DECAL
PROCESSING GUIDE
Recommended Processing Techniques
for all Decal Films
DECAL PROCESSING MANUAL Table of Contents
Subject Page
Introduction 2
Storage of Vinyl 3
Installation Tools 4
Selection of Application Paper 5
Screen Printing 6
Die Cutting 7
Substrate
Substrate Preparation Installation Considerations
8
Application Procedures General
Corrugated Sections and Weld Seams Cold Weather Installation
Hot Weather Installation
9 10 11 12
Cleaning 13
Removal 14
INTRODUCTION
This manual is intended to describe the best practices for installing Arlon Vinyl Film Products 22T, 52P, 67A, 70A or 72A as screen printed or die cut decals on flat and corrugated painted steel container walls and doors.
Material description and basic behavior:
Vinyl decals as a class, are composed of polyvinylchloride (PVC) vinyl film, coated with pressure sensitive adhesive and carried on a silicone coated release liner. Two major subclasses of decals are divided by vinyl film type: cast and calendered. Briefly the difference between cast and calendered films are thickness, flexibility and thus conformability.
Cast film is 30 to 40% thinner than calendered film and much less stiff, which gives it an edge as regards remaining fixed to surface irregularities such as rivets, corrugations and weld lines. Other differences, such as better overall life
expectancy for cast film and better abrasion resistance for the thickest, most highly engineered calendered film (72A type) are important to specifiers but have little effect on converters and installers.
The adhesive coating is sticky to the touch and requires only adequate pressure to achieve permanent bond to its intended surface. This pressure is usually achieved with a squeegee although brushes and automatic laminators are also used in certain circumstances. The thicker and more rigid the film the more pressure is needed to make complete contact between the adhesive surface and substrate. Alternatively, thicker film is easy to handle and, due to its stiffer nature, easier to install.
Finally, the silicone coated paper release liner serves to protect the sticky adhesive from contamination, provide a stable surface for sheeting, die cutting and screen printing as well as easy removal at the time of application.
Both vinyl and adhesive are affected by temperature: the vinyl becoming soft and easily stretched at high temperature and conversely very much harder and rigid when the temperature drops. The adhesive becomes very tacky at high
temperature but paradoxically loses ultimate adhesion. In fact heat guns and flame torches are used to warm film and assist in removing decals. Understanding this heat sensitivity allows fabricators and installers alike to adapt to changing weather conditions and continue using these materials through winter and summer extremes.
Release liner is based on paper which has been first coated with either clay or polyethylene followed by silicone to provide easy separation from the adhesive. The various coatings of the liner effect cost, performance and environmental stability. The most useful and easiest to process of these paper based release liners is heavy paper coated on both sides with polyethylene and finally coated with an “easy-release” silicone; they are also the most stable. Known as “polycoated liners” these are the premier release liners for decals. The best among these provide little edge curl, easy die cutting and high strength which allows accurate and tear free backslitting as well as security against liner ripping during installation.
Liners are sensitive to wetness and environmental humidity. A release liner which has been allowed to get wet is ruined, even when redried. Polycoated liners are less sensitive than less expensive clay coated types.
All processing steps and recommendations as well as installation techniques are derived from observation of production methods and subsequent success or failure of the created markings, lab testing and failure research conducted at the Arlon research facility in Santa Ana, California and major container fabricators or converters. While decal production and downstream processes: welding, painting and location of decal installation station in any particular fabrication facility may differ from site to site the basic properties of the decal film, adhesive and release liner described herein remain constant and relative to all converters and end-users.
STORAGE OF ARLON® VINYL
Vinyl on Rolls: Vinyl product stored at controlled conditions will remain flexible and retain high tack for at least a year after purchase. Arlon employs the “first in, first out” inventory system and strongly recommends this to distributors and end-users. No matter what storage conditions exist it is important to consume materials promptly, avoid mixing old and new lots, protect film from excessive ambient moisture and ensure roll edges remain flat and unwrinkled. If product is certain to be on the shelf for an extended period before being completely consumed, then store it in the coolest part of the facility and control relative humidity near 50%.
