There are two basic structures of sign making double-sided tapes. You get tapes that consist of three main layers: two adhesive layers on either side and a carrier material in the middle. The carrier provides strength and stability, while the adhesive layers create bonds with both the sign and the mounting surface. The other structure is foamed acrylic adhesive which doesn’t have a carrier as it is all adhesive.
The most common double side tapes used in sign making:
Acrylic based tapes: These can be either white or clear and are comprised of 3 layers: A plastic carrier film with a layer of adhesive on each side. The acrylic adhesive forms an increasingly strong bond over time through a process called "wet out" where the adhesive flows into the microscopic surface irregularities of both materials.
Examples in the sign industry include Stykra 230 (mounting and acrylic bonding) & Stykra 500 Banner Tape
Foam tapes: These feature a foam core carrier that provides cushioning and conformability to uneven surfaces. The foam also helps distribute stress across the bond area, making these tapes excellent for surfaces that are a little more uneven or have deviation. They typically come in white or black, with thicknesses ranging from 0.4mm to 3mm. Foam tapes are excellent for general purpose sign mounting including internal foam signs, nameplates and health & safety signage.
A Popular option for sign makers includes the Stykra 180.
Foamed acrylic tapes: These premium tapes, offer exceptional holding and viscoelasticity power which can withstand stressful forces. They use a specialised solid acrylic adhesive system that creates molecular bonds with the bonding surfaces. This range is often know as VHB, UHB or Structural Bonding Tapes which can achieve strength comparable to mechanical fasteners or liquid adhesives.
The Stykra 700 is an excellent example that is designed to replace flush rivets when manufacturing sign blanks using aluminium sign channel.
Considerations when selecting a tape for your sign project
Surface materials: Different surfaces require different adhesive formulations. For example, high surface energy materials like metal and glass bond well with most tapes, while low surface energy (LSE) materials like plastics and powder-coated surfaces need specialised adhesive formulations. The Stykra range has a variety of LSE tapes suitbale for plastics in the sign industry.
Environmental conditions: Consider exposure to UV light, temperature fluctuations, and moisture. Outdoor signs need tapes with excellent weather resistance and temperature stability. Foamed acrylic tapes are usually the go to option when dealing with demanding bond requirements.
Load requirements: Calculate both the static (weight of the sign) and dynamic (wind load) forces the tape will need to withstand. This helps determine the required tape width and type.
Success is all in the Application
To achieve the best performance from your double sided tapes its important to follow the manufacturers instructions however these steps are generally considered good practice:
- Clean both surfaces thoroughly using a strong solvent degreaser (e.g Stykra EXT Cleaner), isopropyl alcohol or a manufacturer-recommended cleaner. Any dust, oil, or contamination will significantly reduce bond strength.
- Apply at temperatures between 65-100°F (18-38°C) for optimal results. The adhesive flows better at warmer temperatures, creating stronger initial bonds. However there are tapes available that can be applied as low as 0°C and still achieve their optimum bond strength over time.
- Use firm pressure when applying the tape and mounting the sign. This pressure activates the adhesive and ensures good contact with both surfaces. Often failures occur when adequate pressure has not been achieved between the bonding materials. Pro Tip: Rubber rollers are great for applying even pressure.
- Allow time for the bond to develop. While most tapes provide good initial hold, full bond strength typically develops over 24-72 hours. Foamed Acrylic Taped (VHB, UHB) will usually require 72 hrs to reach full bond strength. It is very important to allow for the dwell time before mounting fabricated signs such as post and panel systems.
A few professional tips for best results:
Consider using primer on porous, powder coated surfaces or in challenging environments. Primers such as the Stykra EXT primer can significantly improve adhesion by creating a better surface for the tape to bond to.
For heavier signs, use multiple strips of tape rather than one wide piece. This distributes the load more effectively and provides redundancy in case of partial failure.
Always test the tape in a small area first, particularly with painted or coated surfaces, as some finishes may be incompatible with certain adhesives.
Remember that proper surface preparation and application technique are just as important as choosing the right tape. A premium tape applied poorly will not perform as well as a standard tape applied correctly.