GB2028175A - Process for rinsing or other treatment of articles in plants for surface treatment - Google Patents

Abstract

In the surface treatment of articles with intermediate steps, such as rinsing, between two surface treatment steps, the intermediate step is carried out in a transfer car 4 which moves the article 3 from one surface treatment station 1 to another, the intermediate step ionate being at least partly carried out while the transfer car is moving. In the case of rinsing, rinsing water is supplied via hose 10 to spray nozzles 6 within the car 4. A collecting tray 7 is provided beneath the car. <IMAGE>

Description

SPECIFICATION Process for rinsing or other treatment of articles in plants for surface treatment The invention relates to the surface treatment of articles and especially to the rinsing of the articles between each surface treatment.

The surface treatment of articles made of metal or plastics material is often effected in aqueous solutions. This is the case, for exam ple, in electroplating, bonderising and anodis ing. The treatment is comprised of various steps; in the case of electroplating metals, for example, the treatment can roughly be divided into degreasing, pickling, electroplating (if necessary, in various stages and/or with various plating metals) and after-treatment.

Between these so-called active treatments, rinsing operations are necessary to remove adhering residues of the solution from the preceding bath before treatment in the next bath commences. Transference of the articles from one active bath to the next without an intermediate rinsing operation is possible only in a few exceptional cases.

In most cases transfer cars having electrically driven moving and lifting mechanisms are used for transporting the goods undergoing treatment from one treatment station to another and for lowering them into and lifting them put of the baths, and in most cases several such units, operating independently of one another, are used in each plant.

The rinsing stations constitute a substantial proportion of the overall size of a plant. Thus, relatively expensive production areas are required for the rinsing operations, which play no direct part in the overall surface-treatment process, and, in addition, last only a short time in each case.

In order to reduce the area required for the plant it has already been proposed to carry out the rinsing operations or other operations required between the active bath treatments in a chamber mounted on the transfer car and equipped with a spraying device, and to separate off the rinsing liquid that runs off by means of a collecting apparatus, likewise mounted on the transfer car, which can be slid or swung into position beneath the chamber after removing the goods undergoing treatment from the active bath (DE-OS 2 550 794 and British Application 46773/76).

Despite the advantages associated with this process there is however a need to reduce still more the time taken by the goods undergoing treatment to run through the plant.

The present invention provides a process for surface treatment of articles wherein an intermediate step between two surface-treatments is carried out in the transfer car which moves the article from one surface-treatment station to another and is carried out partly or completely while the transfer car is moving.

Using the above process, the goods undergoing treatment have a shorter transport time through the plant in comparison with known processes in which all steps are carried out in stationary vessels.

The transfer car is movable from one surface-treatment vessel to another and comprises a compartment for the intermediate step and usually a means for lifting the article from a surface-treatment vessel and means for lowering the article into a surface-treatment vessel. The transfer car is generally moved from a position above one vessel to a position above another vessel. In most cases there are several surface-treatment vessels in the plant (as, for example, in electroplating processes) and the article is conveyed to each such vessel in turn. Although there could in principle be a separate transfer car for each operation, there is advantageously a single such car serving all the surface treatment vessels.

Usually the intermediate step is a rinsing step, serving to remove any adherent material from the previous surface-treatment vessel, which is preferably an aqueous bath. Water is, for example, a suitable rinsing medium.

Thus, the present invention especially provides a process for rinsing an article in plants for the surface-treatment of articles, wherein the rinsing operation after a surface-treatment is carried out in a compartment mounted on the transfer car which moves the article from one surface-treatment vessel to another and is carried out partly or completely while the transfer car is moving.

Preferably the intermediate step is effected by means of spraying and the transfer car is provided with an internal spraying device and outlet means for waste spraying material. 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 the 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. A single collecting device is preferably used.

Normally, the article will undergo an intermediate step such as rinsing after each surface treatment.

Preferably the treatment with the rinsing agent is non-continuous: the article is rinsed periodically for short periods each time. The rinsing liquid may be supplied to the transfer car for example by means of a hose line which is continuously under pressure and moved along by the transfer car, the amount of rinsing liquid supplied being controlled for example by a solenoid valve installed on the transport car. The supply of rinsing liquid to the transfer car may also be effected into a reservoir mounted thereon by way of station ary filling devices at separate points in the plant and the liquid conveyed further to the spraying (or rinsing) device by a pump in stalled on the transfer car.As stated above the rinsing liquid is suitably collected in a dish which, during the rinsing operation, is ar ranged beneath the goods undergoing treat ment, and drains away by way of a drainage connection piece into collecting pipes ar ranged alongside the plant; preferably the collecting pipes are so subdivided that sorting of the different kinds of waste liquor is effected.

In a preferred method in accordance with the invention an article is subjected to surface treatment, with preferably aqueous solutions, in an installation consisting of baths arranged in succession, the article to be treated is transported by means of one or more manually or, preferably, automatically controlled transport cars and the rinsing operations necessary between the active-bath treatments are carried out at least partly during movement of the article by the transport car by spraying in a chamber connected to or mounted on the transport car, which chamber surrounds the article to be treated after it has 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 car and moves therewith and which can be slid or swung under the chamber after the article to be treated has been lifted out of the active bath.

In principle, the method of the invention can be used in spraying surface-treated articles with any 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.

