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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. Cleaner effluents Better workplace air quality
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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 • Cleaner effluents • Better workplace air quality • Improved health and safety in brazing operations
ELIMINATION OF HAZARDOUS CHEMICALS AND METALS • Cadmium from Brazing Filler Metals • Lead from Plumbing Soft-Solders • CFC Solvents from All Applications • Hydrazine from Industrial Applications • Asbestos from Insulation
Boric Acid Boron Oxide Elemental Boron Potassium Bifluoride Potassium Fluoride Potassium Pentaborate Potassium Tetraborate Silicon Dioxide Sodium Tetraborate (Borax) Wetting Agents COMMON BRAZING FLUX CHEMICALS
HAZARDS ASSOCIATED WITH GENERAL-PURPOSE FLUXES • Working with raw flux • Brazing at elevated temperatures when HF and BF3 gases are released • Discharging raw flux and flux residues into plant effluent, and entry into water system
EXPOSURE LIMITS AND HAZARD LABELS FLUORINE ACGIH OSHA NIOSH OSHA D.O.T. COMPOUND TWA-TLV TWA-PEL TWA-REL Label Label Boron Trifluoride 1 ppm 1 ppm 1 ppm - Poison Hydrogen Fluoride 3 ppm 3 ppm 3 ppm Toxic Corrosive Potassium Bifluoride 2–5mg/m3 2–5mg/m3 2–5mg/m3 Toxic Corrosive Potassium Fluoborate 2–5mg/m3 2–5mg/m3 2–5mg/m3 Toxic - Potassium Fluoride 2–5mg/m3 2–5mg/m3 2–5mg/m3 Toxic -
POTENTIAL HEALTH ISSUES FROM FLUORIDE-BEARING FLUX • Irritation to skin and fingernails by the raw flux. • Irritation of the eyes, mucous membranes, and respiratory system by gases and fumes generated during brazing. • Calcium depletion (sclerosis) of the bones, and mottled teeth from long-term exposure to fluoride gases and fine-fume particles. • Potential health hazards from discharge of untreated flux and flux residues into water supply.
PHYSICAL PROPERTIES OF SILVER-BRAZING FLUX WITHOUT POTASSIUM BIFLUORIDE* Form: Creamy Paste Color: Off White Specific Gravity: 1.5 Water Content: Less than 35% Viscosity @ 22C/72F: 140,000±14,000 Centipoises Fluorine Content: 18.0% Flash Point: None Freezing Effects: None Heating Effects to 50 C / 122 F: None Activity Temperature Range: 485–870C / 900-1600F * not boron-modified
PHYSICAL PROPERTIES OF FLUORIDE-FREE SILVER-BRAZING FLUX Form: Creamy Paste Color: White Specific Gravity: 1.4 Viscosity @ 22C/ 72F: 225,000 ± 20,000 Centipoises Fluoride Content: Less than 50 ppm Flash Point: None Freezing Effects: None Heating Effects to 50C/122F: Minimal Activity Temperature Range: 670-870C / 1235-1600F
TEMPERATURE RANGES FOR FLUXES AND FILLER METALS Recommended Activation Maximum Flux Temperature Temperature Average Fluoride-Bearing 570C / 1050F 870C / 1600F Fluoride-Free 670C / 1240F 870C / 1600F Recommended Filler Liquidus Maximum Alloy Temperature Temperature BAg-28 (40% Ag) 710C / 1315F 802C / 1475F BAg-36 (45% Ag) 688C / 1270F 785C / 1450F BCuP-4 (6% Ag) 718C / 1325F 785C / 1450F
FILLER METAL SPREAD AS A FUNCTION OF BASE METAL, FILLER ALLOY, AND FLUX BASE FILLER ALLOYS METAL FLUX BAg-28 BAg-36 BCuP-4 Brass Fluoride-Free Excellent Excellent Excellent Fluoride-Bearing Excellent Excellent Excellent Copper Fluoride-Free Moderate Moderate Moderate Fluoride-Bearing Excellent Excellent Poor Mild Fluoride-Free Moderate Moderate Poor Steel Fluoride-Bearing Moderate Moderate Poor Furnace Temperature: 785C/1450F Time in Furnace: 60 Seconds Excellent Spread: >2.0cm2 Moderate Spread: >0.5cm2<2.0cm2 Poor Spread: <0.5cm2
PHYSICAL PROPERTIES OF HIGH TEMPERATURE FLUX WITHOUT POTASSIUM BIFLUORIDE Form: Creamy Paste Color: Dark Brown Specific Gravity: 1.7 Water Content: Less than 30% Viscosity @ 22 C / 72 F: 200,000 ± 20,000 Centipoises Fluorine Content: 3% or Lower Flash Point: None Freezing Effects: None Heating Effects to 50C/122F: None Activity Temperature Range: 760 - 1205C / 1400 - 2200F
PHYSICAL PROPERTIES OF FLUORIDE-FREE HIGH TEMPERATURE BRAZING POWDER FLUX Form: Powder Color: White Specific Gravity: 1.5 (Average) Fluorine Content: Less than 50 ppm Volatile Content: <0.1% Flash Point: None Freezing Effects: None Heating Effects to 50C/122F: None Activity Temperature Range: 760–1205C/1400-2200F
BASE METAL, AND FILLER METAL RELATIONSHIPS Flux Category Base Metals Filler Metals Silver Brazing Copper and Copper-based All (BAg) Alloys without Potassium Alloys, Ferrous Alloys Phos-Copper Bifluoride Stainless Steel (BCuP) Alloys Silver Brazing Copper and Copper-based Cd-Free BAg Alloys Fluoride-Free Alloys, Select Ferrous Phos-Copper BCuP Alloys Alloys High Temperature Ferrous Alloys, Carbides CDA 681, CDA 773; Brazing without Manganese containing Potassium Bifluoride Nickel Alloys High Temperature Ferrous Alloys, Carbides CDA 681, CDA 773; Brazing, Fluoride-Free Manganese containing Nickel Alloys
PRIMARY SKIN IRRITATION STUDY OF SILVER BRAZING FLUXES FLUX WITHOUT FLUORIDE-FREE POTASSIUM POTASSIUM FLUX BIFLUORIDE BIFLUORIDE FLUX PRIMARY 1.5 2.3 5.9 DERMAL IRRITATION INDEX (PDII) CLASSIFICATION Not a primary Not a primary A primary irritant. Non- irritant. Non- irritant. corrosive to skin. corrosive to skin. 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 • Addresses workplace safety by reducing toxic emissions • Addresses the long-time issue of skin and fingernail irritation • Substantially reduces the fluoride effluent emission in local and regional waterways • Complements the Cadmium-Free workplace with much safer fluxes
SUPERIOR MANUFACTURES QUALITY FLUXES. OUR BUSINESS IS SOLVING PROBLEMS