Zinc is generally known as a material that protects iron and steel against corrosion. But it can do much more. For example, zinc is suitable for the production of high-quality die-cast parts in large quantities. The team at Zinkteknik knows just about everything there is to know about zinc. At the manufacturing company's headquarters in southern Sweden, you can even attend a "Zinc School" to expand your knowledge of this versatile material and its applications. CEO Jens Svensson explains the advantages of working with the material: "Zinc is very design-friendly, you can produce almost any geometry from a single block. It is also very resistant and malleable. It allows tight tolerances and a wide range of coatings, and thanks to its relatively low melting point, it can be recycled with little energy input."

Zinkteknik has grown steadily since it was founded in 1985. The workforce of 170 employees is spread across the two European sites in Bredaryd and Mostar in Bosnia. The precision parts manufactured in these two plants are largely supplied to the automotive industry, but also to customers in the electronics, ICT and construction sectors. "Requirements are constantly increasing, especially in the area of safety-critical automotive parts, such as seatbelt components. We produce more than 300 million parts per year and essentially pursue one goal: the highest possible quality," says Svensson. As a Tier 2 supplier to OEMs and vehicle manufacturers worldwide, Zinkteknik has to meet very high quality standards - "zero-defect production" is the motto of the automotive industry.

Reliable quality assurance

Per-Erik Edman, Quality Assurance Engineer at Zinkteknik, explains the challenges of achieving "zero defect" in his specific area, zinc casting: "With quantities of 30 to 40 million pieces per year for a single component, it is not possible to inspect each part individually. That's why we initially set up an inline process monitoring system to monitor quality." This enabled Ed-man's team to reduce the return rate to less than ten parts per year and series - a very low number compared to the enormous quantities. The question now was: how can this high level be further improved and zero-defect production achieved? "As is so often the case, the last step is the most difficult. But a favorable opportunity arose: one of our customers, a Tier 1 supplier, recommended that we take a look at Kistler's test automation solutions," continues Edman.

Not long after its first contact with Kistler in 2016, Zinkteknik ordered a KVC-821 - the latest generation of automatic inspection and sorting machines for quality assurance at the end of the production line. Zinkteknik's engineers teamed up with Kistler's machine vision experts to find the best camera configuration for detecting faulty safety-critical automotive parts. "When we were in Germany to work with the Kistler team on failure analysis, we had a very open discussion about what was possible and how best to achieve the desired results. Kistler's experts were also very clear when something was not possible and at the same time looked for alternatives on how to overcome the challenge in other ways."

The KVC-821 enabled Zinkteknik to inspect millions of produced zinc parts for shape and surface defects. This enabled the company to finally achieve its goal of "zero defects". "The result was very convincing," recalls Edman. "We supply one of our largest customers with safety-critical automotive parts that are intended to save lives - and we have not received any more complaints from them since then." Inspired by this success, Zinkteknik investigated the potential of integrating further Kistler automatic testing machines into its production lines in order to optimize further series production.

Fully automated end-of-line inspection and sorting

Zinkteknik now operates seven KVC-821 inspection systems to monitor the production of five different parts - two more will be added in the near future: one more system for the Swedish site and the first for Bosnia. Karl Persson, Production Engineer at Zinkteknik, explains the process: "In the beginning, we used the first Kistler system as a standalone solution, where some steps still had to be done manually. But of course we wanted to integrate the test cells into our highly automated production lines. At a certain point, we realized that we had to go further to achieve this goal." Zinkteknik met this challenge in 2018 by expanding its Swedish site in order to fully integrate Kistler's end-of-line testing solutions - they are now located in a completely new hall: "At the moment, we have seven systems that are directly connected to the automated production line. This allows us to easily compensate for fluctuating quantities of different parts throughout the year. We are still working on a fully automated forklift feeder, which is expected to be completed by the end of 2020," adds Persson. "We have been using the systems for test automation in ongoing production for around three years. We have received comprehensive support from Kistler throughout this time. The team has always been ready to answer our questions. They have helped us with many challenges and have even helped us generate new business opportunities for Zinkteknik."

The success of zero-defect production has provided decisive impetus for both approaching existing customers and acquiring new ones. Kenneth Mag-nusson, sales engineer at Zinkteknik, says: "When I visit customers, sales engineers from Kistler are available on request. This gives us more weight in presentations to potential customers. This is of course another reason why we value Kistler so much as a partner and why we want to expand our collaboration in the future."