DE1427683A1 - Method and device for covering objects with two-component materials - Google Patents

Description

Dipi.-ing. Walter Meissner Dipi.-ing. Herbert Tischer

BERLINSSCGrunewalcf), HERBERTSTRAasE ss. MUNICH

Fernepreoher: 8 87 72 37 - Wireword: Invention Berlin

Postal checking account: W. Milasner, Berlln-Weet 122 82 1 ^ 4 2 7 6 63

Bank account ι W. Meissner. Berliner Bank A.-Q .. Depka 3β, ' *, ή? ViIlI

Beriln-Halensee. Kurfüretenöamm 130 ₁ BERLIN 33 ([GRUNEWALD}, the J I. MHL

Neil Rudolph Wallis, Oxfordshire / England

Patent application
Method_and_device_for_drawing_objects_with

The invention relates to methods and devices for surrounding objects with two-component coating materials.

Two-component coating materials are used for certain purposes, one component being, for example Epoxy or a polyurethane resin and the other a hardener is. When the two components are mixed, the mixture has a very short life and accordingly it is in some cases impossible to treat these materials by conventional methods or with conventional equipment To apply objects.

There are known methods for coating objects with a one-component liquid, in which the liquid Coating material is thrown out in finely divided form from a rotating spray head and is on precipitates the objects to be coated under the influence of an electrostatic field.

The invention provides methods and apparatus by which two-component Überzugsmaberialien under the influence of an electrostatic field to lie objects j χ ■ - ■; de rschl atre η.

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On the one hand, the invention consists in a method for. Coating objects with a two-component coating material, in which the two components of the coating material come separately from two nozzles, from which they are brought onto a rotating spray head and the material is thrown out of the rotating head in finely divided form and impacted on the object an electrostatic field is deposited.

On the other hand, the invention consists in a device for coating objects with two-component coating materials and includes means for supplying the two components of the covering material by two particular ones Nozzles on a rotating spray head and means for maintaining an electrostatic field between the rotating head and the objects to be coated

The two individual nozzles can be arranged coaxially or their axes can also be separate. If the two nozzles are arranged coaxially, preferably has the inner nozzle has a circular cross-section through which the hardener is passed, and the outer nozzle one annular cross-section through which the resin is passed '. The coaxial nozzles can be arranged directly behind a rotating disk on which the two Mix components and be thrown outwards by centrifugal force «

When the two nozzles are separated, their axes are preferably parallel and their outlets are in one level. In order to assist the mixing of the two components, there is preferably the rotating spray head from two coaxial shells. The hardener is led to the inner shell, from the front edge of which it is in Is pushed out towards the outer shell to which the resin is fed *

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Methods for carrying out the invention are provided using of the drawings} in these is:

Figure 1 is a partially sectioned side view of an electrostatic spray gun according to the invention;

FIG. 2 shows an enlarged illustration of the spray head of the pistol according to FIG. 1;

FIGS. 3 and 4 are enlarged views of FIG coaxial nozzles shown in the head of Figure 2;

Figure 5 is an illustration of a complete electrostatic Spray system according to the invention;

FIGS. 6, 7 and 8 show a side view, a front view and a perspective illustration a double-cup spray head for use with two separate nozzles in an embodiment according to the invention;

Figure 1o is a section on the line χ - χ of Figure 9j which points in the direction of the arrows;

Figure 11 is a side section of the shell member according to the invention, and

FIG. 12 shows a side section of a further exemplary embodiment according to the invention,

In Figure 1 it can be seen that the pistol includes a barrel 21 in the form of an insulating tube. Run 21 will be surrounded by a bracket 22 by which a handle 23 is attached to the drum. The handle 23 contains a trigger 24 which controls a microswitch 25 attached to a cable 26 leading to the rear of the gun leads.

