| 摘要 |
<p>The subject matter of the invention is a composite sheet structure having at least two layers of initially liquidpermeable material at least one of which layers is an initially resilient material with open and connected cells, and a thermosetting resinous material which impregnates the layers and which has been cured while the layers are maintained under compression, there being fibrils having a length not in excess of about 1/16 inch in the resinous material, the fibrils preferably being more numerous adjacent the interface of the two layers than in the portions thereof spaced from the interface. Further in accordance with the invention, such a composite sheet is preferably manufactured by applying a mixture of the resinous material, in liquid form, and the fibrils between the two layers and then compressing the two layers and heating them to the curing temperature of the resinous material whereby the liquid resinous material is driven through the two layers and then cured and whereby the concentration of the fibrils in the final cured composite sheet is greater at the interface of the two layers than in the portions spaced from the interface.</p> |
