Schunk, OptoTech, and Weiss Climate Technology implement innovative eyeglass lens production

Up to 800 glasses can be produced daily in the Leica Eyecare pilot factory. (Weiss Klimatechnik GmbH, proprietary image)

The climate device Vindur Compact is a true all-rounder and ensures the necessary climate conditions and air purity. (Vindur® Compact, Weiss Klimatechnik GmbH, own image)

The name Leica stands worldwide for optics, precision, and the highest quality – made in Germany. This also applies to the Leica Eyecare brand, with which Leica has entered the high-end spectacle lens market in artisanal quality. During the construction of the production facility, which also functions as a show lab, two Schunk companies, OptoTech and Weiss Climate Technology, were able to contribute their expertise. OptoTech designed the factory and equipped it largely with machines from its own portfolio. Weiss Climate Technology provided the climate control equipment and also supplied special heat ovens.

Premium spectacle lenses – made by Leica

Correction lenses are custom-made glasses for demanding customers. Whether single-vision, multifocal, or progressive lenses: these can be further refined and personalized as needed – with a variety of options. To ensure that Leica Eyecare’s premium spectacle lenses always meet the highest standards, the optical machinery specialist OptoTech was commissioned to establish a production line. Currently, around 800 correction lenses can be produced daily in a single-shift operation. Thanks to the expansion phase already considered in planning, production can be scaled up to 500,000 lenses per year in multi-shift operation. Pilot factory for Leica Eyecare spectacle lenses.

Innovative technologies for the optical industry

OptoTech is a specialist and innovation leader in optical manufacturing. The company was founded in 1985 and has been part of the Schunk Group since 2018. Its portfolio includes a wide range of machines for fine optics, measurement technology, coating, and spectacle optics. Oswin Lack, VP of Strategic Accounts & Technology and a true veteran of the optical industry, recalls the beginning of the project at the end of 2021. "We received the order to build a complete pilot factory. Given the COVID crisis, supply bottlenecks, and skilled labor shortages, this was a real challenge, which we could only realize through good collaboration and close coordination with strong partners like Weimer in construction and Weiss Climate Technology in climate control."

Complex planning with expansion stages

After finding a suitable hall, OptoTech began planning the new manufacturing line. This had to cover all requirements as a pilot factory and be fully production-capable. At the same time, possible expansion stages and scaling had to be considered during planning. These requirements were met, among other things, by using modular components and planning open spaces for additional machines. Furthermore, all utility lines were to be laid out so that they could be quickly and easily converted for increased capacity. Since the hall was previously used as a warehouse, a complete conversion was necessary. This involved not only walls and floors but also all utility lines for water, electricity, and compressed air.

Intelligent and modular logistics

The planning team laid out the production line with various directional changes and open spaces for future expansion stages. The IQ-Logic system from OptoTech plays a crucial role in lab automation. Notably, the IQ-Star towers placed at different locations store and distribute spectacle lenses in a highly flexible and demand-oriented manner. For example, it is possible to consider different cooling times for lenses or buffer waiting times when a single lens needs to be re-manufactured.

Machines for all processing steps

OptoTech’s own portfolio allowed the production to be perfectly aligned with high-end manufacturing in lot size 1. This included, among others, the fully automatic unpacking system DeBoxer, blocking and deblocking stations, as well as high-end turning and grinding centers for freeform spectacle lenses and polishing machines. The finishing spectrum ranges from coloring and engraving to hard coating for durable surfaces. Another highlight of the production are the specially developed logistics boxes, which are central components of the world’s only paperless spectacle lens production. The boxes are equipped with bar and DMC codes as well as RFID tags, enabling all relevant information about the glass and production process to be accessed at any time via the central lab management software.

Cooling technology for process environment

An important component for the production of high-quality spectacle lenses is also the process environment at certain points. Especially during coloring and hardening, specific climate conditions and air purity levels must be maintained. After an intensive analysis, Weiss Climate Technology developed a tailored and high-performance overall concept. Kai-Uwe Hölzel, Head of Technical Sales & Planning: "We built the concept around our Vindur Compact air conditioning unit. For cooling, a sufficiently large chilled water system with a buffer tank was already planned, so that we can easily retrofit additional cooling for the hall later."

Vindur® Compact air conditioning unit

Different production and room conditions had to be considered for supply and exhaust air management. For example, during turning and grinding, exhaust air with relatively high temperatures is generated, while in the clean room for hardening, it is important that the humidity does not become too high despite higher air exchange rates to ensure a stable process. Hölzel explains: "For us, the challenge was to combine different requirements in one system and to meet the short-term needs. By using our proven standard equipment, we were able to quickly offer a reliable solution."

Companies of the Schunk Group working hand in hand

One of the special features of the new pilot production is the close collaboration among various Schunk companies. In addition to optical machines from OptoTech, Weiss Climate Technology made a significant contribution. Furthermore, a total of seven furnaces and an in-line furnace from Weiss Technik’s Strategic Business Area Heat Technology are in use. OptoTech gives an overall positive assessment: "We are pleased to have implemented the project so successfully in such a short time. It has shown how well collaboration within the Schunk group works and what can be achieved when everyone works together. We are proud and excited to have laid the perfect foundation for a possible further rollout with the modular spectacle lens factory for Leica Eyecare."