Filling Market Needs

Servo control and integrated inspection promote tube-filling efficiency.

By David Vaczek Senior Editor

Tube packaging accommodates a wide range of product properties and container materials that challenge filling and sealing machines. Vendors of automated tube-filling machines have offered improved solutions for ensuring fill accuracy and seal integrity, while maintaining machine efficiency and speed.

“Filling is the heart of the tube packaging process. That’s why we spend a lot of time and effort to build in as much flexibility as possible,” says Goran Adolfsson, president, Norden of Sirius Machinery Group (Branchburg, NJ).

“Servo options, different fill nozzles, and alternative materials for pumpcontact parts are some of the variables to be considered,” Adolfsson adds.

Servo-controlled filling has become the standard for modern-generation machines. “Servo control bumps up system efficiency. Parts move where they are supposed to go, and the system confirms the task was completed. We use servos on the volumetric piston fillers and in other areas where the process is improved by consistency and precision,” says Gary Lowden, sales manager, ProSys Innovative Packaging Equipment (Webb City, MO).

“Servo control opens the door for configuring the system for speed, and it provides greater feedback to the operator. We will use cams on the machine where you have a fixed constant motion,” Lowden adds.

ProTrac 140 and 220 automatic tube fillers from ProSys will feature up to 14 servo motors. The 140 model features two filler heads for production of 140 tubes per minute, whereas the 220 handles 220 tubes per minute with two heads.

Servos are replacing gearbox-driven cam, chain, or belt systems for indexing the main drive and for control of lifts that move the tubes up to the filler heads.

“With unlimited adjustability, you are able to infinitely adjust the fill stroke and infinitely adjust the up and down tube lift movement. You can pretty much adjust to the needs of any product on the market,” Adolfsson says.

Oystar IWK offers state-of-the-art servo-driven machines as well as camdriven machines.

Bernie Conlon, president of Oystar USA Pharmaceutical Packaging Division (Fairfield, NJ), Oystar IWK, says that units with physical cam drives provide a lower-cost option for smaller companies that may feel they don’t have the technical capability to support the servo electronics.

But Conlon says flexibility for handling products with different properties is one benefit of servo-controlled dosing. “Cams require physical design and tooling to accommodate different cam profiles. More often than not, the cam profile isn’t perfectly suited to the application. Users accept slower speeds, and a certain percentage of rejects,” Conlon says.

“You can adjust a servo-controlled dosing system on-the-f ly while the machine is running. Challenging products can be filled efficiently, and once you have found the profile for a particular product, you save it to memory,” Conlon adds.

Watching Out for Mistakes

CIVision (Aurora, IL) is helping companies phase out manual tube inspection and protect against label mix-up. One global personal healthcare company is now verifying alphanumeric and 2-D Label Control Numbers using the CIVision Pro Series.

Manufacturers with large product families stock different-sized tubes for the same product as well as same-sized tubes for different products, so avoiding mixups is a constant effort, explains Scott Stone, marketing director for CIVision. “Our vision inspection system ensures that the filler is being presented with the proper version of a decorated tube, matching it to the order,” he says.

The CIVision Pro system is also being used to inspect for clean tube crimps. “We are helping companies replace manual inspection sampling,” he says.

“Companies can now perform 100% inspection.” CIVision’s global client is even employing the systems at its contract packagers around the world. “We help ensure that contract packagers around the globe are complying with corporate quality initiatives,” Stone says.

For supporting accurate fill levels, servo filling may be integrated with checkweighing systems for automatic fillvolume monitoring.

ProSys features integrated check weighing with a feedback loop to the filler control. “When the system detects a drift in the fill volume, the fill station is automatically adjusted or we throw up an alarm,” Lowden says.

