Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D1/00—Processes for applying liquids or other fluent materials
  • B05D1/32—Processes for applying liquids or other fluent materials using means for protecting parts of a surface not to be coated, e.g. using stencils, resists
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D51/00—Making hollow objects
  • B21D51/16—Making hollow objects characterised by the use of the objects
  • B21D51/26—Making hollow objects characterised by the use of the objects cans or tins; Closing same in a permanent manner
  • B21D51/30—Folding the circumferential seam

Definitions

• connection must be post-annealed more or less so that the sealing compound hardens and cannot flow out of the fixed connection, or can be dissolved out by aggressive foods or solvents.
• the object of the present invention is to propose a method for the tight connection of two workpieces, such as metal wall parts, according to which both the mechanical processing step of curling and the repeated application of heat can be dispensed with.
• this object is achieved by means of a method, preferably according to at least one of the claims, in particular according to claim 1.
• Ver ⁇ connection edge portion of one workpiece is fed and then by folding the edge portions of the two workpieces into each other, these are tightly connected to each other.
• At least one metal wall part comprises a connecting edge part according to the above statements, and that the further wall part is at least almost perpendicular to or on the coated edge part or .
• the connecting edge part is fed in and the two metal wall parts are tightly connected to one another by folding the edge parts of the two wall parts into one another.
• a metal wall part comprises a connecting edge part according to the above statements
• the further wall part comprises an edge part projecting almost perpendicularly to it, that the further wall part is at least almost perpendicular to or on the coated edge section resp.
• the connecting edge part is fed, the edge part of which comes to lie parallel to the one connecting edge part, then the two edge parts are at least partly connected to one another by spot welding and then the two metal wall parts are folded into one another by folding the edge parts of the two wall parts into one another be tightly connected.
• the methods described above are particularly suitable for producing a metal can.
• the activation of the powdery or plastic-like material in the coating of the connecting edge section can take place in that the material is applied to the edge section by means of flame spraying.
• coating material used may be, for example, also be a 'l- or 2- Komponentensy- stem, which at least partly, Ein ⁇ effect of ultraviolet curable or light is. Ent- speaking, the system is activated before or during application to the edge area by means of UV or daylight.
• the coating material can also be a reaction resin system, which consists for example of epoxy resin, an unsaturated polyester resin or a polyurethane resin.
• a reaction resin system which consists for example of epoxy resin, an unsaturated polyester resin or a polyurethane resin.
• Other reactive resin systems can also be used, but depending on the requirements, e.g. due to the contents in a container, must be suitable for chemicals or food.
• the system can also be either a powder coating or a so-called liquid plastic system with a correspondingly sufficient viscosity.
• thermoplastic materials are also proposed for the coating, which, however, are preferably at least partially crosslinkable in order to ensure, for example, sufficient chemical resistance to the possible content in the can.
• thermoplastic materials which are preferably applied to the edge area in the form of a powder coating, are to be melted at least partially before or during the application in order to form an at least almost homogeneous film-like coating on the edge area.
• thermoplastic materials can be both a polyester, a polyamide, polyurethane, PVC or a polyolefin, such as, for example, polyethylene. These materials are preferably applied in the form of powder coatings, but it is it is also possible, for example when applying PVC, to apply so-called plastisol materials in liquid, highly viscous form to the edge area.
• the coating materials represent largely reactive systems that are activated before and / or during the application to the edge area, it is advisable to use the two workpieces, respectively. fold the two edge parts into one another as soon as possible after the coating process or to connect with each other so that the coating, resp. the sealing compound has a sufficient elasticity. If the connection of the two workpieces is waited too long, depending on the type of coating material, there is a risk that it will become brittle, which means that there is a risk of breaking during the folding process. However, this danger exists less or hardly with only partially crosslinked thermoplastic coating materials.
• a metal can which consists of a base, a body and a cover
• the edge portion of the base is first coated with a powder or plastic-like material, this before and / or during the application to the edge area is activated. If the can has a square base crack, for example, then the four edge parts of the square base are to be coated accordingly. Following the coating of this edge section, resp. Border parts, the can body is guided at least almost vertically on all sides to the coated edge part of the floor and the two edge parts, respectively. Two corresponding edge parts of the bottom and the fuselage are firmly connected to each other by folding the. The lid is attached to the still open side of the fuselage analogously to the method described above.
• the above-mentioned methods are generally suitable for producing tight connections between two flat workpieces or. for producing containers from individual flat workpieces.
• the methods described above are particularly suitable when using metal workpieces, they can of course also be used for connecting workpieces, for example consisting of a plastic.
• the connection is finally additionally mechanically secured by folding the two edge parts, it is of course a prerequisite that the material used for the production of the workpiece permits a machining process, such as folding.
• FIGS. 7 and 8 shows the coating station according to FIGS. 7 and 8 for coating an edge section in operation
• FIG. 11 shows the assembly according to FIG. 10 in cross section, the can bottom being specially designed
