Ventilation grille - having bars with sodium silicate cores and PVC casings and others forming distance pieces

摘要

The ventilation grille is for mounting in doors, walls, etc. its bars each comprising a natrium silicate core and a PVC casing. Only some of the bars are of natrium silicate and PVC, while the remainder act as distance pieces, typically extending vertically and being of aluminium T-section, with slots cut in the webs to accommodate the first set of bars. The grille frame can be rectangular, comprising two each horizontal and vertical bars, each with a natrium silicate core and a PVC casing.