Tag Archives: benchtop goniometer
A Frequently Asked Question BTG Labs Decided to Answer
When measuring and quantifying surface energy, a common question arises: “Does roughness impact contact angle measurements obtained by the Surface Analyst?” While there exists some studies and speculations, this was still a grey area. So, BTG Labs decided to take matters into their own hands. The Materials & Process Specialists at BTG Labs constructed a research project to study the effect–or lack thereof–of roughness on contact angle measurements.
BTG Lab’s Scientists used a Surface Finish Comparator. This nickel plate containing 21 panels of varying roughness and texture is representative of surfaces typically encountered in manufacturing processes. The Surface Analyst showed no correlation of contact angle with roughness. …Read More
The Study of Goniometry
Contact angle goniometry is the study of the characterization of liquid/solid interactions. The first benchtop goniometer designed at the NRL (U.S. Naval Research Laboratory) served as a monumental advance with a way to measure contact angles to measure surface energy. Today, more and more companies are realizing the need for surface monitoring as the use of bonding is replacing mechanical fastening within manufacturing. In order to reliably bond, a clean surface is necessary. Thus, measurement of surface energy is important when bonding, coating, sealing, printing, painting, or cleaning. But, the standard benchtop goniometer has its limitations, rendering it less than ideal in a manufacturing setting where surface preparation is key to bonding.
Limitations of the Benchtop Goniometer
While the benchtop goniometer is an acceptable instrument for use the lab, its size and measurement technique create limitations for use in other settings. Moreover, the process in which the goniometer measures surface energy only applies to smooth, flat surfaces. This obviously has its set backs on the production floor as manufactured parts can have rough or curved surfaces. To measure surface energy, the benchtop goniometer uses a syringe to build a bead of liquid which is touched to the surface for deposition. The user then measures the contact angle from a horizontal profile by visual examination. This technique requires significant training and leaves plenty of room for human error. Thus, the benchtop goniometer primarily applies in a laboratory setting with minimal environmental variables and thoroughly trained users. …Read More