 2.2 In the commercial production of wings and hulls whose main component consists of a core of XPS (extruded polystyrene), the prior art that all known methods apply a solvent-free binder such as 2-component epoxy resin systems or white glue on the core surface to subsequently the reinforcing and applying force-absorbing coating. The binders used serve to bond the core and the outer layer. The material properties of the XPS core are not changed. The viscosity of the binders used is viscous compared to an aqueous solution. Due to the setting time of the binder and the Aufstellneigung the outer layer must either be pressed with devices or curing in a vacuum can be performed. Depending on the binder used, the hardening process lasts from 6 to 24 hours, whereby the final strength only occurs later and may even be achieved only by warm aging. As a reference, the GM and patent literature DE 3039403 A1 . DE 2725870 B1 as well as that GM 7139554 by Siegfried Eichstetter and common literature from manufacturers of fiber composites (R + G).
• 2.3 The generally existing problems are thus: high tool expenditure, high time expenditure in particular the hardening times up to the usability. Significant increase in weight due to the binder, as due to the Viskostiät the binder application in the thin film process is not possible. Increased weight worsens the flight characteristics and increases the Mindeslandegeschwindigkeit. High landing speeds thus include a high level of kinetic energy as the velocity is quadratic. E kin = m / 2 × v ² For very small models, an airfoil made in the described manner becomes too heavy. Overall, the wing is very stiff and carries a risk of breakage under peak loads. Often there are problems with the application of the final layer in the form of ironing film due to the heating of the XPS core by the foil iron and subsequent outgassing of the residual water content. Bubbles form under the film.
• 2.4 The present invention is therefore based on the object to enable a cost-effective production of components without having the disadvantages described. The method is suitable for the production of small series and allows an extremely high variability in the shape of the components to be produced. It is essentially based on 4 process steps, but already after the 2nd process step a derivation for the production of components is possible. In the following, the process steps are marked with a) b) c) and d).
• a) For the resulting final shape of the component, a core of any shape is cut out of an XPS blank in the CNC hot wire cutting process. Since the low density of XPS during the foaming process is achieved by the high degree of air inclusions, it is important for the production of lightweight components to minimize the residual water content of the trapped air in the XPS core.
• 2.4 a) The cut core or the blank material must thus be stored in a heated storage room, under control of the humidity, in order to achieve evaporation of the residual water content. This results, on the one hand, in a slight reduction in mass and in an improvement in the surface quality by avoiding the formation of vapor bubbles during the ironing of the end product. The core is subjected to visual inspection for compliance with the desired shape. Smaller irregularities can be corrected by sanding with a sanding pad to ensure optimum profile fidelity. Subsequently, the resulting sanding dust is removed. The core can be designed with or without integrated reinforcement elements. This is dependent on the thickness of the desired body. With very low material thickness or large overall length, the introduction of a reinforcing element makes sense. The reinforcing element can be in any shape. (GFK or CFK round rod or tube, CFK reinforced box spar, GFK or CFRP Rovings or rectangular strips, solid solid wood versions such as pine or other suitable types of wood) The reinforcing element can be made with 2K epoxy resin or white glue with the core depending on the type of material used get connected. The necessary for the inclusion of the connecting element recess is created either also in hot wire cutting process or by means of a CNC portal milling machine. Likewise, the recesses for necessary components of the RC system (remote control) such as For example cut outs for the servos, the receiver or the power supply and the cables to be laid with the CNC portal milling machine from the core material. Likewise, the recesses can be created by means of preformed hot wires in the hot wire cutting process. The body to be created can be designed in one piece or in several parts. To absorb the forces arising in flight, the core can also be reinforced with ribs which are identical to the wing contour of the body (wing profile). As a result, the e can be made removable which depending on the size of the component can be very useful. This can be z. For example, be achieved by a screw. The ribs may also protrude from the profile contour to allow, for example, a fastening of the wings in biplane or chassis and or drive elements.
• b) When the preparatory measures have been carried out on the core, a low-viscosity acrylate-based binder is applied to the core. This is done by spraying, rolling or brushing to be able to dose the applied amount. The low-viscosity binder penetrates into the pore structure of the XPS core in the first step. As a result, the compressive strength of the individual wetted beads is increased, and the binding of the XPS beads with each other improved. After curing of the air-drying binder, this results in improved elasticity and compressive strength of the XPS core. A second coating process seals the surface and again increases the compressive strength. The core is permanently prevented from absorbing moisture. At 20 ° C, the drying time is about 60 minutes. If components are to be produced for small models, then at this point the body can be removed from the process and the component prepared for final assembly. In the wing described by TapFall a wing of the nose area and the end edge of the e (adhesive tape) is reinforced and is ready for the installation of RC components and the application of the ironing foil with the foil iron. The applied binder layer allows a lasting ironing of the wing without this deforms thereby. Depending on the ironing foil used, the temperature is between 80 and 110 ° Celsius. (80 ° C is the lowest necessary temperature for the melting of the heat-sealable adhesive located on the inside of the ironing film) The ironing film is not shrunk at these low temperatures. The wing remains dimensionally stable. The application of the ironing film has a decisive influence on the fracture and bending strength and serves only in the side effect of the optical design. Instead of the film also commercially available fabric material can be applied for ironing.
• 4. c) For larger components, the prepared core must be planked to increase the stability. In this case, the layer thickness of the applied cover material is to be considered in advance. The core must therefore be cut correspondingly smaller to later achieve a corresponding dimensional accuracy of the component. The core can additionally be stabilized by reinforcing the edges with adhesive tape. The binder to bond the core and cladding consists of a solvent containing contact binder which could not be used without prior treatment of the XPS core as it would attack the core. The core surface is roughened with a sanding pad and then cleaned from the sanding dust using compressed air. The binder is then applied by spraying, brushing or rolling on the core and on the inside of the cover material. According to the instructions for use of the entprechende binder a short ventilation time must be observed. In this time, solvents gase out and it is thus to ensure good ventilation of the work spaces.
• d) After the flash-off time, the cover material is aligned with the core and fixed to the core by pressing the cover material once. A later correction of the position of the cover material is not possible. Depending on the number of sides of the present body is now proceeded with each side accordingly until all sides of the body are planked in this way. In the case of a wing or a fuselage, the body can now be provided with a final surface by ironing on an ironing foil or ironing fabric. Again, temperatures between 80 and 110 ° C are used. In order to ensure the durability of the body in the case of extreme loads (crash), the applied foil in your surface must not be damaged. This means that the other components are not attached to the cover material, but on the applied film to avoid damage to the surface structure of the cover material. This is easily possible by adhering to the manufacturer's instructions of the respective adhesive manufacturer.

