tesa® 8694

tesa^® L-tape is a reactive adhesive tape, which can be activated by wavelengths of 365 nm or 460 nm. tesa^® L-tape can be used for bonding of transparent or opaque substrates. tesa^® L-tape can be activated before or after lamination onto the first substrate. Transparent substrates such as clear plastics can be bonded before activation by light. At least one substrate must be light-permeable to enable the activation of tesa^® L-tape. The bonded parts are then exposed to light to start curing of the adhesive.
Bonding of opaque substrates:
a) activation after lamination on the first substrate
At first, remove the covering liner of tesa^® L-tape and laminate the tape onto the first substrate. The laminated parts are then exposed to light. The second substrate is bonded by applying sufficient pressure (≥3 bar) within 5 min after activation.
b) activation before lamination on the first substrate
At first, the die-cut of tesa® L-tape is activated by light. The covering liner of the die-cut must be light-permeable (e.g., clear PET) to enable the activation of the tape. After activation the die-cut is laminated onto the first substrate. The second substrate is then bonded by applying sufficient pressure (≥3 bar). Lamination and bonding must take place within 5 min after activation.

Lamination conditions

• Before curing tesa^® L-tape has initial tack and can be laminated like a common PSA tape
• For any lamination step a pressure of at least 1 bar is recommended to ensure proper wet-out of the adhesive

Bonding and curing conditions

• Light source: Lamp of 365nm or 460nm
• Light dose: 20 - 50 J/cm² at 365nm or 30 - 60 J/cm² at 460nm
• Activation time: ≥30 s
• Pressure: ≥3 bar
• Bonding time: ≥30 s

Bonding strength values were obtained under standard laboratory conditions. (Material: PC test specimen / bonding conditions: Light dose: 52 J/cm² at 460 nm; activation time: 45 s; pressure: 10 bar for 30 s).
To reach maximum bonding strength surfaces should be clean and dry.