Abstract: A kit is provided for making a panel structure for an external side wall or a covering of a building; the kit has a plurality of section elements elongated along a longitudinal axis, designed to be fastened to a support and having respective seats which are open at the top and at their longitudinal ends and are designed to form, together, a longitudinal channel; the kit is provided with panels, engaging the channel, and with a seal made of flexible material and having a strip portion to cover at least two consecutive joint zones between the section elements.

Abstract: The plant is intended for performing the plasma surface treatment of an alveolar sheet (10) of plastic material having a first and second outer face surface (12, 14) and an inner alveolar surface (16). The plant comprises means able to allow the simultaneous and independent treatment of each of said outer surfaces (12, 14) and inner surface (16) with a respective plasma (96, 98, 100) with which a process fluid is associated, said fluid being deposited on one of said surfaces (12, 14, 16).