CHICAGO — Daca Instruments is displaying for the first time what it calls the world's smallest twin-screw compounder.
The Micro-Compounder batch compounds about 4-5 grams of material in a conical unit that recirculates the material to provide an infinite number of length-to-diameter screw ratios, controlled by residence time, said Alejandro Andreatta, president of the Coleta, Calif., private firm.
Andreatta said Daca has sold seven of the machines around the world since it introduced them in 1994.
The most recent sale was to Monsanto Co. for a research lab in St. Louis, he said in an interview at Daca's booth. The compounding unit fits in the palm of a hand but it carries a hefty price tag for such a small machine. Andreatta said the base price is about $57,000.
A researcher typically runs the compounder at 100 revolutions per minute for two to five minutes to get thorough mixing. It can compound a range of materials, but very highly filled materials might be too viscous for it to handle.
Researchers have used it to make conductive polymers, reactive compounds and liquid crystal polymers. It is electrically heated and air cooled and can run at 752§ F. A monitor displays torque and load on the motor.
Andreatta said the Micro-Compounder extrudes a strand that can be injection molded into tensile or impact test bars using Daca's Micro-Injector injection molding instrument.
Daca built its first Micro-Injector for NPE so it does not have an official list price yet, but Andreatta estimated its base cost will be about $7,000, including one mold.
Daca's other main product is its lab-scale fiber production machinery comprising the Spinline and Piston Extruder. Daca designed the system to make as much as 3,300 feet of oriented fiber from highly viscous materials. Andreatta said it costs about $40,000.