Uncertainty in Manufacturing

From start to finish, manufacturers rely on process controls that are predictable, dependable and consistent. This is the only way to deliver reliable, high-quality products. Controlling adhesion and cleaning processes found throughout manufacturing operations is crucial to achieving the predictable high performance all manufacturers seek.

Certainty means different things to different manufacturers, however. No two processes are created equal nor are they found in the same place on the supply chain spectrum and therefore have varying quality assurance needs.

Uncertainty in Manufacturing Adhesion

Companies fall into one of three categories depending on where they exist in the supply chain and the concerns that come along with their differing objectives:

  • Component Manufacturers: These manufacturers are predominantly in the business of creating components that will later be assembled into a final product. They are sensitive to new and existing specifications required by their customers. The components manufactured by these companies will be integrated into a production process that will include cleaning and adhesion operations. Their customers are concerned with critical surface quality and so they have to be as well.
  • Component Assemblers: These organizations are predominantly in the business of arranging and assembling components to create a final product. Their process includes procedures such as painting, coating, bonding, laminating and printing. If the final product quality is poor due to inadequate adhesion performance, this company’s reputation suffers and costly fixes are required to solve recalls and warranty claims.
  • Vertically Integrated Manufacturers: Manufacturers who carry the product from beginning to end (fabrication to final assembly) have the task of coordinating the totality of operations so the entire organization needs to have streamlined communication around surface critical processes to ensure predictable adhesion performance. In order to scale up new product innovations to many production lines, increase agility and time to market, these companies need specifications and inspections to achieve complete
    control over their adhesion processes.

And within each organization there are two types of teams:

  • Teams preparing a new product design to scale up to production who must make considerations for mitigating likely issues that will arise.
  • Teams in production who must control every variable that can affect adhesion success.

Controlling adhesion and cleaning processes found throughout manufacturing operations is crucial to achieving the predictable high performance all manufacturers seek.

Regardless of where manufacturers exist in the supply chain, or who you are in the organization, every manufacturer has a crucial need to build assurance into their adhesion or cleaning processes.

Download your personal copy of this eBook

Predictable Adhesion in Manufacturing Through Process Verification. 

This eBook is the definitive guide to improving your manufacturing process to eliminate adhesion issues. Trust the experience BTG Labs  shares in this document to help you improve your process. 

Download your PDF by completing the form to the right. 

Define Your Adhesion Process

Manufacturers are accustomed to only thinking of their adhesion process as the point at which a coating or adhesive is applied, when surfaces interface and the curing process. Redefining the adhesion process to include every aspect of the production process that affects adhesion gives manufacturers a more holistic picture of what it takes to achieve successful adhesion. Applying this new way of looking at adhesion reveals what are called Critical Control Points. These are any point in the entirety of a production process where a material surface has the opportunity to change, intentionally or not, making either a higher or lower quality surface.

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Redefining the adhesion process to include every aspect of the production process that affects adhesion gives manufacturers a more holistic picture of what it takes to achieve successful adhesion.

Here are some important questions manufacturers are asking that get to the heart of their need to control multiple areas of their production process to ensure quality:

  • What steps in my process affect adhesion performance?
  • How can we validate that our current surface preparation process is sufficient
  • How can you predict adhesion failures in a production line before they occur?
  • Are there methods of inspecting surfaces on the production line that guarantee proper adhesion?
  • How do I ensure our adhesion process satisfies customer expectations and regulatory standards?
  • How do I guarantee that the surface adhesion and treatment processes that were developed in the laboratory are being implemented properly on the factory floor?

Define The Problem

Part of why the questions above are persistent in the minds of manufacturers is due to the problem being amorphous and ill-defined. It may be clear that the end result is paint chipping, seals cracking, adhesives not sticking, coatings applying unevenly and so on. But what’s the cause? Does the issue originate with the cleaning and preparation equipment, the quality testing methods currently used (or not used) or are the materials themselves to blame?

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The root cause of these types of problems can only be found when taking a full step back to look at the three things that need to be precisely controlled to ensure reliable, predictable adhesion and working backwards from there.

