Method and apparatus for manufacturing resin-impregnated sheet material
AssigneeMatsushita Electric Works, Ltd.
InventorsToshiyuki Matsumae, Kunji Nakashima, Hajime Kojima
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Abstract
A resin-impregnated sheet material is manufactured by passing a sheet material through a vacuum space of a reduced pressure sufficiently different from ambient atmospheric pressure for sufficiently deaerating the sheet material at the vacuum space, and impregnating the thus deaerated sheet material with a resin varnish while utilizing the pressure difference between the atmosphere and the vacuum space, the sufficiently deaerated sheet material being impregnated quickly and reliably with the resin varnish to provide the resin-impregnated sheet material of high quality.
Claims18
A method of manufacturing a resin-impregnated fibrous sheet material comprising the steps of preparing a vacuum space having mutually independent inlet and outlet means through which a sheet material is guided into and out of said vacuum space in an airtight manner, reducing the pressure in said vacuum space to a vacuum sufficiently different from the ambient atmospheric pressure outside the vacuum space for deaerating said sheet material, passing the sheet material into the vacuum space to deaerate the sheet material, impregnating said deaerated sheet material with a liquid resin, said impregnating step including at least the step of applying said varnish to only one side of said sheet material within said vacuum space without applying pressing forces to said sheet material, and drying the impregnated sheet material.
An apparatus for manufacturing a resin-impregnated fibrous sheet material comprising a vacuum chamber defining a vacuum space therein and having airtight inlet means and airtight outlet means, means for guiding a sheet material into said vacuum chamber, means for moving said sheet material within said vacuum chamber while guiding it over a predetermined distance between said inlet and outlet means, vacuum means coupled to said vacuum chamber for reducing the interior pressure of said vacuum space to a vacuum sufficiently different from the ambient atmospheric pressure outside the vacuum chamber for achieving a deaeration of the sheet material, impregnating means provided in association with said vacuum space for impregnating said deaerated sheet material with a liquid resin, said impregnating means including at least means within said vacuum space for applying resin to only one side of said sheet material without applying pressing forces to said sheet material and means for moving said sheet material along guide means provided inside and outside said vacuum chamber.
Dependencies are inferred from the claim text.