Agitating – Rubber or heavy plastic working – With specified discharge means
Reexamination Certificate
1998-10-16
2001-09-11
Cooley, Charles E. (Department: 1723)
Agitating
Rubber or heavy plastic working
With specified discharge means
C366S272000
Reexamination Certificate
active
06286988
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an extrusion head being suitable for homogenizing, mixing and heating/cooling of the material supplied from the extruder before it.
2. Description of the Prior Art
The toothed wheel of the present invention is driven for the adjustable shear effect and thus it can increase the mixing effect and the outlet temperature combined with a high shear speed and so it releases the vulcanization process. An extrusion head with shear effect to reach a predetermined temperature for elastomers is known and already in operation. A mixing effect cannot be achieved by this known extrusion head. The shear head technology is cost-intensive in that it is expensive to buy and has a relatively high energy consumption. Furthermore, some manufacturers in the plastics and rubber industry use such combinations of extruders with preflanged gear pumps in order to achieve a continuous final product with less pulsation. This process also does not provide a mixing process. Furthermore, German Patent publication DE3024552A1 shows a tangent system working with different circumferential speed and wiping blades in an open trough to discharge the material. German Patent Publication DE4114265A2 shows a toothed wheel system in a trough to melt plastic granulates or flakes being pressed out by the toothed wheel system to enable a filtering process.
German Patent Publication DE3426436A1 shows a combination of tangent systems working into each other.
The actual two-step pump design achieves a better heating of the material to be processed by the double crushing of material from the tooth gaps. This results in further savings at the following heating times.
The earlier described systems cannot produce a defined mixing process as well as not providing controllable friction heat.
SUMMARY OF THE INVENTION
The invention is based on the problem that an extruder with mixing effect has to be designed in that the material flows out of the extrusion nozzle in an homogenized and mixed way at a predetermined temperature.
According to a preferred embodiment of the invention, an extrusion head is provided for homogenizing, mixing and heating or cooling material supplied by an extruder. The material supplied flows around an upper divided toothed wheel and fills all gaps of the toothed wheels in the assembly. The material flow is regulated by a dam. The material supplied in the outer areas of a lower toothed wheel is returned again and is crushed through the upper divided toothed wheel into the outer area in axial direction to the center where it is mixed with the extruded material; then it flows to the outlet of the extrusion head again. The shear and mixing effect can be predetermined by the toothed wheel geometry.
An object of the invention is to provide an extrusion head with a mixing device for providing an adjustable mixing effect adapted for different materials and careful homogenization because of shearing.
Another object is to provide an extrusion head with a mixing device which generates no thermal load by friction during the extrusion process.
Yet another object is the provision of an extrusion head with a mixing device and a continuous material outlet due to the optimum homogenization.
It is also an object to provide an extrusion head with a mixing device for yielding extrusion products made of difficult materials with dimensional accuracy greater than that of the prior art.
Yet a further object of the invention is to provide an extrusion head with a mixing device for producing prevulcanized elastomers.
Another object is the provision of an improved extrusion system with a reduced extruder length.
It is still a further object to produce an improved extrusion system having decreased energy and investment costs.
Other objects will be apparent from the description herein and the appended claims.
For a further clarification of its basic principle, two of the design types of the invention are shown in the drawings and are described hereinafter:
REFERENCES:
patent: 1595470 (1926-08-01), Johnson
patent: 2481646 (1949-09-01), Conklin
patent: 2487732 (1949-11-01), Schanzlin
patent: 2515201 (1950-07-01), Dulmage et al.
patent: 2692405 (1954-10-01), Gayler
patent: 2767437 (1956-10-01), Marshall
patent: 2871794 (1959-02-01), Mosbacher
patent: 2880455 (1959-04-01), Mineah
patent: 3174408 (1965-03-01), Miller
patent: 3177127 (1965-04-01), Longstreth
patent: 3831906 (1974-08-01), Wakeman
patent: 4097206 (1978-06-01), Schonherr
patent: 4336213 (1982-06-01), Fox
patent: 4642040 (1987-02-01), Fox
patent: 4707139 (1987-11-01), Valenzky et al.
patent: 4721589 (1988-01-01), Harris
patent: 5048405 (1991-09-01), Takahashi et al.
patent: 5076770 (1991-12-01), Dabling et al.
patent: 5108275 (1992-04-01), Sager
patent: 5153009 (1992-10-01), Voigt
patent: 5190450 (1993-03-01), Ghosh et al.
patent: 5267847 (1993-12-01), Bohm et al.
patent: 5304053 (1994-04-01), Gohlisch et al.
patent: 5310256 (1994-05-01), Boden
patent: 5378415 (1995-01-01), Gohlisch
patent: 5829872 (1998-11-01), Mizuguchi et al.
patent: 93020 (1972-10-01), None
patent: 3133647 (1983-03-01), None
patent: 3833777 (1990-10-01), None
patent: 0 165 218 A3 (1985-05-01), None
patent: 58-24405 (1983-02-01), None
patent: 58-183210 (1983-10-01), None
Plastics Engineering, Specifying a Total Gear Pump System, Feb. 1994, pp. 19-23.
Cooley Charles E.
Hochberg D. Peter
Holt William H.
Vieyra Katherine R.
LandOfFree
Extrusion head having toothed wheels with mixing device and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Extrusion head having toothed wheels with mixing device and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extrusion head having toothed wheels with mixing device and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2544643