In addition storage position and location in the warehouse or rack is important for other reasons. As all vinyl materials are laminated to paper based release liner care must be taken to keep them from direct contact with concrete floors or unsealed exterior concrete or masonry walls. If rolls are stored out of their protective box, it is important to store them upright with space between roll and floor. This prevents the development of mottling (dulling) at points of contact with either the floor or adjacent rolls.
If excessive direct moisture contact occurs with graphic film, the following damage may follow:
• The liner will expand at the location of moisture contact, causing surface mottling.
• The silicone release coating on the liner may delaminate or become inconsistent and cause difficult weeding.
• The paper will tend to curl or become “wavy” when it is unwound. Curled product edges make automatic sheet feeding, screen printing, die cutting, weeding, laminating with application tape and back slitting very difficult.
Recommendation:
• Keep the product cool and dry (preferably in its box - this also helps with color and lot number I.D.).
• Do not lay a roll directly on its side for extended periods.
• Use product in order of delivery.
• Never expose product to wet conditions even for a short time. If the product becomes saturated while on the release liner it will not process properly, even when re-dried.
Finished Graphics: Store cut and masked graphics flat, in a clean, dry, cool place. Never subject fabricated graphics to moisture, excessive humidity, direct sunlight or temperatures above 38°C (100°F). When the application paper is left on a decal outdoors for any significant time it will permanently bond to the graphics. Finished graphics should be stored flat, rather than rolled to prevent the plies from delaminating and forming bubbles or wrinkles. If rolling is needed for transport then roll loosely with the graphics facing outward and liner inward. This will reduce the amount of tunneling or separation between graphics and release liner.
INSTALLATION TOOLS
Before starting an installation it is best to have the appropriate tools handy to avoid interruptions during the application.
Starting and stopping midway through sign fabrication can be costly.
• Plastic squeegee (~5 x 7 cm) – Lidco www.lidcoproducts.com
• Low friction sleeves for squeegees – cloth or application tape
• Masking tape - 2.5 cm (1 inch) rolls
• Marking pencil – Thick leaded carpenter or wax type
• Lint-free rag
• Cleaning liquid: Isopropyl alcohol/water blended @ 1:1 ratio in spray bottle
• Razor knife
• Short bristled “Rivet” or weld line brush
• Tube of clear edge sealant – silicone or acrylic
Squeegee Note:
Plastic Squeegees are to be the medium soft nylon type with tapered blades and must be kept straight and nick free.
When the edge of a squeegee blade becomes deformed or nicked wrinkles and bubbles are created during installation.
Squeegees may be wrapped with cloth or application tape in order to reduce friction but the thickness of the wrapping should be no more than three wraps deep. More wrapping will reduce the amount of blade edge pressure to the extent that it is impossible to assure adequate contact with the painted surface.
Installers who soak the edge of a squeegee with silicone sealant to improve application speed risk transferring the silicone to the face of the vinyl. Use sealant to lubricate squeegees only when applying against transfer tape – not unprotected vinyl.
SELECTION OF APPLICATION PAPER
Once vinyl is die cut and weeded, application paper (also called transfer tape, premask or prespacing tape) is applied over the remaining film. This application paper serves many purposes. First, it protects the surface of the vinyl from damage during storage and installation. Secondly, it serves as a stabilizing medium with which to transfer very flexible, easily distorted vinyl from the liner paper to the substrate.
Application Tape is made of thin paper tissue for both cost and performance reasons. Paper provides obvious advantages in that it is compatible with many stages of sign fabrication. One can write on it easily for registration marks and it is more compatible with wet application techniques should that type of application be encountered due to paper’s ability to absorb and transmit water to the graphic face. Wetting may be needed in certain circumstances to reduce adhesion between the vinyl film and application tape, making it easier to strip the application tape away from the applied graphics without lifting the graphic.
Proper lamination of application paper or film is a relatively simple procedure. Although this seems to be a minor step in the production process, adherence to a few basic rules can help avoid major installation disasters.
1. Take the time to select the right application paper for your shop. This will require some simple comparative tests. For example, application paper comes with either low, medium or high tack adhesive. Choose a tape which bonds sufficiently to lift the graphics off the liner. After the graphics are applied, the application paper should remove easily without tearing. In short, select an application paper that is easy to use over a wide range of films and substrates. When winter temperatures arrive and cause the decal adhesive to lose initial tack it is a good idea to select a lower tack application tape which will not lift the graphic when stripped away.
