Polymeric moldings reinforced with tows of fibers
AssigneeApplied Research of Australia Pty. Ltd.
InventorsEdward Philip Thicthener, Peter John Hastwell
Life of this patent
Estimating the term…
Abstract
Discrete carbon or other electrically conductive fibers are added to a fluid formulation of settable resin in a bath, and a number of tows of non-conductive fibers, for example glass, are drawn through the bath, entraining and partly aligning the conductive fibers and being wetted by the resin. The tows are then bunched into a bundle, causing most of the conductive fibers and concentration zones to render the moulded product conductive to electrostatic charge.
Claims20
A method of forming an electrically conductive product of non-conductive fiber reinforced plastics with a resistivity of less than 10.sup.5 .OMEGA.cm comprising entering a mix of fluid but settable plastics resin material and discrete conductive fibers of carbon or metal into a bath in a weight ratio not exceeding 2% by weight of conductive fibers based upon the weight of resin in said bath, said conductive fibers having a mean aspect ratio exceeding 100,
- drawing a plurality of tows of nonconductive reinforcing fibers through said bath, wetting said tows with said fluid resin, entraining some of said conductive fibers into concentration zones around said wetted tows, passing the wetted tows over a curved surface, bunching said wetted tows into a bundle, applying said bundle to a shape forming surface, and retaining said tows substantially in contact with said shape forming surface while said resin sets.
A method of forming an electrically conductive product of non-conductive fiber reinforced plastics comprising entering a mix of fluid but settable plastics resin material and discrete conductive fibers into a bath in a weight ratio not exceeding 2% by weight of conductive fibers based upon the weight of resin in said bath, said conductive fibers having a mean aspect ratio exceeding 100,
- drawing a plurality of tows of nonconductive reinforcing fibers through said bath, wetting said tows with said fluid resin, and entraining some of said conductive fibers into concentration zones around said wetted tows, bunching said wetted tows into a bundle, applying said bundle to a shape forming surface, and retaining said tows substantially in contact with said shape forming surface while said resin sets,
- further comprising passing said bundle of wetted tows through a sizing nozzle and between die cavities of an open die wherein said shape forming surface defines said die cavities and closing said open die and applying pressure to said bundle of wetted tows to conform an envelope shape of said tows to the shape of said surface,
- wherein a downstream portion of said shape forming surface is a bolt thread forming surface and an upstream portion of said shape forming surface is a bolt shank forming surface of smaller cross-sectional size than the thread forming surface,
- further comprising forming a bolt with a shank longer than said shank forming surface by firstly forming a bolt with a shank of length equal to the length of the shank forming surface, opening the dies, withdrawing the threaded end outwardly from between the dies thereby drawing further said wetted tows of the bundle between the shank forming cavities of the die, and again closing the die to clamp a portion of said shank and applying pressure to said wetted tows while the resin thereof sets.
A method of forming a molded product of settable resin reinforced with fibers comprising drawing a bundle of tows of reinforcing fibers through a bath comprising fluid but settable resin mix and discrete conductive fibers of carbon or metal, said conductive fibers being present in the bath in an amount ranging from greater than 0 to not greater than 2.0% by weight based upon the weight of resin in said bath, said conductive fibers having a mean aspect ratio exceeding 100, drawing the bundle of tows between die cavities of an open die, closing the die to conform an envelope shape of the tows to the shapes of surfaces which define cavities in the die,
- and further comprising pinching a portion of the tows of the bundle with a portion of the die to reduce the size of the tows and to radially constrict the die cavities of at least one end of the die sufficiently to inhibit expulsion of resin from that said end, and subjecting a remaining portion of said tows to a high pressure while the resin sets, wherein a product with a resistivity of less than 10.sup.5 .OMEGA.cm is formed.
A method of forming a molded product of settable resin reinforced with fibers comprising drawing a bundle of tows of reinforcing fibers through a bath comprising fluid but settable resin mix and between die cavities of an open die, closing the die to conform an envelope shape of the tows to the shapes of surfaces which define cavities in the die
- forming a bolt with a shank longer than said shank forming surface by firstly forming a bolt with a shank of length equal to the length of the shank forming surface, opening the dies, withdrawing a threaded end outwardly from between the die thereby drawing further said wetted tows of the bundle between the shank forming cavities of the die, and again closing the die to clamp a portion of said shank and apply pressure to said wetted tows while the resin thereof sets, and
- pinching a portion of the tows of the bundle with at least one end of the die sufficiently to inhibit expulsion of resin from that said end, and subjecting a remaining portion of said tows to a high pressure while the resin sets.
A method of forming an electrically conductive product of non-conductive fiber reinforced plastics comprising:
- forming a bath comprising a mixture of fluid but settable resin material and discrete conductive fibers of carbon or metal, said conductive fibers being present in the bath in an amount ranging from greater than 0 to not greater than 2.0% by weight based upon the weight of resin in said bath, said conductive fibers having a mean aspect ratio exceeding 100,
- drawing a plurality of tows of nonconductive reinforcing fibers through said bath;
- wetting said tows with said resin;
- entraining some of said conductive fibers into concentration zones around said wetted tows;
- passing said wetted tows over a curved surface;
- bunching said wetted tows into a bundle;
- applying said bundle to a shape forming surface;
- retaining said tows substantially in contact with said shape forming surface while said resin sets;
- and
- removing said tows from said shape forming surface as an electrically conductive product with a resistivity of less than 10.sup.5 .OMEGA.cm.
Dependencies are inferred from the claim text.