  1. Composition of the adhesive or coating material
  2. The adhesive or coating application and curing processes
  3. The composition and properties of the first few molecular layers of the surface receiving the adhesive or coating

It is common for manufacturers to have a well-established materials system which includes the adhesive or coating material and the type of metal, polymer, composite or other material. It is extremely costly to replace these material systems, but when manufacturers get desperate and frustrated because the problems are not getting solved, this could be the r oute they go down. Additionally, the processes for applying coatings and adhesives ar e well understood and standardized as well as being very expensive to overhaul. Our experience tells us that the composition of the adhesive and the application and curing process are responsible for only a fraction of adhesion failures.

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Most manufacturers are completely unaware of the third factor that needs to be controlled. Adhesion is a chemical reaction that relies on very specific conditions to be met on an extremely delicate surface of the material being bonded or coated.

Without this foundational knowledge, looking for the root cause of adhesion issues will not yield conclusive results.

Diagnosing the problem at the molecular level is the only way to truly identify the problem’s source and find a precise solution.

Manufacturers will sometimes make drastic changes to their process without thoroughly examining all three of these factors, and the consequences can be dramatic. If adhesion problems persist then failure can lead to wasted time on the part of engineers trying to remediate the issue, wasted resources thrown at solutions that aren’t based on definitive data and safety concerns around consumers using a product that isn’t reliable, exacting a huge reputational cost. Exploring the root cause narrows the scope of possible problems so cost effective, impactful, and timely modifications can be made.

Things Manufacturers Do On Their Own

Manufacturers always have the option to try to answer questions of how to ensure cleanliness, bond success and adhesion process control on their own. This seems like a reasonable approach for companies with considerable r esources, internal laboratories and successful implementation of process control methods in other areas of business. Regardless of the size of a company, though, there are several things that can be done without outside help if that’s the choice they decide to make. All of these options have offered manufacturers some favorable results and may ameliorate adhesion issues for some amount of time, but none of them are permanent fixes.

Many manufacturers have resigned themselves to the belief that scrap created by not meeting quality standards or by destructive testing methods is simply the cost of doing business. It’s true that if there are no methods in place that successfully reduce or eliminate the scrap rate then that loss needs to be accounted for and baked into the process as collateral damage. This isn’t ideal since it isn’t a solution to the problem and reducing costs through scrap rate abatement should be a goal of every manufacturer.

Accept the scrap rate

Many manufacturers have resigned themselves to the belief that scrap created by not meeting quality standards or by destructive testing methods is simply the cost of doing business. It’s true that if there are no methods in place that successfully reduce or eliminate the scrap rate then that loss needs to be accounted for and baked into the process as collateral damage. This isn’t ideal since it isn’t a solution to the problem and reducing costs through scrap rate abatement should be a goal of every manufacturer.

manufacturing-scrap-because-of-poor-adhesion

Take methods developed in the lab and apply them onto the production floor

If a manufacturer has a laboratory on site then this is a viable option. If the lab is a surface science laboratory, all the better, although this is very rare. The equipment necessary to do molecular analysis to determine surface quality at various points throughout the adhesion process (i.e. XPS, FTIR, benchtop goniometer measurements, etc.) are extremely expensive and require highly qualified surface scientists to be able to properly interpret the data. Along with the materials science expertise, it is necessary to have the support of manufacturing process experts who can successfully implement and scale up the data analysis to the production floor. 

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It is necessary to have the support of manufacturing process experts who can successfully implement and scale up the data analysis to the production floor.

Critical thinking

It is possible to thoughtfully analyze the adhesion issue without scientific equipment but this will only take you so far. You can ask questions like: how is the failure manifesting? Is it random or systematic? Is it only associated with certain parts? Is it related to the geometry of the parts? How are we evaluating cleanliness? These are all valid questions that are important to ask but often this can be where the problem-solving ends and so the problem persists.

A/B testing to perform root cause analysis

Manufacturers can take the time to isolate every single element of their production process and test minute changes against the control group to see if the variance causes the failure that is occurring. This is extraordinarily time-consuming and tedious while offering no guarantee that once the offending aspect of the process is identified that remediation steps will be clear.

