MXPA06006600A - Method for furnishing a sheet edge by a strip - Google Patents

Abstract

A method to furnish the edge portion of sheet (1) with a strip, as a strip (2) of plastic material using device (3) comprising a die space (7). The edge of sheet (1) is fitted inside device (3) that feeds plastic material to die space (7) and by means of restrictive organs (8) and die surfaces, of which device the escape of heated plastic material from a die space (7) is avoided, the sheet is arranged to move in regard to the feeding (3) device, the sheet edge being inside said device, die space (7) of device (3) is heated during the process.

Description

METHOD OF SUPPLY OF SHEATH EDGE THROUGH A STRIP Description of the Invention The invention relates to a method that supplies the edge portion of a sheet or sheet with a strip, such as a strip of plastic material using a device comprising a matrix separation. The invention relates, above all, to anodic and cathodic sheets used in the processing industry, the edges of which, by means of a plastic strip, must be maintained in an electrically non-conductive form. Previously known is the injection molding method of plastic material, where based on the use of a material matrix, an object similar to the matrix is produced. Matrix applications are also known, wherein before the injection molding process in the matrix, ready-made objects are placed, for example, metal objects that are totally or partially placed in the matrix. The plastic strip means that the edge of the sheet could be achieved with a matrix for pressure casting on the length of the edge of the sheet, where the edge of the sheet would have been taken towards the matrix, the mold and the matrix of the sheet. the strip could be opened and the sheet with its strips would be removed. As an example of this, the patent application of the States REF may be mentioned. 173686 United No. 5, 928,482. A production process of this type requires a large and expensive matrix. Compaction on the matrix would be complicated and perhaps impossible based on the use of high injection molding pressures. One edge of the sheet could be made at the same time and even slight variations in thickness would cause immediate compaction problems in the matrix. It could also be considered the placement of a profile strip already made in some way on the edge of the sheet, however, the placement is a difficult method and by means of this would not be achieved a sufficient fusion of the strip on the surface of the sheet , so that the oxygen of the electrolytic bath could not penetrate between the strip and the sheet. Further known from the publications EP 028284, EP 707937 and US 5, 336,349 is a method of producing an edge portion of a plastic material using an extrusion device comprising a separation or matrix space. In these publications, the edge is placed in the matrix separation of the extrusion device and the sheet is moved with respect to the separation of the matrix. The adhesion of the strip can not be ensured in the applications presented previously, because the strip is initially cooled in the portions where it makes contact against the cold edge of the sheet. In order to solve the disadvantages and problems presented above, a new method is developed, which is characterized in that the matrix separation of the device is heated during the process and the sheet is heated at its edge portion at least at a temperature of 10-200 ° C higher than the temperature of the plastic mass directed towards the matrix. The advantage of the invention is that the supply of the edge of the sheet with a plastic strip can be automated with ease, when this is a process that is carried out on a belt or sliding guide in movement. The opposite edges of the sheet can be supplied with a strip at the same time. In the method, a completely short extrusion die is sufficient, in which the plastic material is fed to the edge of the sheet. Due to the short extrusion die, the variations in the thickness of the sheet can be compensated by wedge or insert lips. Due to the adequate temperature set for the material, no high pressure is necessary, either in the die or in the extruder and by pre-heating the sheet edge in the strip a force is obtained which maintains the compression in the sheet and by cooling the strip produced it is ensured that the shrinkage is finally effected on the inside of the strip.