The table below gives a rough comparison among two of the several brands of application tape on the market. In addition to those referenced below are Main Tape and 3M Brand.
F
2. Use a single sheet of application tape to cover a vinyl graphic rather than trying to get by with overlapped pieces of tape. Overlapped application tape results in a line of small bubbles at the overlap during final installation.
3. Take care in applying application tape to a vinyl graphic. Wrinkles and bubbles caught in the application tape result in wrinkles and bubbles in the installed vinyl. Also, avoid stretching the application paper, this helps prevent poor graphic registration and wrinkles and curl.
When removing graphics from liner, lift away slowly. Be sure that the tips and leading edges of the graphic film do not remain with the liner. If the vinyl has trouble separating from the liner a method for easier removal is to turn the graphic upside down (so the graphics are face down) and strip the liner away from the graphic on the workbench.
American Biltrite
Inc.
R-Tape
Corporation Best for
Made in USA USA
Low Adhesion 6560 4000 Cool Weather
Application Larger Graphics
Mid Adhesion 6582 4050 Cool Weather
Application
Medium Sized Graphics
High Adhesion 6592 4075 Warm Weather
Application Small Sized Graphics
SCREEEN PRINTING
Arlon always recommends customer’s determine which inks are most suitable for use depending upon not only ink adhesion to the base vinyl, but on effective processing through the desired screens, color matching ease, and the ink effect on tack and shrinkage of vinyl.
Ink and Clear Coats which Arlon has determined will give good performance on its’ vinyl are as follows:
Supplier Ink Clear Coat
Sericol PY APR
Manoukian Thermoplus, Type 49 Thermoplus
Chaiyaboon GVPL 0892
No matter which inks are used Arlon recommends the screen printer perform a simple test for each batch of ink and vinyl that are to be combined to determine how well they adhere. This test is referred to as a “*snap test”, is quite easy to do and uses rather common materials.
The screener prints a test block approximately 6 cm X 12 cm on the intended vinyl through a 180 mesh screen, dries the print at 78°C (158°F) for 5 minutes, allows the sample to cool, then using a special tool or razor blade scribes several 2.5 cm lines parallel and approximately 1mm apart across the web and again perpendicular to the first, creating a
crosshatching pattern. These scribe marks are only meant to cut into the ink layer, not the base film.
Once the crosshatched pattern is made the tester affixes a specific tape and snaps the tape away from the printed vinyl.
The bond between film and ink is said to be adequate if very few of the scribed blocks of ink come away with the tape.
There will be a certain amount of ink dust and shredded ink form the scribing process that comes away no matter what.
This is simply a surface effect and not cause for concern.
Due to the wide range of seasonal humidity, paper release liners are typically protected against moisture sensitivity by various barrier coatings: usually polyethylene or clay. Polyethylene coatings assure first rate processing ease due to the superior ability to stay flat throughout the process steps from sheeting through final masking and backslitting. Polycoated papers also handle better during decal applications as they provide greater strength while installers quickly strip the initiating release liner band on the work bench in preparation for installation then later peel away the remaining liner from the partially attached decal. Weaker papers often rip or split causing installers to lose time and create scrap.
During the printing process use only the manufacturers suggested thinning solvents and never exceed recommended levels. When inks become too thinned they suffer from a wide range of defects. Not only do they lose color and hiding power the wet ink does not dry adequately or achieve good bond to the vinyl. Even in the event that the thinned ink is completely dried, ink flexibility and durability are compromised.
Arlon recommends jet drying through a forced air oven with racking between passes to ensure the solvents are
completely removed between each color pass. If the ink and film remain saturated with solvent between color passes both components suffer: the ink will rewet and stick to the reverse side of the release liner when stacked and possibly
delaminate when application tape is removed while the film and adhesive may either shrink badly or bubble when installed.
