Abstract: Sheet material, for example for a swimming pool cover 12, comprises an upper layer 14 of mid-IR absorbing material and a lower layer 16, with bubbles 18, which absorbs visible light. The material passes at least 25% of radiation in the near-IR region, thus promoting heating of the water while suppressing growth of algae. Inorganic particles are used to block visible radiation and pigments are used to block mid-IR radiation.
Type:
Grant
Filed:
June 3, 2016
Date of Patent:
August 11, 2020
Assignee:
Plastipack Limited
Inventors:
Timothy James Fielder, Peter Anthony Adlington, Remi Wache, Steven Kenneth Clowes, Stephen Sweeney
Abstract: In a plastic sheeting material incorporating an array of bubble cells, the cells are shaped with two chambers connected by a constricted region. The chambers are part-spherical e.g. in the form of truncated spheres. The constricted region has concave side walls and/or a concave top wall. The sheeting may have two, three or more layers. Molds for producing the sheeting material have suitably-placed suction holes.