| 摘要 |
<p>This invention relates to improvements in making mats of continuous fiber strand using controlled reciprocating strand feeders. More particularly, the invention relates to improvements in making continuous fiber glass strand mats having more uniform density by electronically controlling both the rate of reciprocation and the rate at which strands are deposited onto the surface of a moving conveyor while also reducing the vibration associated with the feeders. Still more particularly, the invention relates to improvements in the production of two continuous fiber glass strand mats, one having uniform mechanical properties while the other possesses directionally dependent ones. In the preferred embodiment, brushless stepper or indexing motors are used to reverse the direction of reciprocating strand feeders quickly and smoothly so as to minimize their vibration. Also provided are variable speed electric motors in conjunction with a programmable logic controller and frequency inverter to adjust the rate at which strand is deposited by the feeders onto the moving conveyor. It is shown, by way of example, that these improvements result in increased uniformity of both mat density and thickness.</p> |
