Category Archives: Surface Tips & Tricks
For the past five years BTG Labs has been a major presence at the annual meeting of the Adhesion Society. This year we are heading to Hilton Head, SC Friday 2/15 – Tuesday 2/19, to share our insight into how adhesion success begins and ends at the surface of materials used in bonding.
BTG Labs’ CEO and Chief Scientist, Dr. Giles Dillingham, has been an active member of the Adhesion Society since the 1980’s and is a Robert L. Patrick Fellow of the Society. He has over 120 publications and patents and is teaching two sessions at this year’s Short Course as well as presenting at the conference during the Society Meeting.
Dr. Dillingham’s first education course on Friday will examine the basic principles of adhesion and surface chemistry: how they are inextricably codependent and what the nature of their relationship is. The concepts he’ll be discussing is the science at the heart of all the work BTG Labs does. It’s this foundation that has allowed us to build an extensive customer base within a wide range of industries to develop and enhance manufacturing processes.
The next course Dr. Dillingham will be leading takes the fundamentals of the first course and expands on them by exploring how to analyze and control the chemical makeup of a surface. The understanding that comes from the surface analysis allows for the proper control of the surface chemistry which, in turn, makes it possible to reliably predict adhesion success. This correlation between chemistry and adhesion is the fuel that powers BTG Labs’ technology.
Corona treatment is one of the most commonly used methods in adhesion processes for preparing materials like film and polymers manufactured on large rolls. Corona treatment is used to activate the surface, or create a molecularly amenable condition on the surface for adhesion, of a rolled material requiring coating, printing, laminating or painting.
The treatment works by discharging high-voltage, high-frequency electricity from an electrode in a ceramic tube that runs the length of the roll of material needed to be activated. The electricity is sent through the material to an electrically-grounded, metal roll called the treater roll, that the material is wrapped around. This interaction between the electrode and the metal roll creates a visible flash on the surface of the material roll as it moves between the two components. The results, however, are completely invisible to the human eye. Like was stated earlier, this treatment is altering the surface at a chemical level. Therefore, there is no visual test that could ever offer confidence that the treatment was successful at creating a chemically clean surface. Only a measurable, quantitative inspection gives the data necessary to take action on.
Parts washers are the heavy-duty, hardworking machines that have become irreplaceable staples in any automotive or machined part manufacturing process. As manufacturing processes have become more sophisticated, the industries using parts washers includes not only industrial metals and aerospace materials but also more delicate applications such as medical implants and electronic devices.
But what are the Critical Control Points within a parts washer system? What are the elements that get overlooked and result in adhesion failure even though the parts SEEM clean?
Co-written with Elizabeth Kidd, BTG Labs’ Custom Applications Scientist.
There’s a logical fallacy akin to a “what’s good for one is good for all” mindset that is devastating when applied to surface treatment in adhesion processes. Polymers are rapidly being developed and synthesized for niche applications to push the limits of current physical properties of materials. Polymers that are available today did not even exist a few years, or even months, ago. These different materials possess very particular molecular qualities that require distinct treatment approaches in order to compensate for their differences.
In order to utilize these cutting-edge plastic technologies, manufacturers need to be aware of the effect on the full material system – the baseline material, the adhesion, and outcome of bond performance.
The chemical make-up of the baseline material surface is where it all begins and controlling this aspect of the process can stop adhesion failure at the source. This is, however, often the most overlooked and least understood component of successful adhesion.
The pervasiveness of electronics in every manufacturing industry has provided unique challenges. Manufacturers are tasked with protecting these components
in environments that make
electronics vulnerable to even minute amounts of moisture, debris and environmental contamination.
A useful solution to this problem is conformal coating. Conformal coating is a thin (usually 25-75µm thick) chemical or polymer film (parylene and acrylic are popularly used, depending on the application) that covers an electronic component to act as a barrier against contamination and a defense against moisture. While, this capability massively enhances the protection of, and therefore the reliability of, electronics, manufacturers have been overlooking a key element to dependability in this system: surface condition.
Here are four major factors that could lead to poor adhesion which manufacturers are often unaware of the impact they have:
Plastics are ubiquitous a material as they come, and there is nary an industry that does not utilize them in an adhesion application; medical device, automotive, aerospace, consumer goods, and flexible film and packaging industries all exploit the versatility of polymers in manufacturing. Take a closer look at medical device and automotive industries and you’ll find that the same polypropylene used to make car bumpers in the automotive is also used to make life-saving implantable medical devices.
Polymers are generally chemically stable materials. While this is a desirable quality for other purposes, it is the industry’s greatest challenge to overcome for adhesion applications (coating, bonding, printing, priming and painting). In order for these materials to adhere successfully they have to undergo some type of surface activation process, like plasma treatment. This process will impart chemically reactive groups on the surface and increase chemical reactivity. This reactivity is a quantifiable material property called surface energy. Plasma treatment is a convenient, cost effective means of achieving surface activation of polymers. Before the plasma treatment can accomplish the proper activation of the surface, the chemistry of the polymer must be considered.
This week BTG Labs and Plasmatreat got together to co-present a webinar that de-mystifies plasma treatment as it relates to polymer chemistry.
Understanding surface state at each manufacturing step will allow you to gain complete control over your surface treatment and bonding operation. Here at BTG Labs, we provide a process control check that quantifies that surface state with a simple number.
Control the process, control the number, control the product.
When a material begins its journey through a manufacturing process it becomes crucial to know and control everything that happens to that material as it makes its way down the line. There are two major factors to consider when understanding and controlling what happens to the surface of that material: the actual physical space of the warehouse and the time it takes to get through the entire process of being bonded, coated, painted, sealed, glued or printed. If you don’t know precisely what is occurring at each Critical Control Point and you don’t continually monitor the surface throughout the duration of the process, you could be trending towards adhesion failure and not even know it.
Ever wonder what a hungry BTG Process Engineer is pondering while preparing the turkey for the feast of gratitude to be shared around the Thanksgiving table? The sharp minds at BTG Labs are ever vigilant in the quest for a surface state properly prepared for the task at hand; whether that be parylene conformal coating, interfacial bonding of composites, catheter coating, or turkey roasting. For the application (turkey) to be a success (taste good) there are Critical Control Points that must be closely monitored throughout the process (roasting up the bird).
What is a Critical Control Point?
A Critical Control Point (CCP) is any point in the manufacturing process where the surface condition of a material has the opportunity to change—intentionally or unintentionally—and impact adhesion, in a positive or negative way.
Why should you care about them?