The invention makes it possible to reduce considerably the time taken by the goods undergoing treatment to run through the surface treatment plant and, therefore, is particularly advantageous industrially.

The invention will now be described in further detail, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a cross-section through a plant suitable for carrying out the process according to the invention; and Figure II shows a longitudinal view of the same plant, partly in section.

Referring to Figs. I and II, a vessel 1 contains a solution 2 for the active surface treatment of an article 3. A movable transfer car 4 is arranged to move the article 3 from the vessel 1 to another such vessel by raising the article and by moving it from a position above, preferably immediately above, a treatment vessel to another such position above a different vessel and by then lowering the article into that vessel. The plant contains two or more such vessels, each usually containing different surface treatment solutions. A spraying compartment 5 is mounted on the transfer car 4 to surround the article in its lifted position, and is supplied with water by way of a nozzle system 6. The chamber is advantageously provided with a sound-absorbing lining in order to keep the noise level low for the operating personnel.A collecting dish or tray 7 with sloping base is arranged underneath the transfer car 4, and connected thereto, and connected with a drainage connection piece 8 mounted above a collecting pipe 9 arranged alongside the plant. As shown in Fig. II, the collecting dish 7 is movable horizontally, above the treatment vessels. A hose line 10 is provided for supplying the rinsing water to the transfer car 4, one end of this hose line being connected to the transfer car and the other end being connected to a stationary pipeline.

The hose line 10 is suspended from brackets 11 provided with rollers movable in a guide rail 1 2. The hose line 10 can thus be moved along the plant. A solenoid valve 1 3 fitted to the transfer car 4 regulates the metering in of the rinsing water, the control of the valve being dependent on the programme.

The rinsing operations required between the active treatment stages are carried out in the spraying compartment 5 which moves with the transfer car 4.

Thus, in use, the article 3 undergoing treatment is lifted out of the active baths 2 with the aid of the transfer car 4 and hangs on the transfer car 4 in the spraying compartment 5 inside the nozzle system 6. As shown in Fig.

II, the collecting dish 7 has been moved out of its former position 1 5 that makes it possible to lift out the goods undergoing treatment, to a position beneath the spraying compartment 5. The article is rinsed using nozzle system 6, the rinsing water running off the article 3 being collected in the collecting dish 7. Thus, the rinsing operation can be carried out without the rinsing water that is running off being able to enter the active bath 2. The collecting dish 7 is moved with the aid of an electromotor drive 14. The water flowing out of the collecting dish 7 by way of the drainage connection piece 8 is fed into the collecting pipe 9 which is arranged alongside the whole travel region of the transfer car 4.

As a result, it is possible to carry out the rinsing operation while the transfer car 4 is moving, which produces a considerable saving in time.

Depending on the treatment programme, treatment stations which have to be approached successively may be directly adjacent but may also to some extent be spaced quite far apart from one another; thus the journey time is often sufficient for carrying out the whole rinsing programme.

Furthermore, it is also possible to carry out some of the rinsing operation at any desired point in the plant when the transfer car 4 is stationary, wherein the collecting pipe 9 can be so subdivided and the location of the transfer car so selected that sorting of the different kinds of waste liquor can be effected.

The rinsing water generally flows out of the drainage pipe 9 into the waste liquor processing plant.

Claims (14)

1. A process for surface treatment of an article, wherein an intermediate step between two surface treatments is carried out in a transfer car which moves the article from one surface treatment station to another and at least partly is carried out while the transfer car is moving.

2. A process as claimed in claim 1, wherein the intermediate step rinses residual material from the article that has been surface treated.

3. A process for rinsing an article in a plant for surface treatment, in which a rinsing operation after a surface treatment is effected in a compartment mounted on the transfer car which moves the article from one surface treatment vessel to another and at least partly is carried out while the transfer car is moving.

4. A process as claimed in any one of claims 1 to 3, wherein the operation carried out in the moving transfer car is carried out by spraying.

5. A process as claimed in claim 4, wherein the spraying material is supplied to the transfer car by means of a hose line which is continuously under pressure and moved along by the transfer car.

6. A process as claimed in claim 4, wherein the spraying material is supplied by stationary filling devices at separate points in the plant into a reservoir mounted on the transfer car and conveyed further to the spraying device by a pump installed on the transfer car.

7. A process as claimed in any one of claims 1 to 6, wherein the article is treated in the moving transfer car successively and periodically.

8. A process as claimed in any one of claims 1 to 7, wherein the article is treated in the moving transfer car with material which after use is collected in a device arranged beneath the article undergoing treatment.

9. A process as claimed in claim 8, wherein the collecting device is slid or pivoted into the collecting position after the article has been lifted out of the surface treatment vessel.

1 0. A process as claimed in claim 8 or claim 9, wherein the collecting vessel is in the form of a tray.

11. A process as claimed in any one of claims 8 to 10, wherein the material drains away from the collecting device by way of a drainage connection piece into collecting pipes arranged alongside the plant.

1 2. A process as claimed in claim 11, wherein the collecting pipes are so subdivided that sorting of the different kinds of waste material is effected.

1 3. A process as claimed in any one of claims 1 to 12, carried out substantially as described herein with reference to, and as illustated by, Figs. I and II herein.

14. A process as claimed in any one of claims 1 to 13, wherein the or each surface treatment is electroplating, bonderising or anodising.

1 5. An article which has been treated by a process as claimed in any one of claims 1 to 14.