Posts by Emily Leporati
Today, the mobility of electronics allows us to broaden the range of when and where we use them. Consequently, electronics encounter threats such as water, extreme temperatures, shock, and contaminants. BTG Labs’ Surface Analyst™ helps electronics manufacturers build a product to stand up to elemental threats. This fast, easy, accurate, and non-destructive handheld device verifies surface cleanliness levels in order to bond, coat, and print properly on a surface.
Typical Surface Analyst Applications in Electronics Manufacturing
- Monitor cleaning processes for solder flux
- Verify surface readiness for conformal coating in circuit board manufacturing
- Ensure strong bonds on solar panels
- Guarantee bonding of print on electronics
- Predict adhesion for UV cured adhesives
- Measure cleanliness levels of silicon wafers used in integrated circuits
- Ensure coatings on composite conductive equipment
- Inspections on glass used in consumer electronic devices
Adhesive Bonding Repair
The two principle materials used in aircraft manufacturing, metals and polymers, tote particularly reactive surfaces. This leaves them highly susceptible to contamination. As adhesive bonded repairs become more and more popular in the industry, knowing and understanding surface preparation and surface habits becomes crucial.
BTG Labs’ Chief Scientist Dr. Giles Dillingham produced the paper, “Qualification of Surface Preparation Processes for Bonded Aircraft Repair,” to present at an annual SAMPE Conference. This paper discusses the use of adhesive bonding in the field of aircraft manufacturing and the importance of surface monitoring.
As metals and polymers experience exposure to contamination on the manufacturing floor and in the field, it is necessary to know and understand the relationship between contaminants and the surface. The difference between a well cleaned and a poorly cleaned surface may only be a few molecular layers, and may be the determining factor of a successful bond or a weak bond.
Webinar: Measuring Surface Energy in Manufacturing and Repair of Composites to Assure Quality of Bonded Interfaces
Thu, Jun 9, 2016 2:00 PM – 3:00 PM EDT
This interactive tutorial provides a comprehensive look at common industry practices, including typical surface preparation methods for composites and an overview of the basic scientific principles involved in measuring surface energy and how it relates to material performance in manufacturing and repair. This presentation will focus on universal methods and techniques used to measure and achieve durable and consistent surface preparation in manufacturing across all industries. Ensuring surface condition and consistency is a vital component for guaranteeing success in sealing, coating, bonding, painting, printing or cleaning.
- Common surface preparation methods and techniques for composite substrates.
- What is surface energy and why is it important to maintain and understand it in manufacturing.
- How to measure surface energy in a manufacturing or repair environment.
- Using surface energy measurements to modify surface energy, determine process optimization, and perform quality assurance.
BTG Labs will be attending the SAE (Society of Automotive Engineers) AMS Aerospace Organization Coatings Committee (AMS G-8)’s annual meeting May 3-5. Dr. Giles Dillingham and Lucas Dillingham will present on “An Integrated Approach to Quantification of Contaminant Effects on Surface Sensitive Processes.” The presentation is based on a collaboration with Lockheed Martin Skunkworks under DARPA support about a new approach at studying surface contaminants. This new approach proposes studying contaminants according to their chemical structure rather than the conventional way which studies the effects of complex contaminant mixtures without identifying and studying individual contaminants. G-8, a branch of SAE, studies adhesive bonding of composites and composes the handbook for bonding composites in aircraft, as well as the publication of the CMH-17 Handbook. SAE strives to standardize language relevant to data generation, testing, and reporting of composites. Below is the abstract for Dr. Dillingham’s presentation.
An Integrated Approach to Quantification of Contaminant Effects on Surface Sensitive Processes ~ Lucas Dillingham, Giles Dillingham / BTG Labs
The detrimental effects of a contaminant are determined by i) the amount of the contaminant in the environment, ii) the affinity of the contaminant for the critical surface, and iii) the compatibility (i.e. solubility) of the contaminant in the adhesive or coating. The most common approach for evaluating contaminant effects has been to evaluate the effect of a complex blend of multiple contaminants. Because this approach provides no information as to what makes a given contaminant detrimental, it limits our ability to predict the effect of an untested contaminant. Developing an understanding of the relationship between contaminant structure and effect can lead to more intelligent design of surface preparation processes, more robust adhesive and coating formulations, and more reliable manufacturing processes.
BTG Lab’s Collaborations
This paper, written as part of an ongoing collaboration between BTG, Southwest Research Institute, and Lockheed Martin Skunkworks. Funded by the Defense Advanced Research Projects Agency (DARPA), the collaborators examine and develop techniques for engineering a certifiable bonded method for aircraft manufacturing. The use of composites is increasingly employed in aircraft manufacturing to replace titanum and aluminum. However, composites weaken by the use of fasteners such as bolts and rivets. This is where the implementation of adhesives comes in. The understanding of surfaces requires knowledge on how an adhesive will stick to the surface and the presence of contaminants.
A New Approach
Studying the effects and habits of contaminants can be an essential step in any bonding or adhesion process as a contaminant can significantly influence the success of an adhesive or bond. All surfaces contaminate upon exposure, making them inevitable to any process. Thus, understanding the relationship between a contaminant structure and the effect it has on a bond will help develop more productive monitoring procedures for preparation processes, stronger adhesives and coating formulations, and more reliable construction.
The current method to evaluate the effect of contaminants on a surface entails examining a complex cocktail of them. However, not all contaminants in the blend might exist in a given manufacturing environment. The cocktail method fails to inform us of the effects an individual contaminant will have on a surface.
Solvent wiping and sanding procedures can greatly affect the surface energy of a substrate. To investigate the surface energy differences following different preparation procedures of an epoxy composite laminate, researchers created several different surface conditions utilizing different cleaning techniques. For this experiment, a BTG Labs Surface Analyst™ obtained measurements.
The Surface Analyst is a fast, easy, accurate and nondestructive instrument that measures the contact angle of water applied to the surface in a precise, controlled manner. This contact angle is determined by how strongly the surface energy of the substrate and the liquid deposited interact. The relationship between this contact angle and surface energy is complex, but well understood. More importantly, this relationship correlates with the adhesive strength of a paint, coating, print or adhesive to the substrate.
Adhesion and Surface Processes
Dr. Giles Dillingham, President and Chief Scientist of BTG Labs, will be teaching two short courses at the annual meeting of the Adhesion Society in San Antonio, TX on Friday and Saturday, February 19 and 20, 2016.
The courses, titled “Surface Energetics and Adhesion” and “Surface Modification and Surface Analysis,” are comprehensive introductions to the science and technology of adhesive bonding, adhesive chemistry and formulation, and design of adhesively bonded structures. …Read More
Fluid Deposition Style of Contact Angle Measurements
Measuring the contact angle of a fluid on a surface provides an accurate reading of surface energy. However, methods of depositing the droplet and measuring the contact angle vary. With this sensitive process, every detail and particularity effects the measurement.
Common surface measurement instruments, such as goniometers, use an automated syringe needle to deposit a single drop of fluid. However, the manner in which the drop of fluid is deposited greatly impacts the contact angle and entails precise control. Furthermore, the composition of fluid used effects the measurement and potentially the surface.
Alternative fluids can be dangerous to the user and contamination to the material. This often requires the use of a coupon, or sample rather than a measurement on the actual surface of the material in question. Furthermore, a single drop does not have the ability to measure on diverse surfaces.
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