*ASTM #3359
CUTTING
All decals must be die cut in preparation for masking: in some cases the release liner itself will be backslit in preparation for installation. Cutting may be either kiss (thermal or steel rule), complete perimeter die cut or square guillotine cut depending upon the decal application. Back slitting of liner will always be done via a rotary razor knife wherein sheets of decal are passed under an adjustable rotary razor edge.
Steel Rule Decal Cutting
• As with printing it is important to use the strongest, flattest release liner one can afford for all cutting operations – in most cases this means polyethylene coated paper. The advantages of release liner thickness and strength are many, but the most obvious is that it is very forgiving of minor inconsistency in the calibration (adjusted through shimming) of the die cutting plates, and die blade edges. During the initial setup adjustments will be made to optimize the cutting depth across the face of the decal. The best shim stock to use is very thin but hard paper of less than 25µ gauge. This allows for fine calibration of the backing plate and very uniform cut depth. When many copies of a decal are to be produced it is to be expected that slight distortion of the backing plate will occur. In this case the vinyl will begin to weed with difficulty and finally become impossible to weed at certain locations along the cutting perimeter. Additional shims will be needed in those locations. It is often better to set-up the die with slight penetration of the cut into the face of polycoated liners rather than having to constantly adjust during the die cutting operation.
Thermal Die Cutting
• Liners also have an impact on thermal die cutting where the sudden change in temperature as the die plate approaches the film can cause the liner to pucker and curl: this action will ruin registration of the cut and loss of the decal. Moisture stabilized liners are a must where thermal die cutting is required.
• Thermal dies cut vinyl on the basis of dwell time and temperature. Usually the contact dwell time is less than 1.5 seconds and magnesium die plate temperature between 105° and 120° C, (220° and 240° F) for best results.
Many operators use lubricant to facilitate removal of cut materials. It is important to restrict the use and amount of lubricants since they will contaminate the face of the decal and cause transfer paper to fall off the decals.
Backslitting
It is important to set-up a backslitting run with very sharp and uniform razor knives and make fine adjustments to the pressure using a test piece of decal.
• Rotary blades used for backslitting tend to dull prematurely when slitting uncoated kraft type paper. This will cause problems during application, such as tearing and shattering of the paper when the liner is rapidly stripped away. Again, polycoated liners do not create such issues.
SUBSTRATE PREPARATION
Before installing graphics a clean substrate is critical. Although many cleaners do an adequate job, some outperform others for specific applications. Based on our experience, recommendations for final cleaning are the following
:
Substrate Cleaner
Painted Metals Isopropyl Alcohol a.k.a. Isopropanol
@ 1 to 1 mix with water.
Large Panels on Vehicles Degreaser, if needed, then IPA and water mix.
See Riveted Application for details.
Note: It is common to think that strong solvent will be the best cleaner for surfaces that are hard to stick film to. In the case of many plastics and paints this is wrong. Cleaning with strong solvent such as MEK and acetone can lead to premature sign failure via embrittlement, cracking and crazing or loss of gloss.
Use the mildest solvents possible - only clean until the surface dirt is gone.
Paints: All paints should be dried and cured before installation of decals.
As many container paint coatings are solvent carried, (thus dehydration activated) the ratio of solvent to resin of the wet paint must not vary without increasing the drying cycle. If more solvent is added to reduce viscosity and improve spray atomization then the subsequent finished coat will be too thin as well as take much longer to dry than with the proper solvent ratio. Similarly heat and ventilation during the entire drying process must result in a consistently dry and cured paint coating. It is important to remember that paint continues to cure after exiting the drying ovens – even after becoming dry to the touch or “tack-free”. Ambient temperature, steel temperature and relative humidity are the key factors to consider. All these affect the rate of paint drying and cure; both in the ovens as well as in the important minutes between leaving the oven and decal application. During extremes of high humidity or low temperature precautions should be taken to be sure that paint is well cured before application of decals to avoid decal failure.
High ambient humidity will delay drying, both oven drying, as well as the post-curing process when containers leave the drying unit. When decals are installed over incompletely cured paint they will quickly lift over stress areas and edges.
It is unlikely that an alcohol/water wipe will completely eliminate all latent volatiles in the paint coating but it will remove those condensed directly on the surface. Adhesion may improve enough through such a surface wipe to allow complete bonding of the film upon squeegeeing. Other options are listed on page 10.
