摘要 |
A method of making an intumescent seal comprises: providing a tubular holder having a longitudinal bore or interior chamber defined by a thickened longitudinally extending portion of the holder contiguous with a relatively thin wall of the holder; filling the bore of the holder with solid intumescent material; and thereafter removing a longitudinally extending part of said thickened portion thereby to leave part of said thickened portion as a baffle within the holder, the space left by said removed part forming a strait having a longitudinally extending opening to the exterior of the holder and a longitudinally extending opening to the bore of the holder. Preferably the thickened portion is square or rectangular and at a corner of the holder and the removal of said part of the thickened portion leaves two webs one of which constitutes the baffle and the other being at the exterior of the holder. |