Abrasive tool making process – material – or composition – With synthetic resin
Reexamination Certificate
2000-01-10
2001-10-16
Marcheschi, Michael (Department: 1755)
Abrasive tool making process, material, or composition
With synthetic resin
C051S294000, C051S295000, C051S307000, C451S526000, C451S536000
Reexamination Certificate
active
06302930
ABSTRACT:
BACKGROUND
This invention provides a durable, nonwoven abrasive product having a significantly longer useful product life compared to conventional, but similar abrasive products.
Nonwoven, low-density abrasive products made of a uniform lofty web of continuous three-dimensionally bonded polyamide filaments, such as those abrasive products described in U.S. Pat. No. 4,227,350 (Fitzer), have found successful application for treating or conditioning various types of surfaces. These applications include, in part, removing mill scale from steel coil stock, blending of weld lines, preparing surfaces for painting or other coating operation, and removing various surface coatings in repair and maintenance operations. These successes have spurred the inevitable pursuit of providing increased value to the end user for such abrasive products and particularly for increased useable product life.
When current low-density abrasive products are used, for example in an automotive body repair shop, in the form of 4 to 6 inch (10.1 to 15.2 cm) diameter discs, these discs may encounter many sharp edges as the discs are used to clean or prepare automotive surfaces for coating, filling, welding, and other operations. Sharp edges include those associated with bent sheet metal, fasteners, fastener heads, rust-perforated sheet metal, and the like. While these types of surfaces are effectively cleaned or prepared by the low-density abrasive disc, cleaning and preparation operations around sharp edges exact a toll, causing the low-density abrasive product life (the time it takes to wear the abrasive product from its initial diameter to a diameter equal to that of its central attachment fixture) to be much shorter than desired. Under extreme conditions, the abrasive product life may be as short as one minute or less.
Related product life or product use life concerns also arise from the practice of abrading a workpiece by using the face of these discs, instead of by using the circumference of the disc. Invariably, methods using the face of these discs involve the flexing, bending, or otherwise exerting lateral forces on the abrasive disc, in some cases, to an extreme amount of flexing or bending.
SUMMARY OF THE INVENTION
The present invention provides an improved nonwoven abrasive product. The improved abrasive product has a porous, lofty web of multiple layers of coiled, autogenously bonded thermoplastic filaments, binder resin, abrasive granules and size resin, and typically exhibits product life of at least twice that of conventional, but similar, abrasive products. In one embodiment, the present invention provides a porous, lofty web that, before adding binder resin, abrasive granules or size resin, has a coil weight in the range of between 17 and 28 g/24 in
2
(1.097 and 1.808 kg/m
2
) and preferably in the range of between 18 and 23 g/24 in
2
(1.162 and 1.486 kg/m
2
).
In another embodiment, this invention provides a porous, lofty web that exhibits periodic coil density variations in the machine direction, referred to in this specification as “variegation”, of a magnitude of between 10 and 20 mm.
In still another embodiment, this invention provides a porous, lofty web of multiple layers of coiled, autogenously bonded thermoplastic filaments, binder resin, abrasive granules and size resin, and exhibits a measured load at a 1.52 cm deflection (averaged values) of greater than 3.20 kg.
In other preferred embodiments of the claimed invention, the porous, lofty web has a uniform cross-section of at least one layer of filaments. Each layer of filaments includes a multitude of continuous three-dimensionally undulated filaments made of extruded thermoplastic material in which adjacent filaments are interengaged and autogenously bonded where they touch one another. These undulated filaments preferably are made of polyamide polymers and have diameters of about 5 to 125 mils (0.127 to 3.175 mm) and more preferably have diameters of about 14 to 20 mils (0.355 to 0.508 mm). When the porous, lofty web exhibits variegation, useful amounts of variegation include those having variegation periods (distance between density peaks) of between 10 and 20 mm. The porous, lofty web is impregnated or coated with a tough binder resin that both bonds a multitude of abrasive granules uniformly throughout the web and further bonds adjacent filaments to one another. In preferred embodiments an additional size resin is also impregnated or coated over the web, binder resin and abrasive granules to further bond the abrasive granules to the web.
REFERENCES:
patent: 2958593 (1960-11-01), Hoover et al.
patent: 3260582 (1966-07-01), Zimmer, Jr. et al.
patent: 3401491 (1968-09-01), Schnabel et al.
patent: 3537121 (1970-11-01), McAvoy
patent: 3686049 (1972-08-01), Manner et al.
patent: 3687759 (1972-08-01), Werner et al.
patent: 3691004 (1972-09-01), Werner et al.
patent: 3837988 (1974-09-01), Hennen et al.
patent: 3852152 (1974-12-01), Werner et al.
patent: 3936337 (1976-02-01), Stapp
patent: 4018575 (1977-04-01), Davis et al.
patent: 4227350 (1980-10-01), Fitzer
patent: 4355489 (1982-10-01), Heyer et al.
patent: 4991362 (1991-02-01), Heyer et al.
patent: 5282900 (1994-02-01), McDonell et al.
patent: 5346516 (1994-09-01), Alkhas et al.
patent: 5363604 (1994-11-01), Heyer
patent: 5573844 (1996-11-01), Donovan et al.
patent: 5733825 (1998-03-01), Martin et al.
patent: 5811186 (1998-09-01), Martin et al.
patent: 5928070 (1999-07-01), Lux
patent: 916 287 (1982-03-01), None
patent: WO 98/23800 (1998-06-01), None
patent: WO 98/53956 (1998-12-01), None
3M Innovative Properties Company
Allen Gregory D.
Marcheschi Michael
LandOfFree
Durable nonwoven abrasive product does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Durable nonwoven abrasive product, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Durable nonwoven abrasive product will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2595599