Tag Archives: water contact angle
In some industries–including film and flexible packaging–dyne is the primary language. BTG Labs’ Surface Analyst uses water contact angle measurements as a fast easy, objective, and non-destructive alternative to dyne inks.
The main concern we hear from manufacturers is that both the suppliers and the customers speak dyne as their standard.
The answer is the Surface Analyst’s Dyne Mode. This unique feature takes the Surface Analyst’s default contact angle measurement and automatically converts the measurement into a dyne/cm readout, directly on the instrument. This mode allows manufacturers to maintain their investment in the dyne measurement language.
BTG Labs believes in dyne measurements, but not dyne inks. Manufacturers using dyne inks struggle with inaccuracy and subjectivity, leaving much room for error. Furthermore, because of dyne inks’ destructive nature, users can’t measure on the actual part. This leaves dyne inks virtually impossible for testing the part on the factory floor. …Read More
We’re talking about invisible surface chemistry, of course.
“Usually, the customer knows there’s something wrong with the surface, but they don’t know what,” says M&P Engineer and R&D Chemist Brooke Campbell. She and Elizabeth Kidd, our R&D Chemist and custom application scientist combine their analytical expertise with the instruments in our highly sophisticated lab; they evaluate, characterize, and optimize critical surface processes for industries from consumer goods, medical device, aerospace, and everything in between.
Using highly advanced instruments such as the XPS (X-ray Photoelectron Spectroscopy), FTIR (Fourier Transform Infrared Spectroscopy), Instron, goniometer, and of course, the Surface Analyst, the lab performed various tests to evaluate the surface. They then characterize the issue. This usually entails identifying a contamination or an issue with surface preparation. Lastly, they deduce an answer.
In some instances, Brooke explains, the customer has implemented an instrument in their manufacturing processes. All is well until they come across a batch that is out of spec. They know there isn’t a problem with the instrument, but that’s it. So, their puzzle makes its way to the M&P lab for investigation. …Read More
Roosevelt University, a liberal arts college in the Loop of downtown Chicago perfectly contrasts antiquated and contemporary architecture. Roosevelt’s first venue, constructed in 1889 just in time for the World Fair, is 17 floors of beautiful Art Nouveau structure. The Auditorium Building encompasses ornate railings and scaffolding, topping off with a regal library and a lofty tower overlooking Grant Park. However, because of its age, the Auditorium Building demands constant attention and is inefficient in the frigid Chicago winters and hazy summers.
Their new building, the Wabash Building, erected in 2012 is just the opposite. Its 32 towering floors of curved glass superintends the Auditorium Building, arriving amongst the structural giants of Chicago. Illustrating the epitome of modern design, this highly efficient, state of the art structure is LEED certified.
When looking up at the two buildings, old charm vs new-age sleek, the phrase comes to mind: they just don’t make things like they used to. But, there’s necessity behind this. As the global population rises, infrastructure becomes denser, and resources become scarce, engineers concentrate on building smarter. Designing a building that spares no expense—in terms of efficiency in operation and manufacturing of these smarter materials—is pivotal. This all begins in the research and development lab and extends to the manufacturing floor. Materials and processes are developed to allow for more efficiency in both the production of materials and the final construction. Guaranteeing bonds will hold; paint, print, and coatings will stick; seals will persevere; and cleaning processes will clean effectively is crucial to manufacturing a product that will withstand stresses of any structure.
That is why more and more manufacturers are turning to the Surface Analyst™. This hand-held instrument ensures any surface is ready for effective bonding, coating, cleaning, sealing, printing, or painting. The ability to verify and quantify critical surface processes on the manufacturing floor is the keystone to efficient manufacturing and smarter structures.
A high-grade window manufacturer, for example, uses the Surface Analyst to verify plasma treatment on vinyl window frames prior to sealing. This guarantees the windows will efficiently heat or cool a structure while also withstanding the elements of rain, wind, and snow. …Read More
This week, BTG Labs will attend the CMH-17 PMC Coordination Meeting in conjunction with ASTM D-30 in Salt Lake City, Utah. The purpose of this gathering is to present and collaborate on the latest in composite advances and standards and contribute to document updates.
CMH-17, the Composite Materials Handbook, is the go to reference and guide for aerospace manufacturers who adhesively bond composite parts. It features standard, vetted composite technologies as well as standardization for data collection and analysis of composite processes. BTG Labs maintains a strong connection with CMH-17 by presenting at working group meetings and contributing to content.
This year, BTG Labs’ Chief Scientist Dr. Giles Dillingham and Research and Development Engineer Tim Barry will attend the March meeting to collaborate and present.
