012 bathroom fitting
Technical Report
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The Perfect Mix of Old and New

The centerpiece of the new “one-piece flow” process was a robotic retrofit for grinding and polishing kitchen and bathroom fixtures which combined interlinked high-volume production with highly-flexible, order-controlled manufacturing. SHL implemented a cost-effective, integrated solution using a mixture of existing, overhauled, and new robotic arms.

The enterpiece of the new “one-piece flow” process was robotic retrofit for grinding and polishing kitchen and bathroom fixtures which combined interlinked high-volume production with highly-flexible, order-controlled manufacturing. SHL implemented a cost-effective, integrated solution using a mixture of existing, overhauled, and new robotic arms. Since 1984, KWC AG, part of the German Hansa-Group based in Stuttgart, has been renowned for “Swiss Excellence” in the kitchen and bathroom faucet sector. As the Swiss market leader, with approximately 380 employees, KWC manufactures its own products exclusively at its Unterkulm, Switzerland, site and exports to 50 countries worldwide. As with other industries, KWC’s business has experienced marked changes over the ensuing years due to ever-increasing expectations of design and functionality.

Furthermore, the competitive pressures brought on by globalization require highly productive and cost-efficient manufacturing systems. While this is relatively easy to accomplish when using high automation levels in settings involving volume-oriented production for larger batches, the challenges are significantly greater with regard to order-based small and midsized manufacturing. For KWC AG, all of the series production systems for the company’s core competencies – casting, machining, grinding, polishing, bright chromium plating, as well as component assembly and final assembly – were in place from the beginning. The introduction of a new line of kitchen and bathroom faucets was the impetus for the search for a new, forward-looking manufacturing philosophy. Roland Affolter, Production & Logistics Manager and executive officer, explains:

We were faced with a typical trade-off. While we had very powerful production systems, we were often no longer able to use them efficiently. We had been accustomed to stockpiling from series production, but we found ourselves obligated to do order-based manufacturing in order to make deliveries within a period of three days. We needed different, highly flexible, and universally applicable capacities. At the same time, we wanted to continue to make our production processes leaner. In order to keep the costs of our production system revision at reasonable levels, we decided to gradually implement a comprehensive retrofit project. This also allowed us to supply customers at full capacity during the renovation phase.

The "AIN" Project – Once Again, Courtesy of SHL

Today we can say that Operation AIN (from the German “Alt in Neu" for “old into new”) has been a success. Manufacturing and intra-logistics expert Roland Affolter gives a large part of the credit for this to long-term, proven partners such as SHL Automation AG. SHL has been supplying and installing robotic grinding and polishing systems at KWC for many years. This includes 13 complete systems to date, two of which form part of the "AIN" retrofit project. KWC’s specifications required SHL to reuse the robotic grinding part from a grinding and polishing system designed for a specific product and merge it with a new robotic polishing unit and a new workpiece pallet conveyor system to form a flexible and universally capable grinding and polishing cell.

The new cell consists of a robotic grinding unit, a manual workstation for any required rework, a robotic polishing unit, various control panels, and of course the workpiece pallet conveyor system. While the robotic grinding unit from the high-volume line was used, the robotic polishing unit had to be built from scratch to allow it to be integrated into the manufacturing and material flow process of the stand-alone grinding and polishing cell. SHL supplied and installed a new robotic polishing system, essentially comprised of a Kuka KR30/2 industrial robot with a KR C1 controller and basic clamping device, four P1000 ROB polishing machines, and a pallet conveyor system.

A Solution without Complications

The scope of the project also included overhauling the existing robotic grinding systems before finally reinstalling the complete set of machinery as an integrated cell. The work was performed in stages, first on Line 1A, and then on Line 1B.

The project went smoothly without causing any bottlenecks in capacity or delivery. This was because most of KWC’s production lines exist in duplicate (for redundancy, availability, capacity and supply security), and because the technicians and engineers from SHL had tested their components and performed prep work in advance.

The Quality Team Ensures “Zero Defect” Hand-off

Compared to the former high-volume manufacturing processes in interlinked lines, today’s workflow is as follows. For each robotic grinding and polishing cell, a qualified skilled worker is responsible for rework and inspection, as well as for loading workpiece pallets with blanks, and for unloading the finished parts into their transport containers. The worker places the fixtures (10-15, depending on model and type) onto the workpiece pallet in the correct position. The conveyor system moves the pallet toward the robotic grinding unit. There, the pallet is completely emptied of workpieces, which the robot machines and puts back on the pallet. Then, the conveyor system transports the pallet to a manual workstation where an operator inspects the workpieces and reworks them, if necessary.

A Process that Is Both Highly Productive and Flexible at the Same Time

From there, the pallet moves to the robotic polishing unit, where the workpieces are again automatically processed. Then, the pallets arrive at their final destination where a worker performs another visual inspection on the finished parts, and puts the “OK” ones into containers for the electroplating process. Thus operators perform both monitoring and reworking functions, i.e., they are responsible for their own process and quality control. Through the process, the operators are supported by a programmer and tool setter, who each support several lines or cells.

While a little unusual, this manufacturing strategy is very pragmatic in its design, and works very well with the parallel implementation of the Kanban system with its related philosophy of worker supervision and responsibility. Roland Affolter summarizes this as follows:

Integrating robotics and grinding and polishing specialists in a kind of manufacturing cell seemed to us the logical solution if we wanted to achieve a manufacturing process for quality faucets that is both highly productive and highly flexible. One-piece flow and order-driven manufacturing in small series allows us to deliver any requested product within three days. This worked so well, even during our renovation and new installation phase, that we were always able to deliver on time, despite this Herculean task. And last but not least, our partnership with SHL saved the day again, particularly because SHL technicians and engineers came through for us with a very efficient integrated solution that made use of a mix of existing and overhauled technologies, including new robotics.

...SHL technicians and engineers came through for us again with a very efficient integrated solution that made use of a mix of existing and overhauled technologies which included new robotics...