Fiber additives for reinforcing plastic matrices
AssigneeCaterpillar Inc.
InventorJames R. Carlberg
Life of this patent
Estimating the term…
Abstract
A reinforced plastic composition that possesses excellent wear resistance and weld line strength without a significant increase in the flexural modulus. The reinforced plastic composition for forming molded and extruded products has a plastic matrix with a plurality of fibers dispersed therein. The fibers are present in the range of about 1% to about 30% by weight of the plastic matrix. The reinforced plastic composition has a weld line strength greater than 66% of the weld line strength of the plastic matrix without the fibers. The plastic composition is particularly useful for making thrust washers, pump seals, piston rings and other dynamic bearing and sealing components for engines, transmissions and drivelines.
Claims22
A reinforced plastic composition for forming molded and extruded products, comprising:
- a plastic matrix, said plastic matrix being selected from a group consisting of polyphthalamide, polyethersulphone, polyphenylenesulphide, polyetherketone, and polyetheretherketone;
- and
- a combination of fibers dispersed within said plastic matrix, said fiber combination being one of carbon-ceramic fibers and ceramic-glass fibers, said fiber combination being present in the range of about 1% to about 30% by weight of said plastic matrix;
- and
- said carbon and ceramic fibers in said carbon-ceramic fiber combination, and said ceramic and glass fibers in said ceramic-glass fiber combination being respectively present in a weight ratio in the range of about 1:3 to about 3:1 with respect to each other;
- and
- said plastic matrix reinforced with said fiber combination having at least a 10% greater wear resistance, and a 10% greater weld line strength retention and no greater than 10% increase in flexural modulus than the corresponding wear resistance and weld line strength retention and flexural modulus respectively, of a plastic matrix reinforced with one of carbon fibers, ceramic fibers and glass fibers, when compared at a same total fiber weight % loading in said plastic matrix, and
- said reinforced plastic composition having a weld line strength of at least 75% of a weld line strength of said plastic matrix.
A reinforced plastic composition for forming molded and extruded products, comprising:
- a polyphthalamide thermoplastic matrix;
- and
- a combination of fibers dispersed within said thermoplastic matrix, said fiber combination being one of carbon-ceramic fibers and ceramic-glass fibers, said fiber combination being present in the range of about 1% to about 30% by weight of said thermoplastic matrix;
- and
- said carbon and ceramic fibers in said carbon-ceramic fiber combination, and said ceramic and glass fibers in said ceramic-glass fiber combination being respectively present in a weight ratio in the range of about 1:3 to about 3:1 with respect to each other;
- and
- said thermoplastic matrix reinforced with said fiber combination having at least a 10% greater wear resistance, and a 10% greater weld line strength retention and no greater than 10% increase in flexural modulus than the corresponding wear resistance and weld line strength retention and flexural modulus respectively, of a thermoplastic matrix reinforced with one of carbon fibers, ceramic fibers and glass fibers, when compared at a same total fiber weight % loading in said thermoplastic matrix, and
- said reinforced plastic composition having a weld line strength of at least 75% of a weld line strength of said thermoplastic matrix.
An injection molded article formed from a reinforced plastic composition, said composition comprising:
- a polyphthalamide thermoplastic matrix;
- and
- a combination of fibers dispersed within said thermoplastic matrix, said fiber combination being one of carbon-ceramic fibers and ceramic-glass fibers, said fiber combination being present in the range of about 1% to about 30% by weight of said thermoplastic matrix;
- and
- said carbon and ceramic fibers in said carbon-ceramic fiber combination, and said ceramic and glass fibers in said ceramic-glass fiber combination being respectively present in a weight ratio in the range of about 1:3 to about 3:1 with respect to each other;
- and
- said thermoplastic matrix reinforced with said fiber combination having at least a 10% greater wear resistance, and a 10% greater weld line strength retention and no greater than 10% increase in flexural modulus than the corresponding wear resistance and weld line strength retention and flexural modulus respectively, of a thermoplastic matrix reinforced with one of carbon fibers, ceramic fibers and glass fibers, when compared at a same total fiber weight % loading in said thermoplastic matrix, and
- said reinforced plastic composition having a weld line strength of at least 75% of a weld line strength of said thermoplastic matrix.
Dependencies are inferred from the claim text.