Valk Welding: News

Using the PTAW process including easy programming of handling robots made Omco International to invest in 7 handling robots worldwide.                                                                                

Using the PTAW process Omco International with their headquarters in Belgium, has invested in 7 handling robots in order refurbish moulds for the glass industry. In doing so Omco could reduce strongly on material, labour and energy costs for refurbishing the glass moulds. Additional advantage is that the welding quality is very reliable creating a worldwide quality standard at Omco.

Concept is a Fanuc handling robot which is handling the glass moulds under a fixed position PTAW torch. Valk Welding has build standard concepts with a torsion free basis so that these frames can be programmed and shipped throughout the whole world and nowadays are being used in the production facilities from Omco International in Belgium, Austria, United Kingdom, Romania, Turkey and United States (Ohio).

 

Omco International belongs to one of the largest glass mould manufactures worldwide with factories in Europe and United States, Omco is producing moulds for bottles. The moulds consisting out of 2 halves are being exposed during the production process of producing bottles to extreme high temperatures (up to 1200°). Due to these high temperatures these moulds wear rapidly and have to be refurbished with a weekly interval. The cast-iron moulds are difficult to be welded with a standard welding process. Based on this Omco International is preparing the moulds with a nickel coating which can be repaired easily afterwards. The glass moulds can be repaired up to six times which will prologues the lifecycle of these moulds to 7 weeks. With these moulds a total amount of 1 million bottles were produced before they have to be replaced.

Material costs increased to sextupled
The refurbishing of the surface was realised before by Omco using the fuse welding process. In this process nickel powder is being transferred to the mould using an oxy acetylene flame. Using this process a lot of nickel is lost and cannot be retrieved. Since the nickel price has sextupled in the last years, a new process had to be found to refurbish the glass moulds. Omco International was aware what they wanted to use.

Danny Buré, plant manager at Omco International in Belgium (Aalter): “We already had robotised the handling of the glass moulds although this was done with old systems which only can be programmed using the offline programming method. We therefore wanted to replace these old robots by modern handling robots which can be programmed offline preferable using a standardised programs. Next to that we wanted to replace the fuse welding process by the PTAW process and did look for another way to pre-heat the moulds. This kind of specific process changes should be investigated together with your supplier in order to be successful. We have supplied the new induction heating system including gripper and PTAW equipment to Valk Welding and asked them to support us in the handling and welding application. This cooperation was fairly easy due to the fact that Valk Welding has a lot of expertise in handling, welding as well as programming applications. Complete cell is build at Valk Welding in Alblasserdam, tested and consequently send to Aalter. Because the cell is build on a torsion free frame the cell could be directly taken into production. Finally Valk Welding has supplied several identical cells and we are saving now money on material, energy and programming time in all our facilities worldwide.”

PTAW process
For recharging the high nickel layer on the glass moulds, the plasma transferred arc welding (PTAW) process is being used. PTAW is a plasma powder welding process in which nickel alloy in powder is being added to the arc and sprayed on the surface. For this application Valk Welding has build a stationary welding torch in the production system and the nickel powder is being sprayed on the product handled by the robot. The pre-heated glass mould is taken by the gripper of the handling robot and mover under the stationary welding torch in such a way that the powder can be transferred to the glass mould in an optimum position. Next to the reduction of lost material, higher and constant quality is an important factor of using this system. Positioning of the product using the handling robot under the stationary torch is completely automated and repetitive. Based on manual processes this will produce the highest and most constant welding quality.

Fanuc handling robot
Valk Welding has used for the handling of the glass moulds a Fanuc R-2000iA/165F robot with a handling capacity of 1565 kg which will pick up the pre-heated moulds from an indexing table and consequently positions the glass mould under the PTAW torch. After the complete welding process the product will be positioned on a conveyor system. The positioning of the glass moulds for the robot is effective by a rotary positioner so that the glass mould can be pre-heated during the welding process of the previous product.

Simplified programming
Programming is done using a CMRS application. CMRS is Custom Made Robot Software specific developed by Valk Welding on customer’s specifications in order to reduce programming time.

CMRS developed for Omco is suitable for products within one family however with different dimensions which are automatically programmed using variables. Advantage of this system is that the products can be welded with the same welding parameters resulting in identical quality of all welded products. In addition to this, the CMRS developed by Valk Welding, is automatically generating the programs from coordinate files supplied by Omco. The same files are being used for milling and grinding operations within the Omco group. Based on the developed welding parameters programming of new series takes just a fraction of the old programming method.

Shorter return on investment
Every facility of Omco International is using one cell which is suitable for production of 100 moulds a day. By reducing manpower in this new set up, lower energy costs and a 40% reduction on material costs using the PTAW process, the return on investment is expected to be in one year. More and more automation of production processes in the metal industry are asking for integration of welding and handling automation. Combining welding and handling processes in one project do give advantages for jiggles welding which are seen as one of the most important grow markets in the near future. At this moment several projects are being installed in production sites throughout all Europe where a pick and place robot is positioning sub components and a welding robot is performing its welding task on these products. In this way expensive jigs can be eliminated which does not only saves money for the jig itself but also engineering and development time of these jigs, according to Remco Valk, CEO Valk Welding group.