Only the most fervent plastisol printers use plastisol on towels and the end product produced by these plastisol devotees is not very soft nor very absorbent. Most everyone else agrees that towels should be printed with waterbased inks, but very few people know how to do it. This article will not make anyone an expert towel printer, but it may help the novice avoid some pitfalls along the way.
Remember that you are coloring loops that can move in thier own length in any direction. This eliminates fine lines from consideration because a fine line willdisintegrate into a scattering of dots when the loops are disturbed. As a general rule, lines finer than three times the length of the loop must be avoided. Given loops 3.2MM (1/8 in.) long, lines finer than 9.5MM (3/8 in.) wide must be avoided.
SELECTING AND MODIFYING INKS
If I were not concerned about ink costs, the environment and using the safest possible inks, I might select one of the many so called waterbased inks that contain up to 40% mineral spirits because they dry a little quicker in the oven and produce prints with a very soft hand without additives.
For best hand use only transparent inks and bases and avoid pigment levels over 4% if possible. Towels are seldom printed with fluorescent colors or even with a strong black because the high pigment loading required gives a harsh hand.
Most ready for use ink such as PAVOCLEAR INKS are supplied at the proper viscosity for use on T-shirts and are therefore too thick to penetrate terry cloth enough to color both sides of loops and have a soft hand. Most must be reduced with water and some also require addition of a penetrant to achieve proper color saturation. Don’t be surprised if over 25% water (1 part water to 3 parts ink) is required. 33% (1 part water to 2 parts ink) or more may be required in Pavoclear Inks, but they can handle it and wash well. Other inks may not. Some colors such as black require more reduction than others. Start out by adding water until the press-ready ink runs off the spatula in a continuous stream after mixing. If reduction makes the colors too weak, it may be necessary to add a little pigment, but keep in mind that pigment loading of over 4% should be avoided or hand might be effected. When making inks or bases for towel printing from components we recommend approximately 2.00% PAVONINE THEZ THICKENER be used initially. Remember that when some pigments such as Jet Black S71 and Ruby Red S24 are mixed into some base the viscosity will increase so the percent of thickener can not be etched in stone.
Stencil: Water resistant.
Mesh:Use the finest possible mesh that gives adequate penetration in a single stroke. Meshes in the 77 to 110 range are commonly used.
Squeegee: 60 to 70 durometer dull, rounded, beveled or slanted sharp as required to achieve adequate penetration. A fast stroke usually improves penetration.
Reduction: Reduce with water as described in paragraph 3 under the above heading, “SELECTING AND MODIFYING INKS”.
Unmodified PAVOCLEAR INKS already contain the maximum recommended amount of Lo Crock Softener (LCS), but up to 0.5% may be added to inks after reduction with 25% water without effecting washfastness. Up to 2% LCS can be added to inks made by pigmenting PAVOCLEAR-B (PACL-B) BASE or most competitive transparent inks and bases, however, washfastness should be tested prior to making an production run.
Most printers are not equipped to overall print towels or even to print an image large enough to be effective on large towels. Some printers have found that they can get around this problem by spray dyeing the towels overall prior to printing. Towels are normally laid out with loose wrinkles or waves on papers that can be disposed of or a washable surface and then sprayed with two complementary colors from opposite low angles. The dyed towels are then line dried, fixed in laundry dryer that reaches 250ºF or higher or oven dried prior to printing. For more information on spray dyeing see the Introduction to Pavonine Inks and Systems booklet.
Towels are best dried in gas or forced hot air dryers because the loops in the terry cloth material insulate and protect the wet ink from infrared energy. Printers with only infrared dryers can air dry towels on racks or clothes lines prior to running them through the oven. Very few printers have ovens wide enough to fix large size towel prints. Printers lacking wide ovens can fix prints after air drying in laundry dryers that reach 250ºF or more.
Some printers add 1.5% or more PAVAFIX A to the ink and just air dry the towels. Please note that as PAVAFIX A stops working in less than 24 hours, as stacked towels take forever to dry, and as the binders in the ink can not cross-link until the water evaporates, air drying must be completed within a few hours of printing and prior to packing.
If you intend to get really serious about printing towels get a gas oven long enough to allow the towels to stay in it for 4 minutes without slowing production. Pole dryers are preferred by most serious towel printers.
CUSTOMER TESTING REQUIRED!
“Our technical advice and recommendations given verbally, in writing, or by trials are believed to be correct. They are not binding also with regard to the possible rights of third parties and do not exempt you from your task of examining the suitability of our products for the intended use. We cannot accept any responsibility for application and processing methods which are beyond our control, nor can we accept responsibility for misuse by you of the products or use by you of the products outside the specified written instructions given with the products. User must protect sensitive skin, exposed wounds and eyes from contact with products.”
Copyright 1998 Union Ink