Examples of “nitrosol” products * * BOV PRODUCTS Shave Creams Body Sprays Sun Tan (Sun Block) Sprays Depilatories Insect Repellants Bug Killers Cookware Lubricants Food Flavorings Ultra-pure Water Facial Rinses * * OTHER AEROSOLS single compartment Air Fresheners and Deodorants Furniture Polishes (Europe) Hard Surface Cleaners (Europe) Contact Lens Flushing Sprays Water Repellant Sprays - Boots Oral Refresher Sprays Selected lubricants
advantages of “nitrosols” * * Nitrogen is totally eco-compatible. (78% of air.) * * Nitrogen is non-flammable, not a VOC. (No ODP.) * * Nitrogen is completely inert – it will not harm any aerosol product. * * At typically 0 to 0.6% nitrogen in the formulation, more product is delivered. * * It can be filled with either U-t-C or T-t-V gassers, or even in-line or rotary gasser-shakers. (Only U-t-C for BOV productions.) * * Pressures increase only slightly when heated. (Charles Law is closely followed.) * * Propellant cost is almost negligible. * * Sprays are almost silent. (Not frightening to pets or farm animals.)
Disadvantages of “nitrosols” * * Loss of propellant by inverting the can. * * Requires a mechanical break-up (MBU) actuator. * * Produces a fairly coarse spray. * * Delivery rate decreases slightly as product is used. * * Very slight solubility of gas in products. (If it causes unwanted foam in some.) * * Pressure may change (fractionate) some products. * * For quality control, gas weight is negligible. (Pressure testing is required.) * * Even minor leakage can be harmful, since so little nitrogen is present. (After helium, nitrogen is the smallest molecule.) * * Bulk storage is impractical – must use cylinders
Nitrosol pressures MEASUREMENT “BOV” TYPES OTHER TYPES Kg./cm² Bars Psi-gauge Atmosphere Mercury (mm. At 0° C.)3,6006,001 kPascals Dynes/cm² Minimum (bars) Approximate Maximum (bars) Approximate
Nitrosol pressure increases upon heating to 55.4 º c (130 º f) in a hot water bath EXAMPLES SYSTEM TEMPERATURES 21.1 °C54.4 °C Kg./cm² Psi-gauge Kg./cm² Psi-gauge Kg./cm² Psi-gauge Kg./cm² Psi-gauge Kg./cm² Psi-gauge
Pressure temperature coMPARISIONS NITROGEN VS. AIR-FREE ISO-BUTANE TEMPERATURE PRESURE NITROGENISO-BUTANE 21.1 °C 70.0 °F 9.85 Kg/cm²2.18 Kg/cm² 140 psi-gauge31 psi-gauge 40.0 °C °F 10.5 Kg/cm²4.64 Kg/cm² 150 psi-gauge66 psi-gauge 54.4 °C °F 11.1 Kg/cm²6.82 Kg/cm² 158 psi-gauge97 psi-gauge 71.1 °C °F 11.7 Kg/cm²9.78 Kg/cm² 166 psi-gauge139 psi-gauge 82.2 °C °F 12.1 Kg/cm²13.9 Kg/cm² 172 psi-gauge198 psi-gauge °C °F 12.8 Kg/cm²>20 Kg/cm² 182 psi-gauge>284 psi-gauge
THE PRESSURE DROP DURING CONSUMER USE of “nitrosols * * EXAMPLE: Initial pressure kg./cm² (10.34 bars or 150 psi-gauge) at 21.1 °C Determine pressure when 95% is dispensed. * * For a fill to 72.5% of the can volume: The final pressure is 2.27 kg./cm² (32.3 psi-g.) * * For a fill to 70.0% of the can volume: The final pressure is 2.57 kg./cm² (36.5 psi-g.) * * For a fill to % of the can volume: The final pressure is 2.86 kg./cm² (40.7 psi-g.) * * For a fill to 65.0% of the can volume: The final pressure is 3.16 kg./cm² (44.9 psi-g.)
THE PRESSURE DROP DURING CONSUMER USE of “nitrosols” * * EXAMPLE: Initial pressure 7.03 kg./cm² (6.70 bars or 100 psi-gauge) TASK: Determine the pressure when 95% is dispensed. * * For a fill to 72.5% of the can volume: The final pressure is 1.27 kg./cm² (18.0 psi-g.) * * For a fill to 65.0% of the can volume: The final pressure is 1.85 kg./cm² (26.8 psi-g.) * * For a fill to 60.0% of the can volume: The final pressure is 2.29 kg./cm² (32.0 psi-g.) * * For a fill to 55.0% of the can volume: The final pressure is 2.70 kg./cm² (38.4 psi-g.)
FOR BOV s ONLY: THE PRESSURE DROP DURING CONSUMER USE of “nitrosols” * * EXAMPLE: Initial pressure 5.27 kg./cm² (5.12 bars or 75 psi-gauge) at 21.1 °C Determine pressure when 95% is dispensed. * * For a fill to 70.0% of the can volume: The final pressure is 0.93 kg./cm² (13.2 psi-g.) Considered marginal or too low. * * For a fill to 60.0% of the can volume: The final pressure is 1.57 kg./cm² (22.3 psi-g.)Acceptable.