GB1568986A

GB1568986A - Process for spraying articles

Info

Publication number: GB1568986A
Application number: GB4677376A
Authority: GB
Original assignee: Schering AG
Current assignee: Bayer Pharma AG
Priority date: 1975-11-10
Filing date: 1976-11-10
Publication date: 1980-06-11
Also published as: FR2330467B1; SE7611830L; DE2550794C2; DE2550794A1; FR2330467A1; NL7612479A; CH614138A5; IT1067290B; AT349284B; ATA830776A

Abstract

The article (5) to be treated, after immersion in the active bath (1), is for washing not immersed in a number of washing baths which are connected one after another and also serve as storage containers for the washing liquid, but is brought into an arrangement, situated e.g. above the active bath (1), with a spraying chamber (4), in which the washing takes place by means of spraying lines (6) and nozzles. In this case, a washing-water collecting tray (3) has been brought under the spraying chamber (4), from which the washing water is conducted to storage containers. It is consequently possible to forgo a number of washing stations. The passage time of the articles to be treated is shorter. The storage containers for the washing water can be accommodated at a distance from the active bath (1), e.g. in the basement. The floor space requirement for the installation in the room, in which the active bath (1) is situated, is consequently reduced. The shape of the storage containers for the washing water does not depend on the shape of the articles to be treated and an inexpensive shape can consequently be selected. The arrangement is suitable e.g. for installations for galvanising, bonderising or anodising.

Description

(54) PROCESS FOR SPRAYING ARTICLES (71) We, SCHERING AKTIENGESELLSCH AFr, a body corporate organised according to the laws of the Federal Republic of Germany, of Berlin and Bergkamen, Federal Fepublic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a method of spraying articles following surface treatment, more especially surface treatment in aqueous solutions, and is concerned in general, though not exclusively, with spraying for rinsing purposes.

Surface treatment of articles made of metal or synthetic plastics materials is often effected in aqueous solutions. This is the case, for example, in electroplating, corrosion protection treatments and anodizing. The process is made up of various process stages which, for example in electroplating metals, may be roughly classified as degreasing pickling-electroplating (possibly in various stages and/or with various plating metals)after treatment. Rinsing operations are necessary between these so-called active treatments in order to remove from the articles the adherent residue of the solution from the preceding bath, before treatment in the next bath can begin. Transferring the articles under treatment from one active bath into the next bath without an intermediate rinsing operation is only possible in a few exceptional cases.

In previously proposed surface-treatment processes, the rinsing operation is normally carried out in three stages: (1) Rinsing in nonflowing water (N) which is only changed at relatively long intervals and thus becomes ins;reasingly enriched with solution from the preceding active bath. Nevertheless, a large part of the active bath solution adhering to the articles being treated is removed by such rinsing and, as a result, the water consume tion in the next rinsing operation (using pure water) may be reduced.

(2) Rinsing in flowing water (F2) in the second station of a cascade rinsing system. The rinsing water constantly runs in from the first station and out again via spillway.

(3) Rinsing in flowing water (F1) in the first station of a cascade rinsing system. Pure water constantly flows in and out again to the second station.

To intensify the rinsing, the contents of the container are usually agitated, e.g. by blowing in air.

The rinsing can be made even more thorough if the goods are not immersed in the rinsing water but sprayed with it. Although this process is not always possible with hollow articles or tubes, it is advantageous in the case of many other types of article.

In most cases transport trucks having electrically driven traversing and lifting mechanisms are used to transport the articles under treatment from one treatment station to another and for lowering the articles into the baths and lifting them out again, and in most cases several units working indendently of one another are used in each installation.

The rinsing stations form a substantial part of the whole extent of an installation.

Thus, a relatively large amount of expensive production area is required for the rinsing operation which plays no direct part in the overall surfaces-treatment process and, in addition, only lasts for a short time in each case.

The rinsing tanks must be matched to the active tanks in their geometrical form and construction, and to a certain extent their fittings must also correspond. In electroplating plants the rinsing tanks are made predominantly of sheet steel which is subsequently coated on both sides with ebonite for protection against corrosion. The tanks are provided with supporting devices for the article carriers on which the articles to be electroplated are suspended. Owing to the usually rectangular shape and to the need to support the weight of the rinsing liquid and of the article carrier, the construction of the tanks must be appropriately sturdy.

