| 摘要 |
<p>Panels are fitted to ceiling and/or walls, to reduce sound energy. They are used in installations for combating noise indoors, esp. from machines, conveyors, manhandled workpieces or other sources inside factories. The panels (2) are made from carton material formed by fibre casting. They are 2.5-5mm., pref. 3-3.5mm. thick, with holes (5) of pref. approx 2.7 mm. dia. at intervals of pref. approx. 2.5 cm. and with humps (6) in the intervening spaces. Waste paper can be used, esp. waste from packaging manufacture, pref. together with plastics waste.</p> |