Brief Description of the Figures In the following, the invention is described with reference to the attached figures, in which Figure 1 shows the elaboration of a strip on the edge of a moving sheet, Figure 2 shows the case of Figure 1 observed starting from the end, Figures 3a and 3b show some edge shapes of the sheet, Figure 4 shows the strip at the edge of the sheet, Figure 5 shows a closing device for a die opening, Figure 6 shows the heating of the sheet edge, Figure 7 shows a strip and sheet seen from the end, Figure 8 shows an exhaust pipe around the strip. Figure 1 shows the preparation of the plastic strip 2 that will be processed for the edge of the moving sheet 1 by means of the device 3. The edge of the sheet 1 is directed to move through the device 3. In the device 3 the hot plastic arrives along the tube 6. In the device there is also a heating resistance 4 which keeps the strip forming matrix included in the device at a regulated temperature. Figure 2 shows the device from the end without any plastic feed within the separation 7. The separation 7 is a matrix separation that is reached through the device 3 which defines the profile shape of the strip 2 that is being produced The edge of the sheet 1 is led towards the separation of matrix 7. On the surface of the sheet 1 the matrix separation is pressed with the restrictive organs 8, which are for example, drag lips. These organs prevent the plastic material from being placed on the surface of the sheet 1 faster than it is intended. The ends of the matrix separation 7 are open. The opening of one end of the matrix separation 7 is completely stopped by the sheet 1 and the removal of the strip 2. The entry opening of the matrix separation of the sheet 1 is in this mode only stopped by the sheet 1. When the plastic material of the passage tube 6 is fed by the pressure towards the matrix separation 7 it fills the matrix separation, collides with the moving sheet and leaves together with the sheet as a ready-made list. The feed pressure and the feed amount within the matrix separation 7 are regulated so that the plastic material does not extrude faster than the time that the sheet 1 is able to leave through the exit orifice of the separation matrix 7. It is also not allowed that the material is extruded out of the inlet of the matrix separation 7. Figure 3a shows the slot 9 that improves the adhesion of the sheet 1 on the edge, and Figure 3b shows a series of 10 holes that also improve adhesion. Figure 4 shows the strip already made 2 on the sheet edge. Thanks to the strip 2 the edge of the sheet remains neutral and does not collect any amount of copper on its surface. Figure 5 shows an application, wherein the entrance hole of the sheet edge can also be closed in the same way as the portion, the sheet edge of which is not obstructed. The deflection plate 12 is pushed forcefully towards the stops 8. The spacing in the deflection plate 12 is only slightly larger than the thickness of the sheet. Figure 6 shows the manufacture of the strip 2 on the edge of the sheet 1, by means of which the sheet 1 is heated from both sides by means of the burners 14. The flames 13 are directed towards the area on the edge, on which is intended to be spliced or introduced the strip 2. The sheet 1 is heated to a temperature about 10-200 ° C hotter than the mass of plastic in the extrusion matrix 3. If the sheet was colder than the plastic mass, immediately after extrusion, the dough forming strip 2 would cool and harden first in its portions against sheet 1. Once the outermost portions of strip 2 have cooled and have shrunk in remarkable shape at the same time, by means of which, the coatings of the strip open the sheet. The temperature of the sheet 1 that lies before the matrix 3 can be controlled, for example, by pyrometric measurement. The intensity of the temperature can be regulated based on the measurement during the regulation of the intensity of the flame or for example, during the regulation of the distance of the flame from the sheet. In order to avoid the phenomenon of detachment or stripping of the strip described above it is necessary that the sheet 1 is hotter than the plastic mass in the extrusion die 3. This means first of all, according to the Figure 7, that the outer surfaces of the strip are cooled and hardened, and after that, thanks to the hot sheet 1, for example, the molten plastic mass in the place 15 finally cools and shrinks, by means of which , the strip 2 remains in contracted position around the edge of the sheet. The edge of the sheet can be heated by a gas flame, heat of radiation or, for example, by the principle of eddy currents. The strip 2 made on the sheet edge is immediately cooled in the most suitable manner by means of a jet of air by means of which the surface of the strip first hardens. The chilled and produced strip 2 can be covered from one of its edges by means of the open tube 16 (Figure 8), which is placed around the strip immediately after the device 3 and inside of which the air flow is released or injected. As a result, the air flow does not escape and a smaller air jet is sufficient for the cooling of the strip. It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (7)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A method of supplying the edge portion of a sheet with a strip, such as a strip of plastic material using the device that includes a separation of matrix in the method of which the edge of the sheet is placed inside the device that feeds plastic material to the separation of matrix and by means of restrictive organs and matrix surfaces from which the escape of plastic material is prevented When the device is hot from the matrix separation, the foil is positioned to move with respect to the plastic material feeding device, the foil edge is inside the device, characterized in that the matrix separation of the device is heated during the process and the sheet is also heated, so that its edge portion reaches a tempera At least 10-200 ° C hotter than the temperature of the plastic mass fed into the matrix. The method according to claim 1, characterized in that the strip produced is cooled by means of the cooling impact, for example, of the flow of air directed on the outer surface. 3. The method according to claim 1, characterized in that forms such as holes, slots or similar forms that improve the adherence of the strip are used at the edge of the sheet. The method according to claim 1, characterized in that the supply pressure of the plastic material to the matrix separation is set so low that the strip adheres to the sheet and the edge running from the end of the separation The matrix can cause a substantially comparable back pressure in its discharge orifice. The method according to claim 1, characterized in that the sheet is moved on the sliding guide, while the sheet edge is moving through the matrix separation of the device. 6. The method according to claim 1, characterized in that the device is moved along the edge of the sheet. The method according to claim 1, characterized in that the free portions of the sheet at the entry end of the matrix separation are always sealed, for example, by means of the part.