The head of the gun contains a rotatable shell 28 made of insulating material. The two components of the Coating material are by means of two color lines 29

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and 31 and brought under pressure to the rotating tray

The shell 28 is rotated by an air motor which is in the Barrel 21 is housed, and the air is supplied through an air line 34 which runs through the barrel of the gun • the air motor delivered. The air motor also serves as a electrical connection between the high voltage source and the shell 28. The high voltage source consists of , an electrolytic conductor 26, as it is in the English Patent applications 39 302 and 49 577 is described.

At the end of the barrel 21 two nylon blocks 39 and 4o are attached, which can be seen better in FIG. The block 39 contains a conical hole in which a compound Feed device 32 is attached to which the paint lines 29 and 31 are connected.

The composite feeder 32 is in the Figures 3 and 4 shown in detail. There it can be seen that it has an inner nozzle 27 which is connected to the pipeline 29 and an outer nozzle 3o, which is connected to the pipeline 31. Inside the nozzle 27 is a conical needle 33. The needle is movable with respect to the nozzle 27 in the axial direction. Figure 3 shows their foremost position in which they Nozzle 27 closes completely, while FIG. 4 shows the rear position in which the nozzle is completely open. Furthermore, the nozzle 27 can be moved in the axial direction of the nozzle 3o, and again in FIG shown front position in which it is used to close the nozzle 3o, while in Figure 4 in its rear Position is shown in which the nozzle is fully open. A device for adjusting the axial The position of the needle 37 and the nozzle 27 is shown in FIG. 2 by the knurled nuts 34 and 35, respectively.

The shell 28 contains a metal spindle insert 63 in which the end of the drive shaft of the motor is fixed · 909846/0050 -5-

The tray 28 also includes a flat disc 64 which is connected to an outer shell-shaped part 45 by three straps 66. The opening of the shell runs conical to a relatively sharp edge 67.

The device according to Figure 5 contains a hand gun 2, that is similar to that shown in Figures 1 to 4 and is used in a spray booth 15. The object to be covered is represented by a chair 1, the is grounded by a metal hook 16. This connects the chair with the earth rail 17. The pistol is with the remaining devices connected by a multiple cable 18, which has an air line 34 for the motor, two color lines 29 and 31, a high voltage cable 36 and a trip control cable 26 contains.

The trip control cable 26 connects the microswitch 25 nit the control unit 3, which is connected to a high-frequency high-voltage generator 7 is attached, the housing of which is grounded. The control unit 3 and the high voltage generator are connected to the network by the connecting cable 15. The control unit is connected by an intermediate cable 9 connected to a set of three remote-controlled valves 19 * 2o and 8. The valve 19 connects the paint line 31 via a further line 11 with a container 13 for the resin. The valve 2o is in the air line 34 for the Motor via line 7o, on a combined moisture separator and on an automatic lubricator and a spray controller 1o and another Air line 12 is connected to the main air inlet 14. The valve 8 connects the paint line 29 via another Line 71 with the container 4 for the hardener.

The air inlet 14 is also through the reducing valves 72 and 73 connected to the interior of the containers 13 and 4, so that the resin is fed to the line 11 under pressure and the hardener xjbot is passed to line 71 under pressure

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will. The measuring devices 74 and 75 are used to display the Pressure in the tanks.

The control circuit 3 is such that when the Trigger on the gun is pressed, pressurized air is supplied to the motor to rotate the bowl 28, and when the bowl is rotated at sufficient speed, the paint valves 19 and 8 are opened so that Resin and hardener are fed under pressure to the nozzles 3o and 27, respectively. When the trigger is released, will the hardening valve is closed first. After a short time, the resin valve 19 is closed and then becomes the air valve 2o is closed, whereby the engine is stopped.

