Tru Temp Finishing System

October 01, 2014

High quality black oxide finishes, with zero/minimal labor cost, are achieved when using the new Birchwood Technologies CNC TRU TEMP finishing system. The non-polluting, low-temperature process is now available in a user-proven, integrated programmable hoist and tank line to automatically process iron and steel components with a high quality black oxide finish.

Designed specifically for handling the patented TRU TEMP process, this self-controlled tank line eliminates the labor costs normally required with manual hoist lines. The CNC process line eliminates process guesswork and generates highly repeatable results. The standard, 110-gallon tank line system produces 4000 to 6000 lbs of finished parts per 8-hour shift and the line can be sized and configured to accommodate any volume of work or production capacity.

"Users of this new CNC TRU TEMP system report consistent, high quality finishes and very low operating costs," reports Mark Ruhland, Birchwood Technologies vice president. "The combination of high capacity and minimal labor requirements makes for a very short payback period, as little as 12-18 months. The capital cost is far lower than that of a small machining center and the ROI is much better. The installation meshes well with ISO programs."

The program of the CNC system can process up to three part loads concurrently, for a maximum throughput of about five loads per hour. The hoist and superstructure can be built to handle any size load and are operated by an Allen Bradley PLC digital control with a touchscreen panel and manual joystick backup. The hoist locates itself accurately along the process line by means of a rack and pinion driveline, combined with setdown saddles on each tank. Process tanks are constructed of mild or stainless steel, or reinforced polypropylene, as appropriate to the application. Tanks can be laid out in two ways: with pickup and drop-off points at opposite ends of the line, or with a single load/unload station with the hoist pickup and drop-off at the same point. The line is very sturdily constructed and installed on the job site, and is supplied with complete operator training.

The TRU TEMP CNC hoist processes parts through the following station sequence: Station 1: Load Pickup; Station 2: Alkaline Soak Clean; Station ¾: Double Counterflow Rinse; Station 4: Mild Acid Primer/Prep; Station 5: Cold Overflow Rinse; Station 6: TRU TEMP Black Oxide; Station 7: Cold Overflow Rinse; Station 8: Rust Preventative Oil; Station 9: Load Dropoff. Process cycle is about 28 minutes.

The user-proven TRU TEMP finish produces a durable satin-black magnetite coating just 0.5µm thick (20 millionths) with no effect on material hardness. The finish withstands up to 100-200 hours of neutral salt spray (ASTM B117) or several hundred hours of humidity (ASTM D1748), verified by independent testing. The high level of corrosion protection is important for both long-term part storage and/or overseas shipment.

Related Glossary Terms

  • black oxide

    black oxide

    Black finish on a metal produced by immersing it in hot oxidizing salts or salt solutions.

  • computer numerical control ( CNC)

    computer numerical control ( CNC)

    Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.

  • hardness


    Hardness is a measure of the resistance of a material to surface indentation or abrasion. There is no absolute scale for hardness. In order to express hardness quantitatively, each type of test has its own scale, which defines hardness. Indentation hardness obtained through static methods is measured by Brinell, Rockwell, Vickers and Knoop tests. Hardness without indentation is measured by a dynamic method, known as the Scleroscope test.

  • machining center

    machining center

    CNC machine tool capable of drilling, reaming, tapping, milling and boring. Normally comes with an automatic toolchanger. See automatic toolchanger.