FR2665847A1 - Installation for the electrostatic powder-coating (powdering) of objects moving through a spray enclosure - Google Patents

Abstract

Installation for electrostatic powder-coating of objects moving through a spray enclosure, of the type having a conveyor (1) carrying pallets (2) carrying workpieces (components) (3) and circulating above the opening of a chamber (5) having a bath of fluidised pulverulent material, the polarity of which is opposite that of the workpieces (3), characterised in that it furthermore includes, in combination with the chamber (5), a powder-coating enclosure (7) which can move vertically and, in the closed position, forms, together with the chamber (5), a closed space surrounding the workpiece (3), and the opening plane (P) or parting line (junction plane) of which is also the plane of movement of the workpiece.

Description

 The invention relates to an installation for electrostatic powdering of moving objects in a spray enclosure.

 An example of such a device is described in French application 83 13826.

 It is a device composed of a structure traversed by the material to be coated and comprising electrodes creating an electrostatic field. The running plane of the material to be coated is vertical creating on each end a first vertical opening.

 The opening plane or joint plane of the two parts of the structure is horizontal.

 The main drawback is the existence of vertical and horizontal openings multiplying the possible leaks.

 The Applicant has had the idea of overcoming this drawback while looking for a simple, economical and handy device.

 To do this, it has proposed an installation for electrostatic powdering of moving objects in a spray enclosure, of the conveyor type carrying pallets carrying parts and circulating above the opening of a bath of fluidized pulverulent material, the polarity is opposite to that of the parts, characterized in that it also comprises, in combination with the chamber, a powder coating enclosure movable vertically and forming, in the closed position, with the chamber an enclosed space surrounding the part, and the plane of which 'opening or parting line is also the part's running plane.

The invention will be better understood with the aid of the description below given with reference to the following appended figures - FIG. 1 is a sectional view of an installation with a workpiece pallet conveyor passing over a electrostatic fluidized bath - figure 2 represents an improvement of the device of figure 1 by means of a closed volume enveloping the part - figure 3 is a diagram of the installation according to the invention in longitudinal section
The preferred nonlimiting embodiment of FIG. 3 consists of - a conveyor or transfer chain (1) for example with parallel flexible belts - a fluidized bath chamber (5) arranged below the conveyor (1) - pallets (2) workpiece carrier placed on the conveyor (1) and comprising slots or any other form of light (4) suitable for the passage of powder streams - of parts (3) placed on the pallets (2), and of which the polarity is the opposite of the polarity of the chamber (5) - an enclosure (7) of dusting placed above the conveyor (1), movable vertically according to the arrows (F), and the opening of which is directed towards the conveyor.

 The enclosure (7) and the chamber (5) together form a closed space enclosing the part and intended to limit in a manner known per se the electrostatic field (8) of diffusion of the powder.

 The originality lies in the fact that the pallet and / or the conveyor form the joint plane of the two parts (5,7) of the closed space.

 To allow the diffusion of the powder, the pallets (2) and the conveyor (1) must be perforated and their lights substantially placed in concordance. The chamber (5) is located between the parallel belts of the conveyor, under the plane of travel of the perforated pallets carrying the parts.

 The main advantage of this device is its simplicity. Another advantage is that the scrolling plane (P) is also a plan for closing the enclosed space, which limits the maximum possible openings and leaks.

 Another advantage consists in using a conventional type conveyor or pallet transfer without having to make modifications or adaptations to cooperate with the powdering installation.

 Of course, alternative embodiments are possible, for example as to the shape and / or dimensions of the chambers and enclosures, without going beyond the ambit of the present invention.

Claims (2)

1. Installation for electrostatic powdering of moving objects in a spray enclosure, of the conveyor type (1) carrying pallets (2) carrying parts (3) and circulating above the opening of a chamber (5 ) bath of fluidized pulverulent material, the polarity of which is opposite to that of the parts (3) characterized in that it also comprises, in combination with the chamber (5), a powder enclosure (7) movable vertically and forming, in position closure, with the chamber (5) a closed space surrounding the part (3), and whose opening plane (P) or joint plane is also the part's running plane. 2. Powder coating installation according to claim 1, characterized in that the conveyor and the pallets are perforated and their lights substantially placed in concordance.