COVER STORY
ENGEL DEMONSTRATES IT CAN DELIVER BIG WITH PRECISION, FLEXIBILITY AND SPEED TO ACCOMMODATE A PARTNER’S RAPID RESPONSE TO PRODUCING NEST-AND-TUB PACKAGING FOR VACCINE VIALS.
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ll-electric, high-performance machines by ENGEL combine efficiency with precision. The decisive factor prompting Röchling Medical to invest in eight e-motion machines was the overall package, including digitalisation. In the production of nest-and-tub systems, the two largest machines, each with a clamping force of 5000 kN, impress with self-regulating temperature control processes. Nest-and-tub systems provide packaging for liquid pharmaceuticals in the form of vials or prefilled syringes. COVID-19 has led to a massive increase in global demand, as vaccine vials are also offered in this packaging form. For Röchling Medical at its Brensbach, Germany site, nest-and-tub systems are a new application which demands flexibility from injection moulding production. Focused on vials, five sizes of nest inserts are currently produced at Röchling on two new all-electric ENGEL e-motion injection moulding machines. The same applies to the standardised
tubs for all nest sizes, which require the highest clamping force of 5000 kN across the entire range of parts. To set up the moulds flexibly, the two machines intended for this application were ordered in size 500 and designed identically. “In the near future, the two 5000 kN machines will be in action 24/7 for nest-and-tub production,” says Marco Treuner, Technical Project Manager at Röchling Medical. EXTRA FEATURES BOOST EFFICIENCY IN THE CLEANROOM The nest-and-tub packaging dimensions are standardised to accommodate different filling and sterilisation systems by different suppliers. Throughout the filling and production process, vials remain in the nest, thus avoiding falling over or colliding with each other. The vials are well protected in the nest’s honeycomb structure. For 50 mL tubs, there are 16 vials per nest. The lower the filling quantity, the more vials there is room for in a package, and the more honeycombs the nest inserts have. POM is used for this demanding component geometry. This economical material reliably withstands cleaning and sterilisation before the filling process. But due to its pronounced shrinkage during cooling, POM places high demands on the stability and repeatability of the injection moulding process. Added to this is the mould design, which has many long, closely spaced cores. “We need very rigid mould mounting platens and particularly small centring diameters to avoid overmoulding, even with the very large platens of the e-motion 500,” says Treuner. The e-motion machines come with highly rigid platens as standard. ENGEL designed the platens with a particularly small centring diameter of 80 mm specifically for the nest-and-tub application at Röchling. The two e-motion 500 injection moulding machines in cleanroom design (easy-to-clean surfaces, closed lubrication systems and some more features reducing particle emissions) are equipped with a linear robot from the viper series and GMP-compliant belt conveyors — both of which ENGEL developed and produced. In addition, tailored solutions for Röchling make the large machines even more efficient than their standard counterparts. The cable ducts are enclosed, smaller cable bundles are routed in hoses, and the control cabinets have their own heat exchangers to prevent air turbulence at this point. Because the nest components are too unstable to stack when they are taken off the mould, additional U-shaped belt conveyors were installed above the clamping unit as a post-cooling section. Only 15 minutes after part removal, the viper robot picks up the components from the post-cooling conveyor and cycles them out via the larger belt conveyors for stacking in boxes. SMART TEMPERATURE CONTROL Constant temperature control is crucial for the dimensional accuracy of the demanding POM parts. Treuner explains: “We have to ensure repeatable quality as early as possible in the production process.” Quality controls (QC)
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