Classifications

• • 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
  • B05D1/00—Processes for applying liquids or other fluent materials
  • B05D1/02—Processes for applying liquids or other fluent materials performed by spraying
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/16—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/24—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with means, e.g. a container, for supplying liquid or other fluent material to a discharge device
  • B05B7/26—Apparatus in which liquids or other fluent materials from different sources are brought together before entering the discharge device
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/24—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with means, e.g. a container, for supplying liquid or other fluent material to a discharge device
  • B05B7/26—Apparatus in which liquids or other fluent materials from different sources are brought together before entering the discharge device
  • B05B7/262—Apparatus in which liquids or other fluent materials from different sources are brought together before entering the discharge device a liquid and a gas being brought together before entering the discharge device

Definitions

• the invention concerns a method for spray-coating substrate surfaces which enables different thermoplastically processable materials to be applied to very different types of surfaces by means of spray technology.
• Known methods include these of deep-drawing, vacuum deep drawing and pressing for the processing of sheets into formed parts or individual layers.
• sheets are applied to very different types of substrates by adhesive or hot-melt bonding.
• heavy layer sheets are placed on carpet or bulkhead zones, where they are attached by adhesive or hot-melt bonding.
• Injection molding thermoplastic injection molding or reaction injection molding (RIM)
• RIM reaction injection molding
• the material to be employed for example, polyurethane
• the mass distribution for all superstructures is determined by the mold geometry. This also prevents the purposeful acoustic optimization of individual vehicle types (engine versions) within a series, which would be desirable in acoustic terms.
• thermoplastic materials are effected either from a melt by means of one or more nozzles, or via a “cold” plastic powder by means of heating above a flame during the flight phase and a carrier gas, or directly by hot surroundings during the flight phase.
• these methods have very low throughputs and are only conditionally suitable for the coating of substrates, i.e., only for temperature-resistant ones. In the coating of textiles, the high temperatures would destroy the textile material before application is completed.
• the spray method also finds application in powder regeneration.
• DE 10 2005 050 890 A1 describes a method and device for producing a nanocomposite in which the separation of extractant and dispersant, if any, from a polymer melt is effected by a high pressure spraying method.
• the polymer droplets solidify abruptly as a consequence of the rapid cooling taking place in the relaxation of the high pressure level to environmental pressure. This generates the nanocomposites.
• cross-linking PUR-based systems are employed as a heavy layer for spraying. Details are found in DE 101 61 600 A1 and DE 10 2005 058 292 A1. These materials are very expensive and cannot be recycled.
• EP 0 524 092 B2 describes a method and device for producing an article with a profiled cord.
• the profiled cord is produced by an extrusion die connected with the extruder through a heated flexible pressure tube, and laid down.
• DE 30 47 727 C2 describes a method for producing thin protective films by spraying liquefied thermoplastic material onto a substrate.
• the method described herein is supposed to enable the use of conventional hot spraying devices, in which injection material is molten and thus liquefied, which can then be applied immediately to the surface to be protected. It is further described that the tendency of these materials to form beads upon impinging on the surface has until now prevented the formation of a sufficiently homogeneous film, but according to this description, this problem is supposed to be overcome in the simplest way by a simultaneous or subsequent sintering process.
• the sintering is effected by heating the sprayed-on thermoplastic material in order to arrive at a uniform, smooth and pore-free application.
• the heat required for sintering can be supplied to the thermoplastic material externally by radiant heat, warm air supply or the like. It may be reasonable to spray the thermoplastic material onto a previously heated surface, so that the sintering process occurs simultaneously with the spraying, and thus a time-optimized course of the process is obtained.
• the sintering process effected after the material's impinging on the surface is very complicated and again puts the substrate material under a thermal load.
