QUESTION: What type of
overlaminate should be used for fleet graphics?
ANSWER: The substrate and
durability requirements determine which type of film is best for fleet
graphics. One rule of thumb used in this selection process dictates using a calendered-vinyl
overlaminate with a calendered vinyl film and a cast-vinyl overlaminate with a
cast vinyl film. Either a cast or calendered vinyl graphic.
Here’s the reason. Similar
films typically expand and contract at the same rate. If not, the overlaminate
does not move at the same rate as the
base film, the overlaminate can delaminate from the graphic. base film or substrate. A tunnel could also
form between the two films.
QUESTION: Can I use
calendered vinyl overlaminates outdoors?
If yes, which ones?
ANSWER: Some, but not all, calendered vinyl
overlaminates can be used for outdoor applications. Generally these
overlaminates are good choices for protecting flat surfaces, such as signage
and some vehicle graphics.
1 mil polyester
overlaminates can provide economical protection for construction site signage. Safety labels and exterior graphics, which
are exposed to chemical spillage, are best protected with a polyester
overlaminate.
QUESTION: Why are polyester
overlaminates the best choice in protecting graphics from chemical spillage?
ANSWER: Graphics on chemical
tankers are frequently subjected to chemical spillage. Acids, caustics and
solvents can quickly erode the ink and clearcoating system of printed fleet
markings, as well as leech the plasticizer from pigmented vinyl, embrittling it
and causing the film to crack. Cement-truck graphics, which are easily damaged
by caustic cement and harsh cleaning chemicals, should also be
overlaminate-protected.
Although vinyl overlaminates
are usually best for vinyl markings, chemical tankers and cement trucks are an
exception. For protecting markings subject to chemical damage, polyester
overlaminating film was the best choice 20 years ago, and remains so today.
Polyester exhibits outstanding chemical and temperature resistance -- features
that also make it an excellent protective film for warning labels. But, because
polyester isn't conformable, it can't be used over rivets, corrugation or
compound curves. Furthermore, it shouldn't be used to protect such flexible
surfaces as awnings.
QUESTION: Do calendered
vinyl overlaminates protect a graphic from UV light
ANSWER: Just about any overlaminate will provide some
protection against the bleaching UV rays of the sun. So how much added life will the overlaminate
provide for a print? It depends on a lot of things. Altitude and latitude are two key determining
factors. Days of exposure to the sun is key, too. But the most important factor of all is the
ink. If the ink has problems with fade resistance, an overlaminate won’t
perform miracles. All fluorescent colors -- and even certain non-fluorescent
colors, such as magenta -- will always be vulnerable.
What really determines how lightfast
a print is, is the fade resistance of the ink itself. Period.
Some, but not all,
overlaminates provide UV protection by either absorbing or reflecting UV light.
With one type of overlaminate, substances in either the facestock or adhesive
absorb UV light. The absorbers convert UV radiation to heat, which prevents
print damage. The film's UV blockage is cumulative; eventually, the substances
reach a saturation point at which the film can't absorb any more light. The
other type of overlaminate merely reflects UV rays.
When choosing an
overlaminate for screenprinting applications, test the components before using
them in production. Because they need a thicker layer of ink, screenprinted
graphics typically require an overlaminate with a heavier coating weight of
adhesive. An overlaminate with a thin adhesive coating will bridge the edge of
the ink deposit, causing a slight, but noticeable, air pocket.
QUESTION: What is the proper
way to roll an overlaminated show graphic for shipping and storage?
ANSWER: The best advice is
to store and ship prints flat, whenever possible. This is especially true, if
you use polyester overlaminates. Generally, a flexible overlaminate, such as
vinyl, is preferred for rolled graphics.
If you need to roll a print, roll it with the printed image to the
outside of the roll. Don’t roll the print too tightly or you’ll end up with
tunneling between the overlaminate and the print. This is especially true with
constructions of media and overlaminate thicker than 15 mils. As a rule of thumb, the inside of the roll
should be no less than 12 inches in diameter.
QUESTION: What are the
differences between paper and film release liners used for overlaminates?
ANSWER: The type of release
liner used with pressure-sensitive overlaminating films can affect the finished print's appearance.
Using a paper liner, some cold glue overlaminates exhibit a mottled, or
"orange peel," pattern, which is especially noticeable over dark
colors. The mottling effect results from the adhesive picking up the mirror
image of the rough, paper surface. To correct the effect, manufacturers are
improving the paper's smoothness. Some overlaminates use exceptionally smooth paper release liners. One advantage of a paper liner over a film
liner is that it is easier to separate from the overlaminate.
Polyester and other types of
plastic release liners are perfectly smooth.
The smoothness of the plastic liners makes the adhesive of an
overlaminating film perfectly smooth.
Hence, overlaminates with
polyester liners aren't prone to mottling or orange peel. One disadvantage of plastic release liners
can be very difficult to remove from an overlaminate.
QUESTION: Can calendered
vinyl overlaminates be used for floor graphics?
ANSWER: Liability is a major
concern for retailers, graphics producers and raw-material manufacturers. If a
shopper falls on a slippery graphic, someone could get sued. Because of the liability associated with floor graphics, many film manufacturers
do not warrant the use of their
overlaminates for use in the manufacturing of floor graphics.
QUESTION: Which overlaminate
is the best for floor graphics?
ANSWER: Floor graphics is a
demanding application, pushing graphics materials to its limits. Graphics must
withstand extraordinary abuse from pounding foot traffic, dirt, grease, grit
and chemical cleaners.
Several types of
overlaminates have designed for these applications. Polycarbonate makes the
best choice for floor applications because this tough, resilient film can
withstand daily traffic, and its matte texture prevents slippage. However,
polycarbonate film is expensive. Thus,
calendered vinyl overlaminate is an economical, but less durable, alternative.
Whichever film you choose, all floor graphics should be waxed with a product
recommended by the film manufacturer to prevent edge lifting.
To ensure that a floor
graphic is slip-resistant, overlaminates are rigorously tested. The industry
standard is American Standard for Testing Materials (ASTM) D2047. The ASTM test
checks the overlaminate's coefficient of friction, the force required to move
one material over another. In essence, the test measures the traction a
pedestrian could expect as he/she walks on a floor graphic.
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.
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