Implement new cleaning and activation steps

surface-activationIf a surface doesn’t seem to be getting clean enough, manufacturers will sometimes add steps and expensive equipment into their process to try to really get the surface clean. These steps can lead to hiring whole teams dedicated to wiping a surface, purchasing primer and application equipment to apply to surfaces before paint, or buying additional parts washers or surface activation equipment that may not be necessary. All of these are expensive gambles because there is no guarantee that these new steps and procedures will actually lead to adhesion success.

Replace existing cleaning and activation equipment

Instead of looking at ways to optimize existing cleaning and activation methods, manufactures may scrap their entire cleaning process in favor of completely new equipment. The only time this should be necessary is if it can be verified that the current equipment itself is the cause of the substandard quality. Often times, the machines aren’t optimized to clean or activate a surface to the extent necessary. They could also be overtr eating without anyone being aware. Additionally, the issue could stem from surfactant remaining on the surface after cleaning with no way of detecting its presence.

Swap material systems

When manufacturers are battling against adhesion failure or the inability to clean sufficiently they will sometimes settle for a lower quality material that just happens to successfully bond or take to the cleaning process better than the more ideal, high quality material. This will often lead to product feature changes due to lower quality components, just so they can overcome adhesion issues.

swap-out-materials

Implement surface quality test methods

dyne-testing-exampleThere are many tests available to manufacturers that give an indication of whether a surface is properly prepared for an adhesion application or has been cleaned of certain contamination. These tests include dyne solution tests, the water break test, lap shear tests, peel tape tests, millipore tests, ionic contamination tests and many more. Manufacturers need to be aware of the drawbacks to these because many ar e destructive to the surface and material being tested as well as only giving a subjective r esult based on a pass/fail metric. Most of these tests have limited applicability, low sensitivity, only qualitative results and no ability to indicate the source of contamination.

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A Better Way to Gain Certainty

gain-certainty-in-adhesion-processManufacturers do not have to countenance scrap or make uneconomical alter ations to their production adhesion or cleaning process based solely on hope or partial information. Steps can be taken to ensure that surface quality control will be possible in a proposed production system or an existing one. Companies can achieve precise surface cleanliness and quality goals if they implement the following methods of process control and validation.

Identify your Critical Control Points

Critical Control Points are any point in the entirety of a production process where a material surface has the opportunity to change, intentionally o r not, making either a higher or lower quality surface. Common Critical Control Points include any time handling occurs (e.g. receiving incoming material, storage and maneuvering of materials), any cleaning or activation steps and the bonding or coating operations themselves. All of these points need to be fully controlled and manufacturers need to have a high awareness of the surface quality going into and coming out of each of these points.

Measure and understand the variability of surface quality of incoming material

Before materials even arrive in the production facility manufacturers should be aware of what they are getting. Manufacturers can test the impact of surface quality variability by running material with known states of varying quality through their process to see if adhesion performance issues occur. Once the manufacturer understands what kinds of surface quality the process can tolerate, they can then devise strategies for dealing with this variability. Some strategies include:

  • Separate out low quality material that adversely impacts the pr ocess, not allowing it to proceed.
  • Send low quality material off for additional processing to bring it up to specification (e.g. pre-cleaning)

  • Return the material to the supplier

Determining a baseline by which all downstream operations can work off of and validating that the standard has been met on arrival, sets a pr ecedent of clarity and control for everything that follows. For instance, relying on the consistency of incoming material cleanliness and quality means that if a shipment of dirtier than usual components arrives without being validated against the standard for cleanliness, the cleaning and adhesion pr ocess won’t be prepared to compensate for that difference. The whole process will have been compromised until the problem is noticed.

Determining a baseline by which all downstream operations can work off of and validating that the standard has been met on arrival, sets a precedent of clarity and control for everything that follows

Define successful performance

Much like having a solid starting point, having a clear end in sight helps bring the entire adhesion process into focus. Developing a precise metric for what constitutes success at the very end allows for each previous step to only work towards that goal. Narrowing the scope of the outcome with quantitative quality objectives provides certainty about how close or far away the process is from producing the desired results.

Use quantitative measurements to create surface quality specifications

Using non-destructive measurement devices that can be implemented directly into the production process is the best way to create surface quality specifications and monitor the life of the surface.

Knowing your number before and after each Critical Control Point is crucial to ensuring predictable adhesion.

