| 20080237914 | Methods for making fiber reinforced polypropylene composites using pre-cut fiber - The present disclosure is directed generally to methods for making fiber reinforced polypropylene composite pellets using pre-cut fiber fed to a compounding extruder by improved fiber feeder systems. One form of the method includes feeding into a compounding extruder at least 25 wt % polypropylene based polymer, from 5 to 60 wt % pre-cut organic fiber, and from 0 to 60 wt % inorganic filler; and extruding, cooling and pelletizing the resultant mixture of components to form fiber reinforced polypropylene composite pellets; wherein the pre-cut organic fiber is fed from a feeder including a feeder hopper, one or more conditioning augers/agitators, one or more metering augers below the feeder hopper, and a means for controlling the speed of the conditioning augers/agitators and metering augers; and wherein an article molded from the pellets has a flexural modulus of at least 2.07 GPa and exhibits ductility during instrumented impact testing. In another form, the feeder includes a feeder hopper, two or more counter-rotating metering rollers, one or more separating rollers below the metering rollers, and a means for controlling the speed of the metering rollers and separating rollers. In yet another form, a circle feeder may be used to feed the pre-cut fiber. | 10-02-2008 |
| 20090130443 | Fiber pellets, method of making, and use in making fiber reinforced polypropylene composites - The present disclosure is directed generally to synthetic organic fiber pellets, methods for making such pellets, and methods of using such pellets for making fiber reinforced polypropylene composite resins. The synthetic organic fiber pellets include at least 80 wt % of a synthetic organic fiber chosen from polyalkylene terephthalates, polyalkylene naphthalates, polyamides, polyolefins, polyacrylonitrile, and combinations thereof, and from 2 to 20 wt % of one or more waxes. The synthetic organic fiber pellets are produced using a pelleting press process. Also provided is a method for making fiber reinforced polypropylene composite pellets including feeding into a compounding extruder at least 25 wt % polypropylene based polymer, from 5 to 60 wt % of synthetic organic fiber in the form of the synthetic organic fiber pellets, and from 0 to 60 wt % inorganic filler; extruding the polypropylene based resin, the fiber pellets, and the inorganic filler through the compounding extruder to form a fiber reinforced polypropylene composite melt; cooling the fiber reinforced polypropylene composite melt to form a solid fiber reinforced polypropylene composite; and pelletizing the solid fiber reinforced polypropylene composite to form fiber reinforced polypropylene composite pellets; wherein an article molded from the composite pellets has a flexural modulus of at least 2.07 GPa and exhibits ductility during instrumented impact testing. Articles molded from the fiber reinforced polypropylene composite pellets find application as automotive parts, household appliance parts, or boat hulls. | 05-21-2009 |
