FR2493189A1 - METHOD FOR REMOVING LAYER LAYERS AND DEVICE FOR IMPLEMENTING SAME - Google Patents

Abstract

A.PROCESS FOR REMOVING LAYERS OF LACQUER AND DEVICE FOR ITS APPLICATION. B. PROCESS CHARACTERIZED IN THAT THE LACQUERED PARTS ARE COOLED USING LIQUEFIED GAS AT LOW BOILING TEMPERATURE TO MAKE THE LACQUER BROKEN, THEN THESE PARTS ARE PASSED BETWEEN AT LEAST TWO 7 ROTATING SHAFTS IN OPPOSITE DIRECTION, VERTICALLY ARRANGED, AND ON WHICH ARE FIXED A LARGE NUMBER OF PUNCHING TOOLS IN THE FORM OF 8 CHAINS OR WIRES. C. THE INVENTION CONCERNS MEANS FOR CLEANING SUSPENSIONS ETC. OR OTHER ORGANS USED IN LACQUERING PATHS.

Description

The present invention relates to a method for removing layers of

lacquer on the suspensions

  lacquered materials and the various parts of a lacquering

  tinu. Lacquer is deposited on the suspen- sions or supports of continuous lacquering paths, which must be lacquered. The expression "Illa" used in this context also concerns enamel coatings, which also applies to other parts of a lacquering path, which receive a layer of lacquer during the lacquering operation. lacquer, chemical solvents or gas burners are used.

  require a lot of work and are troublesome for the environment.

  ronment. Often, there are also harmful emissions of vapors which must be protected from the personnel performing the work. The lacquer suspensions must also be removed from the endless transport chain, which necessitates stopping the lacquering operation that is carried out.

in general continuously.

  The object of the present invention is to create a method for removing the lacquering layers from the suspensions used for lacquering and the various parts of a continuous lacquering path, enabling the lacquer to be removed without it being necessary to stop the continuous operation of the installation and which avoids long work,

  expensive and harmful to the environment.

  For this purpose, the invention relates to a process of the above type, characterized in that the lacquer-coated parts are cooled with a liquefied gas at a low boiling temperature in order to make the lacquer brittle and then these pieces are passed between at least two trees

  rotating in opposite directions, arranged vertically, and on the

  which are set a lot of typing tools fit

of c1aine.s or son.

  Thanks to low temperature liquefied gas

  The boiling point in the lacquer and enamel layers induces a different expansion of the substrate, which leads to the formation of capillary fissures making it easy to remove the layers thus dislocated. using a shock. This method can be integrated in a continuous working process in a continuous lacquering path, even if the removal of the lacquer is an operation that must be done after several passes of the suspensions in the lacquering path. The lacquer particles thus removed by shocks are then collected and training is avoided.

  poisonous or harmful gases or vapors for the environment

  ment. In addition, it is not necessary to use

aggressive chemical

  The cooling of the coated parts is done in the most advantageous manner by immersion in a bath containing liquefied gas at low boiling temperature, because in this case the cooling is the most

  fast, which is advantageous if the process is part of

  Grantee of a lacquering path, endless.

  A device for carrying out the process according to the invention consists essentially of a receptacle for the lacquer removed, at least one pair of shafts.

  turning in the opposite direction above the receptacle, and which

  a large number of strapping tools in the form of chains or wires, as well as a bath of liquid nitrogen associated with the receptacle. Preferably, there are three pairs of shafts rotating in opposite directions bearing striking tools, as these are generally perfectly sufficient for

  remove the lacquer layer by striking it.

  It is advantageous that the trees

  in the opposite direction with the striking tools form a narrow path through which pass the lacquer suspensions attached to the transfer chain. Trees in a pair can also be brought close together so that the ends of the chains or wires of two trees

touch during rotation.

  The device according to the invention is advantageously associated with the guide rails of an endless lacquering path, so that the suspensions pass through

  successively the bath and pass on the rotating shafts.

