| 摘要 |
<p>A nap (3) is needled on its two faces by two needling heads (6a, 6b). The two heads (6a, 6b) are offset relative to one another in the longitudinal direction of the nap. The needles (8) of each head (6a, 6b), which are driven in a vertical reciprocating movement, penetrate into the nap to a depth at most equal to its thickness (and greater than half this thickness), the nap being supported by a conveyor (41a, 41b) which is itself supported by a bearing surface (53a, 53b). Since the needles have barbs directed towards their base, portions of fibres are returned towards the inside of the nap during each retraction movement of the needles, thereby increasing the cohesion of the nap. The conveyors (41a, 41b) drive the nap by adhesion. Application to the needling of short and/or brittle refractory inorganic fibres, such as rock wool, which can be used for the insulation of boilers, pipework, etc. <IMAGE></p> |