In use, the pistol is held with the head at a short distance from the object to be coated and the ribbon nuts 34 and 35 are adjusted so that the necessary amount of resin and hardener is supplied. Then, when the trigger 24 is pressed, the rotates Shell 28 and resin and hardener mix at the outlet of the nozzle 3o, as FIG. 4 shows. The mixture of resin and hardener is guided to the rear surface of the disc 64, and the mixed materials are driven by centrifugal force thrown onto this surface and form a film on the inner surface of the walls of the bowl 65 · The mixed Material flows to the conical edge 67 and becomes -yron of this Edge atomized. The material is charged by the electrostatic field and consequently becomes the one to be coated Object attracted because this is the closest object to earth potential "

If the two components of the coating material do not mix by the time they exit the nozzle 3o, the material cannot harden and clogs the nozzles. Closing the hardener valve 8 before the resin valve 19

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also ensures that the outlet of the nozzle 3o is flushed out by pure resin when the device is switched off will. Furthermore, the equally long delay in stopping the engine ensures that this pure resin will clean the shell 28 washes out to prevent the resin from adhering to the bowl.

An advantage of the embodiment of the invention according to Figures 1 to 5 is that it is present when Guns intended for spraying normal one-component materials can be used.

It is not always desirable to be relatively complicated To use coaxial nozzle arrangement of this embodiment and in such cases, for example the embodiment according to FIG. 6 should be preferred.

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In this embodiment, two separate nozzles 81 and 82 are used instead of a single nozzle assembly 52, and the shell 28 is replaced by a double shell 83. The shell contains an inner flat washer 84 which rests on a socket 85 to which the end of the motor shaft is screwed. The flat disk 84 is connected to an inner cup-shaped part 86 by three straps 87 »88 and 89. The shell-shaped part 86 forms a whole with a flat annular part 9o, which is connected to the outer shell-shaped part 91 by the three bands 92, 93 and 94. The opening of the outer shell-shaped part is conical to a relatively sharp edge 95, which is arranged in front of the front edge of the inner shell-shaped part.

The open end of the nozzle 81 is arranged a short distance behind the disk 84 and is slightly behind the annular part 9o. In use, resin is supplied to nozzle 82 and resin to nozzle 81. The hardener pushes to the rear surface of the disc 84 and is

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Trifugal force thrown on this surface and forms on the inner side of the walls of the inner cup-shaped Partly a film. The centrifugal forces cause the hardener to move towards the front edge of the inner bowl-shaped part flows and is flung radially away from this edge. Similarly, the resin is applied to the rear surface of the annular part 9o out and forms a film the inner surface of the walls of the outer shell 91 · The ejected hardener mixes with the resin on the inner surface of the outer shell, and the composite Material is sprayed from the leading edge 95. The compound Material is charged by an electrostatic field and thus becomes the object to be coated attracted

The remaining parts of the gun may be similar to those of Figure 1 and the arrangement may be like that of Figure be made.

A modification of the exemplary embodiment of the invention according to FIGS. 6, 7 and 8 is shown in FIG. In in this case a triple shell takes the place of the double shell 83 to ensure that the two Components are fully mixed before being sprayed. On the other hand, the arrangement can be practical like those according to FIGS. 6, 7 and 8. Since there is no material from the rear of the tray assembly to the inner wall of the outermost shell is supplied, the outermost shell 95 can directly with the shell 91 through a continuous ring 97 connected.

The arrangement of the nozzles and passages is in this embodiment in a nylon block 4-o, such as Figure 1o showed

Figure 11 shows a modification of the arrangement of Figure 6 in which the outer shell 91 is in the form of a removable

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Ring owns. This ring can, for example, be pressed onto the outer wall 98 of the shell arrangement, a shoulder 99 on this outer wall serving to fix the ring. The ring can be slidable and removed and discarded at the ends of each spray period. It is then recommended that a new ring be pressed on before spraying, and in this case difficulties arising from the deposition of resin can be eliminated. The embodiment according to FIG. 9 can also be modified in that both outer sleeves 91 and 96 and the connecting ^{ring 97 <ϋ θ have the} form of a single displaceable annular member which is pulled removably onto a shoulder, as FIG. 11 shows.

