Usm Corporation

Other

Scientific Process & Research, Inc.

Zehev Tadmor

Peter Hold

Lefteris N Valsamis

Pradip S Mehta

Hans R Scharer

Imrich Klein

Arthur D Siegel

Jan-Chin Yang

A machine for processing solid and viscous plastic materials includes a screw element having a shearing flight and a scraping flight. Upon rotation of the screw, the shearing flight shears the plastic material and the scraping flight guides the material to the shearing flight. Preferably, the screw includes a plurality of threads which extend from one end of the screw to the other, and which include a plurality of shearing and scraping flights.

Screw element having shearing and scraping flights

A rotary processor for high-shear processing of plastic or polymeric materials comprises a rotor having end discs and at least one mixing disc therebetween, the rotor closely surrounded by a housing to defined annular processing chambers flanking each mixing disc, with a high-shear-mixing transfer gap defined between the mixing disc and the housing. Channel blocks are deployed at circumferentially spaced apart positions in adjacent chambers to cause transfer of material through the transfer gaps, with dispersive mixing occurring in the transfer gaps. Some embodiments have plural channel blocks in the chambers, evenly spaced apart. The channel blocks extend generally into and to the bottom of a chamber, and have two working surfaces divergent from a central region of the chamber and convergent toward the disc walls defining the chamber. The working surfaces and disc walls defined two high-shear-mixing recycle gaps through which a portion of the material passes and is mixed. The channel block configuration is also used in a single chamber rotary processor.

Rotary processor apparatus and method for extensive and dispersive mixing

Novel rotary processors and devolatilizing methods which provide extremely efficient devolatilization of materials, including viscous and visco-elastic materials and which involve a devolatilizing stage including a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial closure surface operationally arranged with the channels to provide enclosed processing passages. Each passage of the devolatilizing stage includes inlet means, outlet means and a channel blocking member all associated with the stationary element and arranged and adapted so that material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. The passages are interconnected by material to transfer grooves formed in the closure surface and operationally communicate with a vacuum source to provide a highly efficient devolatilizing stage. The novel devolatilizing stage is characterized by features which provide control of the processing volume available within the passages and of the transfer volume available within the transfer grooves. These volumes may then be coordinated with other processing variables to effect a foam devolatilizing mechanism in which nucleation of bubbles of volatiles within the material, bubble growth and bubble rupture occur during substantially plug-flow movement alternating with non-pressurizing shearing within the novel devolatilizing stage.

Rotary processors for devolatilizing materials

Rotary processors and method for devolatilizing materials

Novel rotary processors and methods which provide extremely efficient devolatilization of particulate materials which contain substantial amounts of volatiles and in which the boiling point of the volatiles presents separation problems. The processors and methods involve a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial closure surface operationally arranged with the channels to provide enclosed processing passages. Each passage includes inlet means, outlet means and a channel blocking member all associated with the stationary element and arranged and adapted so that material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. The passages are interconnected by material transfer grooves formed in the closure surface and are arranged to provide at least a melting stage and a devolatilizing stage which operationally communicates with a vacuum source. In the preferred embodiment, particulate material sprayed with a devolatilization aid or carrier substance is fed to the melting stage through a vacuum hopper, melted, collected and transferred through a strand die mounted at the inlet to the devolatilizing stage. The material in the form of thin strands undergoes unrestricted flash foaming while falling a predetermined distance into the devolatilizing passage, is carried forward, collected, sheared to release the volatiles and is discharged from the devolatilizing stage.

Rotary processors and devolatilizing methods for particulate materials

Novel and improved processes and apparatus for processing particulate materials which can be converted to the liquid state. Essentially, the process and apparatus involve feeding a particulate material to an annular processing passage for melting and controlled processing. The annular processing passage is provided by a rotatable element carrying at least one processing channel, and a stationary element which provides a complementary, coaxial surface arranged with the channel to provide the enclosed processing passage. Also associated with the stationary element are an inlet for feeding material to the passage, an outlet for discharging material, a material collecting end wall surface for the passage and a member or members extending into the processing channel providing a material restraining surface between the inlet and outlet and occupying a predetermined portion of the melt pool space between the end wall and the restraining surface. Rotation of the rotatable element establishes relative movement between the rotating inner channel wall surfaces and the restrained particulate material, causing only liquid (melted) material in contact with the rotating channel walls to be dragged forward to the end wall surface for controlled processing and discharge. Controlling the size of the melt pool space provides control of processing characteristics for the liquid material collected in the melt pool space.

