Oskar Rüegg AG | The fewer manual steps, the better

Components for the automotive industry have to meet strict quality standards. Yet with increasing cost pressure, companies in this sector are being forced to make their manufacturing as cost-effective as possible. To meet this challenge, a Swiss manufacturer of high-grade formed metal parts invested in customised cleaning trays. These allow the manual steps necessary in parts handling to be reduced to a minimum ? while simultaneously doubling the batch volume. The savings made in this way allow amortisation of the investment within just one year.

Oskar Rüegg AG is based in the Swiss town of Pfäffikon and operates globally in the supply industry. Founded in 1891 as a mechanical workshop, the company today produces large series of highly complex machined aluminium, stainless steel and non-ferrous metal parts as well as assemblies using pressing, bending and deep-drawing techniques. These parts are used in the automotive, audio, lighting, electrical and electronics industries, as well for mechanical engineering and building applications. "A large part of the formed metal parts we produce goes to so-called "tier 1" suppliers in the automotive industry.

These include many visible and functional parts for lighting units, such as light screens, reflectors or casing shells for the electronic control system of the lights", explains Monika Schibler, who is responsible for maintenance, environmental management and workplace safety at Oskar Rüegg and is integrated in the decision-making process for special tasks. These special tasks include parts cleaning. Before the workpieces can be delivered or preassembled to form assemblies, the oil used during pressing has to be removed. The company uses a modern, environmentally friendly VAIOCS (Vacuum Assisted Inorganic Organic Cleaning System) from EMO Oberflächentechnik for this.

This system works in a vacuum and is operated with DOWCLENE 1601, a non-chlorinated solvent based on modified alcohols. To meet the various cleanness requirements, the process steps of spray cleaning, immersion cleaning, steam degreasing and drying, as well as the rotary and pivoting movements of the cleaning basket are selected via programs on the control system.

The cleaning basket plays an important role

70 to 80% of the parts are cleaned as bulk goods in standard baskets, while the other 20 to 30% are cleaned as positioned goods in specially manufactured workpiece holder systems. Some time ago, Oskar Rüegg experienced quality problems, whereby the bulk parts were being deformed during the cleaning process. This prompted the company to look for alternative cleaning baskets. It was following a tip from Cleantec AG, the Swiss representative of EMO Oberflächentechnik, that they became aware of the company Metallform Wächter from Bretten, Germany. "We were very impressed with the company's Mefo-Box system. It was the only system in which all components could be combined with one another in virtually any mix. Metallform also gave me a guaranteed maximum temperature, up to which we could perform the subsequent heat treatment of the bulk parts in the baskets. All other manufacturers told me that we couldn't do that with their cleaning baskets. The Mefo-Box was not the cheapest system, but the quality was right and the baskets are extremely durable", explains Ms. Schibler. The company also has Metallform manufacture the workpiece holder systems for the parts to be cleaned as positioned goods. And Oskar Rüegg regularly presents the design department at the basket manufacturer with tough tasks. This was also the case when developing a cleaning tray which, to increase profitability, had to be matched precisely to the packaging container of an Oskar Rüegg customer.

Packing 35 parts with a single movement

Having received an order for the production of casing half-shells for the electronic control unit of lights, the company had to develop a workpiece holder system that would meet extremely strict cleanness requirements. However, due to a subsequent change to the specs, this cleaning basket was no longer ideal. Following the pressing work, the half-shells are placed in special plastic trays and transported to the degreasing unit. A changeover procedure takes place here, during which the parts are laid individually into the workpiece holder system for cleaning. The batch size was around 330 parts. The parts then have to be packed in trays provided by the customer, each of which holds 35 pieces, and hermetically sealed ready for transport. This required a further manual changeover procedure, during which each of the 35 parts was rotated individually and placed in the packaging. The large proportion of manual work not only made the production process more expensive, it also led to bottlenecks in capacity before the cleaning unit. Special shifts had to be worked to clean all the parts produced. The Swiss company therefore turned to Metallform with the task of developing a cleaning basket that would allow the large number of manual steps to be reduced to a minimum, but which still offered the best cleaning quality. The contact at Oskar Rüegg was again impressed with Metallform's design collaboration and excellent consulting.

Metallform's design department developed a workpiece holder to perfectly match the transport and packaging trays. The company can now transport 35 parts from the transport tray to the cleaning basket and then, following the washing process, onward to the packaging stage with just a single movement. The challenge here was to keep the parts secure while still being able to release them easily without damaging them during refill processes. This made the overall cleaning and packaging process significantly faster and more economic. In addition, several of the new workpiece holders can be grouped together to form a batch, which has nearly doubled the batch volume.

An investment that pays for itself

For Oskar Rüegg, the redevelopment of the workpiece holders required a significant initial investment. "With the cleaning baskets, we have the potential to make huge savings. Indeed, the savings are so great that the investment will have paid for itself within just a single year", explains Ms. Schibler.