Figure 12 shows a further modification of the arrangement according to Figure 6, in which the bowl-shaped rotatable member through replacing a disc-shaped rotatable member of the type described in British patent application W 34-015 will. As described in detail in this application, the particular form chosen is intended to to ensure that the spraying is practically entirely mechanical and not under the influence of a electrostatic field is carried out. For this purpose, the rotatable member is without sharp edges on it Outer surface formed so that the discharge current that normally occurs between the rotating member and the object is kept very small.

In the illustrated embodiment, the rotating member has the shape of a disc 1o1 made of insulating material consists. The middle part of the surface of the disc in front of the object to be coated is flat and the outer part of this surface is rounded to avoid sharp edges. The inner surface of the disc is a round one Trough 1o8. In the trough 1o8 there is a metallic insert 1o9 »with the insulating shell 1o1 through it

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three screws 11o is connected. From the center of the Insert 1o9 protrudes a spindle 1o2 which is provided with a threaded hole through which the rotatable member is connected to the shaft of the drive motor «The surface of the insert from which the spindle protrudes forms two annular troughs 1o3 and 1o4, which are separated from one another by a rising lip 111. The outside wall of trough 1o4 slopes outwardly towards the rear of the insert, as can be seen at 113. Concentric with the disk 1o1 and a short distance from it on the same side as the spindle 1o2 is a annular member 1o5 of the same diameter and shape as the disc 1o1. The annular member 1o5 is attached to a nylon block 39 by three screws, one of which is labeled 1o6 and spaced through Spacer is arranged as can be seen at 1o7.

In the gap between the disc 1o1 and the annular Link 1o5 there is a sharp edge 112, which is exposed by the electrostatic field through the two links 1o1 and 1o5 is electrically shielded. The peripheral edges, which form part of the surface are an oblate spheroid. The two nozzles 81 and 82 pass through the fixed link 1o5 up to a short distance from the surface of the flat insert 1o9 through.

In use, the disk 101 rotates at a speed of, for example, 10,000 revolutions per minute rotated, and the hardener is fed through the nozzle 81 to the trough 1o3. The hardener is made by centrifugal force guided on the lip 111, from which it is sprayed by contact with ■ air. The resin becomes in a similar way guided through the nozzle 82 to the trough 1o4 and forms through the centrifugal force forms a film on the inclined part 113. The hardener that leaves the lip 111 also becomes the inclined part where it mixes with the resin "

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The composite material then flows to lip 112, from which it is through. Sprayed on contact with air. Because the shielding effect of parts 1o1 and 1o5 is the electrostatic field that is between the rotating Limb and the object is held in the gap between the limbs in which the lip 112 is located, ineffective.

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Claims (16)