Process and apparatus for processing plastic and polymeric materials

Novel and improved methods and apparatus for processing liquid or viscous materials. Essentially, the methods and apparatus involve feeding liquid materials to an annular processing passage for controlled processing. The annular processing passage is provided by two elements. One is a rotatable element carrying at least one processing channel. The other element is stationary and provides a complementary coaxial surface arranged with the channel to provide the enclosed processing passage. Also associated with the stationary element are an inlet for feeding material to the passage, an outlet for discharging material from the passage, an element near the outlet providing a material collecting end wall surface and an element positioned between the inlet and outlet providing a liquid material spreading surface. Rotation of the rotatable element toward the spreading surface provides a coaction between the rotatable element and the spreading surface so that relative movement is established between the rotating inner channel walls and liquid material between the inlet and the spreader surface. Because of the relative movement, the liquid material is spread toward the walls and dragged by the walls through a clearance between the sides of the spreading surface providing member and the side walls as thin layers providing central spaces of the passage downstream of the spreader surface which are free of liquid material. Means are arranged for communicating with the free central spaces to add materials to or withdraw materials from the free central space.

Method for processing plastic and polymeric materials

Novel, improved rotary processors which include a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial, closure surface operationally arranged with the channels to provide enclosed processing passages. The so-formed plurality of processing passages provide a highly efficient processing stage particularly for melting polymer material. Each processing passage of the processing stage includes inlet means, outlet means and a channel member associated with the stationary element and arranged and adapted so that material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. In rotary processors of this invention the clearance between the rotary surface carrying the channels and the stationary coaxial closure surface is relatively wide and permits substantial amounts of material to be interchanged between passages of the processing stage. The interchange provides especially efficient, intensive mixing for material processed in the stage. Also, the interchanged material which passes through the relatively wide clearance can be subjected to conditions of high shear and high temperatures.

Rotary processors

Apparatus for processing plastic and polymeric materials

Sealing means for controlling leakage of material between closely spaced apart, relatively moving coaxial annular surfaces. Essentially, leakage is controlled by providing a plurality of helical sealing channels on one of the relatively moving surfaces to resist flow of leakage liquid between the surfaces. The sealing means are particularly adaptable for controlling leakage from processing passages of rotary processing apparatus.

Seals for rotary processor

A seal construction and rotary processor including the seal construction in which the seal includes nested truncated conical members of thin stiffly-resilient material interposed between relatively rotatable coaxial surfaces with inner edge portions of the members adjacent and in flow resistant relation to one, and outer edge portions adjacent and in flow resistant relation to the other of the surfaces, marginal portions at either the inner or the outer edge portions of the loops being held to enable pressure against the loops to force the outer or inner edges respectively into improved sealing relation to the surface to which they are adjacent.

Rotary seal construction and processor

Improved means for aligning processing members at various positions in processing passages of rotary processors. Essentially, the alignment means (or alignment elements) comprise a non-rotatable member positioned in the processing passage and shaped to at least partially interfere with flow of material in the passage. The shaped member is designed to perform certain processing functions on material in the passage such as blocking, collecting, mixing, spreading, restraining etc. The member is positioned so as to be non-rotative with the passage but is flexibly supported so as to 'float' axially in the passage and is self-centering in the passage by hydrodynamic action.

Processing element

A multi-stage rotary processor for plastic and polymeric materials which are, or become in the course of processing, viscous liquids, including an annular housing, a rotor coaxial with and rotatable with respect to the housing and having a cylindrical surface in slidable sealing relation with the interior of the housing, a plurality of annular channels formed in the cylindrical surface and cooperating with the housing to form annular processing passages, transfer passages, which are preferably channels in the surface of the housing for cooperation with the cylindrical portions of the rotor, to provide passage for transfer of material between processing passages and blocking members extending into the channels to hold material in the processing passages for relative movement with respect to the channel walls for processing. In a preferred structure the transfer channels are formed and the blocking members may be mounted in removable flow director units including surfaces forming part of the surface of the annular housing.

Rotary processor

An extruder machine for processing thermoplastic materials such as low density polyethylene, the extruder incorporating a body having a bore therethrough with a rotor or screw journalled therein. The rotor has several successive mixing and pumping sections. The mixing sections on the rotor are multiple flighted defining primary and secondary channels having their discharge and entrances respectively blocked or restricted by annular dam arrangements. The rotor includes a plurality of adjustable dams, arranged across the channels, permitting a variation in the degree of homogenization which may be performed upon the extrudite. The dams may be radially displaceable to vary the distance between the radially outer surface of the dam and the surface of the bore.

Adjustable homogenization extruder

Sealing means for controlling leakage of material between closely spaced apart, relatively moving coaxial annular surfaces. Essentially, leakage is controlled by providing a pumping channel on one of the surfaces and a leakage liquid retaining channel on the other surface. The pumping and leakage liquid retaining channels are cooperatively arranged to resist flow of leakage liquid between the surfaces. The sealing means are particularly adaptable for controlling leakage from processing passages of rotary processing apparatus.

Growing community of inventors

Teaneck, NJ, United States of America

Zehev Tadmor