tesa HAF® 8478

tesa® HAF 8478 is a thermosetting film based on phenolic resin and nitrile rubber. This brown double-sided tape has no backing. It is protected by a strong paper liner.

tesa® HAF 8478 is halogen-free and compliant with current ROHS standards.

At room temperature tesa® HAF 8478 is not tacky. It is activated by heat and pressure during defined intervals.

tesa® HAF 8478 enables extremely strong and age-resistant bonds between different materials, especially on porous substrates.

tesa® HAF 8478 features:

• Excellent conformability for porous and curved substrate surfaces
• Produces low oozing ratio
• Reliable and age-resistant bonds between plastic and metal surfaces, even on very small bonding areas
• Suitable for long-term applications that are exposed to heavy stress
• Bonds remain elastic

tesa® HAF 8478 is especially recommended for bonding of metal components to various plastic or metal surfaces, e.g. SUS or AL to PMMA, PC or ABS:

• Bonding of frame to mobile phone housing
• Nameplate bonding for handheld devices

Technical recommendations:
tesa® HAF 8478 is not self adhesive. It is activated by heat and pressure over a certain interval. The following values are recommendations for machine parameters to start with.

1. Pre-lamination:
During pre-lamination, the adhesive tape is laminated onto the metal substrate. This step does not affect the shelf life of the adhesive tape. Pre-laminated components can be stored over the same period of time as the adhesive tape.

Machine setting:

• Temperature¹ 90 – 120 °C
• Pressure² 2 – 6 bar
• Time 1,5 – 3,0 s

2. Bonding:
Remove the liner from tape after pre-lamination step. Place the plastic part onto the metal component. Apply sufficient temperature through the metal part while applying pressure for the bonding time to reach sufficient bonding strength.

Machine setting:

• Temperature¹ 180 – 220 °C
• Pressure² 2 – 10 bar
• Time 3,0 – 10,0 s

To achieve optimum performance a cooling step (while applying pressure) directly after the bonding step is recommended.

¹ ‘Pre-lamination’ and ‘Bonding’ temperature refer to the data that is measured at the surface of heating mould.
² ‘Pre-lamination’ and ‘Bonding’ pressure refer to the force that is transformed from mould surface directly to the bonding area.

Storage conditions according to tesa® HAF shelf life concept.

Note: Bonding strength values (mean values) were obtained under standard laboratory conditions. (Material: AL & AL test specimen / Bonding conditions: Temperature = 180 °C; Pressure = 10 bar; Time = 7 sec).