The present invention provides a method of spraying an article following surface treatment thereof which comprises lifting the article, after surface treatment thereof in a vessel, by a lifting device into a spraying chamber which is situated above the vessel and is provided with an internal spraying device and with outlet means for waste spraying material, the said outlet means being arranged to prevent waste spraying material from entering the surface treatment vessel.

Especially important forms of the method of the invention are those in which the surface treatment is an electoplating, corrosionprotection, (for example, in which the article is "Bonderised"-Trade Mark) or anodizing treatment.

The spraying material is preferably a liquid and the outlet means then includes a collecting device which is moved into position under the spraying chamber after the article has been lifted therein. The collecting device is advantageously slidable or pivotable into and out of collecting position, and will generally be in the form of a tray, preferably inclined to assist outflow of waste liquid through a discharge nozzle or port.

The spraying will generally be conducted to rinse adherent residual material from an article after surface treatment, which is preferably surface treatment with an aqueous solution. Also, there will generally be a plurality of surface-treatment vessels in which the article will be treated in turn (as, for instance, in electroplating processes). Although there could in principle be a separate spraying chamber for each spraying operation, there is advantageously a single spraying chamber which is attached to the lifting device and is conveyed by that device to be in a position to receive the article from each surface-treatment vessel in turn. The lifting device will also serve to convey the article being processed to each surface-treatment vessel in turn, and, where a single collecting device is used, also conveys that device to each spraying position in turn.Normally, the article will be sprayed after each surface treatment.

In a preferred method in accordance with the invention articles are subjected to surface treatment, preferably with aqueous solutions, in installations consisting of baths arranged in succession, the articles to be treated are transported by means of individual, manually or automatically controlled transport trucks, and the rinsing operations necessary between the active-bath treatments are carried out above the active baths by spraying in a chamber connected to the transport truck, which chamber surrounds the articles to be treated after they have been lifted out and is provided internally with a spraying device, and the rinsing liquid running off is carried away via a collecting device which is also connected to the transport truck and which can be slid or swung under the chamber after the articles to be treated have been lifted out of the active bath.

In principle, the method of the invention can be used in spraying surface-treated articles with an desired fluid (for instance, drying air), or even in spraying with solid particulate material (for instance, for finishing purposes), but the spraying material is preferably a liquid, more especially an aqueous liquid.

Several forms of method according to the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a transverse section, partly in diagrammatic form, of an apparatus suitable for carrying out the method; Fig. 2 is a side elevation of the apparatus of Fig. 1, partly in section; and Fig. 3 is a diagrammatic representation of one form of method.

Referring to the drawings, the spraying operation (preferably rinsing) preferably takes place above, more especially immediately above, the active bth (1) out of which an article (5) has previously been lifted. For this purpose, a collecting device (3), for the rinsing liquid (normally water), which is connected to a transport truck (2), is pushed or swung under the goods after the lifting operation.

In addition, the transport truck (2) is provided with a chamber (4) which in the lifted position surrounds the article under treatment. On the inner sides of the chamber are fitted spraying devices (6) by means of which the rinsing liquid or liquids is sprayed onto the article (5). The chamber is advantageously provided with a sound-absorbing lining (7) in order to keep the noise level low for the operating personnel. The rinsing liquid is fed to the spraying system on the transport truck through a pipe or hose coupling (8), which is closed automatically in known manner by a stationarily mounted electromechanical, hydraulic or pneumatic drive (9) as soon as the transport truck is in the position in which the rinsing operation is to take place.

The rinsing liquid sprayed onto the article (5) runs off into the collecting pan or tray (3), the base of which is inclined towards one side is provided at the lowest point with a discharge nozzle (10). When the transport truck is in the position in which the rinsing operation takes place, the discharge nozzle is positioned above a stationarily mounted inlet funnel (11) from which the liquid is further fed through pipes (12) to a storage container.

