| 摘要 |
Insulation material, for example resin-bonded fibrous insulation material, is provided with at least one longitudinal line of weakness 4 which may comprise a line of perforations 26 or a line of cut 4 extending substantially but not completely through the thickness of the material. The insulation material when in roll form can be carried by a stockist in one standard width which may be divided into smaller widths along the lines of weakness. Apparatus for producing the line of weakness comprises a circular saw (15, fig 3) which cuts partially through the insulation, thereby providing a line of cut 4. Perforations 26 are manufactured by using a circular knife (21, fig 3) having triangular cutouts (24, fig 3). |
