concentration-based limits. Existing indirect dischargers that discharge more than a million gal/year would also have mass-based limits.

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2 concentration-based limits. Existing indirect dischargers that discharge more than a million gal/year would also have mass-based limits. Existing indirect dischargers that discharge less than a million galiyear would have concentration-based limits. Most finishers will be affected by either Phase 1 or II of this rule. Look for it in the Federal Register and find out the details. Then cal1 your congress persons andar Bi11 Sonntag and let them know how you feel about the legislation. EPA wants to know. It wants your input. Be a part of the Common Sense Initiative. EPA is extending its hand in a type of peace offering. We should accept the invitation. PF

3 A computerized anodizing line prepared Aluminum Shapes for growth and success... ounded in 1954, Aluminum Shapes is today the largest independent F extruder in the country. It has eight extrusion presses ranging in size from seven to 26 inches. Truly al1 under one roof means that at Aluminum Shapes. The facility also has a billetcasting facility, fully automated fabrication department, computerized die design, andan 1 X-ft-long vertical painting facility. The company provides services to the transportation, construction, and architectural industries. To add to its complete in-house capability, Aluminum Shapes decided to upgrade its existing anodizing facility in Philadelphia. Rather than adding to the 30-year-old plant, the company built an entirely new facility across the river where al1 of the extrusions are currently produced. The anodizing line that Walgren Co., Grand Rapids, Michigan, designed and recently installed at Aluminum Shapes in Dellaire, New Jersey, is one of the most sophisticated systems of its kind in the world. Four fully automatic, 4,000-lb hoists, controlled by a 486 computer coupled with an AIB 530 PLC, produce up to 30,000 sq ft per shift of Class 1 and Class II architectural finishes. The computer controls the whole line, including load entry, rectifier output, electrolytic coloring recipe and tank times. There are two anodizing tanks, each with 15,000-amp rectifiers. One 8,000-amp AC power supply handles the electrolytic color tank. The AC power supply is a DC superimposed AC machine with independent half-wave modulation. The system produces up to 1,100 sq ft per load of electrolytic colored work using a center cathode in the anodizing tank and center electrode in the color tank. Load entry is accomplished using a mouse to select the next racking station to be run. After clicking on the load position, a load entry screen allows the operator to enter the information specific to that load: ANODIZING line is topable of random processing using a computer integroted system. COMPUTER PROGRAM controls 011 facets of the anodizing protess. APRIL PRODUCTSFINISHING 51

4 .*., -. - FOCUS: Anodizing EXAMPLES of some of the ports Aluminum Shapes manufactures ond onodizes. 1. Customer name 2. Part number 3. Job number 4. Extrusion length 5. Square feet per load 6. Current density desired 7. Etch time 8. Tilt or no tilt 9. Color recipe The computer then calculates the rectifier setting in amps and sends the signa1 to activate the rectifier when the load is in the tank. If the calculated amps are higher than the rectifier s capacity, the computer will set the maximum of 15,000 amps and extend the tank time to achieve the thickness desired. Al1 the load information becomes a permanent record for that bar. 52 PRODUCTS FINISHING The custom software program uses Wonderware for the screens provided and is coupled with a special software development that allows random processing of loads. Each load is tagged with its own appropriate information and can have a different tank sequence and time in tank. There are 22 tanks in this line. Tanks are constructed of either i,- inch mild-steel plate with MS bracing and painted with acid-resistant paint; 10 gauge stainless steel with stainless bracing; or one-inch polypropylene with stainless bracing (see Table 1). These tanks are 33-ft long and eight-ft deep and vary in width. The cathode systems for the anodizing tanks are constructed of extruded, one-half by six inch 6063 alloy. The color electrode is made up of grade A pure tin with a one-half by two inch cross section and suspended from aluminum headers. Two multiple-compressor, 1 OO-ton chillers co01 the two anodizing tanks, color tank, etch tank, rectifiers, and color power supply. The acid is pumped continuously from the anodizing tank, through a plate-and-frame, 3 16 stainless steel heat exchanger APRIL. 1995

5 TABLE I-Aluminum Shapes Tank List Tank Quote Actual Tank Tank Width Tank Tank No. Cycle Temp. Inches Material Material ******************f******2******************~******************,*******~******** Fut. Etch Alk. Clean MS. 2. Rinse 48 MS. 3. Etch M.S. 4. Rinse 48 MS. 5. Rinse 48 MS. 6. Desmut SS 7. Rinse W/ Barwash SS 8. Transfer Rinse SS 9. Fut. Anodize Fut. Rinse Anodize Polypro. Others 12. Rinse WI Barwash Anodize Polypro. Others 14. Rinse SS 15. Electrocolor Potypro. Others 16. Rinse WI Rim Spfay SS 17. D.I. Rinse/Fut. Color, 60 Polypro. Others 18. Rinse WI Bartiash SS 316SS Rinse SS 316SS 20. Seal SS 316SS 21. Seal SS 316 SS 22. D.I. Rinse SS 316 SS 23. Hot D.I. Rinse SS 316 SS 24. Drain and back to the tank. Chilled water is scrubber removes fumes prior to dispumped counter current from the charge. The two anodizing stations chiller through the heat exchanger to also have scrubber systems. Stainremove heat (see the refrigeration less-steel covers seal tanks to conschematic). tain the steam and conserve energy. LIP exhaust hoods capture fumes The system uses an acid-purificafrom the etch tank. A 50,000-cfm tion unit to continuously remove the APRIL PRODUCTS FINISHING 53

6 EMPLOYEES load extruded aluminum pietes for proíessing aluminum from the anodizing tanks and recover sulfuric acid that would normally have to be decanted. When it comes to consistent color and thickness control, it is hard to match the performance of Aluminum Shapes. They have taken the necessary steps to position their company as the quality leader in the aluminum extrusion anodizing industry for the next century. PF More Information? To obtain more information on products or processes mentioned in this article, circle corresponding numbers on the Reader Service Card. Anodizing systems and process controls..,,,.,,.,.. Circle 294 To request an additional copy of this article, write on company letterhead to Reprints, c/o PRODUCTS FINISHING, 6600Clough Pike, Cincinnati, OH

Many types of anodic coatings exist through an electrolytic formation. The important ones you need to know are:

Many types of anodic coatings exist through an electrolytic formation. The important ones you need to know are: ANODIZING MACHINE Anodizing is a process of treating the surface of an aluminum to convert it to aluminum oxide. Anodizing aluminum takes so many processes to arrive at the state of aluminum oxide. The