Stock material or miscellaneous articles – Hollow or container type article – Polymer or resin containing
Reexamination Certificate
2001-09-25
2004-08-03
Nolan, Sandra M. (Department: 1772)
Stock material or miscellaneous articles
Hollow or container type article
Polymer or resin containing
C264S040100, C264S219000, C264S220000, C264S225000, C264S255000, C264S257000, C264S258000, C264S324000, C428S543000
Reexamination Certificate
active
06770340
ABSTRACT:
BACKGROUND OF THE INVENTION
Viscous fluid(s) (e.g., polymers, plasticizers, colorants, powders, foods, etc.) are often blended with other viscous fluids and/or additives to obtain composite materials having certain desired properties. However, because of their extremely high molecular weight, polymers, for example, are intrinsically difficult to process. In fact, polymer blending has traditionally been accomplished by forcibly melting and mixing the materials together in a batch mixer or extruder, such as single-screw or twin-screw extruders.
Unfortunately, when blending polymers or other viscous fluids in a conventional manner, the morphologies (i.e., the shapes adopted by minor and major components) of the resulting composite cannot be adequately controlled. For example, when blending polymers to form a multilayered film, such as through coextrusion, it is virtually impossible to obtain a film structure that has a large number of thin layers. Some methods have been developed, such as layer stacking, to obtain multilayered films with a relatively large number of layers. However, such methods are inflexible, difficult to control, extremely complicated, and costly to utilize.
In addition to the difficulties currently encountered in forming multilayered films, similar difficulties have also arisen in forming other types of structures from a blend of viscous fluids. For example, when forming fibers from polymers within an extruder, the polymers are simultaneously sheared and melted such that the morphology of the blend often typically forms a dispersion of droplets. In order to form a fiber structure in one component, for example, the sizes of these droplets must be sufficiently large so that viscous forces acting on them can overcome interfacial tension (i.e., for capillary numbers exceeding the critical capillary number). To form such large droplets, the minor phase concentration must be high enough to promote coalescence of small droplets within the extruder.
Thus, at lower concentrations, minor component droplets do not undergo sufficient coalescence before arriving at the die entrance and thus, the small droplets cannot effectively form fibrils. Instead, in such situations, a dispersion of fine droplets is eventually obtained. On the other hand, when the concentration of the minor phase component is larger, coarser droplets and fibrils may eventually form.
In response to some of these difficulties, extruder designers have attempted to provide some control over blend morphology. For instance, extruder designers have provided limited processing flexibility by offering different screw designs, a range of shear rates, and adjustable operating temperatures. However, such design alterations and modifications are time-consuming, costly, and offer relatively no ability to selectively control blend morphology.
In addition, chaotic mixing has also been utilized to improve the blending of polymers. For example, one method for blending polymers using chaotic mixing was described, for example, in two articles entitled “Emergence of Fibrillar Composites Due to Chaotic Mixing of Molten Polymers” by Y. H. Liu and D. A. Zumbrunnen (Polymer Composites, Vol. 17, No. 2, April 1996) and “Auto-Processing of Very Fine-Scale Composite Materials by Chaotic Mixing of Melts” by D. A. Zumbrunnen, K. C. Miles, and Y. H. Liu (Composites, Part A, Vol. 27A, No. 1, 1996).
Moreover, another method, as described in “Chaotic Mixing in Extrusion-Based Melt Spinning of Fibers” by M. Ellison, D. Zumbrunnen, B. Gomillion, and Jiong Wang (National Textile Center Annual Report, http.//www.ntcresearch.org, November 1998) was also developed to form fibers utilizing chaotic mixing. In particular, as shown in
FIG. 1
, a continuous flow chaotic mixer
110
includes a fixed outer cylinder
112
and two rotating inner cylinders
114
and
116
. Two polymers can be provided to the mixer by two conventional extruders
118
and
120
. Within the mixer
110
, the polymers can be blended by rotation of the cylinders
114
and
116
.
Nevertheless, none of the above methods have been totally successful in fully controlling polymer blending to selectively form certain coherent structures (e.g., multi-layered films, fibers, interpenetrating blends, droplet dispersions, and the like) with desired characteristics, such as thin-layered, small diameter, etc.
As such, a need currently exists for an improved method of blending viscous fluids (e.g., polymers) and a method of controlling such blending to obtain certain coherent structures with desired characteristics.