Contact angle measurements are a highly reliable, quantitative test method for determining the preparedness of a surface for adhesion or the chemical  cleanliness of the surface. These measurements are taken by depositing a drop of liquid on a surface and measuring the extent to which that dr op expands or constricts on the surface, providing a numerical value of chemical cleanliness. Knowing this number before and after each Critical Control Point is crucial to ensuring predictable adhesion.

ballistic-deposition-to-measure-surface-energy

Don’t neglect the effect of aging on surfaces

Manufacturers need to complete a comprehensive ageing study to determine the effect of storing material not currently in the primary production process. The chemical state of surfaces is altered over time through ambient contamination or degradation of previous treatments. All of these things can have an effect on performance and must be considered when introducing these materials into the production process. The ageing study needs to provide data on how long surface cleaning lasts and how it deteriorates.

Inspect surface quality before and after surface treatment, preparation and cleaning steps

Any time a surface is cleaned (using parts washers, ultrasonic baths or hand wiping with solvents) or activated (plasma and corona treatments, abrasion or chemical etching) validation needs to be intrinsic to these steps. These operations look different depending on the industry and application the manufacturer is working in but in order to have certainty about the effectiveness of these steps it is imperative to quantitatively measure the difference in surface quality before and after. The span between the two numbers of fers crucial insight into whether these steps are fully optimized.

Enlist the expertise of a surface science laboratory

surface-scientistA laboratory staffed with qualified personnel and sophisticated surface analysis equipment are instrumental to determining the proper surface quality specifications in a truly controlled production process. Finding and leaning on the expertise of scientists who focus on the effects of surface quality on manufacturing adhesion processes is paramount to solving adhesion and cleaning issues. These are fundamentally chemical issues that originate at the smallest molecular level and therefore require the insight of scientists with an understanding of these sciences. With the help of these material science experts, companies can easily and effectively break down their process in order to implement the proper controls to achieve successful adhesion and desired surface cleanliness. Additionally, these scientists can be enlisted to conduct annual audits to ensure any new methods and equipment are still functioning properly.

With the help of these material science experts, companies can easily and effectively break down their process in order to implement the proper controls to achieve successful adhesion and desired surface cleanliness.

Equip your process with the proper inspection equipment

Setting up verification steps at each Critical Control Point requires equipment that is designed to be implemented into production processes and not merely to be used only in laboratories. The equipment needs to be able to quickly and reliably take contact angle measurements directly on the material surfaces to produce real-time data that can be used to create an audit trail of surface quality and track process drift and variation. The equipment needs to be flexible enough to inspect any surface geometry, have automated functionality, have portability and can work within processes that are already in place.

Headlight-Inspection-Surface-analyst-3001

How We Help

BTG Labs is dedicated to helping manufacturers gain the certainty they crave. Through process verification using the proper inspection techniques, equipment and data, predictable adhesion and surface quality are completely possible to achieve.

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Our approach begins with a Process Walk where our Process Experts go through a proposed or existing production line to identify the Critical Control Points and make best practice recommendations about how to properly manage these points.

Our Material Science Experts have the equipment and experience required to do extensive root cause analysis to determine the sources of adhesion issues and potential problems to avoid. They provide optimization strategies for getting the most out of cleaning and treatment equipment.

Through process verification using the proper inspection techniques, equipment and data, predictable adhesion and surface quality ar e completely possible to achieve.

For manufacturers developing new products, we help get these new processes online by ensuring validation is occurring throughout the scaling up to production. We can help determine surface quality specifications that need to be put in place at the inception of new processes. We also help characterize performance of output and offer products that monitor and verify all of these standards at each Critical Control Point.

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Next Steps

For more information about how BTG Labs works to give confidence and clarity to manufacturers, download the ebook: BTG Lab’s Guide to Adhesion Science for Flawless Manufacturing.

Reach out to us to request your free Process Walk so you can start down the path to taking full control of your adhesion process.

Download your personal copy of this eBook

Predictable Adhesion in Manufacturing Through Process Verification. 

This eBook is the definitive guide to improving your manufacturing process to eliminate adhesion issues. Trust the experience BTG Labs  shares in this document to help you improve your process. 

Download your PDF by completing the form to the right.