In a preferred embodiment, the collecting pan (3) is arranged laterally of the spraying chamber (4). Before the rinsing process begins, the movably mounted pan is pushed under the article (5) by means of a drive (13), which is preferably electromechanical, and remains in this position at least until the rinsing process has been completed and at the longest until the transport truck (2) has moved on to the next active bath in the treatment sequence.

Advantageously, the rinsing operation is arranged to commence automatically when the article (5) has been lifted into the spraying chamber (4) and the collecting tray (3) has been moved into position below the spraying chamber.

Referring to Fig. 3, an important advantage of the process of the invention is the fact that supply tanks (14, 17, 18) for the rinsing liquids may be arranged in any desired positions near to or below the actual surface-treatment vessels. Thus, for example, they may be posititoned on a floor below the installation itself, e.g., in a basement. In this way valuable and expensive space on the production floor is saved. Also the form of the supply tanks (14, 17, 18) may be chosen as desired, without any limitation imposed by the lay-out on the production floor. Preferably, simple and cheap round tanks made of synthetic plastics materials are used.

The rinsing process may be adapted to all requirements both with regard to the preceding active bath and the treatment of waste rinsing liquid. A pump or pumps (15) serve to feed the rinsing liquid from the supply tanks to the spraying devices (6). In most cases it is possible to use only one pump for several rinsing baths and the change-over is effected by means of switchable valves (16), which are preferably electrically actuated magnetic valves.

In addition to saving production space, the process of the invention offers the further advantage that the time taken by the articles (5) undergoing treatment to pass through the installation is shorter. During the whole of the rinsing process after an active-bath treatment, the articles being treated remain in the same position. The time taken for the trnsport of the rinsing liquid or for switching over the magnetic valves (16) from one rinsing bath (18) to the next (17) is short compared with the time required in the hitherto usual process to transport the goods being treated to the first rinsing bath, to lower them into the latter for immersion rinsing, to lift them out again and to repeat this process at each rinsing station in the rinsing process.By saving on transport capacity it is possible in the case of larger installations to do away with one or more transport trucks and the control means associated therewith.

There is also the possibility of using one rinsing system common to two or more active baths, provided that from the chemical point of view the pre-requisites for this are fulfilled.

This leads to a further reduction and thus a lowering of the cost of the entire installation.

WHAT WE CLAIM IS: 1. A method of spraying an article following surface treatment thereof which comprises lifting the article, after surface treatment thereof in a vessel, by a lifting device into a spraying chamber which is situated above the vessel and is provided with an internal spraying device and with outlet means for waste spraying material, the said outlet means being arranged to prevent waster spraying material from entering the surface treatment vessel.

2. A method as claimed in claim 1, in which the spraying material is a liquid and the outlet means includes a collecting device which is moved into position under the spraying chamber after the article has been lifted therein.

3. A method as claimed in claim 2, in which the collecting device is slid or pivoted into collecting position.

4. A method as claimed in claim 2 or claim 3, in which the collecting device is in the form of a tray.

5. A method as claimed in any one of claims 1 to 4, in which there is a plurality of surface-treatment vessels and the lifting device also serves to convey the article to each such vessel in turn.

6. A method as claimed in claim 5, wherein the spraying chamber is attached to the lifting device and is conveyed by that device to be in a position to receive the article from each surface-treatment vessel in turn.

7. A method as claimed in claims 4 and 6, wherein the collecting device is also attached to the lifting device so as to be conveyed thereby.

8. A method as claimed in any one of claims 5 to 7, wherein the article is sprayed after each surface treatment.

9. A method as claimed in any one of claims 1 to 8, wherein the or each spraying operation is carried out directly above the surface-treatment vessel out of which the article has last been lifted.

10. A method as claimed in any one of claims 1 to 9, wherein the spraying chamber is provided with a sound-absorbent lining.

11. A method as claimed in any one of claims 1 to 10, wherein the spraying material for the or each spraying operation is fed to the or each spraying device from a supply container or containers arranged in any desired position near and/or below the surface treatment vessel or vessels.