  The device according to the invention is then an integral part of the lacquering installation. If it is not necessary to remove the lacquer layers after each lacquering operation, the diXSpositif according to the invention can be used in

2493,189

  parallel to the endless lacquering path, so that the suspen-

  only pass through this device when it is necessary

  sary. A particularly important advantage of the process according to the invention lies in the fact that the lacquer layers are basically removed without the need to slow down the speed of transfer of the lacquering path or without the need for stopping as is the case, for example, in the known solutions for removing lacquer layers on the suspensions. To avoid losses of gas, it is possible to precede the immersion bath with a cooling path in which the

  suspensions using gas from the lacquering bath.

  The present invention will be described in more detail with the aid of the accompanying drawings in which

  FIG. 1 is a perspective view

  simplified circuit of a device according to the invention.

  FIG. 2 is a longitudinal section

  of a tree on which the striking tools are attached.

  The device represented in FIG. 1 shows part of a transfer rail 1 of a continuous lacquering path. The transfer chain of which we see the links 2 passes in the transfer rail 1. The links 2 carry the lacquer suspensions 3. The direction of transfer 23 is indicated by the arrow 4. The device according to the invention consists of a receptacle 5 provided under the guide rail 1 for receiving the lacquer removed by striking, and a continuation 6 in the form of a hopper, on the receptacle 5. The extension 6 hopper-shaped carries three pairs of shafts 7 rotating in opposite directions, and which partially come

  protrusion in the extension 6 shaped hopper. The provision

  Rotating shaft drive 7 is not shown.

  The chains 8 are welded on the rotary shafts 7. The meaning

  of rotation is indicated by the arrows 9.

  The receptacle 5 and the rotary shafts 7

  are preceded by a bath 10 containing liquid nitrogen

  In practice, rotary shafts 7 are also

  surrounded by a protective cover, not shown.

  The suspensions 3 coated with lacquer first pass through the bath 10 which cools them down at low temperature and the lacquer detaches and becomes brittle. Then the suspensions 3 pass between the three pairs of shafts 7 rotating in opposite directions. The chains 7 welded on the shafts 7 hit the lacquer made fragile to remove it without leaving any remains; this lacquer falls into the receptacle 5.-From there, the suspensions 3 come out again to return to the entrance of the

continuous lacquering path.

  Figure 2 is a sectional view of a rotary shaft 7, hollow. Both ends of the shaft 7 are

  closed by cover plates Il. A training tree

  12 is attached to the lower plate 11; this shaft 12 is connected to a not shown drive means. A large number of chains 8 are welded to the shaft 7. The form of the chains is arbitrary, however, circular ring chains are preferably used. The chains 8 can also be replaced by elastic threads or

steel cables.

  It is inevitable in the case of lacquering paths that not only the lacquer suspensions, but also other parts of the lacquering path receive lacquer. Now, from time to time, we must also remove the

lacquer of these various pieces.

  This can be done in a simple way by hanging these various pieces on the links of the chain

  transfer instead of suspensions 3.

Claims (1)

  1) Process for removing lacquer coatings from lacquer suspensions and parts of a continuous lacquering path, characterized in that the lacquer coated parts are cooled using a low temperature liquefied gas boiling to make the lacquer brittle, then these pieces are passed between at least two trees (7)   rotating in opposite directions, arranged vertically, and on the   which are set a lot of typing tools fit chain (8) or son.   Process according to claim 1, characterized in that the cooling of the lacquered parts is carried out by immersion in a bath (10) containing a   liquefied gas at low temperature.   3d) Device for implementation   process according to claim 2, characterized by a reception   tackle 5 to receive the lacquer removed, at least one pair   shafts (7) rotating in opposite directions and mounted   above the receptacle, and on which is carried a large number of strikers in the form of chains (8) or son, and a bath (10). immersion, containing liquefied nitrogen,   bath that is associated with the receptacle.   Device according to claim 3, characterized by a path defined by three pairs of trees   rotating in opposite directions and carrying striking tools. ) Device according to any one   Claims 3 and 4, characterized in that the bath,   the receptacle and the rotating shafts in the opposite direction are   associated with the guide rail (1) of a lacquering path in   tinu so that the lacquer suspensions (3) pass   successively in the bath then between the rotating shafts.