Announcing PFA+ powders Whitford takes an old favorite and enhances it with dramatic improvements in release...

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1 Announcing powders Whitford takes an old favorite and enhances it with dramatic improvements in release... Makers of the world s largest, most complete line of fluoropolymer coatings

2 PFA: The good and the bad PFA powders have been around for years, covering a broad spectrum of applications. These run from thick films for corrosion resistance that protect chemical vessels to providing long-lasting release for commercial bakeware to coating reprographic rollers. But PFA is not without problems. The three most common are (1) permeability, (2) lack of smoothness in thicker films and (3) difficulty in application. These come from PFA s inherent nature as a high-molecular-weight polymer, which means poor melt-flow, resulting in rougher surfaces and micropores both of which reduce overall performance. Introducing 150% Everything adds up to 100%. And, in nonsticks, it has always been true. Until now. It used to be that, if one wanted to improve a nonstick s durability, for example, it was at the sacrifice of its release (or some other important characteristic). Now Whitford breaks the rules (again), with new. This breakthrough not only improves the release of the original PFA, but also adds significantly to the life of the release itself. PFA plus what? Whitford R&D has been able to produce blends of PFA and other proprietary ingredients that offer properties substantially better than those of PFA itself. The blends can be adjusted to meet specific requirements by selective use of fillers, reinforcements, colors and other additives mixed in at the nanoscale level, all of which result in far more uniform powders. Not only does it offer significantly improved performance in current applications, but it opens the door to a wide variety of new applications. (at 200X magnification) is rough, with many crevasses, cracks and other imperfections that collect residue, which in turn reduces release. Dramatic reduction in surface defects (at same 200X magnification) is considerably smoother, with fewer imperfections, leaving the surface to function more freely in terms of release. Scratches, irregularities and other defects tend to trap residue, which attracts more residue. And this worsens over time due to thermal cycling and repeated exposure to foods and chemicals. So the coating loses more and more of its nonstick. A sideby-side comparison of PFA and tells more. Shown above are conventional PFA and Whitford s. Both are three-coats, with a film thickness of 150 microns. Shown below are graphs of surface roughness. The differences are obvious. surface roughness at a dry-film thickness of 80 µm surface roughness at a dry-film thickness of 80 µm Compare plain PFA s pitted profile with the relative smoothness of the. Smoothness actually improves with film thickness. The graphs were taken with Whitford s non-contact profilometer. 2

3 The laser microscope exposes the extensions caused by multiple pinholes in PFA. is virtually free of pinholes (and shows a much smoother surface). Whitford s advanced laser microscope technology makes it possible to examine surface coatings closely in three dimensions. Both of the coatings shown above are composed of three-coats, with film thickness of 150 microns, at a magnification of 200X. The images highlight the dramatic differences Improved surface topography between plain PFA and in the vertical dimension. In fact, examination of different substrates with different grades of plain PFA yields the same conclusion: tends to form deep pinholes, even when applied in multiple coats, whereas Whitford s is virtually free of pinholes and other surface defects. Penetration of a coating via surface defects has long been a cause of problems in many applications, even when coatings are applied in multiple coats to help cover up such defects. Pinholes, cracks, fractures and other defects enable fluids and gasses to pass through a coating. It s obvious that the fewer the interstitial spaces and defects, the greater the resistance to permeation and the greater the performance life of the coating. Superb resistance to permeation 3 This is one of the many advantages of. The photos above show identical panels that were exposed to dilute hydrochloric acid for 12 hours. The plain PFA was permeated, the acid caused a white blot around the drop, and the coating shows failure. The resists such permeation, with the drop of acid still erect and entirely on the surface. The coating continues to perform, unaffected by the acid.

