Signmaking: Guide For The Correct Usage Of Self-Adhesive Materials
- Rolls should be stored on end, to avoid pressure marking. Extremes in temperature and humidity should be avoided. High temperatures can lead to adhesive bleed, causing problems with the sprocketed material in particular, whilst humidity may cause problems with the backing papers such as curl etc.
- All self-adhesive vinyls should be allowed 24 hours to acclimatise to workshop temperatures and humidity levels, before usage.
- An ideal storage condition, recommended by most manufacturers, is 15°C-25°C and at 50% relative humidity.
- Avoid storing in direct sunlight or near heaters.
- Keep the rolls off the floor, as dampness from the floor may be absorbed into the backing paper.
- Ensure the depth/pressure setting of the plotter blade is correct for the vinyl being used. Not cutting deep enough will create difficulties in weeding the waste matrix. Whereas cutting too deeply into the siliconised backing paper, may cause delamination of the paper onto the adhesive side of the vinyl when removing the cut lettering from the backing paper. It is always recommended to test cut the vinyl, by producing some lettering in the same size as the finished work.
- Cutting the vinyl, then leaving for some time before the weeding process, may lead to difficulties in weeding the waste and removing the lettering. These problems are caused by the adhesive flowing back and are especially noticeable in warmer conditions.
- Cold conditions may cause the face of the film to harden and become brittle. This in turn can cause the blade to skid across the surface and cause the film to break when weeding. We would recommend using a new blade in cold conditions and to allow the film to acclimatise to room temperature.
Weeding is the process and the name given to the removal of the waste matrix, prior to the transfer of the cut lettering.
- Tweezers and scalpels are the most common tools used for weeding.
- To begin the process, start at one corner and work across the image in short diagonal movements, usually in a right to left direction.
Transfer of the pre-spaced image
After the waste matrix is weeded away, the cut lettering has to be transferred accurately from the backing paper to the finished substrate using Application Tape. We stock a variety of Application Tapes to achieve this successfully.
As a general rule, matt permanent vinyls require a higher tack Application Tape than a gloss vinyl, and smaller images require a higher tack tape than larger ones. No one tape will be ideal for all jobs, however we have various tapes that will work for most applications.
- Apply the Application Tape smoothly to the weeded image, avoiding wrinkles and bubbles wherever possible.
- Squeegee the Application Tape down using a plastic applicator.
- Start from the centre and work outwards – follow a pattern similar to the ‘Union Jack’.
- Turn the vinyl over, so that the Application Tape is facing down on the bench and the backing paper is facing upwards. • Remove the backing paper, starting at one corner and peeling back diagonally at an angle of 180°.
Removal of existing vinyl signage
- To remove old lettering, use a heat source, i.e. a hair dryer or heat gun, to soften the vinyl, then strip the vinyl slowly off the substrate. This tends to leave a residue of adhesive on the substrate.
- Using an adhesive remover such as RAPIDREMOVER, spray the adhesive residue and let it penetrate for 30-60 seconds.
- Use a squeegee to remove as much of the adhesive as possible.
- Now spray some RAPIDREMOVER onto a rag or paper towel and wipe the area clean.
- Finally, clean the entire area with water and detergent then degrease as detailed below.
RAPIDREMOVER can be used on a wide variety of surfaces, including most plastics, glass, fibreglass and painted surfaces that have been properly cured (for further information see our RAPID range of products). Avoid use on latex painted surfaces, Styrofoam or Styrene surfaces.
Preparation of the substrate
- The substrate must be free from grease, dirt and foreign matter before application.
- The safest and easiest way to clean and degrease the surface is to use Avery Dennison Surface Cleaner, a non-toxic, degreasing agent that remove most waxes and silicones.
- This will thoroughly degrease the surface in preparation for the application of the vinyl graphic.
Application of the pre-spaced image
There are two basic methods of applying self-adhesive vinyl’s, depending on the size/complexity of the image and difficulty of the substrate. In all cases, ensure that the sign is applied above the minimum recommended application temperature (see Technical Data Sheets for the minimum application temperatures of each product).
Please take note that these are minimum temperatures. Most self-adhesive vinyl manufacturers recommend the range of 15°C-25°C as the ideal temperatures for the application of self-adhesive vinyl’s.
- Dry application – used in the majority of cases.
- Wet application – used to apply large or multi-coloured images and also recommended for application onto glass surfaces.
One of the secrets of good long term application is to have optimum contact of the adhesive to the surface. Any gaps between the adhesive and the surface will inevitably, through time, lead to adhesive failure.
Dry application – top hinge method
|Before commencing, establish exactly where the sign is to be located, then tape the sign into position using small pieces of masking tape. Use 2” masking tape to create a hinge – half the masking tape on top of the sign and the other half on the application surface. Squeegeethe masking tape hinge firmly into position.|
|To apply, lift the sign away from the surface and fold back on the hinge. Peel off about 6” of the backing paper then lower the sign, keeping the adhesive away from the application surface.|
|Starting at the top in the centre, squeegee down and outwards towards each edge in turn. Remove another 6” of backing paper and keep repeating the process, using overlapping strokes, until the sign is completely applied (for large pre-spaced signs, do as above but slit between each letter, so that every letter can be applied individually).|
|Now carefully remove the application tape, diagonally at 180°. Air bubbles can be removed by puncturing the bubble with a pin, then squeegee the trapped air towards and out of the puncture.|
|Finally re-squeegee the sign, paying particular attention to the top and leading edges. If the sign is long and narrow, the same procedure can be adopted with the hinge on the edge of the sign, instead of the top.|
This method is used when applying large or multi-coloured signs and window graphics, and assists greatly in the elimination of air bubbles. The application of a liquid to the adhesive forms a barrier, which temporarily neutralises the adhesive and allows the graphic to be repositioned several times. To save time and money an Application Fluid such as RAPIDTAC or RAPIDTAC II can be used.
|Shake the RAPIDTAC spray bottle well before use. Spray the fluid onto the adhesive or onto the substrate and float the image into position as before. Excessive use of RAPIDTAC will result in longer cure times for the adhesive, so use sparingly.|
|Squeegee the image as before.|
|After allowing only a few minutes to pass, spray the Application Tape with RAPIDTAC and squeegee again.|
|Carefully remove the wet Application Tape diagonally at 180°.|
|Finally re-squeegee over the entire sign again, paying particular attention to the top and leading edges.|
Independent laboratory tests showed that RAPIDTAC, in comparison to soapy water, could significantly improve the adhesive bond. The tests showed 300% better adhesion after 6 hours, 50% after 24 hours and a 10% improvement in the overall adhesion peel values.
Wet application is the ideal solution for window graphics as it gives a perfect finish from both sides of the window, but it is a longer process as the adhesive will take time to bond when wet, meaning you cannot remove the application tape quickly.
To overcome this time issue we would recommend 2 products, our KleenTear KT50 Medium Tack application paper and RAPIDTAC II. This combination will allow you to remove the application tape from a typical glass etch vinyl in around half the time it would take with the ORIGINAL RAPIDTAC, and several times quicker than just using soapy water other application tapes.