Conlon says that companies can avoid overf illing by using integrated checkweigh solutions. “Customers will often look to overfill by a gram or a gramand- a-half to make certain the customer is getting a full tube. With a closed-loop feedback system, the fill gets more accurate as the day goes on. You have a comfort level, and you are overfilling by less. If you are doing 30 million tubes a year, and you have reduced your overfill by a gram, that can be signif icant,” Conlon says.

Servo control with integrated checkweighing also addresses changes in product-f low characteristics that can occur during the production run. “If the product viscosity begins to change, dosing volume will change,” Conlon says. “

With older technology, you have to stop the machine at intervals for a QC check and adjust the machine manually if the fill volume has fallen off. That’s a lot of product not going out the door if the machine is down 15 or 20 minutes,” he adds.

Norden of Sirius is launching an integrated checkweigh and cartoning solution that features robotic picking to an integrated checkweigher and cartoner. A robot picks and places the tubes to the checkweighing station. Tubes are therefore handled in a controlled manner rather than rolling free on a moving belt. A second robot picks the weighed tubes and presents them to the cartoner. The system supports 100 cycles per minute, Adolfsson says.

“We maintain control of the tube, from checkweighing through to cartoning. We are building this now for our single-, twin-, and three-f i l l-head machines, and it will be available on our five-head tube fillers,” he adds.

Subnil Packaging Machines (Mumbai, India) has launched the Condor 300 tube filler, which is integrated with a cartoner and bundler. A case packer will soon be added to provide a complete tube-packaging line solution, the company announced.

Resource Conservation

Newer tube-filling machines from Norden of Sirius Machinery Group (Branchburg, NJ) feature software for turning the machine off at intervals when the operator steps away. Machines are programmed to restart at set times, so they are up and running when the operator returns, or they can be set to shut down after an interval if the filler isn’t in use.

“This software is a first baby step, as we try to develop greener solutions,” says Goran Adolfsson, president.

 “The operator can set the machine to automatically come up several minutes before they expect to return. So, no time needs to be spent in restarting the machine, and electricity and compressed air are conserved while the machine is not in use,” he adds.

The line supports 300-tubes-perminute production. Tubes are manually transferred to a cassette for subsequent transfer to a servo-driven conveyor. A servo-driven rotary pickup device loads the tubes into the holders, for bottomup- fill, vertical-product dosing. Indexing as well as the main drive are also servo driven, the company reports.

Bottom-up filling is widely deployed. The fill nozzle may be started at the back side of the cap at the bottom of the tube. The tube is then lowered as the fill proceeds.

With viscous products, this process minimizes or eliminates air entrapment or inconsistent filling. And splattering on the seal area that can occur with more fluid products is avoided.

Product characteristics will dictate the style of feeding system used. Low viscosity products can be fed to the metering system of the tube filler from a gravity hopper. For less-fluid applications, surge tanks or pressure chambers are typically used.

“Surge chambers were originally designed for high-viscosity products.

We use them more broadly for ensuring product is kept sterile or clean. The surge chamber is completely closed to the outside. This can supplant a heated vessel for high-viscosity products, which reduces costs,” says Lowden.

To handle high-viscosity products, Oystar IWK units employ a pressure cylinder with an inlet port on the top and a discharge port on the bottom for feeding to the fill pump. A sensor-monitored-andcontrolled piston delivers constant pressure on the product to enable consistent dispensing, Conlon says.

Conlon notes that fluid product can be delivered in a closed system by running a pipe from the mixing or storage vessel directly to the filler pump.

Vendors offer a variety of solutions for ensuring control of the tubes in the processes of loading, filling, and discharge. ProSys machines use magnets to stabilize tube holders in a consistent position.

Conlon says that tube holders keep tubes well controlled during tube orientation, filling, and sealing.

“Where you traditionally lose control of the tubes is in loading and discharge.”

The Oystar IWK TFS 80 series automatic tube fillers employ an orbital transport track. The system eliminates mechanical handling steps for moving the tubes to a vertical position for filling. Horizontally oriented tubes coming off the feeder ramp are pushed into horizontally positioned tube holders at the loading point. The radius of an angled race track brings the tubes to a vertical position at the filling station. After filling and sealing, the loop track transports the tubes back to horizontal position for discharge.

