Method and apparatus for extruding cementitious articles
OwnerHong Chen, Richard John Burwood +2inventors
InventorsHong Chen, Richard John Burwood, Ian Andrew Maxwell, Nilmini Sureka Goringe
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Abstract
A method and apparatus (20) for extruding fibre cement. The extruder comprises a casing (30) with a pair of inter-meshing self-wiping screws (40) rotatably mounted therein. The screws continuously mix and or knead the components of the fibre cement provided through various feed means (61, 62) to form a substantially homogeneous paste and force the paste through a die (50) to form a green cementitious extrudate suitable for curing.
Claims25
A fibre cement extruder having a casing and at least a pair of intermeshing self-wiping screws rotatably mounted therein, said screws being arranged to continuously mix and/or knead the components of the fibre cement to form a substantially homogeneous paste and force the paste through a die to form a green cementitious extrudate suitable for curing.
A fibre cement extruder as claimed in any one of the previous claims wherein a vacuum section is provided along the length of the screws, the upstream end of the vacuum section being defined by a counter threaded portion of the screw, the counter threaded portion adapted to provide a back flow of the pace and thereby form a fluid seal, a second fluid seal being formed at the downstream of the vacuum section by the pace immediately prior to entry into the dye, the vacuum section being connectable to a vacuum source for degassing the paste.
An extrusion system for extruding fibre reinforced cement comprising
- feeder means adapted to continuously feed components for the fibre reinforced cement to an extruder,
- a fibre cement extruder as claimed in any one of the previous claims, and
- a die.
A method of extruding fibre reinforced cement comprising subjecting the components of a fibre reinforced cement composition to an extruder having at least a pair of intermeshing self-wiping screws to mix and/or knead the components of the fibre cement to form a substantially homogenous paste and force the paste through a die.
Dependencies are inferred from the claim text.