Switzerland-based Wild & Küpfer (W&K) relies on two Kern Micro machining centres from Kern Microtechnik to produce injection micromoulded parts that meet exceptionally high quality standards. The machines, a Kern Micro and Kern Micro HD, are housed in the company’s tool shop and expected to deliver the high levels of precision and productivity demanded by its customers.
The Kern Micro HD machining centre, installed at W&K in 2020.
W&K was founded 40 years ago and operates according to its credo that ‘visions should turn into ideas and then into products’. The company offers its customers a complete production chain solution, from consulting and development to toolmaking and production to assembly of parts in a cleanroom, then finally logistics, ensuring that the product arrives at its destination on time and undamaged. This dependable all-in-one solution is valued by customers from a range of industries, including automotive, dental, electrical, pharmaceutical and telecommunications. Most take advantage of the entire chain, working closely with W&K’s plastics experts right from the development phase.
Daniel Wild, who has been with W&K since 2000 and has been managing the company as chief technology officer (CTO) alongside his brother Tobias since 2019, explained: “We produce a wide variety of plastic components and assemblies that our customers need for their end products. The batch sizes average around 100,000 pieces per year, but we also have customers who only need a few 1,000 or more than 100 million pieces per year. We can do that too.”
The products are as diverse as the industries served. W&K produces curtain sliding elements, special bottle caps and electrical connector strips as well as safety-relevant closure systems for the anti-doping sector and complex medical technology (medtech) assemblies used for, among other things, insertion devices for placing stents. This naturally requires a great deal of know-how. It starts with the assessment of whether and how the desired plastic parts can be manufactured and ends with the production and delivery of injection moulded serial parts. The quality standard is always very high, regardless of whether ten thousand or millions of products are required per year.
Part quality has been prioritised from the outset
Development, toolmaking and production take place between consultation and delivery. In addition, W&K produces all of the moulds for its injection moulding machines in-house. According to Wild, the reason for this is: “Eighty percent of part quality is down to the tool. At this point, we don't leave anything to chance, and we don't make any compromises regarding the technical equipment.”
W&K has prioritised quality since it was founded by Tobias Wild senior (Daniel and Tobias Wild’s father) and Peter Küpfer (their uncle) in 2014. Back then, the company solely produced graphite electrodes and sought a 5-axis machine that could also run throughout the night without an operator. Daniel Wild said: “Kern Microtechnik was very well known in this context, so there was an evaluation and we decided on a Kern Micro.” The Kern Micro was configured for dry milling of graphite electrodes and performed this task 24/7 for many years.
The transition to mixed operation
In 2019, Daniel and Tobias decided to invest in a second machine that would allow the company to meet an increasing volume of orders. This machine needed to enable the company to transition to mixed operation, meaning it would need to be capable of machining not only hardened steel, non-ferrous and hard metals but also wet graphite automatically, without any need for retooling. Daniel Wild continued: “We evaluated, tested and this time agreed even faster that we would best solve current and future challenges with the Kern Micro HD. Once installed, the Kern Micro HD took over the milling of graphite and copper electrodes, hardened mould inserts and carbide parts in an average, small series batch size of 50 pieces.
To achieve the best results, Kern engineers adapted the Kern Micro HD perfectly to the needs of W&K. They designed and integrated a special cooling lubricant preparation, a ring nozzle and a large tool magazine with 210 spaces for HSK-E40 holders. This means that mixed operation always works simply and reliably.
In addition, W&K values the Kern Micro HD’s ability to be completely automated with a System 3R cell and its many smart components such as the wear-free, actively temperature-controlled linear motors, which achieve accelerations of up to 2 g and rapid traverse speeds of up to 60 m/min.
Kern engineers also upgraded W&K’s Kern Micro so that it could be used for wet as well as dry manufacturing, which involved removing the dry suction unit and adding a wet suction unit and a flood cooling unit. The Kern Micro stands next to the Kern Micro HD and is used manually to make post-production changes to single parts should the need arise.
A comparison of traditional methods with the Kern Micro HD
Wild compared the time it took to produce a part using traditional methods with the time it takes W&K to produce it on the Kern Micro HD. This part was a round core with an external thread made of carbide, which is frequently produced at W&K. It is required to manufacture a plastic screw cap for a syringe closure in medical technology.
The core was traditionally produced using sinker electrical discharge machining (EDM) and manual polishing, which took three and five hours, respectively. However, W&K is able to produce it on the Kern Micro HD without an operator in only two hours, achieving a surface finish that is equal to that of manual polishing.
An outstanding technology and strong teamworking ethos
The Kern Micro HD maintains the reputation of the Kern Micro machine range for delivering the high levels of precision and productivity needed in today’s industrial settings. Stephan Zeller, area sales manager at Kern Microtechnik, elaborated: The outstanding technology of this machine has become well known since its introduction to the market in 2019 and is very well established among our customers. A wear-free hydrostatic machine like the Kern Micro HD is really unique on the market.”
The Wild brothers not only advocate Kern Microtechnik’s machines but its strong teamworking ethos. As Daniel Wild concluded: “It’s like ours. Everyone supports everyone and does not think in the short-term but always in the medium- to -long-term.”
Tools milled on the Micro HD and resulting W&K plastic parts.
Kern Microtechnikwww.kern-microtechnik.com