Adhesives for bonding transformerboard: partial discharge and ageing behaviour

Large power transformers are usually in operation over several decades. During operation, high temperatures frequently occur. Because of these high temperatures, the insulation materials are subjected to accelerated ageing processes. It is necessary to ensure that all materials used in transformers do not lose their functionality over the decades of operation; for example, the adhesives used in bonded transformerboard must not lose their mechanical strength.