If a failed decal is stripped off rather than repaired it will be noticed that the film has become rubbery due to solvent attack from the paint. It is also very common to remove a failed decal and replace it with another from the same batch of decals and find that it adheres well – this is because the paint has had a chance to completely outgas and cure.
APPLICATION PROCEDURES
Rule of Thumb:
Only make substrate contact with the area of film to which you can apply high-squeegee pressure. While squeegeeing, work in the direction of the corrugation or weld line from the center, outwards, toward the edge in overlapping strokes.
Air is easily trapped between the surface of the adhesive and sign. A sign installer who squeegees toward the nearest edge will find that the possibility of air entrapment is minimized.
Overlaps:
When sections of vinyl are joined the overlap pattern should be with the upper or forward section overlapping the lower or rearward. This will allow water, snow and dirt to run off rather than accumulate on the exposed edges.
The Method
1. To create a uniform overlap, first tape a cutting strip onto the substrate. A 5 cm (two-inch) piece of thin steel at 1.6 mm inch (1/16inch) thick is a good dimension for a cutting strip.
2. Lay both pieces of vinyl over the cutting strip.
3. Place a metal straight edge where the two pieces of film cover the cutting strip. With a sharp utility knife, cut through all layers . 4. Remove the straight edge, excess film and the cutting strip.
5. Complete the squeegeeing procedure to create a proper overlap with uniform and straight edges.
Joined sections of film should overlap at least 1.6 mm”.
DECAL
1st Stroke 1st Half 2nd Half
Installation On Corrugated Container Walls
General: As the valley of any corrugation is a place of high stress the decal must be installed with minimal application stretch or bunching. Never bridge the angle of a corrugation then stretch the film to make contact – the memory of the film will exert too much force on the adhesive and the film will lift away from the angle.
Steps:
1. Remove the center band of release liner to reveal the adhesive and locate the graphic at its two upper registration marks. Whenever possible locate the first squeegee stroke over the high section of a corrugation as there is less chance of developing wrinkles or bubbles as compared to when the first squeegee stroke is in the valley of a corrugation. Pass the squeegee over the center line parallel to the direction of any corrugations or weld seams.
Starting from the center of decal squeegee with each stroke overlapping the last, proceed toward the nearest edge. The vinyl should be draped over each corrugation rather than bridged then pressed into the valleys. Vinyl installed by exaggerated stretching will inevitably pop back off the surface and the graphic will quickly fail.
Complete installing each entire corrugation row before moving to the next in order to avoid wrinkles and retain proper material registration. A final stroke along the inside angle (valley) of a corrugation with the edge of the squeegee will insure all bubbles are located and the vinyl has made good contact. This is a critical step.
2. Weld seams will be installed similar to corrugations with one exception. Due to the uneven shape of a weld seam a plastic squeegee will not force complete contact of the vinyl to the painted surface. A softer tool, such as a hard bristle brush must be used. After initial installation with the squeegee edge along the weld line and the application paper has been removed the brush should be used to burnish the decal completely in place. It is recommended that the edges of the decal crossing over a weld seam are to be sealed with a dab of clear silicone or acrylic sealant. The sealant is never to be forced under the edge of decal but smeared from the decal over its edge onto the painted container.
3. As fasteners such as screw or rivet heads are encountered they should be dealt with in four steps.
• Sweep over rivet heads with the squeegee at a low angle while applying. Make sure the squeegee covers the entire head of the rivet or wrinkles will develop at the edge of the rivet. At this point the rivets will be covered with a loose dome of application paper laminated to vinyl and must be fixed securely to the whole surface of the rivet and surrounding panel. Remove application paper; slowly pulling away from graphics at a low angle.
• Punch holes around the rivet, press vinyl in place at ambient temperature with a rivet brush.
• Secure the vinyl around the rivet with heat of 150°C (300°F) and rivet brush using a circular motion.