• DT 16 46 051 B2 describes a method for applying polymeric coatings to solid surfaces by spraying on a molten thermoplastic polymer. Thereafter, melting of the polymer and supplying the melt in a pressurized gas stream by relief embossing are performed, and the sprayed gas/polymer jet is subjected to heat jet treatment on its way to the surface to be coated. It is described that the thermoplastic polymer of any grain size is converted to the molten state in extruders or piston cylinder means, and sprayed onto the surface to be coated, which is previously heated, by means of pressurized gas using a compressed air injection nozzle in the form of a gas/polymer jet heated by a heat jet stream.
• DE 32 25 844 A1 describes a method and device for the application of layers of thermoplastic materials or hot-melt adhesives.
• a method for the application of layers of thermoplastic materials or hot-melt adhesives is described in which the plastic or hot-melt adhesive employed is molten, then atomized and sprayed.
• the temperature of the molten plastic or hot-melt adhesive is kept constant up to the moment of spraying.
• the device for performing the method includes a heatable melting means for a plastic or hot-melt adhesive, a heatable spraying means having a nozzle, a heatable device for supplying the molten material into the spraying device, a temperature measuring and temperature closed-loop control system, as well as closed-loop control systems for the supply and discharge of a molten material and the heated spraying gas, if any.
• DE 42 31 074 A1 describes the use of plastic powders as a filler in sprayable coating compositions, paints and sealing compositions. It describes the use of powders of a density range of from 0.1 to 2.0 g/cm 3 having an average grain size of at most 0.2 mm, obtained by mechanical comminution of solid plastic material that may contain mineral fillers, as fillers, optionally in addition to further fillers, in sprayable paints, coating and sealing compositions based on one- or two-component polyurethane binders.
• DE 101 61 600 A1 describes a method for spraying on plastic layers. It describes a method and device for applying a filler-containing plastic layer to a shaped surface, wherein a mixture containing a mixture of binders, a solids conveyor and a filler is sprayed onto the shaped surface by first producing a free jet for spray application from a mixture containing a mixture of binders and the solids conveyor, followed by metering the filler into the free jet to the incompletely polymerized mixture of binders.
• the method is suitable, in particular, for the spray application of heavy layers as employed in conventional mass-spring systems.
• DE 10 2005 058 292 A1 describes a method and device for producing coated formed parts.
• a method and a device for producing formed parts containing a layer of polyurethane in shot operation in which the reactive components are mixed by means of a cylindrical mixing chamber, and the reaction mixture produced subsequently flows through a flow channel and is sprayed onto the surfaces of a substrate, where it cures, followed by cleaning the flow channel by a gas stream.
• thermoplastically processable materials can be applied to different kinds of substrate surfaces in the form of a film in a desirable and defined way.
• the above object is achieved by a method for spray-coating substrate surfaces, in which
• a method for spray-coating substrate surfaces comprises the following steps :
• the core of the invention is essentially the fact that a thermoplastically processable material is molten alone or as a compound in a mixture with other thermoplastically processable materials with or without fillers in an extruder, pressurized with an inorganic carrier gas or vapor under a defined pressure, pressed as a mixture through one or more orifice nozzles, released to atmospheric pressure, and cooled down only on the substrate surface.
• a compound is directly mixed in a twin-screw extruder.
• this twin-screw extruder is followed by, for example, a single-screw extruder or a melt pump.
• thermoplastically processable materials can be employed as materials for spraying, irrespective of whether they are homopolymers or compounds, unfilled or filled with non-melting materials.
• thermoplastically processable materials such as homopolymers, co- and terpolymers as well as thermoplastically processable elastomers, especially selected from acrylonitrile-butadiene-styrene (ABS), polyamide (PA), polylactate (PLA), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyether ether ketone (PEEK) and polyvinyl chloride (PVC) including copolymers and compounds thereof, which may optionally contain further components, especially fillers.
• ABS acrylonitrile-butadiene-styrene
• PA polyamide
• PLA polylactate
• PMMA polymethyl methacrylate
• PC polycarbonate
• PET polyethylene
• high-performance materials such as PEEK
• PEEK may also be sprayed with a high proportion of gas and an associated viscosity reduction.