12. A method as claimed in any one of claims 1 to 11, wherein the or each spraying operation is arranged to commence automatically when the article has been moved into spraying position and the collecting device (if needed) has been moved into collecting position.

13. A method as claimed in claim 6 or in any one of claims 7 to 12 when appended thereto, wherein a coupling connection between the spraying material supply and the spraying device is made automatically when the lifting deivce reaches the position in which a spraying operation is to take place.

14. A method as claimed in any one of

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. arranged to commence automatically when the article (5) has been lifted into the spraying chamber (4) and the collecting tray (3) has been moved into position below the spraying chamber. Referring to Fig. 3, an important advantage of the process of the invention is the fact that supply tanks (14, 17, 18) for the rinsing liquids may be arranged in any desired positions near to or below the actual surface-treatment vessels. Thus, for example, they may be posititoned on a floor below the installation itself, e.g., in a basement. In this way valuable and expensive space on the production floor is saved. Also the form of the supply tanks (14, 17, 18) may be chosen as desired, without any limitation imposed by the lay-out on the production floor. Preferably, simple and cheap round tanks made of synthetic plastics materials are used. The rinsing process may be adapted to all requirements both with regard to the preceding active bath and the treatment of waste rinsing liquid. A pump or pumps (15) serve to feed the rinsing liquid from the supply tanks to the spraying devices (6). In most cases it is possible to use only one pump for several rinsing baths and the change-over is effected by means of switchable valves (16), which are preferably electrically actuated magnetic valves. In addition to saving production space, the process of the invention offers the further advantage that the time taken by the articles (5) undergoing treatment to pass through the installation is shorter. During the whole of the rinsing process after an active-bath treatment, the articles being treated remain in the same position. The time taken for the trnsport of the rinsing liquid or for switching over the magnetic valves (16) from one rinsing bath (18) to the next (17) is short compared with the time required in the hitherto usual process to transport the goods being treated to the first rinsing bath, to lower them into the latter for immersion rinsing, to lift them out again and to repeat this process at each rinsing station in the rinsing process.By saving on transport capacity it is possible in the case of larger installations to do away with one or more transport trucks and the control means associated therewith. There is also the possibility of using one rinsing system common to two or more active baths, provided that from the chemical point of view the pre-requisites for this are fulfilled. This leads to a further reduction and thus a lowering of the cost of the entire installation. WHAT WE CLAIM IS:

1. A method of spraying an article following surface treatment thereof which comprises lifting the article, after surface treatment thereof in a vessel, by a lifting device into a spraying chamber which is situated above the vessel and is provided with an internal spraying device and with outlet means for waste spraying material, the said outlet means being arranged to prevent waster spraying material from entering the surface treatment vessel.

14. A method as claimed in any one of

claims 1 to 13, wherein spraying material is pumped to the or each spraying device.

15. A method as claimed in claim 14, wherein there is a common pump for a plurality of different spraying materials and the selection of spraying material for the or each spraying operation is effected by means of a switchable valve or valves.

16. A method as claimed in claim 15, wherein the or each valve is electro-magnetically actuated.

17. A method as claimed in any one of claims 1 to 16, wherein the or each surface treatment is conducted with an aqueous solution.

18. A method as claimed in claim 17, wherein the or each surface treatment is an electro-plating, corrosion-protection or anodizing treatment.

19. A method as claimed in any one of claims 1 to 18, wherein the or each spraying operation rinses rsidual material from the article that hs been surface treated.

20. A process in which articles are subjected to surface treatment, preferably with aqueous solutions, in installations consisting of active baths arranged in succession, the articles to be treated are transported by means of individual, manually or automatically controlled transport trucks, and the rinsing operations necessary between the active-bath treatments are carried out above the active baths by spraying in a chamber connected to the transport truck, which chamber surrounds the articles to be treated after they have been lifted out and is provided internally with a spraying device, and the rinsing liquid running off is carried away via a collecting device which is also connected to the transport truck and which can be slid or swung under the chamber after the articles to be treated have been lifted out of the active bath.

21. A surface-treatment and spraying process conducted substantially as described herein with reference to Figs. 1 and 2 or Figs.

1 to 3, of the accompanying drawings.