Lean and Clean

Compact, easy-to-change blister machines allow a generics maker to run small batches of several products.


With the IMA Win.Pack machines, Merck Generics runs a medium-speed line packaging at about 200 blisters/minute and 100 cartons/minute.

To respond to competition from lower-cost economies, Merck Generics (Potters Bar, UK) has been reducing costs and diversifying its production. “Over the last few years, there has been a drive toward lean production and just-in-time operations,” says Paul Le Sueur, engineering manager at Merck Generics. “In the past, we used to keep large stockholdings of products and do batch sizes of 30,000. [Now,] it is not unusual for us to run a 1000- or 15,000-pack batch,” he says.

Smaller batch sizes mean more-frequent changeovers. “Early on, Merck decided to reduce the number of blister profiles so that simple, dedicated size-changeover tooling could be used,” says Le Sueur. His team needed a blister machine that was simple to set up and change sizes, and that could handle a wide range of products and forming materials efficiently. It had to be a compact machine, given the limited space in the packaging rooms.

“We looked at a range of suppliers, but only IMA, with its IMA Win.Pack TR135, could supply a compact line that offered the output and level of technology wanted by Merck,” says Le Sueur. “The TR135 machines are designed to adjust to different forming materials as well as handle small changes from different suppliers or different material batches.” To date, Merck has invested in eight Win.Pack lines. The company now has more than 300 sets of tooling for the eight lines.

The IMA Win.Pack TR135 has special guarding to contain feeding areas, which are also under negative pressure.

About 90% of generic products are tablets, often in biconvex shapes or with flat-beveled edges 5–10 mm in diameter, explains Le Sueur. They are typically packaged in PVC or PVdC, and Aclar is occasionally used. “To be able to handle a wide range of these products, we had invested in a substantial amount of tooling for the Win.Pack machines. Constantly growing volumes at Merck Generics have justified this.”

Merck Generics attempts to use one standard blister profile on each machine. Le Sueur reports that size changes involve replacing forming tooling and the sealing roller, changing cameras, changing the Laetus bar code readers, and changing carton parts. “The whole line, including cartoner, checkweigher and overwrapper, will be completely changed over in 45 minutes.”

Merck doesn’t cut any corners during this expedited changeover. “We have a strict cleaning regime, which always involves removing all the guards for cleaning. This accounts for a significant part of the 45 minutes. A mixture of both operators and engineers perform size changes, but the Generics team’s SOPs and batch documentation make up the longest procedure. I believe the design of the IMA Win.Pack TR135 lines and our setup have kept machine changes to an absolute minimum. It used to take two to three shifts before we were ready to run a new product in a new blister. This has now been reduced to less than one shift.”

The compact IMA Win.Pack TR135 machine line fits nicely in the limited space in Merck Generics’ packaging rooms.

Each line is dedicated to a blister size and two to three cartons for that blister size, says Le Sueur. Different products are handled on one blister format. “The result is a very fast setup. Cleaning is the longest operation, along with batch documentation. Changing to another blister of the same format only involves replacing three pieces of tooling (the sealing roller and two forming plates), a process that takes only 10 minutes. Completely changing blister size takes only 20–30 minutes.”

One IMA Win.Pack TR135 line is dedicated to high-potency products in a room with a negative-pressure environment. The IMA Win.Pack TR135 has special guarding to contain feeding areas, also under negative pressure. “We use an IMA Swiftlift tablet elevator, which is also specially guarded with an enclosed hopper. The negative pressure extends to the IMA Swiftlift to avoid operator exposure to high-potency products.” Dust extraction and fume extraction are also in place.

For maximum efficiency, Merck tries to schedule production in order to avoid size changes. Efforts are paying off. “Before the IMA Win.Pack lines, Merck relied on a very manual size-changeover operation. With the Win.Pack machines, we have progressed to a medium-speed line packaging at about 200 blisters per minute and 100 cartons per minute. Operators and technicians could still see what was happening on the line and control the quality.” In addition, Merck Generics has invested heavily in training and engineering to resolve most machine problems internally very quickly.

“We have formed a very strong relationship with the IMA headquarters in Italy and the IMA UK branch to get advice immediately when there is a problem we cannot fix,” says Le Sueur. “The reassurance that parts can be delivered in under 24 hours when needed ensures that breakdowns are minimized. Common spares for all eight lines means that we have minimized our spares stock. We have appreciated that when we buy tooling from IMA, it is tested and validated on their product and materials. When putting tooling into production, we know it will work and we won’t lose time trying to modify the tooling to make it run correctly.”

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