Cold Weather Installation
Decals are best applied at temperatures between 10º and 35ºC (50º and 95ºF). In this range the tack of the adhesive is high enough to attain high instant bond to painted surfaces but not so high that repositioning is difficult. In addition the PVC film itself is elastic enough to take the shape of textured surfaces without cracking but not so soft and malleable that stretching and distortion are a problem.
The low temperature installation limit is about 5ºC (40ºF). As one approaches this temperature film becomes increasingly stiff and adhesive loses more and more tack. In fact when temperatures fall below –5ºC there is almost no tack left and decals will not stick at all. At this low temperature (air or substrate) adhesive will not “wet – out” or flow to the paint surface enough to remain in place either when removing the application tape or as a long term decal. Without adding heat at some point during the installation cycle or waiting for a long period between application and application tape removal the decal will lift away during installation or soon afterwards. Heat may be applied to the decal or the container itself prior to installation or the container between installation and application tape removal. Once the film is successfully applied to the container the service temperatures are –40ºC to 93ºC.
Preparation techniques for installing decals in cold weather can be found below:
Low Temperature Strategies:
• Heating Stock
While there are many methods to improve low temperature application success, the least effective is to heat the vinyl film. However, by using an electric blanket or heating pad placed on top of the stack of decals it is possible to warm the stock right up to the point of installation. If only small improvements in tack level are needed this may be all that is required.
• Heating Container Prior to Installation
Using electric heat lamps stationed one meter away from the work surface at one station before the application location on the assembly line (or passing a heat gun across the work surface) enough heat can be transferred to the container that the temperature will rise 10 to 20 degrees quickly. While the temperature will not remain elevated long it will allow installation and removal of application tape to proceed without delay.
• Heating Graphics After Installation
Passing a heat gun over the surface of the applied film while resqueegeeing will generate enough adhesion to allow application tape removal immediately after the graphics have cooled back to room temperature.
• Using Lower Tack Application Tape
Purchasing application tape with a lighter tack level will reduce the lifting forces on the applied decal and reduce the amount of decal delamination.
• Reducing Tack of Application Paper on Site
Just prior to removing application paper, lightly spray a water/liquid soap mix (99 to 1) uniformly across the decal. Wait about 30 seconds for it to soak through. Remove the paper at a low angle to the surface of the container in the direction of the weld or corrugation lines. The bond of application paper will drop enough to remove it from the decal without pulling the decal away.
• Time
Allow vinyl a longer dwell time between decal installation and removal of application tape.
Hot Weather Installation
During summer periods when humidity and temperature rise it is important to adjust both container paint conditioning and installation technique.
Container Conditioning:
Background:
Paint viscosity is affected by heat. This is due to the increasing resin solvating effect of the any carrier solvent as
temperature rises with effect of paint resin expanding and of course a subsequent viscosity increase. It is common for the paint mixing technician to continue adding solvent until paint viscosity is reduced to the proper level for best spray and leveling characteristics. While added solvent does indeed improve spray processes it also upsets the drying and curing balance of the paint in the paint drying oven for two reasons:
1. In response to the lowered resin solids level in the adjusted paint and in order to achieve the specified cured paint thickness more wet paint is applied. As the wet film thickness increases drying takes longer in both the oven and post oven drying process.
2. Also in response to the lowered solids level a greater amount of time at temperature will be required to cure an equal amount of wet coating; since the amount of wet coating will be increased to achieve the specified dry coating thickness the drying time will increase even more.
Solvent based paint “cure cycle” is determined by temperature and humidity in both the drying oven as well as during post-curing. The higher the relative humidity at a given temperature the less effective will be forced air passing over the wet paint at evaporating away the solvents which carry the paint and give it the proper spraying, atomizing and leveling characteristics. Similarly, the drying which continues to occur when the container leaves an oven will also be slowed when humidity rises.
The net effect of higher heat and humidity as it applies to the success of graphic installation is that if no adjustments for increasing the solvent removal from the paint before the graphics are installed then those solvents that remain latent in the paint will prevent good adhesion as well as degrade the vinyl film itself.
A good indicator that paint curing is not complete enough during installation is that the decal will lift at the edges or blister within a day or two of installation. Lifting often occurs along weld lines and the valley of corrugations since these are areas of highest tension but in extreme cases it can happen anywhere on the decal.