• FIG. 13 shows two joined edge parts of a metal container before the flanging, with spot-welded welding points.
• a workpiece 1 comprises an edge section 3.
• a spray gun 5 is used to spray powder-like material 13 onto the edge section 3 through a nozzle 7.
• the powder 13 is thermally activated by means of a flame 9, which is generated in a ring around the nozzle 7. The activation takes place e.g. Part of the fact that the workpiece itself. the edge part of which is heated by the flame 9 during the application. This heating also improves the adhesion of the coating to the edge area.
• the powder material 13 is fed from a storage container (not shown) to the nozzle 7.
• the coating creates a coated edge section 15 on the workpiece 1.
• a collecting pan 17 or a suction device is also provided for collecting sprayed powder material 13 which does not get onto the workpiece.
• FIG. 3 again shows a perspective top view of how a second workpiece 21 with the edge part 23 is fed against the coated edge part 3/15 of the workpiece 1 at a right angle. 3, the edge portion 23 is angled perpendicular to the workpiece 21. The workpiece 21 with the edge 23 is placed on the coated part 15 in such a way that a tight connection is created.
• FIG. 7 and 8 show a transport device which is suitable for feeding workpieces 1 to a coating station, where the edge portion is coated.
• Fig. 7 shows the transport arrangement in side view and Fig. 8 in supervision.
• the transport device comprises an infeed Conveyor belt 31, which, for example, as shown in FIGS. 7 and 8, can be in two parts, comprising two convex transport surfaces.
• the workpiece 1 to be coated with the edge part 3, such as a bottom of a metal can is fed to a coating station 39.
• the conveyor belt 31 is fed back around a deflection roller 33.
• a removal conveyor belt 35 is provided, which according to the representations in FIGS. 7 and 8 is also bipartite, each with a convex transport surface.
• the conveyor belt or the conveyor belts 35 are transported in the area of the coating station 39 by a deflection roller 37.
• the workpiece 1 fed to the coating station 39 by the conveyor belt 31 is now, as shown in FIG. 9, lifted off the conveyor belt 31 by a tripod-like support 40 before it can be transported further by the conveyor belt 35.
• the workpiece 1 if it is a circular lid base as in the example according to FIGS. 7 to 9, is rotated about its longitudinal axis by rotating the stand.
• the edge part 3 of the workpiece 1 is shown by means of a spray gun 5 analogous to the method shown in FIG 1 to 4 coated.
• the peripheral part is coated over its entire circumference, as a result of which the connecting edge part 15 is formed.
• the stand 40 is lowered again and the workpiece 1 is transported further by means of the conveyor belt 35.
• a station can be arranged for joining the can base to the can body.
• further processing can also be carried out discontinuously, in that the can bottoms with the coated edge portion are fed to a further processing stage.
• a can body 21 comprising the edge part 23 with the can base 1, which comprises a fully coated edge part 15.
• the can body 21 is placed on the can base in such a way that a completely tight connection is created.
• a film thickness in selected in the order of 60 to 90 u.
• the mechanical processing is carried out by folding the two edge portions 23 and 3 and 3 respectively. 15.
• the connection thus created between the can body 21 and the can base 1 is absolutely tight on the one hand and has good mechanical strength on the other hand.
• FIG. 11 shows the cross-section of the assembly of the can body 21 with the can base 1 according to FIG. 10.
• the can base 4 is designed such that the edge part 3 is connected to the center of the can base 1 via a shoulder 4.
• This paragraph 4 has the advantage that it simplifies the centering of the can body 21 when it is placed on the can base 1.
• FIG. 12 now shows a further possibility of improving the mechanical strength of a connecting edge part of a metal container by means of spot welding.
• a selective welding zone 42 can be created by attaching two welding electrodes 41. Since, in particular, according to the above-mentioned explanations, the coating 15 of the edge part 3 is very thin and only covers the outermost edge, this type of spot welding is not a problem.
• the spot welding takes place on the inner part of the edge Part 3, which coating or. is plastic-free. The matter would be different in the case of a can bottom 1, the edge part 3 of which has a bordering or includes a recessed gutter. Experience has shown that the entire channel is lined with coating material, so that the coating material would be destroyed at least locally when a spot weld connection was created.
• FIG. 13 shows the preferred arrangement of such welding spots 42 when connecting a can body 21 to a can base 1 before the flanging.
• the welding spots 42 are preferably arranged in the area of the corners 43.
• the manufacture of a border or of curling on workpiece 1 can be dispensed with.
• the coating of the edge section does not have to be subjected to further thermal treatment before or during the application to the edge section.
• the activation is such that the coating material guarantees sufficient tightness of the connection on the one hand and on the other hand to media such as food and Chemicals that have sufficient resistance.
• FIGS. 1 to 13 can on the one hand be extended to metal cans and metal containers of any design, and in particular also to containers with, for example, a square or rectangular outline.
• the edge area can be coated, for example, by moving a spray gun along the edge and not rotating the workpiece.
• the methods proposed according to the invention can also be used for connecting any workpieces, in particular also for connecting workpieces made of non-metallic materials.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Details Of Rigid Or Semi-Rigid Containers (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6372026

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (3)

Citations (7)

Family Cites Families (1)

• 1989
  • 1989-01-13 DE DE19893900861 patent/DE3900861A1/de active Granted
• 1990
  • 1990-01-07 EP EP19900902215 patent/EP0453491A1/de not_active Withdrawn
  • 1990-01-07 AU AU49630/90A patent/AU4963090A/en not_active Abandoned
  • 1990-01-07 WO PCT/EP1990/000027 patent/WO1990007994A1/de not_active Application Discontinuation

Patent Citations (7)

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