Innovation Polymers Introduces Aquabond 200 Couplant for Long Term Probe Placement
Posted: 2020-1-20
Innovation Polymers introduces a new formulation couplant for long term acoustic coupling.
Aquabond 200 is a lower viscosity polymeric couplant than the initially introduced Aquabond 100. The new couplant can be easily applied without the aid of heating.
Due to its lower viscosity, Aquabond 200 provides an excellent means of coupling probes to refracting wedges or probes and wedges to test components under long term tests, such as flow metering and acoustic emission tests.
Aquabond 200 supports only compression mode pulses. When exposed to air, the liquid remains tacky for several weeks, thereby making it an effective pressure sensitive adhesive; i.e. it forms a bond when pressure is applied.
Applications exist where ultrasonic probes are required to be in place for long periods of time, sometimes in relatively extreme conditions. Typically, ultrasonic corrosion monitoring and ultrasonic flow metering place probes on a surface and take readings on a continuous or periodic basis. Water soluble gels eventually dry and the coupling effect is reduced and then lost.
Innovation Polymers has developed a new ultrasonic couplant that permits long term probe placement without significant coupling losses. The material is a high viscosity liquid polymer with virtually no evaporation at normal working temperatures. The tacky texture makes it an effective pressure sensitive adhesive i.e. it forms a bond when pressure is applied.
In addition to its long-term coupling capabilities, the new couplant is capable of supporting SH shear waves (i.e. it is a nonnewtonian viscous fluid). Because it is not water-soluble, the couplant was selected for application in the North Sea at 300m below the surface. The North Sea application included successful performance demonstration at temperatures from 5°C to 50°C.
To demonstrate the long-term stability of the couplant a test was configured that coupled a 5MHz compression mode probe and a 5MHz SH shear wave probe to a 9mm thick plate of aluminium.
For the compression mode probe the A-scan was gated to display two thickness multiples, whereas for the SH shear wave probe only a single backwall was gated. Over a four-week period, the only significant shift was seen to occur after Day 1 where the thickness of the couplant had gradually reduced to a steady state. Subsequent measurements indicated less than 1dB variation from the average peak value for both compression and shear modes.
At the time of the initial introduction of Aquabond, the test period was 30 days with the only significant change being at the transition from Day 1 as the thickness of the very viscous couplant thinned to a steady state. The test has continued and 120 days after the test started the results show no signs of instability or change. Both the compression mode and shear mode signals have remained constant.
Some suggested applications of Aquabond:
Clamp-on ultrasonic flow-meters
Long-term probe-to-wedge coupling (e.g. automated systems) Underwater shear-wave stress testing
Long-term corrosion monitoring
Outdoor applications where weathering could remove water-soluble gels
Note: Because the liquid polymer is not water-soluble, its removal is made possible with a cloth dampened with naptha or mineral spirits.
Because the liquid polymer is highly viscous, its application is best made by spreading it onto the probe surface with a knife-like blade. Pre-heating to about 40°C helps to reduce viscosity for application.
A comparison of properties:
Aquabond 100
Specific Gravity: 0.91 g/cc
Viscosity: *190,000 cps (centipoises)
Appearance: Clear amber liquid
Flash point: 150 °C
Glass Transition Temperature: -18 °C
Supports shear mode: Yes
Aquabond 200
Specific Gravity: 0.92 g/cc
Viscosity: 50,000 cps (centipoises)
Appearance: Clear amber liquid
Flash point: 120 °C
Glass Transition Temperature: -66 °C
Supports shear mode: No
*approximate value at 55°C. Note: for comparison thick molasses is about 10,000 cps and peanut butter is about 150,000cps.
The new couplant is available from Innovation Polymers under the trade name "Aquabond".
Available as sample size, contact us at innovationpolymers.ca.
Aquabond 200 is a lower viscosity polymeric couplant than the initially introduced Aquabond 100. The new couplant can be easily applied without the aid of heating.
Due to its lower viscosity, Aquabond 200 provides an excellent means of coupling probes to refracting wedges or probes and wedges to test components under long term tests, such as flow metering and acoustic emission tests.
Aquabond 200 supports only compression mode pulses. When exposed to air, the liquid remains tacky for several weeks, thereby making it an effective pressure sensitive adhesive; i.e. it forms a bond when pressure is applied.
Applications exist where ultrasonic probes are required to be in place for long periods of time, sometimes in relatively extreme conditions. Typically, ultrasonic corrosion monitoring and ultrasonic flow metering place probes on a surface and take readings on a continuous or periodic basis. Water soluble gels eventually dry and the coupling effect is reduced and then lost.
Innovation Polymers has developed a new ultrasonic couplant that permits long term probe placement without significant coupling losses. The material is a high viscosity liquid polymer with virtually no evaporation at normal working temperatures. The tacky texture makes it an effective pressure sensitive adhesive i.e. it forms a bond when pressure is applied.
In addition to its long-term coupling capabilities, the new couplant is capable of supporting SH shear waves (i.e. it is a nonnewtonian viscous fluid). Because it is not water-soluble, the couplant was selected for application in the North Sea at 300m below the surface. The North Sea application included successful performance demonstration at temperatures from 5°C to 50°C.
To demonstrate the long-term stability of the couplant a test was configured that coupled a 5MHz compression mode probe and a 5MHz SH shear wave probe to a 9mm thick plate of aluminium.
For the compression mode probe the A-scan was gated to display two thickness multiples, whereas for the SH shear wave probe only a single backwall was gated. Over a four-week period, the only significant shift was seen to occur after Day 1 where the thickness of the couplant had gradually reduced to a steady state. Subsequent measurements indicated less than 1dB variation from the average peak value for both compression and shear modes.
At the time of the initial introduction of Aquabond, the test period was 30 days with the only significant change being at the transition from Day 1 as the thickness of the very viscous couplant thinned to a steady state. The test has continued and 120 days after the test started the results show no signs of instability or change. Both the compression mode and shear mode signals have remained constant.
Some suggested applications of Aquabond:
Clamp-on ultrasonic flow-meters
Long-term probe-to-wedge coupling (e.g. automated systems) Underwater shear-wave stress testing
Long-term corrosion monitoring
Outdoor applications where weathering could remove water-soluble gels
Note: Because the liquid polymer is not water-soluble, its removal is made possible with a cloth dampened with naptha or mineral spirits.
Because the liquid polymer is highly viscous, its application is best made by spreading it onto the probe surface with a knife-like blade. Pre-heating to about 40°C helps to reduce viscosity for application.
A comparison of properties:
Aquabond 100
Specific Gravity: 0.91 g/cc
Viscosity: *190,000 cps (centipoises)
Appearance: Clear amber liquid
Flash point: 150 °C
Glass Transition Temperature: -18 °C
Supports shear mode: Yes
Aquabond 200
Specific Gravity: 0.92 g/cc
Viscosity: 50,000 cps (centipoises)
Appearance: Clear amber liquid
Flash point: 120 °C
Glass Transition Temperature: -66 °C
Supports shear mode: No
*approximate value at 55°C. Note: for comparison thick molasses is about 10,000 cps and peanut butter is about 150,000cps.
The new couplant is available from Innovation Polymers under the trade name "Aquabond".
Available as sample size, contact us at innovationpolymers.ca.
