Machine for producing a cross-linked extruded product

Details Machine for producing a cross-linked extruded product Machine for producing a cross-linked extruded product

1994-06-28

1997-03-11

Kim, Christopher

Chemical apparatus and process disinfecting, deodorizing, preser

Chemical reactor

Organic polymerization

422131, 422137, 422229, 3661552, 3661691, 3661811, 26421121, 26421123, 425146, C08F 200, B01F 504, B29C 4738, B29C 9206

Patent

active

056098316

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND

1. Field of the Invention
This invention relates generally to a machine for producing extruded products, and more particularly to a machine for producing polymers that are cross-linked by adding at least one additive in a polymerization reaction.
2. Description of the Related Art
Machines for producing cross-linked extruded products are known, for example, from German patent 2,554,525, where it is designed as a screw extruder into which the polymer is fed through a feed hopper. The other ingredients that must be added to the polymer are usually injected in liquid form into the lower portion of the feed hopper or directly into the neck part of the extruder of this type of machine.
For complete and uniform cross-linking of polymers, it is crucial for adequate mixing of all ingredients to be achieved. However, this is precisely one of the main disadvantages of the known type of equipment. By merely injecting certain ingredients into the polymer, which is in the extruder feed hopper or in the neck of the extruder, a high additive concentration is achieved only in the area around the injection site. The reaction mixture must then be blended again during homogenization by means of an extruder worm gear with a complicated design as part of the extruder. In addition to the resulting unfavorable conditions for good cross-linking, this requires an extruder with a complex design that can be manufactured only at great expense.


SUMMARY OF THE INVENTION

The primary purpose of the present invention is to create a machine which permits better mixing of the ingredients of the reaction mixture and is less expensive to manufacture than known machines.
An essential feature of the machine according to this invention is that an additional mixing device for premixing all the ingredients of the reaction mixture is provided between the feed device for the plastic granules (polymer) and the extruder. It is especially advantageous here that all the ingredients of the reaction mixture are combined in a container suitable for this purpose, namely the mixer, and are blended together thoroughly until finally an optimum blend of the reaction mixture can be fed to the extruder.
This optimum blending of the ingredients of the reaction mixture also has a positive effect on the efficiency of the extruder as a whole, so the extruder screw required for the production process in the past, having a length/diameter ratio of 30.times.D can, according to this invention, be replaced by an extruder with a length/diameter ratio of 26.times.D. This lightweight extruder lowers the manufacturing cost of the system as a whole.
According to a preferred embodiment of the mixing device according to this invention, mixing takes place in the vertical direction. For this purpose, the mixing device has a central inlet for the plastic granules located at the top in the vertical direction and at least one feed device for an additive located on the side of the mixing device. The additive is injected horizontally through this additive feed port into the flow of granules entering vertically from above. Injection of one or more additives at right angles to the flow of the polymer results in a preliminary mixing of the ingredients of the reaction mixture by means of the flow effect. This is especially so when these feed devices are arranged in the upper area of the mixer, and then after the ingredients of the reaction mixture have filled the interior volume of the mixer from the bottom, they are mixed mechanically a second time with the help of a stirring rod.
The first phase of mixing can be optimized further by arranging the stirring rod coaxially by means of struts running radially from the rod to the mass flow of the incoming plastic granules. With such a stirring rod arrangement, the individual granular particles strike the mounting struts and the stirring rod and thus enter the interior of the mixer with a high degree of turbulence, so the additives injected horizontally are better able to wet the turbulent granular particles. At the same time this

REFERENCES:
patent: 3378235 (1968-04-01), Udy et al.
patent: 3647493 (1972-03-01), Gresch et al.
patent: 3838976 (1974-10-01), Bosch
patent: 3985345 (1976-10-01), Jakob
patent: 4323314 (1982-04-01), Kaiser-wirz
patent: 4363784 (1982-12-01), Hilbig et al.
patent: 4370302 (1983-01-01), Suzuoka et al.
patent: 4778280 (1988-10-01), Brazelton
patent: 4937034 (1990-06-01), Sewell

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