Dr. Dillingham and Barry will present BTG Labs’ work to a joint meeting of ASTM committees D30 and D14.80.01 on adhesives and composites. This presentation intends to create a new standard based on BTG Labs’ Surface Analyst™, a handheld instrument which measures water contact angle in 2 seconds to ensure bonding. The proposed standard especially focuses on the instrument’s unique abilities to deposit water drops via patented Ballistic Deposition technology and image drops from above to determine the contact angle.
The water break test is a common way to test for surface cleanliness. It allows the user to test for the presence of hydrophobic contaminants, which can be detrimental to adhesion. It is usually considered non-destructive to the part because it uses only water.
To perform a water break test in accordance with the ASTM-F22 Handbook, the material is dipped in water and withdrawn vertically. The behavior of that water on the surface reveals the surface energy which is determined by the cleanliness level. If the surface is clean it will show high surface energy and the water will spread out due to its attraction to the surface. This strongly correlates to adhesion ability.
Water break is mostly used on metals to expose the presence of contaminants or after surface processes such as etching, anodizing, painting, priming, coating, grit-blasting, or sanding. However, these tests can be messy and sometimes can result in unintended contaminating due to impure water. The user must also allot a significant amount of time for the part to dry after the test. These tests require a trained user who can determine a “go” or “no go” result. This leads to subjectivity. Lastly, the test can lack sensitivity as a surface can visually appear clean, when it’s not.
In contrast, the Surface Analyst™ is sensitive to the top 2-3 molecular layers of a surface. By using a single drop of highly purified water, there is virtually no mess and no threat to the measurement surface. Furthermore, it’s a small, handheld, user friendly instrument, that has the ability to measure on almost any surface or surface orientation, regardless of shape or roughness. The automatic calculation of contact angle removes operator subjectivity. The Surface Analyst measures on a cleanliness scale as opposed to a binary go/no go result. So measurements taken with the Surface Analyst can more closely map out a surface’s characteristics.
Most Frequently Asked Questions
1. Does surface roughness affect the measurement? Can you measure on curved parts? Because the Surface Analyst uses patented Ballistic Deposition to deposit liquid drops, the user can easily take measurements on surfaces with varied shapes, orientation, and texture. While Ballistic Deposition minimizes roughness effects, if the roughness varies greatly from point to point, there can be a small effect on the contact angle.
2. Does measuring vertically impact the measurement? No. Because the Surface Analyst uses very small liquid drops, surface tension forces on the drop are much greater than gravitational forces. Therefore, orientation of the surface does not effect measurement: vertical, inverted, inclined surfaces all return the same value of contact angle.
3. How does it compare to a benchtop system? Unlike a benchtop goniometer, the Surface Analyst is portable and handheld, and removes subjectivity on the part of the operator in taking a measurement. It is designed to work on the surfaces of manufactured parts: injection molded, machined, sanded, blasted, painted, etc. where a benchtop goniometer is limited when it comes to measurements on parts with contours, shapes, and surface roughness. The precision of the contact angle calculation is equal to or better than a benchtop system.
4. What is the output of the system? What is it actually measuring? The Surface Analyst measures the contact angle of water, which is primarily sensitive to the polar component of the total surface energy. With a simple calibration curve, the water contact angle can be precisely correlated to the total surface energy. The surface energy of a material directly relates to cleanliness and to the potential to form a strong bond with an adhesive or coating.
5. What is the repeatability? The Surface Analyst has a repeatability better than 1° on well-prepared surfaces.
Water Contact Angle as a Quantitative Measurement of Surface Energy
BTG Lab’s Surface Analyst™ uses contact angle of highly purified water ballistically deposited on a material to determine surface energy. This surface energy correlates directly to a material’s ability to adhere. Contact angle effectively measures surface energy because of its strong correlation to surface energy. And, water, because of its polar nature, is a good indicator indicator of surface energy. Thus, measuring water contact angle quantitatively determines surface energy.
Water, as a highly polar molecule, is sensitive to the polar component of a surface. However, molecules on a surface bond together in two ways: by both dispersive (non-polar) and polar bonds. Ergo, total surface energy entails a calculation of the polar component and the dispersive or non-polar component of a surface. However, water contact angle is only sensitive to the polar component. This raises the question from customers:
Utilization and Road Blocks of Dyne Inks
Manufacturers often employ dyne test inks, used for measuring wetting tension, to estimate surface energy (and therefore, surface cleanliness and treatment level). If you have ever used dyne, you know that applying these inks to your surface requires experience, training, and subjectivity. …Read More