Originally Published EMDM January/February 2003
EQUIPMENT NEWS
Recent developments in assembly systems suited for use in medical device manufacturingCompany designs bespoke automated assembly systems
From individual workstations to high-volume assembly lines, process and testing systems for medical device and pharmaceutical companies are routinely designed and built by a company with more than 35 years' experience. AB Precision (Poole) Ltd. (Poole, Dorset, UK) employs engineers with an understanding of US FDA validation requirements and Good Automated Manufacturing Practices 4.0. The company is certified to ISO 9001.
The versatile staff creates flexible, bespoke, special-purpose machinery using computerized design systems and the resources of a comprehensive development workshop. The company will typically start with studies and prototype work to prove a concept before the client commits to a full-scale production machine. Assistance with product design is available to optimize the benefits of automation and to enhance machine operation. The company strongly believes in the importance of working closely with the customer to achieve project objectives.
Transfer system add-ons increase productivity
Two components have been introduced for a transfer system that is suited for the assembly of small medical products. The accumulation-capable curve module and lift transfer unit are available for integration with the TS 1 system developed by Bosch Rexroth AG (Lohr am Main, Germany).
The lift transfer device can reduce assembly times and features easy installation, since the transfer system guide profiles do not need to be cut to accommodate its insertion. The mechanism is composed of durable toothed belts that resist wear and minimize friction. An ESD-protected version of the unit is available.
The accumulation-capable curve uses a rotating disc to transport pallets. By using this module on the TS 1 transfer system, greater quantities of products can be processed and cycle times can be reduced, according to the firm. Available with a 90° or 180° curve, the unit is compatible with pallets measuring 80 x 80 to 160 x 160 mm and is suited for use in ESD-proof environments.
Assembly equipment meets device OEM needs
Drawing on the expertise gained from designing more than 400 assembly and testing machines sold worldwide, a company offers modular systems that can meet an array of medical manufacturing needs. In addition to product assembly, systems from Müller + Kurtz Sondermaschinen GmbH (Winterbach, Germany) can be constructed to perform filling, printing, and dispensing operations. Comprehensive quality inspection capabilities can also be integrated.
Based on a linear in-line transfer architecture, the company's machines can support up to 65 successive steps. Up to 220 cycles per minute can be achieved, and the systems' positioning accuracy is ±0.02 mm at a maximum overall length of 10 m.
The company recently introduced a new generation of assembly and testing machines, the MC.4 series, for cleanroom use. One such machine is currently being used to process infusion sets. The drive components of the MC.4 include fewer moving parts than previous models, and the station drives are enclosed, as are the tabletops. The system offers easy access for cleaning. The machine frame and protective cladding is made of stainless steel, and machine parts that come in contact with the workpieces have been surface treated to meet prevailing hygienic standards. The sorting and feeding technology has been designed to minimize abrasion.
The company can supply a range of compliance and quality documentation and will provide assistance in performing quality assurance tests in accordance with Good Automated Manufacturing Practices 4.0.
UV cure system prevents deformation
Designed for medical applications, a UV cure system provides consistent performance and causes minimal heat rise in the substrate. Tests have shown that the CureMax UV Exposure Lamp, developed by Lesco (Torrance, CA, USA), delivers moderate to high UV intensity with variations of less than 10% across an 8 x 8-in. cure stage. Integrated infrared filtering, heat-conductive perimeter construction, and forced cooling enable the device to achieve a low heat rise even at a high cure power, according to the firm. This feature reportedly eliminates material deformation that may be associated with other flood-lamp products.
A complement to the company's line of adhesive and coating products for the medical industry, the CureMax has a cleanroom-ready stainless-steel housing. The unit comes with safety interlocks and automatic timer and shutter controls.
Peristaltic pump dispenser minimizes contamination
A peristaltic pump dispenser that features selectable and preset flow rates and a reversible flow capability delivers shot sizes as small as 0.006 cm3. The PPD-119 from I&J Fisnar France S.A. (Cergy Pontoise, France) dispenses material directly from a bottle or can, thus reducing the risk of material contamination and eliminating operator contact with the fluid. Because the material never even comes into contact with the dispensing mechanism, maintenance and cleanup operations are kept to a minimum.
The unit is suited for dispensing cyanoacrylates, solvents, and other low-viscosity materials. Dispensing can be controlled manually or by means of the built-in timer. The reversible pump allows tubing to be emptied between work cycles.
Assembly table combines manual and automated operations
A 32-position semiautomatic assembly table is suited for mid-volume applications in which 10,000 to 2.5 million parts per year are processed. The table combines manual workstations with custom automated stations for bonding, powder dispensing, hole punching, welding, quality control, and heat treatment. A stainless-steel version of the Roulette 32 assembly station from Sonderegger Engineering AG (Schaffhausen, Switzerland) is available for cleanroom use. The table measures 1000 x 1200 mm; the assembly wheel that sits inside the table has a diameter of 800 mm.
Spring-coiling machine can process 360 parts per minute
A spring-loaded safety-device assembly system performs spring coiling, component assembly, 100% inspection and testing, boxing, and complete lot traceability. The system developed by Kahle Europea S.p.A. (Caravaggio, BG, Italy) can process from 60 to 360 parts per minute. The equipment can be tooled to assemble a safety device with as many as 10 components.
Each spring coiler is linked to a nest position of the assembly machine. If the spring-coiling machine malfunctions, component loading and assembly at that nest automatically stops; production continues on the unaffected nests. The affected nest of the assembly station then restarts once the malfunction has been corrected.
The system's modular cam stations ensure robust, long-lasting operation. They also enable users to slow down cycle speeds as required for complex sampling inspections, thus preventing product waste and assembly errors.
Rotary indexing machine meets FDA guidelines
A cam-controlled rotary indexing machine suited for cleanroom use and device assembly applications features synchronized work sequences and repeatability. Designed for easy maintenance and cleaning, the Clean Cell developed by OKU Automatik (Winterbach, Germany) isolates the drive system from the assembly and handling area. The table plate is made from coated aluminium, and all machine parts that come into contact with the workpieces are made of high-grade steel or equivalent materials.
The machine complies with all US FDA guidelines, and is available with 8, 12, 16, 24, or 32 workstations. Speeds up to 120 cycles per minute can be attained. Laminar-flow units can be integrated into the machine.
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