A component created in this way is extremely resistant to crashing because it has a very viscoelastic structure. There is a very low risk of breakage and the component can be designed by the use of ironing film or tissue very attractive and arbitrary optical, without having the coarse surface structure of a comparable in crash resistance EPP component. Furthermore, there is a very low component weight, comparable to foam components which are produced by injection or foaming in a mold, but without having their still high fragility. Wanted and unwanted tests (encountering an obstacle such as a steel cable in the air) have impressively confirmed this. For the end user, this means a considerable added value of the purchased product and ensures a considerably longer service life of the respective consumer goods in direct comparison to products of the competitors. For the user of the method thus exists a clear USP, which allows conquering of market shares.

Corresponding execution patterns can be made available if required. Due to the logical connections and traceability, an explanatory drawing can be dispensed with.

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 3039403 A1 [0001]
• DE 2725870 B1 [0001]
• DE 7139554 GM [0001]

Claims (10)

Method for producing a laminated body in the a) for the body to be produced a pre-dried blank b) or core of XPS material is used c) the one with a thin, d) solvent-free, e) Acrylic-based binders f) which penetrates into the structure of the XPS material g) and sealed, h) is treated i) to apply a final layer j) or a solvent-containing contact binder on the core k) and to be able to apply to the inside of a XPS hard foam board l) to coat the core with it. A method according to claim 1, characterized in that the core may contain reinforcing elements which are in the form of a) CFK round rod b) GFK round bar c) CFRP pipe d) GRP pipe e) CFRP reinforced pinewood f) GRP reinforced pinewood g) CFRP Rovings h) fiberglass rovings i) CFRP rectangular strips j) GRP rectangular strips k) pine rods in solid wood l) beech staves in solid wood m) CFK reinforced balsa wood n) GRP reinforced balsa wood o) CFRP reinforced poplar plywood p) GRP reinforced poplar plywood q) CFRP reinforced birch plywood r) GRP reinforced birch plywood s) alloyed aluminum sheet may be present. A method according to claim 1 or 2, characterized in that the surface of the XPS core is reinforced with tape (adhesive tape) prior to applying the planking. Method according to one of the preceding claims, characterized in that the core cutouts for receiving the RC components by a) milling b) hot wire cutting is created contains. Method according to one of the preceding claims, characterized in that the application of the solvent-free binder by a) splash b) delete c) rotten can take place. Method according to one of the preceding claims, characterized in that the treated core by means of a) Ironing film b) ironing fabric c) Covering paper d) adhesive tape can be permanently coated. Method according to one of the preceding claims, characterized in that the treated core by a) splash b) delete c) rolls is provided with a solvent-containing contact binder. Method according to one of the preceding claims, characterized in that on the inside of the XPS foam board by a) splash b) delete c) roll a solvent-containing contact binder is applied. Method according to one of the preceding claims, characterized in that the XPS foam board by means of a) Ironing film b) ironing fabric c) Covering paper d) adhesive tape can be permanently coated. Method according to one of the preceding claims, characterized in that the outermost coating by a) Ironing film b) ironing fabric c) Covering paper d) adhesive tape encloses the body in a form-fitting manner without gaps or recesses.