On Oystar IWK’s high-speed lines, Conlon says robotic tube loading can be deployed for pick and place of up to 36 tubes at a time, supporting 510-tube-aminute production.

Norden of Sirius uses two principal loading methods. Magazine-fed tubes are rolled into a tilter, where they are held by vacuum, rotated 90 degrees, and pressed vertically into the holders. Adolfsson says that vacuum-tilting of magazine-fed tubes is the most prevalent method in use.

In a second method, tubes brought to the filling line are picked robotically for vertical placement in the carrier chain. Tubes in this method don’t need to be mechanically turned for filling, says Adolfsson.

Making It to the Finish Line

MGS Machine (Maple Grove, MN) is completing development of a cartoning line for inserting multiple pharmaceutical items, including tubes, into kits. The MGS Stealth continuous-motion cartoner is being fed automatically with wrapped suppositories, bulk applicators and tubes, and literature.

“This is one of the most diverse lines we’ve ever built,” explains Tim Allen of MGS. “The customer needed us to handle feeding of multiple SKUs, which vary considerably. One SKU can include anything from one to four tubes plus applicators, suppositories, and literature. There are up to 15 types of products.”

Automated feeding begins with MGS’s VersaFeed system, which uses a smart belt to feed the tubes and applicators from bulk. An ICMT (Intermittent to Continuous Motion Transfer) device then collates the kits and transfers them into buckets, which then feed the cartons. “There’s no shooting of tubes and other supplies into space,” says Allen. “The ICMT device follows and loads the buckets for smooth transfer, even at speeds as high as 200 buckets per minute. The drops are timed specifically.”

Allen says such gentle handling was necessary for the tubes in particular and helped MGS secure the project. “Metal tubes are prone to denting, and we proved we could feed them from bulk gently.”

Changeover from one carton size to the next will be simplified through the use of change tooling, Allen says. “It speeds up the changeover process as well as ensures repeatability.”

The new cartoning line also features literature insertion as well as ink-jet printing and vision inspection accomplished on an MGS Carton Inspection Module. In addition, 100% checkweighing is driven by recipes for each of the SKUs.

Factory acceptance tests are scheduled for May. The line will replace manual loading stations that currently take place in different cells. “We’ll be taking what are now fragmented operations and standardizing them, while increasing speed and improving accuracy,” Allen says.

Pharmaceuticals favor metal tubes. At the sealing station, saddle folds are often used to ensure package integrity. The saddle fold prevents high-viscosity product from pushing open the seal when the tube is squeezed, says Conlon. The system’s multiple folds also better accommodate code debossing.

“If you are debossing on both sides of the seal area, you want to have a lot of meat on the back of the crimp, or you could pierce the tube and compromise the seal,” he adds.

Lowden notes that in some cases, dry adhesive may be used to add to integrity of the crimp.

Plastic tubes are preheated at the seal zone with hot air, before indexing to a cooling and coding station.

The code is embossed in the seal web as the water- or glycol-cooled sealing jaws dissipate the heat.

Membrane tubes require tailored sealing solutions, in addition to special nozzles for filling. For sealing tube-intube configurations, ProSys uses a custom hot-air station that directs the heat to the inner surface of the outer tube as well as to the inner and outer surfaces of inner tube, Lowden says.

Newer machines feature Gen 3 design for maintenance and changeover support. ProSys’s ProTrac units support easy changeover, maintenance, and servicing, with fill stations that swing away, and toolfree release systems. The face plate for code embossing features singlebolt removal.

“The huge range of viscosity in products creates a challenge for automated tube filling,” says Lowden.

“Machine efficiency is highly dependent on the quality of the materials, both the product and the container. From the end-user standpoint, support, service, and application experience are always key considerations,” says Lowden.

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