Patent Attorneys Dipi.-ing. Walter Meissner Dipi.-ing. Herbert Tischer BERLINSaCGrunewalcO, Herbertstrasse 2a MUNICH,. _ „_ Telephone: 8 87 72 87 - wire word! Invention Berlin AQ. 1 H 2 7 0 8 3 Posteoheokkonto: W. Meleaner, Berlin-West 122 82 ** · Bank account ι W. Melesner, Berliner Bank Α.-Θ., Oepka SO, J 1 MfI? 196 ^ 5 • Berlln-Haleneee. Kurfüretendamm 18O 1 BERLIN 33 ([GRUNEWALD ^, den "'HerbertetraB · 22 Neil Rudolph Wallis, Oxfordshire / England Method and device for covering objects with materials Patent claims - 1. A method for coating objects with a two-component coating material, characterized in that that the two components of the coating material are fed separately to two individual nozzles, of which they are fed to a rotating spray head, and that the material is thrown from this head in finely divided form and is deposited on the object under the influence of an electrostatic field. 2 .. The method according to claim 1, characterized in that the two components are a synthetic resin and a hardener. 3. The method according to claim 2, characterized in that the two nozzles are coaxial with one another and that the The hardener is fed through the inner nozzle and the resin through the outer nozzle. 4. The method according to claim 3, characterized in that the hardener and the resin are mixed on a rotating disk, from which they are thrown by centrifugal force onto the inner edge of a shell-shaped spray head. 9 0 S 8 4 6/0050 ORIGINAL 5. Device 21211 Covering objects with two-component Materials, characterized by a device for delivering the. both components of the coating material by two separate nozzles on a rotating spray head and a device for holding an electrostatic one field between the rotating head and the object to be coated. 6. Apparatus according to claim 5 »characterized in that both bosoms are arranged coaxially to each other and the inner DU · «circular cross-section and the outer annular Sdhwtri is unconscious. 7 · Device according to claim 6, characterized in that the coaxial nozzles directly behind a rotating Disc are arranged, which is itself within a stale «nfshaped rotating spray head» 3. Gerat naoh Aaepruoh 7, characterized in that a Device for changing the effective cross-sectional area the nozzle a is provided. 9 »Device according to claim 8, characterized in that the Facility to change the effective cross-section of the inner DU · «di · form of an axially displaceable to the inner nozzle fra & el owns. Ίο. Device a & ftk claim 9, characterized in that the inner nozzle door outer nozzle is axially displaceable and that the & * & «?« outer edge of the inner nozzle is so conical, that the axial displacement is the change in the cross-sectional area * the outer nozzle causes. 11. Gfcrät aa & k Aaiprueh 5, characterized in that the Aöheea both DÜifcn vt> n are separated from each other. 12. O "rä% nfctfe. Claim 11, characterized in that the • O9I4S / Ö0S0 1H H27683 Axes of the nozzles are parallel to each other » 13. Apparatus according to claim 12, characterized in that the outlets of both nozzles are in one plane, 14 ·. Device according to claim 13, characterized in that the rotating spray head contains two coaxial shells, and that one component is fed to the inner shell from the inner edge of which they are in alignment with the front Edge of the outer shell is thrown to which the other component is brought up. 15 · Device according to claim 14, characterized in that the spray head has a flat disc in the middle, which is attached to the inner cup-shaped part by several bands is attached, and that the inner cup-shaped part with the annular part, which is on the outer cup-shaped part is connected by further bands, forms a whole " 16. Apparatus according to claim 15.1, characterized in that the opening of the outer cup-shaped part to the sharp Edge is conical, which is arranged in front of the front edge of the inner cup-shaped part « 17 * Device according to claim 16 »characterized in that the open end of the nozzles a short distance behind the middle disc and the open end of the other nozzle in a small distance behind the flat ring-shaped part * I80 device according to claim 17 * characterized in that the spray head contains an outer shell-shaped part which is coaxial with the inner and outer cup-shaped part runs, and immediately with the outer cup-shaped part duJ? o, a continuous Hing is ally * _{BAD0R) G1NAL} 19 · Device according to claim 15 »characterized in that the outer shell-shaped part has the shape of a removable , Ring owns. 2o. Device according to claim 18, characterized in that the outer shell-shaped part, the ring-shaped part and the outermost cup-shaped part the shape of removable Own rings 21 · Device according to claim 11, characterized in that the rotating spray head is a disk made of insulating material contains whose outer surface is rounded to avoid sharp edges and whose inner surface is circular Trough results, and that a metallic insert is arranged in this trough, the inner surface of which with two Rings is provided, which are separated from each other by a lip. 22 · Device according to claim 21, characterized in that the open ends of both nozzles are in two annular troughs of the metallic insert are arranged. 23 · Device according to claim 22, characterized in that a ring made of insulating material is arranged behind the rotating spray head. 24-. Device according to claim 23, characterized in that the sharp edge in the space between the insulating washer and the insulating annular member is arranged. 25 · apparatus according to claim 24, characterized f in that the peripheral edge of the insulating disk umd deyisolierenden annular member as part of the / gläcbji an oblate Sphöroide are formed. 809846 / G05Ü BAD OBiGVNAL