The steel mills can deliver different qualities of materials (tinplate, TSF, LTS, etc …). The prices of the products vary considerably according to their quality. We expose below the kinds of material that can be found in the market:
The products classified in “STANDARD class” do not present important defects in the whole of the surface. Some slight defects are tolerated. The entire surface of the product under normal conditions of storage and use, is suitable for varnishing and printing.
This criterion is valid for materials delivered in packages of sheets already cut to a certain dimension. The products delivered in coil may contain some defects. However, the proportion of the standard class must be greater than 85%.
The products delivered in sheets are free of holes.
The second class consists of sheets that present slight appearance and shape defects (coating – appearance – flattening …). In other words, these imperfections can come from the coating, the support or be a consequence of other manufacturing defects.
Among other defects, folded corners up to 25 mm side or other corner defects are allowed in this quality without exceeding this measurement, insulated wrinkles of 10 mm in length, thin stripes, shallow cylinder marks, slightly accented laminate direction , slight undulations of the surfaces or edges, matt areas, some isolated black dots
Its ability to varnish or print, by ordinary procedures, is not ensured on the entire surface of the plate.
The products that are delivered in second class plates are free of holes.
The third class is constituted by plates that present defects more accentuated than the “second ones” or that affect more surface. Therefore, nothing more than a part of its surface may be usable. Normally these plates are not suitable for varnishing and printing.
Tin plate that can present wrinkles, pitting, folds, joint welds, small holes, unstained areas or lack of lubrication.
Tin plates tinged all over the surface, but with a grayish and non-glossy appearance caused by the refining defect of the tin layer. Differences in thickness or other properties such as tempering, coating, etc.
Mix of leaves of different formats, thicknesses and physical properties.