4 surface Contact angle = 120 surface Contact angle = 130 Wetting is the ability of a liquid to maintain contact with a solid surface, resulting from molecular interactions when the two are brought together. The degree of wetting is determined by a balance between adhesive and cohesive forces. Adhesive forces between the liquid and the surface cause the water to spread across the surface, wetting it more completely. Cohesive forces in the liquid cause it to bead, minimizing contact with the surface as it puckers, drawing up into a more spherical shape. Wetting: measuring the contact angle The contact angle is the angle at which the droplet of liquid meets the surface. The lower the angle, the more hydrophilic the surface, and the lower its release. The higher the angle, the more hydrophobic the surface, and the higher its release. As the photographs above show, PFA has a contact angle of 120 degrees, whereas has a contact angle of 130 degrees. The causes the droplet to pull up and away from the surface, a reflection of the far greater release of compared to ordinary PFA. An ideal way to measure a coating s ability to resist scratches is to drag a sharp object across the coating at a constant speed and pressure (in the cases illustrated above, 400 gms), creating a groove in the coating. Topcoat Primer Scratching is the inevitable result of the abusive Greater scratch resistance Substrate 4 conditions in which many coated articles are used. As such, scratch resistance is important, since many surface defects develop into cracks, which in turn lead to loss of release and premature coating failure. The microscopic photos above (shot looking down at the two scratched coatings) show stark differences in performance. tends to fracture at the edges of the scratch, which leads to additional coating wear. shows no tearing along the edges, since the homogeneity and integrity of the coating prevent such damage.

5 Sugar water Note the blisters Tomato sauce & sugar Worcestershire sauce & sugar Soy sauce & sugar Honey BBQ sauce Orange juice In this comparison, two aluminum panels were coated. Both had one half coated with plain PFA, and the other coated with new. The panels were cured at 750 F (400 C) for 10 minutes. Six of the stickiest, most stain-prone materials were Superior release dropped onto the panels, which were baked at 400 F (205 C) for 30 minutes. Once cooled, each panel was turned upside down and tapped once lightly. The differences are stark except in one ( shows no improvement with soy sauce & sugar). The advantages of New is one of the important advances in coating technology to come out of Whitford s R&D facilities recently. It has generated significant interest among those who have tested it. Here is a brief summary of the improvements achieved with this old favorite : 1. Better and longer-lasting release. 2. Superior smoothness. 3. Virtually free of cracks, pinholes and surface defects. 4. Uniform dispersion of all additives: Pigmented powders are completely uniform in color and color density. 5. Easier to apply. 6. Application: All standard methods of applying plain PFA powder work well with. 7. Multicoats are possible: Liquid topcoats and primers are available if desired. 8. Food-contact compliant: New is FDAcompliant (and conforms to all worldwide regulations regarding food safety). How can new help solve one of your difficult coating problems? For more information, please contact your Whitford representative or Whitford directly. You can us at sales@whitfordww.com. Or, if you prefer, contact the nearest office. For details, please see our website: whitfordww.com. 5

6 How to contact Whitford Whitford manufactures and maintains offices in many countries around the world. For more information, please contact your Whitford representative or the nearest Whitford office (see our website: whitfordww.com) or Note: Patents on have been applied for on a worldwide basis. Makers of the world s largest, most complete line of fluoropolymer coatings NON-WARRANTY: THE INFORmATION PRESENTED IN THIS PUBLICATION IS BASED UPON THE RESEARCH AND EXPERIENCE OF WHITFORD. NO REPRESENTATION OR WARRANTY IS made, HOWEvER, CONCERNINg THE ACCURACY OR COmPLETENESS OF THE INFORmATION PRE- SENTED IN THIS PUBLICATION. WHITFORD makes NO WARRANTY OR REPRESENTATION OF ANY KIND, EXPRESS OR ImPLIED, INCLUDINg WITHOUT LImITATION ANY WARRANTY OF merchantability OR FITNESS FOR ANY PARTICULAR PURPOSE, AND NO WARRANTY OR REPRE- SENTATION SHALL BE ImPLIED BY LAW OR OTHERWISE. ANY PRODUCTS SOLD BY WHITFORD ARE NOT WARRANTED AS SUITABLE FOR ANY PARTICULAR PURPOSE TO THE BUYER. THE SUITABILITY OF ANY PRODUCTS FOR ANY PURPOSE PARTICULAR TO THE BUYER IS FOR THE BUYER TO DETERmINE. WHITFORD ASSUmES NO RESPONSIBILITY FOR THE SELECTION OF PRODUCTS SUITABLE TO THE PARTICULAR PUR- POSES OF ANY PARTICULAR BUYER. WHITFORD SHALL IN NO EvENT BE LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAmAgES. Whitford 2011/WC4/11