To overcome this problem one must create a drier paint film, whether in the drying oven or afterwards. On the other hand it is important to avoid installing on a very hot container. Taking the three possible factors, paint, drying oven and post- oven curing conditions in order, some options are as follows:
1. Paint
Resist using more solvent than absolutely needed to achieve specified viscosity in both the primer and finish coat.
When adjusting viscosity use only the “diluent fraction of the solvent package” rather than both solvent and diluent: this will reduce viscosity more effectively thus keeping the resin solids level higher and diluent evaporates from the resin more easily than the solvent during the drying process.
2. The Drying Oven Cycle
Increase air velocity, temperature and oven dwell time in small increments so both “time at temperature” in the oven, as well as temperature during the post oven curing cycle are increased.
CARE AND CLEANING OF DECALS
Graphics manufactured using vinyl provide the maximum durability available today. Proper care of these graphics is critical to achieving the ultimate life and appearance of the overall decal.
When cleaning vinyl graphics, always use a liquid detergent and water mix. The cleaner selected should be free of strong solvents such as MEK and acetone, as well as highly acidic or alkaline pH.
When preparing cleaning solutions always follow the manufacturer’s instructions for proper dilution and safe use.
Cleaning Procedures:
Manual Cleaning:
• Using clean water, spray the graphics to remove loose dirt.
• Using a mild detergent, wash the graphic with a soft brush, rag or sponge. Never use a hard bristle brush.
• If tar or oil remains on the graphic, clean with a rag moistened with mineral spirits or a citron based household cleaner. Wash again with detergent and water.
• To remove mold and fungus, use a solution of one part household Chlorine Bleachand 30 parts water.
• Finish all cleaning processes with a rinse using clean water.
Pressure Washing:
Vinyl is easily cleaned using pressure washing – but it can just as easily be damaged by improperly handling the water spray or incorrectly blending the cleaning solutions. In order to keep from degrading the vinyl or lifting the edges of the film during pressure washing, it is important to remember the following rules of thumb:
• Nozzle pressure should never exceed 91 kg/cm2 (1,300 psi).
• Water temperature should not exceed approximately 60°C (140°F).
• Nozzle tip should never be closer than 1.5 m (5 ft) from the graphics.
• Angle of water spray should be no shallower than 60 degrees from perpendicular.
• The detergent solution should always be blended with water at the correct ratio – a more concentrated solution can damage both the adhesive and the vinyl.
• Fresh-water rinsing of the cleaned area will prevent streaks and bleach stains from developing later.
REMOVAL OF GRAPHICS
Equipment:
To soften the film and the adhesive a heat source is needed. A propane torch or industrial heat gun will suffice for removing small letters and graphics. For removal of full coverage container graphics use a large torch with soft (red orange) flame.
Film Removal:
Warm the vinyl with a heat source. Keep flame moving to prevent burning the vinyl or the substrate. This heating process softens both film and adhesive. Once film is warmed, pick up an edge and pull the film from the vehicle’s surface at a 15° to 85° angle. If the temperature is too hot, or angle too obtuse film will separate from the adhesive.
Note: Selection of heating method should be based on location of de-identification station and proximity to flammable materials.
ADHESIVE REMOVAL
In some instances, especially after long weather exposure acts on the laminate, adhesive residue may remain on the sign face while the vinyl releases. As removing adhesive involves the use of chemicals always read and follow the manufacturer’s instructions.
For best effect using a chemical remover, saturate the adhesive and keep it wet rather than simply wetting the surface once. Apply the remover by using a rag, a spray bottle or a pressurized sprayer. It has been our experience that allowing the decal to soak under a plastic cover (with edges taped to avoid drying and leakage) for up to 3O minutes then simply scraping the adhesive cleanly away will make the job far easier than immediately scrubbing at the wetted glue. Warm weather will accelerate the action of any adhesive remover. Once the adhesive layer is softened sufficiently one can scrape the jelled coating from the surface with either an old installation squeegee or hard plastic squeegee made for that purpose. The active ingredient in most modern, cirtron based removal fluids is D-limonene – this compound is found both in prepared mixtures as well as from chemical supply facilities around the world.
