It is necessary that connectors are reliably sealed to protect electronics from humidity, media, and corrosion. Automotive suppliers generally use silver-coated connector pins since they are more cost-efficient than gold and more reliable than copper. Silver is given an additional passivation layer to protect it from tarnish and abrasion. This coating is usually based on mercaptan and has been considered difficult to bond, until now.
DELO DUALBOND GE4918 has been optimized for reliable sealing for these types of pins. It not only adheres very well to the mercaptan coating, but also adheres to the typical connector housing materials PA and PBT, even under the stringent conditions of the automotive sector. Since this new sealant is flexible in the cured state, it compensates for the different thermal expansions of metal pins and plastic housings. DELODUALBOND GE4918 offers very good temperature resistance, up to +150 °C, and is able to keep connectors tight after thermal shock Tests ranging in temperature from -40 °C to +150 °C.
Suitable for mass production of connectors
This new sealant enables fast and simple production processes with a high level of safety. The one-component product is easy to dispense, shows good flow properties and can be fixed in 10 to 20 seconds with the help of high-intensity UV light. In shadowed areas that cannot be reached by light, a second curing mechanism allows the adhesive to cure under the influence of air humidity. An in-line tightness test can be performed immediately after UV light fixation.
With this new sealant, which is available for sampling, automotive suppliers can benefit from its silicone-like properties without having to take Special precautions in their production, as is the case with silicones. The outgassing of silicone often leads to contamination of other processes, which is particularly undesirable in painting or coating processes.