Many window cleaners believe that all abrasives scratch glass. Even if it is only very slight. This is simply not true. What is true is that window cleaners are only familiar with commercial products sold by industry suppliers. These products are based on relatively crude abrasives. Powders that have what is called a particle size distribution curve (PSD) which has a bad tail. All abrasive powders have a PSD. We don't care about the front of the curve so much. Because particles which are smaller than our optimum size will not visibly scratch. Such particles if they are as hard as glass must be between 2 to 5 microns. Particles in the tail could easily be 15 to 25 microns or more. If so these are the ones that could scratch. Especially if they form agglomerates because the formulator of the product didn't do it correctly. The question that must be asked is exactly what percentage of the PSD is at or below the crest of the curve.
We must take into consideration what is the hardness of the surface we are working on relative to the hardness of the superabrasive particles we are working with. If they are as hard as or harder than glass they must be about 3 microns at a very high purity. If they are softer than glass than they can be larger. The shape of such particles must also be considered. Particles that have an amorphous shape will much more easily cause scratches. Particles that are flat, tubular, or especially round will more likely rub instead of scratch. Every scratch begins with a Point Impact Fracture or a PIF. PIFs are much more easily created by particles with sharp edges and points. They are even more easily created by particles that are harder than glass, such as diamond. If diamond is used the PSD must be very carefully controlled and lubrication is critical.
My point through all this technology is simply that there are much more effective and higher quality superabrasive powders out there that can be used for non-routine window cleaning. When used along with the correct application techniques then the very best surface will be created. Would you like to see exactly what I am talking about? Just send me an email, text, or give me a call.
Written by Henry Grover Jr.
No comments:
Post a Comment