Changes in your shop environment affects the dimensional stability of a vinyl film's release liner. These changes can cause a liner to curl, which can make graphics fabrication challenging. Learn why...
Would you like paper or plastic? In the sign, screen and digital markets, vinyl film manufacturers generally pick paper release liners. Plastic film liners are more frequently used for label stock. Paper liners afford many advantages compared to film liners. They are very heat stable…more stable at high temperatures because plastic can deform. Paper also provides consistent performance. Most importantly, paper liners are more cost effective than film liners.
The
disadvantage is that because it is paper, it can easily gain or lose moisture
depending on the shop environment. When I worked for screen printers, it was a
common practice to condition the stock the day before a print run to stabilize
the sheet, so it would lay flat on the bed of the press. Sheeted material was
racked face to face so the release liner could gain or lose moisture depending on the shop environment.
Changes in humidity can cause paper liners to grow or contract. When exposed to excessive humidity, some liners
can grow and curl toward the print side. When the liner loses moisture, it can contract causing the sheet to curl toward the liner side. See photograph A.
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| Photograph A. |
Regardless of which way the liner curls, it can mean trouble for printers. The solution is a polycoated release liner. Typically a
plastic resin is extruded onto either one or both sides of a paper sheet. This gives
you the best of both worlds. You can have the advantages of a plastic liner, as well as a cost-competitive paper liner. The polyolefin coating improves the
resistance of the liner to moisture absorption as well as improving the overall
dimensional stability and layflatness of the sheet, as shown in photograph B.
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| Photograph B. |
Other Factors Affect Release Liner Dimensional Stability
Other factors, however, can affect the dimensional stability of the liner during processing at the film manufacturer or when digitally printing and laminating. Here are a couple of examples:
- During adhesive coating, the release liner is exposed to heat, which can dry the liner out. Exposed to a humid shop environment, dry liners can grow and curl. To combat this problem, many manufacturers will remoisturize their liners.
- Exposure to heat can result in the liner losing moisture, which can result in the liner shrinking causing poor layflat or sheet curl.
- Mechanical tension during the lamination process can stretch the overlaminate. Stretched films tend to stretch back to their original shape, which can result in the laminated print curling.
- Printing with heavy concentrations of solvent or ecosolvent ink can result in the print curling. Solvent inks can consist of 70% or more of solvent. When the solvent evaporates, the inks contracts. This often results in the graphic curling to the print side as shown in photograph C.
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| Photograph C. |
Vinyl Application Videos
Squeegee Technique. Nothing is more basic in vinyl application than the squeegee. But some squeegees work better than others. And there are right ways and wrong ways to use this simple tool. This video clip reviews squeegee selection, squeegee care and squeegee technique. Click to Link
Wet Applications. Dry applications are typically recommended for most vinyl applications. For those exceptions to the rule, this instructional video explains the right way to perform a wet application. Click to Link
Application of Window Graphics. Installing vinyl graphics on glass can be challenging, because the adhesive aggressively grabs onto this high energy surface. Repositioning graphics on window is generally difficult, if not impossible. This instructional video explains how to dry apply window graphics right the first time. It also describes the necessary steps required for surface preparation. Click to Link
Transferring Frosted Window Graphics Films. Because frosted window films are highly textured, transferring cut vinyl graphics can be problematic. This video provides direction in selection of the right application tape and how to apply these films quickly, easily and without problems. Click to Link
3-Step Surface Prep. This instructional video describes how to properly clean the surface of a vehicle before applying pressure sensitive vinyl graphics to a trailer or doing a full wrap of a car or van. This three step surface prep involves detergent washing, solvent cleaning and a final wipe down with IPA. Click to Link
Vinyl Application Over Rivets. Applying vinyl graphics on vehicle surfaces with rivets is challenging for most sign makers. Vinyl failures to these surfaces are all too common. This video demonstrates some tips and procedures, used by professional decal installers, which will make these demanding applications easier and more trouble-free. Click to Link
Vinyl Application to Corrugations. Learn how to apply vinyl graphics to corrugations in a relaxed state. Forcing films into the valleys of corrugations puts too much mechanical stress on the film. Sooner or later, the vinyl will lift or tent in valleys. Click to Link
Applying Air Egress Vinyls. Vinyl films with air egress release liners have almost eliminated bubbles and wrinkles from applied graphics. Air egress release liners with their highly textured surface structure are problematic. Not much will stick to these liners other than the vinyl film. At RTape our best premask solution for air egress liners is a special Conform® tape called 4761RLA. Click to Link
About Jim Hingst: After fourteen years as Business Development Manager at RTape, Jim Hingst retired. He was involved in many facets of the company’s business, including marketing, sales, product development and technical service.
Hingst began his career 42 years ago in the graphic arts field creating and producing advertising and promotional materials for a large test equipment manufacturer. Working for offset printers, large format screen printers, vinyl film manufacturers, and application tape companies, his experience included estimating, production planning, purchasing and production art, as well as sales and marketing. In his capacity as a salesman, Hingst was recognized with numerous sales achievement awards.
Drawing on his experience in production and as graphics installation subcontractor, Hingst provided the industry with practical advice, publishing more than 150 articles for publications, such as Signs Canada, SignCraft, Signs of the Times, Screen Printing, Sign and Digital Graphics and Sign Builder Illustrated. He also posted more than 325 stories on his blog (hingstssignpost.blogspot.com). In 2007 Hingst’s book, Vinyl Sign Techniques, was published. Vinyl Sign Techniques is available at sign supply distributors and at Amazon.
© 2016 Jim Hingst
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