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
“BOV” TYPES
OTHER TYPES
Kg./cm²
4.89
8.16
Bars
4.80
8.00
Psi-gauge
69.6
112.3
Atmosphere
4.74
7.90
Mercury (mm. At 0° C.)
3,600
6,001
480
800
0.0000048
0.0000080
Minimum (bars) Approximate
4.00
7.00
Maximum (bars) Approximate
6.00
10.00
MEASUREMENT
kPascals
Dynes/cm²
Nitrosol pressure increases upon heating to 55.4ºc
(130ºf) in a hot water bath
EXAMPLES
SYSTEM
Kg./cm²
Psi-gauge
Kg./cm²
Psi-gauge
Kg./cm²
Psi-gauge
Kg./cm²
Psi-gauge
Kg./cm²
Psi-gauge
TEMPERATURES
21.1 °C
54.4 °C
4.90
5.56
69.60
79.10
6.00
6.80
85.20
96.50
8.16
9.21
112.30
126.7
10.20
11.5
145.00
163.10
10.60
11.90
150.00
168.6
Pressure temperature coMPARISIONS
NITROGEN VS. AIR-FREE ISO-BUTANE
TEMPERATURE
21.1 °C
70.0 °F
40.0 °C
104.0 °F
54.4 °C
130.0 °F
71.1 °C
160.0 °F
82.2 °C
180.0 °F
100.0 °C
212.0 °F
PRESURE
NITROGEN
ISO-BUTANE
9.85 Kg/cm²
2.18 Kg/cm²
140 psi-gauge
31 psi-gauge
10.5 Kg/cm²
4.64 Kg/cm²
150 psi-gauge
66 psi-gauge
11.1 Kg/cm²
6.82 Kg/cm²
158 psi-gauge
97 psi-gauge
11.7 Kg/cm²
9.78 Kg/cm²
166 psi-gauge
139 psi-gauge
12.1 Kg/cm²
13.9 Kg/cm²
172 psi-gauge
198 psi-gauge
12.8 Kg/cm²
>20 Kg/cm²
182 psi-gauge
>284 psi-gauge
THE PRESSURE DROP DURING CONSUMER USE of “nitrosols
* EXAMPLE:
Initial pressure 10.55 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 67.5.0% 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 BOVs 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.