SUPERIOR FLUX MFG CO ENVIRONMENTALLY SAFE BRAZING FLUXES
SUPERIOR FLUX & MFG. CO.
ENVIRONMENTALLY SAFE BRAZING FLUXES DR. Y. BASKIN SUPERIOR FLUX & MFG. CO. INTERNATIONAL BRAZING & SOLDERING CONFERENCE FEBRUARY 18, 2003 SAN DIEGO, CA
MOTIVATION FOR SAFER FLUX DEVELOPMENT v Cleaner effluents v Better workplace air quality v Improved health and safety in brazing operations
ELIMINATION OF HAZARDOUS CHEMICALS AND METALS v v v Cadmium from Brazing Filler Metals Lead from Plumbing Soft-Solders CFC Solvents from All Applications Hydrazine from Industrial Applications Asbestos from Insulation
COMMON BRAZING FLUX CHEMICALS v v v Boric Acid Boron Oxide Elemental Boron Potassium Bifluoride Potassium Fluoride Potassium Pentaborate Potassium Tetraborate v Silicon Dioxide v Sodium Tetraborate (Borax) v Wetting Agents v
KBF BRAZING FLUX DIAGRAM
HAZARDS ASSOCIATED WITH GENERAL-PURPOSE FLUXES v Working with raw flux v Brazing at elevated temperatures when HF and BF 3 gases are released v Discharging raw flux and flux residues into plant effluent, and entry into water system
EXPOSURE LIMITS AND HAZARD LABELS FLUORINE COMPOUND Boron Trifluoride Hydrogen Fluoride Potassium Bifluoride Potassium Fluoborate Potassium Fluoride ACGIH OSHA TWA-TLV TWA-PEL NIOSH TWA-REL OSHA Label D. O. T. Label 1 ppm - Poison 3 ppm Toxic Corrosive 2– 5 mg/m 3 2– 5 mg/m 3 Toxic - 2– 5 mg/m 3 Toxic -
POTENTIAL HEALTH ISSUES FROM FLUORIDE-BEARING FLUX v Irritation to skin and fingernails by the raw flux. v Irritation of the eyes, mucous membranes, and respiratory system by gases and fumes generated during brazing. v Calcium depletion (sclerosis) of the bones, and mottled teeth from long-term exposure to fluoride gases and fine-fume particles. v Potential health hazards from discharge of untreated flux and flux residues into water supply.
PHYSICAL PROPERTIES OF SILVERBRAZING FLUX WITHOUT POTASSIUM BIFLUORIDE* Form: Color: Specific Gravity: Water Content: Viscosity @ 22 C/72 F: Fluorine Content: Flash Point: Freezing Effects: Heating Effects to 50 C / 122 F: Activity Temperature Range: Creamy Paste Off White 1. 5 Less than 35% 140, 000± 14, 000 Centipoises 18. 0% None 485– 870 C / 900 -1600 F * not boron-modified
PHYSICAL PROPERTIES OF FLUORIDE-FREE SILVERBRAZING FLUX Form: Color: Specific Gravity: Viscosity @ 22 C/ 72 F: Fluoride Content: Flash Point: Freezing Effects: Heating Effects to 50 C/122 F: Activity Temperature Range: Creamy Paste White 1. 4 225, 000 ± 20, 000 Centipoises Less than 50 ppm None Minimal 670 -870 C / 1235 -1600 F
TEMPERATURE RANGES FOR FLUXES AND FILLER METALS Flux Activation Temperature Recommended Maximum Temperature Average Fluoride-Bearing 570 C / 1050 F 870 C / 1600 F 670 C / 1240 F 870 C / 1600 F Filler Alloy Liquidus Temperature Recommended Maximum Temperature BAg-28 (40% Ag) 710 C / 1315 F 802 C / 1475 F BAg-36 (45% Ag) 688 C / 1270 F 785 C / 1450 F BCu. P-4 (6% Ag) 718 C / 1325 F 785 C / 1450 F Fluoride-Free
FILLER METAL SPREAD AS A FUNCTION OF BASE METAL, FILLER ALLOY, AND FLUX BASE METAL FILLER ALLOYS BAg-36 FLUX BAg-28 Brass Fluoride-Free Fluoride-Bearing Excellent Excellent Copper Fluoride-Free Fluoride-Bearing Moderate Excellent Moderate Poor Mild Steel Fluoride-Free Fluoride-Bearing Moderate Poor Furnace Temperature: 785 C/1450 F Excellent Spread: >2. 0 cm 2 Poor Spread: <0. 5 cm 2 BCu. P-4 Time in Furnace: 60 Seconds Moderate Spread: >0. 5 cm 2<2. 0 cm 2
PHYSICAL PROPERTIES OF HIGH TEMPERATURE FLUX WITHOUT POTASSIUM BIFLUORIDE Form: Color: Specific Gravity: Water Content: Viscosity @ 22 C / 72 F: Fluorine Content: Flash Point: Freezing Effects: Heating Effects to 50 C/122 F: Activity Temperature Range: Creamy Paste Dark Brown 1. 7 Less than 30% 200, 000 ± 20, 000 Centipoises 3% or Lower None 760 - 1205 C / 1400 - 2200 F
PHYSICAL PROPERTIES OF FLUORIDE -FREE HIGH TEMPERATURE BRAZING POWDER FLUX Form: Color: Specific Gravity: Fluorine Content: Volatile Content: Flash Point: Freezing Effects: Heating Effects to 50 C/122 F: Activity Temperature Range: Powder White 1. 5 (Average) Less than 50 ppm <0. 1% None 760– 1205 C/1400 -2200 F
BASE METAL, AND FILLER METAL RELATIONSHIPS Flux Category Silver Brazing without Potassium Bifluoride Base Metals Copper and Copper-based Alloys, Ferrous Alloys Stainless Steel Filler Metals All (BAg) Alloys Phos-Copper (BCu. P) Alloys Silver Brazing Fluoride-Free Copper and Copper-based Alloys, Select Ferrous Alloys Cd-Free BAg Alloys Phos-Copper BCu. P Alloys High Temperature Brazing without Potassium Bifluoride Ferrous Alloys, Carbides CDA 681, CDA 773; Manganese containing Nickel Alloys High Temperature Brazing, Fluoride-Free Ferrous Alloys, Carbides CDA 681, CDA 773; Manganese containing Nickel Alloys
PRIMARY SKIN IRRITATION STUDY OF SILVER BRAZING FLUXES FLUX WITHOUT POTASSIUM BIFLUORIDE PRIMARY DERMAL IRRITATION INDEX (PDII) 1. 5 CLASSIFICATION Not a primary irritant. Noncorrosive to skin. FLUORIDE-FREE FLUX 2. 3 Not a primary irritant. Noncorrosive to skin. POTASSIUM BIFLUORIDE FLUX 5. 9 A primary irritant. Corrosive to skin. * The Non-Corrosive/Corrosive dividing measurement is 5. 0. The Draize scoring system is used for defining the skin irritation levels.
BENEFITS OF USING FLUORIDE-FREE FLUX v Addresses workplace safety by reducing toxic emissions v Addresses the long-time issue of skin and fingernail irritation v Substantially reduces the fluoride effluent emission in local and regional waterways v Complements the Cadmium-Free workplace with much safer fluxes
SUPERIOR MANUFACTURES QUALITY FLUXES. OUR BUSINESS IS SOLVING PROBLEMS
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