Strawboard Patents

Seminal patent for Straw Board: http://www.google.com/patents/US4451322

Dvorak, U.S. Pat. No. 4,451,322 (May 29, 1984), discloses a compacting apparatus for forming pressed sheets from crude plant fiber, such as straw from stalks of cereal grains. The fibrous material is first dried to have a moisture content of less than 15 wt.% and is stripped and broken down into small fibrous strains of substantially uniform diameter. The compacting apparatus includes a conveyor which transports the dried, cut fibrous material into a chute which, in turn, delivers the fibrous material to a compactor. The chute includes a plurality of arcuately reciprocating plungers which are serially arrayed along the flow path of the fibrous material and which precompact the fibrous material to have a uniform density as it is delivered to the compactor. In the compactor, a ram periodically operates to compact the fibrous material into a tunnel such that the fibrous material is formed into a continuous sheet having a uniform height and width. After exiting the tunnel, the sheet enters a press where heat and pressure are applied to the surfaces thereof to increase the mechanical interlinking of the individual fibers in the sheet. Surfacing material is bonded to the compacted sheet which can then be cut to any desired length.

Reference came from [1]