REFERENCES:
patent: 3426754 (1969-02-01), Bierenbaum et al.
patent: 3558764 (1971-01-01), Isaacson et al.
patent: 3679538 (1972-07-01), Druin et al.
patent: 3801404 (1974-04-01), Druin et al.
patent: 3801692 (1974-04-01), Zimmerman
patent: 3843761 (1974-10-01), Bierenbaum et al.
patent: 4138459 (1979-02-01), Brazinsky et al.
patent: 4257997 (1981-03-01), Soehngen et al.
patent: 4734343 (1988-03-01), Berthier et al.
patent: 4833172 (1989-05-01), Schwarz et al.
patent: 5173235 (1992-12-01), Kamei et al.
patent: 5551777 (1996-09-01), Tjahjadi et al.
patent: 5798077 (1998-08-01), Womer et al.
patent: 5816698 (1998-10-01), Durina et al.
patent: 5921679 (1999-07-01), Muzzio et al.
patent: 6132076 (2000-10-01), Jana et al.
patent: WO 02/26489 (2002-04-01), None
Zumbrunnen et al, Composites, Pt A, vol. 27A, No. 1, pp. 37-47 (1996).*
Zhang et al, AIChE Journal, vol. 42, No. 12, pp. 3301-3309 (Dec. 1996).*
Michael Ellison, David Zumbrunnen, Bridgette Gomillion and Jiong Wang—“Chaotic Mixing in Extrusion-Based Melt Spinning of Fibers” National Textile Center Annual Report: Nov. 1999 entire document.
Michael Ellison and David Zumbrunnen—“Chaotic Mixing in Extrusion Based Melt Spinning of Fibers”—National Textile Center Research Briefs: Apr. 1999 entire document.
Michael Ellison and David Zumbrunnen—“Chaotic Mixing in Extrusion Based Melt Spinning of Fibers” National Textile Center Research Briefs: Aug. 1998 entire document.
Michael Ellison and David Zumbrunnen—“Chaotic Mixing in Extrusion Based Melt Spinning of Fibers” National Textile center research Briefs: Mar. 1998 entire document.
Michael Ellison and David Zumbrunnen—“Chaotic Mixing in Extrusion Based Melt Spinning of Fibers” National Textile center research Briefs: Aug. 1997 entire document.
Y.H. Liu and D.A. Zumbrunnen—“Toughness Enhancement in Polymer Blends Due to the In-Situ Formation by Chaotic Mixing of Fine Scale Extended Structures” Journal of Materials Science: Apr. 1999 entire document.
D.A. Zumbrunnen, K.jC. Miles and Y.H. Liu—“Auto Processing of Very Fine-Scale Composite Materials by Chaotic Mixing of Melts” Composits Part A Vo. 27A: 1996.
Michael Ellison and David Zumbrunnen—“Chaotic Mixing in Extrusion Based Melt Spinning of Fibers” National Textile center research Briefs: Nov. 1996 entire document.
R.I. Daniescu and D.A. Zumbrunnen—“Creation of Conducting Networks Among Particle in Polymer Melts by Chaotic Mixing” Journal of Thermoplastic Composit Materials: Jul. 1998.
Y.H. Liu and D.A. Zumbrunnen—“Emergence of Fibrillar Composits Due to Chaotic Mixing of Molten Polymers” Polymer Composits, vol. 17, No. 2: Apr. 1996.
R.I. Danescu and D.A. Zumbrunnen—“Assessment of Chaotic Mixing as a Means to Produce Electrically Conducting Polymer Composits with Metallic Powders” ANTEC Conference: 1996 entire document.
R.I. Danescu and D.A. Zumbrunnen—“Computational Simulation of the In Situ Formation in Melts of Electrical Pathways Among Particles Transported by Two Dimensional Chaotic Mixing” Proceedings of ASME Heat Transfer Division vol. 4, 1998 Entire document.
R.I. Danescu and David Zumbrunnen—“Creation of Electrically Conducting Plastics by Chaotic Mixing” ANTEC Conference: 1998.
R.I. Danescu—“Chaotic Mixing as a Means to Create Electrically Conducting Networks in Plastics” Doctorial Dissertation Entire document.
Michael Ellison—“Chaos in Polymer Phase Transitions” National Textile Center Annual Report: Aug. 1995 Entire document.
Michael Ellison, Bridgette Gomillion, David Zumbrunnen and Jiong Wang—“Chaotic Mixing in Extr
Kwon Ojin
Zumbrunnen David A.
Chapman Stephen R.
Clemson University
J B Patents. com
Nolan Sandra M.
LandOfFree
Chaotic mixing method and structured materials formed therefrom does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Chaotic mixing method and structured materials formed therefrom, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chaotic mixing method and structured materials formed therefrom will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3357551