Carleton Life Support Systems (Davenport, IA) specializes in ceramic injection-molding technology, producing ceramics capable of generating high-purity oxygen. Its products go into various life support systems, including those used onboard aircraft, and in medical applications, such as residential-based oxygen generators for emphysema sufferers. Carleton products are also used in the metalworking industries.

Carleton rigorously supports a complete quality control program and keeps careful track of its entire production. Regulated by the Federal Aviation Agency and following American Association of Quality Control guidelines, the company has ISO 9001 certification.

Recently, the company adopted a Matthews International (Pittsburgh) ProPoint 2331 system. This permanently marks each ceramic part in a 1-by-3-inch area with a date code and three-character part number, all on one line. Matthews has also helped Carleton develop custom marking software, which allows the company to transmit tracking data via ASCII transmission.

The ProPoint 2331 employs a marking stylus that is suitable for imprinting both plastics and metals with a hardness rating of up to 50 Rockwell C. It operates using a stand-alone industrial touch-screen control unit, incorporating a Microsoft Windows CE operating system. It requires minimal space, allows variable message marking, has a trigger-operated emergency stop switch and is guided by Matthews' own programmable software. The system uses no ink, reducing consumables costs.

According to Carleton manufacturing engineer Brad Bagby, the ProPoint 2331 allows Carleton to track part quantities, machine performance, environmental conditions (principally temperature levels) and raw materials. The company can also tally production trends, the efficiency of operators working on the production line and everything connected with the process.

"We basically keep track of every parameter of every part we make, which gives us 100-percent traceability," Bagby says of the system.

He adds that in the past the company would mark each part manually, a method that was inadequate to the company's quality needs because it was inconsistent and had poor legibility. It also couldn't tie into the company's overall quality program requirements.

"Those are the main reasons for our switching to the Matthews equipment, which is working quite well," Bagby says.

As part its production process, Carleton prepares a ceramic powder mix with a special recipe of plastics and waxes to coat the ceramic as a feed stock for the injection-molding operation. After molding, the ProPoint machine marks each part while it is still in a relatively soft "green state" phase. The parts then undergo a high-temperature sintering operation to remove the plastics and wax, during which the part becomes more dense, shrinking 50 percent volumetrically. The dense, marked ceramic part is later coated with special materials, which permit electrical charging of the part, after which it is heated in an oven. The parts at this stage can separate oxygen from air.

According to Bagby, dimensional precision of ±0.5 percent is normal, but the company can attain ±0.05-percent levels.

For more on parts marking and tracing, call 412-665-2500 or visit