• the amount of the fillers can be varied widely, wherein the amount of the fillers preferably should not exceed 80% by weight, based on the material, because otherwise the cohesion of the coating cannot be ensured.
• the fillers themselves may be inorganic in nature, or polymers that do not melt at the processing temperature, such as rubber, wherein the fillers do not have a preferred direction. Further, inorganic short fibers, polymeric fibers having a melting temperature higher than the processing temperature of the material or the compound as well as natural fibers may be employed as fillers.
• a material structure that differs from layer to layer can be produced by changing the mixture, the thermoplastically processable material and/or the filler itself and the ratio of thermoplastically processable material to filler in the course of the spraying process.
• inert, especially inorganic, gases or mixture of gases as well as vapors suggest themselves as the carrier gas.
• Particularly preferred according to the invention is the use of, for example, nitrogen, carbon dioxide, air or water, which is gaseous at this temperature.
• the carrier gas or vapor is preferably employed at a weight ratio of thermoplastically processable material to carrier gas or vapor within a range of from 100:0.1 weight parts to 100:30 weight parts, especially from 100:0.3 to 100:15 weight parts.
• a pressurized heated gas preferably air, must be supplied, which provides for additional atomizing in a favorable case.
• the nozzles are provided, for example, on a flexible pressure tube and can be moved over the substrate surface by means of robots to enable a complete application of material.
• the nozzle(s) itself is (are) designed, for example, as (an) orifice nozzle(s) with 1 to 50 orifices, preferably 5 to 20 orifices, with a diameter of from 0.1 mm to 10 mm, preferably from 0.5 mm to 2 mm, or orifices having an equivalent cross-sectional area of defined orifice geometry of the mentioned orifice diameters.
• Hot air spray gas
• Slotted nozzles having dimensions of 0.1-3.0 ⁇ 3-30 mm, preferably 0.5-2.0 ⁇ 5-10 mm, may also be employed; in this case too, several slotted nozzles may be provided in the spray head.
• carrier gas within the meaning of the present invention also includes those substances that form gaseous substances by a chemical or thermal reaction, or are converted to the gaseous state. Hot air is particularly preferred in this respect.
• the chemical composition of the spray gas which is preferably guided around the discharge opening of the thermoplast in the form of an annular nozzle, can be the same as or different from the carrier gas.
• Hot air is particularly preferred as a spray gas, which causes further expansion of the carrier gas in the thermoplast and heating of the particle surface.
• thermoplastically processable material A compound of 75% by weight inorganic filler (barite) and 25% by weight of a commercially available plastic mixture of PE/EVA, white oil, flow additive and temperature stabilizer in the form of granules was employed as the thermoplastically processable material.
• the output capacity was 90 kg/h, and the gas quantity (carrier gas) was 1.1 kg/h CO 2 .
• a commercially available pressed mixed fiber nonwoven served as the substrate surface.
• Example 2 In principle, essentially the same setting as in Example 1 was used in a second application in this Example.
• the nozzle has been changed.
• a circular jet nozzle of the BETE company was used, in which heated air as a spray gas in an outer ring around the discharge nozzle heated the mixture of carrier gas and compound.
• the amount of carrier gas was reduced to 400 g/h.
• the filler was reduced to 25% by weight, and the amount of compound was increased accordingly.
• the output capacity was 60 kg/h.
• the amount of air employed (spray gas) was 30 standard cubic meters per hour, heated at 300° C.
• the spraying result was improved over that of Example 1.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Plasma & Fusion (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Laminated Bodies (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)

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Publications (1)

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Citations (7)

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• 2013
  • 2013-05-06 DE DE102013208235.5A patent/DE102013208235A1/de not_active Withdrawn
• 2014
  • 2014-05-06 CN CN201480032422.5A patent/CN105339095A/zh active Pending
  • 2014-05-06 RU RU2015152031A patent/RU2650520C2/ru active
  • 2014-05-06 US US14/895,815 patent/US20160108511A1/en not_active Abandoned
  • 2014-05-06 EP EP14725032.8A patent/EP2994242B1/de active Active
  • 2014-05-06 KR KR1020157034481A patent/KR20160007551A/ko not_active Application Discontinuation
  • 2014-05-06 WO PCT/EP2014/059180 patent/WO2014180817A1/de active Application Filing

Patent Citations (7)

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