Schmersal produces AZM300 with innovative Plasma-SealTight


New manufacturing process for plastic-metal bonds is being tested in first industrial application

A new, innovative process to manufacture plastic-metal bonds is currently being tested in an industrial application. Plasmatreat GmbH has developed a process for hybrid injection-moulded parts in cooperation with the plastic compound manufacturer AKRO-PLASTIC GmbH. This new process provides a significant improvement to bonding in hybrid plastic-metal components and can be integrated into series production lines.

The Schmersal Group is now using this innovative Plasma-SealTight® technology process for the first time in a pilot project to produce its AZM300 solenoid lock. Used on safety doors, this interlock features a metal bracket integrated into a plastic actuator. The bracket engages with an interlock cross-head to ensure that safety door are securely closed.

A reliable, firm bond is crucial during the joining process to produce a highquality, resistant joint between the dissimilar materials plastic and metal. In a plastic-metal bond, interfaces without a special seal represent a constant contact surface where water, air or other media ingress.

The Plasma-SealTight® plasma seal process developed by Plasmatreat and AKRO-PLASTIC offers a completely new approach to providing a highly bonding, media-resistant hybrid joint. In this new industrial solution, the plastic compound formula, the process parameters, and the composition of a plasma polymer seal layer created under atmospheric pressure were matched to one another in such a way that they would create a durable, media-tight bond in the component.

The advantage of the new process is that it not only achieves better product quality, but also a reliable, reproducible, cost-efficient production process with the added bonus of respecting the environment. Thanks to the Plasma- SealTight® technology, there is no need to apply cost-intensive, environmentally harmful chemicals to metal surfaces. Such chemicals are often used to create a firm bond with the help of solventbased adhesion promoters.

The AZM 300 is an innovative safety interlock which is now used in many sectors of industry. AZM 300’s outstanding features include a new patented operating principle with a hub and cross-head. It brings the advantage that the safety door is pulled into its end position when closed and is securely locked free of almost any clearance.

The solenoid interlock operates as an integrated guard catch, hence removing the need to fit a separate catch. An RFID sensor is used to identify the actuator reliably, thus providing three different code levels and,consequently, protection against manipulation. After the new process has proven its worth in the pilot project, Schmersal intends to use it in both new and existing products, thus producing them even more efficiently.

About the Schmersal Group

The Schmersal Group is an international market and expertise leader in the challenging field of machine safety. With the world’s most comprehensive range of safety switchgear products, the Schmersal Group develops safety systems and safety solutions for special requirements in a variety of user industries. Schmersal’s tec. nicum Business Division offers a comprehensive service portfolio to complement the range of solutions offered by Schmersal. Founded in 1945, the company is represented by seven manufacturing sites on three continents with its own companies and sales partners in more than 60 countries. The Schmersal Group employs some 1,850 people worldwide and generated a group turnover of around €240 million in 2018.


Originally founded 30 years ago, AKRO-PLASTIC has formed part of the Feddersen Group since 2004. AKROPLASTIC has grown steadily ever since and today produces more than 100,000 tons of plastic compounds at its production facilities in Germany, China and Brazil. The company operates in an international network, which is able to provide services ranging from development through to logistics.

AKRO-PLASTIC uses the globally standardised compounding and extrusion technology ICX®, which it developed in cooperation with its sister company FEDDEM. AKRO-PLASTIC GmbH and its subsidiary AF-COLOR develop and produce engineering thermoplastics and master batches in Niederzissen, Germany. In 2014, the portfolio was expanded to include bioplastics and the BIO-FED subsidiary was founded at the Cologne location. AKRO-PLASTIC GmbH operates otherproduction sites worldwide – in Suzhou, China, for the Asian market, and in São Paulo State, Brazil, in South America.

About Plasmatreat GmbH

Plasmatreat was founded in Steinhagen, near Bielefeld, Germany, in 1995. On developing its Openair® Plasma technology, Plasmatreat established itself as a leading manufacturer and supplier of plasma systems and a globally active provider of surface technology services. After acquiring Plasma Technology Systems LLC in the US, the company widened its expertise to include Aurora lowpressure plasma technology. Plasmatreat applications are mainly used in industrial microfine cleaning, surface activation and plasma coating on surfaces made of materials such as plastics, metals, glass, cardboard, textiles and composites. With more than 225 employees at 34 locations the Plasmatreat Group has a presence worldwide and provides guidance and support to customers in almost all manufacturing industries – automotive engineering, transportation, electronics, packaging technology, consumer goods, life sciences, textiles and new energies.

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