Valk Welding: 2003

Kopal, manufacturer of fences in Kortemark, West-Flanders, has strongly increased its production capacity for fencing and gates by using a welding robot installation. The installation, supplied by Valk Welding, consists of a Panasonic welding robot in hanging position along a track of 21 m, three clamping places and an exhaust system for welding fumes moving along with the robot over the complete length of the track. The cell is operated by one man, and does the welding work of 2 men per shift.

Although the name Kopal is not known as a brand name on the market, there is a chance that your premises are closed with a gate and fence from this manufacturer. Indeed, Kopal is the largest manufacturer of fences in Belgium and supplies its products world-wide via exclusive installers. Contrary to many companies in other branches,  the company in the Flemish Kortemark is prospering. The increasing need for terrain fencing for both private persons and the authorities, results in an annually growing order book for the company. The order for the construction of two sliding gates of 67 m for a French military airport, is an example of the size and broad scale of the company. However, this growth was largely hindered by a lack of qualified welders. This was one of the main reasons to invest in robotised welding systems.

Kopal now uses a welding robot installation from Valk Welding, with which the production capacity for standard fences could be boosted, 20 manual welders being saved from monotonous work and able to focus on other special projects.

In-house
One of the reasons for the competitive success of Kopal is that the company disposes of its own galvanising and coating installations for its products, thus saving on high transport expenses for the mostly large products. In its hot bath galvanising plant, gates and fences up to 16 m in length can be galvanised and immediately thereafter finished in an automatic powder coating unit. The products of Kopal owe their long lifespan to this finishing. For the extensive programme of banisters, decorative and sliding gates, fences and accessories alsmost the same production method is required. In most cases, this means assembling of cut tube material and profile steel with drilled hole patterns, welded in jigs before being galvanised and coated.

Universal jigs
The use of welding robots in this production environment seems obvious. All components come from a CNC-production environment, hence there is little risk of tolerance problems. The large diversity of heights and widths requires an equally large number of jigs, resulting in too large  and too expensive a solution. That is why Kopal itself has invested in the development of jigs,  aiming at welding as many products as possible with as little jigs as possible. Kopal found the solution in a concept of jigs that can be adjusted in length, and in which at this moment 80% of the products can be clamped. Two clamping places have been provided with these adjustable jigs, so one clamping place is free for putting on tube and profile material, while the other is used to weld a complete set by robot.

Digital welding robot
A  Panasonic VR006L welding robot from the digital Global series forms the heart of the cell. Panasonic offers a complete system with power source, robot, external axes and control, whereby all components perfectly fit together. These components are being further integrated by Valk welding in a complete robot installation. The exhaust system, supplied by the company Lucomex, offers a unique solution for robots that have to be moved over a longer line. The robot now works under the 'exhaust unit' that moves along with the robot over the track. In this, only local air is being exhausted and a relatively small system will suffice. With the exhaust system, collaborators no longer need to operate the welding cell, and won't be exposed to noxious and toxic welding vapours.

Programming
The cell is programmed with the DTPS off-line programming and simulation system of Valk Welding. The supplier delivered complete programming for 2 various (product) models, based on parametric programming. Kopal only has to adjust length and width to be able to simply programme products from the same product family, resulting in simplified programming. Planning the programmes per clamping table is also done with the DTPS system. To do this, Valk Welding supplied a custom-made interface and with just a few clicks the desired fences (model, length, width, distance between banisters, etc.) can be produced at the desired station. Thanks to the rapidly adjustable welding mould, also smaller series can be produced. The system is used off-line, meaning that programming is completely done outside production; no need to interrupt the robot for programming. For Kopal, the off-line programming system was the decisive factor. The highly appreciated level of service and the high reputation of Valk Welding,  gave Kopal the confidence to collaborate with this robot supplier.

Increased capacity and efficiency
Initialy, the welding cell was meant to gain experience with robotised welding and to test the jigs. For the time being, only standard fences with banisters are being welded by robot. The capacity increase resulting from the use of the welding robot is still limited to one shift, but will be enhanced gradually. The experience with the development of the jigs and the use of the welding robot, is now used to robotise the welding production of gates from the Kopal delivery programme. This will be done with a third welding station that is provided with the robot installation. The unit will be further enhanced to create additional stations. If required, a second robot can even be placed on the current track, resulting in double welding capacity. Furthermore, the use of the welding robot will be increased from 8 to 16 hours a day. Not only capacity and efficiency are boosted, but more manual welders are released from monotonous work on standard products and ready to focus on larger specific projects.

(Source: Metallerie 55 - special Welding Week - October 2003 'by Erik Steenkist')