Lakewood, CO

COBE is a world leader in medical equipment manufacturing.  Their BCT division, in Lakewood, Colorado, is responsible for the manufacture of disposable kits for their Spectra^® Apheresis product line.  In layman's terms, apheresis is a process by which blood is separated into its components, such as red cells, white cells, and platelets.  The most common application of apheresis is to gather platelets for infusion into the blood of chemotherapy patients.  COBE BCT’s apheresis kits consist of various parts such as tubes and filters, combined into subassemblies, which are then assembled on color-coded pallets.  The kits are sealed into a package that is used for one donor on a Spectra^® machine, and then discarded.  COBE BCT currently manufactures several types of kits, each with minor differences, so their production line must be able to adapt to the different requirements for each type.  COBE BCT maintains a Clean Room 100K environment to ensure that the kits are not contaminated.  At the time of this writing, COBE BCT holds a significant share of the apheresis market.

Back in 1992, COBE BCT had been using a production process they called the “Batch Process,” in which subassemblies were built on outlying tables, and then moved to central tables for final assembly and packaging.  It became apparent that there was room for improvement, and that some sort of automation to help production flow was in order.

The first production flow experiment at COBE BCT was an oval line consisting of roller (skatewheel) conveyor, where subassemblies were added to a pallet at successive stations and then manually pushed down the roller bed to the next station.  The system had ergonomics problems as well as a relatively slow production rate.  Operators had to continually stand and bend, while placing the kits onto and taking them off of the conveyors.  In addition, the lack of stops made it very easy for a pallet to run into a waiting pallet at the next station.  COBE BCT has always prided itself on maintaining a safe, pleasant environment for its employees, and it was obvious that these ergonomic factors would have to be solved in the next generation of the system.  Despite these problems, this sort of flow environment was clearly what was needed to improve productivity.

The first major design change suggested that the pallets be set up at an angle.  Operators would be able to reach from the bottom to the top of the pallet in a seated position, giving them a sit/stand option and greatly reducing fatigue.  This was achieved by installing a single MonoSpan conveyor underneath the top of the pallet to provide motive power, and rollers on the bottom rail, over which the pallets could glide.  Ergonomic factors were considered carefully before the final tilt angle was chosen.  In addition, power-operated foot rests were installed at operator positions, allowing operators to adjust the foot rests for individual comfort.  Pneumatically-operated stops were placed before and after each operator position to allow for logic control of the line.  “It was an elegant solution,” Fiore said.  “I was concerned about how we would curve the pallets back around to the other side of the line, but Bud was able to come up with an answer.”  What Layne designed was a separate, tight-curving (3-foot bend radius) conveyor that links the two sides of the line.  Motive power is derived from a MonoSpan conveyor running along the bottom of the pallet, with a UHMW-PE guide rail supporting the top.  Transfer is smooth and effortless to and from the curves.

The prototype was installed in December of 1992 in an unused building, so that it could be evaluated and control logic could be designed.  Employees from both the “Batch” and “Skatewheel” lines took turns trying out the new line.  Laurie Harfst, a Production Area Coordinator for COBE BCT, had been a line worker back in 1992 and had spent time on both of the previous lines.  “The [SpanTech] conveyor was an immediate improvement,” she said.  “It was much more comfortable to work on.”  She also noted that it increased both productivity and quality, since it was much easier to inspect the tilted pallets for defects.  The new system was able to decrease the cycle time significantly, and it was obvious to everyone that they had found the solution they were looking for.

Rotating racks, for the “Loop & Channel” and “Flow” subassembly areas on each line, were another requirement for the new system.  “I looked at dedicated systems offered by material handling equipment companies, but they were expensive,” Fiore said.  “By that time, I was familiar enough with the Designer System to have an inspiration: Why not turn a simple MaxiSpan conveyor on its side, extend the rods, and use them to hang the baskets?”  It is probably one of the most unique applications of Designer System conveyors, but they have performed admirably, and at a much lower cost.  Each conveyor is controlled by a foot pedal on the inside end.  To complete the design, a straight MultiSpan conveyor with roller chain was added where the kit comes off the line before packaging.  This allows for accumulation without product damage, before the kit is sealed and sent to shipping.

The order for the first line was entered in February, 1993, and installed that summer.  A second line was ordered in August of 1993, and a third in March of 1994.  In addition, a line was ordered in 1995 for a new plant in Gloucester, England.  All three lines in the Colorado plant operate two shifts a day (13 hours), 251 days per year, with the conveyors running continuously.  In March of 1993, a new formulation of UV-resistant chain was supplied to COBE BCT for cosmetic reasons.  As of this writing, the chain on the conveyor has accumulated over 13,900 hours of run time with no replacement.  Parts orders for the three systems have totaled $22,533, for an average of $5,633 per year.  Cost for the three systems totaled $389,000, yielding an annual maintenance expense of 1.5% of the total system price.  (Much of the parts cost is due to an upgrade to new SEW Eurodrive gearmotors.)  Preventative maintenance includes regular sprocket replacement and quarterly chain cleaning.  Other than preventative maintenance, line shutdowns are almost unknown.  “Total system down time can be measured in hours,” said Fiore.  “When there has been a problem, SpanTech has been very responsive to our needs.”

COBE BCT is a prime example of the flexibility and openness of the Designer System, as well as the ability of SpanTech to deliver a custom solution for an unusual application.  From the beginning, SpanTech’s relationship with COBE BCT has been that of a valued partner rather than simply an equipment supplier.  “We stand behind COBE BCT one hundred percent,’’ said Layne.  When asked why he is committed to Designer System conveyors, Fiore is quick to point out his reasons.  “They are clean, safe, easily maintainable, dependable and cost-effective.  When it comes to problems, it’s almost like that old statement in the movies: ‘It’s quiet … too quiet!’  I keep expecting something to happen, but they just keep on running.”

David Simmons. 1997