Engineering Checklist
Your order will process much faster and smoother if you go through and ask yourself if these points apply to you or not.
Abrasion Resistance is Critical?
If a label is subjected to abrasion, do one of two things. For roll labels, use a 1mil polyester lamination. For sheet labels, use a 1mil lamination or print from the underside of the material ("sub-surface"), as is usually done with sub-surface printed 10 mil polycarbonate for overlays. In all cases, specify the nature of the abrasion, so the design can meet the requirement.
Automatic Application?
Make sure that the requirement for automatic application is called out on a print or other specification. Specify the following: 1) the orientation of the copy, 2) labels to be rolled facing in or out, 3) core sizes, 4) whether a leader is required, 5) whether missing labels are acceptable, 5) web width, 6) slitting tolerances required, and 7) the maximum O.D. allowed.
Chemical Resistance is Critical
Specify the chemicals that the label will be subjected to. Specify a 1 mil polyester lamination, or at least specify UV cured inks, that have some inherent solvent resistance. For strong solvents, like MEK or lacquer thinner, the construction should be tested prior to manufacture.
Label Color Matches the Housing
Supply a housing to Steven Label for our permanent file, and have Steven Label generate a color tolerance set to control color. Alternatively, supply a molded chip supplied by the housing/plastic supplier against which to do the match. Do not use PMS colors.
Label Covers Something
Test the construction for opacity. Even silk screen inks will not cover an opening in a housing or a background of varying colors. Additional printing passes may be required, depending on color. When covering copy on a paper product, such as an incorrect phone number, Steven Label offers label materials with opaque adhesives designed for this purpose.
Label Fits in a Recessed Area
Supply a housing to Steven Label for our permanent file. The fit will be checked each time labels are die-cut. At a minimum, have Steven Label generate a first article die strike for approval prior to production. Do not rely solely on blueprint dimensions to assure an adequate fit.
Label is Applied to a Curved Surface
In almost all cases, the performance of the label material should be tested. The testing needs to be extended and rigorous. Do not just test overnight. Apply samples and test them over at least a week, and try to subject the samples to the humidity and temperature conditions that the product will see in use.
Label is Imprinted
Specify the method of imprinting and the ribbon, ink or pen being used. No material can accept all forms of imprinting. For dot matrix, use a fabric based ribbon like the CGL 79 (see UL/CSA approved ribbons). For thermal transfer, indicate the ribbon being used (wax or resin).
LED's or Other Aligns to Housing
LED's, even though they are part of artwork, must be fully dimensioned on a drawing. This is true of any aspect of the label which aligns to the housing, whether interior punches or copy. It is best to supply a housing for Steven Label's permanent file. In this way, critical alignments can be verified each time a label is produced.
Label Stock Has a Directional Grain
Brushed polyester, brushed polycarbonate and some mil finish aluminum stocks, have a directional grain pattern. This pattern can be used to achieve unique appearances. Be sure to specify which direction the brush should appear relative to the label shape and graphics.
Label is Serialized
Determine with Steven Label, whether the selected press will employ mechanical numbering heads or electronic printing systems. If mechanical machines, determine for the chosen machine: 1) the number of digits, 2) whether alpha characters are available 3) make sure the height and spacing fits in the chosen printing location, 4) and make sure mirror image machines are available if labels are sub-surface printed. If electronic counting is chosen, be sure to specify the counting sequence to be used. Most counting sequences index by 1 in Base 10, ie. 1,2,3,4, etc. Often, however, sequences use letters and numbers, like Base 34 which uses all letters and numerals, except I and O. In all cases, be sure to specify whether missing numbers are acceptable, recognizing that "no missing" numbers is substantially more expensive than "missing identified". Always supply the beginning and ending sequence numbers in writing for each run of labels. Use zeros with a slash through the center (Ø), to avoid confusion with the letter O.
Label has a Barcode
Specify 1) the symbol being used (usually Code 39), 2) the density (number of characters per inch), 3) the height of the code, and 4) whether a check digit is to be included, and if so, which one. If the barcode is serialized, refer to the above item on serialization.
Extreme Temperature Exposure
If the label is subjected to temperatures above or below room temperature, work with Steven Label to select an appropriate material. Vinyls and polyolefins soften and melt above 170°F. Polyesters and Polycarbonates perform well up to about 270°F. Above 270°F, special materials are required like Steven Label's Obsedion, which can withstand temperatures up to 500°F. In low temperature environments, adhesives tend to harden and loose adhesion. Several adhesives work well at refrigerator or freezer temperatures, when applied at room temperature. When labels are applied below 40°F or are eventually subjected to temperatures below -40°F, special materials will be required. Be careful to specify what the application temperature and the temperature in use are expected to be.
Outdoor UV Resistance
Special materials and printing processes are required for labels that are used continuously outdoors. Regular roll label printing processes will fade in less than 3 months. Silk Screen printing, using appropriate inks, is good for 3-5 years. Standard calendared vinyls and polyesters are rated for no more than 2 years outdoors. Cast vinyls, which are used heavily in signmaking and outdoor graphics, are typically rated for 3-5 years.
Low Surface Energy Plastics & Textured
Surfaces Certain plastics, designated as "low surface energy" materials, resist adhesion. For example, Teflon is the lowest surface energy plastic in general use. What makes it great for frying pans, makes it poor for labeling! Plastics that require adhesives specifically designed for low surface energies are Polystyrene, Polyethylene and Polypropylene, among others. High surface energy plastics include Polyester, Polycarbonate and ABS. Textured surfaces require higher adhesive coat weights to fill the hills and valleys. In all cases, be sure to specify the texture and the material on which the label is to be applied.