ASTM C 1048 states:
“7.5 Surface Particles—The production of heat strengthened and fully tempered glass involves the transport of very hot glass on conveyor rollers. As a result of this soft glass-to-roller contact, some glass surface changes will occur. Minute particles (fines), typically invisible to the naked eye, may adhere to one or both glass surfaces. These surface particles may occur from a variety of sources including, but not limited to, the glass cutting and edging process, typical manufacturing plant airborne debris or dust, refractory particles from the furnace roof, and external airborne dirt and grit carried into the plant by the large volumes of quench air used in the process. Particles on the furnace rollers may be picked up by the hot bottom surface of the glass as it travels over the particles. Surface particles invisible to the naked eye are inherent in the heat-treating process and are not a cause for rejection.”
The Glass Association of North America (GANA) has published GANA document (GANA TD- 02-0402).
Does anybody have more documentations that can help in evaluating how to accept or reject such an issue, our understanding that the presence of these particles is acceptable even if visually visible since that there is no clear criteria of evaluation.
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