Stock material or miscellaneous articles – Coated or structually defined flake – particle – cell – strand,... – Staple length fiber
Reexamination Certificate
1999-12-03
2001-02-27
Weisberger, Richard (Department: 1774)
Stock material or miscellaneous articles
Coated or structually defined flake, particle, cell, strand,...
Staple length fiber
C428S360000, C428S361000, C428S400000, C428S401000, C428S402000
Reexamination Certificate
active
06194065
ABSTRACT:
FIELD OF THE INVENTION
The present invention is in the field of agglomeration and more specifically it is concerned with uniform agglomerates of fibrous organic material and mineral material, and a method for their manufacture.
BACKGROUND OF THE INVENTION
Agglomerates of the above specified type are commonly used in the food, chemical, agrochemical and pharmaceutical industries and have many applications, e.g. fertilizers, liquid absorbents (for industrial environments and ecological purposes), herbicides, insecticudes, compost, animal feed, soil mixtures, etc.
However, each application requires an agglomerate having specific qualities, e.g. liquid absorption ability, color, smell, size, shape, taste, weight, hardness, low dust discharge, etc.
Preparing a uniform agglomerate in which each of the above qualities may be controlled, requires first particulating the fibrous material and reducing the size of the other components (mineral material and additives) into small, substantially homogeneous particles, thoroughly mixing and binding with a suitable binder, forming the agglomerate into the required size and shape and finally, drying.
Several agglomeration processes are known. According to one type of process, all the agglomeration ingredients are comminuted and mixed together with a binding agent in a wet form. Then, the mixture is introduced into a lower end of a long inclined drum, which drum comprises heating means and is rotatable along its longitudinal axis. The mixture agglomerates as it ascends along the rotating drum and as it exits from the top end of the drum, it is dry and ready for use.
Another agglomeration method uses a long, inclined conveyor belt for agglomerating the mixture, with heating means provided along the belt for drying the agglomerate.
Both these processes share several drawbacks. First, when using light fibrous organic materials such as paper or cotton, the agglomerate obtained is non-uniform that, owing to the relatively long agglomerating means. Second, the amount of energy required for these processes is substantially high, particularly since the agglomeration drum or belt are essentially long and heat is applied practically throughout their entire length for drying the agglomerate. Furthermore, the equipment is large and heavy and thus requires large space.
Still furthermore, approximately 15-20% of the agglomerate produced according to the above methods is off-size or out of shape and thus requires reprocessing by first re-comminuting the dry agglomerate and then agglomerating it again as above described, since the agglomerate can not be screened during the process in wet form, i.e. prior to drying.
Also, the high temperatures and relatively prolonged drying period required for drying the agglomerate is not suitable for certain materials, e.g. paper fiber, since they are likely to burn. Qualities of other organic materials may be damaged by the excessive heat.
Moreover, these processes provide less control of the above-mentioned qualities, in particular the important parameters of granules size, specific weight, liquid absorption ability and color.
It is the object of the present invention to provide a novel, essentially uniform aggregate of organic fibers and mineral powdered material, with the above-referred to disadvantages being significantly reduced or overcome. It is a further object of the invention to provide a process for the manufacture of such an agglomerate.
SUMMARY OF THE INVENTION
According to the present invention there is provided a process for obtaining an agglomerate comprising:
(a) providing a substantially dry particulated fibrous organic material;
(b) mixing the fibrous material with a powdered mineral to obtain a first mixture;
(c) adding a binding agent to the first mixture to obtain a second mixture;
(d) agglomerating the second mixture in an agglomeration dish; and
(e) drying the agglomerate to a desired dried state.
A further provision of the invention is that the dry particulated fibrous material is provided by processing a non-particulated fibrous organic material so as to separate the fibers from one another to obtain said particulated material.
The binding agent may be added in dry form to the first mixture and the second mixture is than humidified during the agglomeration step. Alternatively the binding agent is a liquid applied during the agglomeration step.
In order to obtain specific qualities of the agglomerate, any of a variety of dry additives are added to the fist mixture, or wet additives to the second mixture, wherein said additives are one or more members selected from the group consisting of fire retardants, color agents, odor absorbent, odor repellents, medical compositions, nutritives, flavoring agents, hardening agents, and moisture absorbents.
In order to minimize the amount of dust throughout the agglomeration process and to minimize environmental effect, the process further comprises removing by suction of dust emitted during the process and returning it to the mixing step.
In a preferred embodiment of the present invention, the dry non-particulated fibrous organic material is processed into particulated fibrous form in a thermo screw press, wherein the organic material is compressed between a pair of rotating screw members forcing it through throttle plates and drying it.
In still a preferred embodiment, the agglomerate discharged from the agglomeration dish is screened prior to drying, wherein off-size and off-shaped particles are disintegrated in wet state into the required size and shape.
For the process according to the present invention, the non-particulated fibrous organic material is one or more members selected from the group consisting of cellulose material or synthetic polymers, wherein the cellulose material is wood, paper or cotton, and the powdered mineral material is one or more members selected from the group consisting of fly ash, quarry dust, clay dust and construction industry waste, such as gypsum, cement etc. The binding agent is an organic substance selected from the group consisting of chemical and organic adhesives, resins and starches, such as, for example, paper pulp waste.
Still preferably, the particulated, dry fibrous organic material has an average length of about 1 mm. and the particle size of the powdered mineral material is less than about 50 &mgr;m. Furthermore, the non-particulated material comprises less than about 40% moisture, whereas after processing, the moisture content of the particulated material is less than about 15%.
The present invention further provides an agglomerate manufactured by the above process and is characterized in that the agglomerated granules are uniform in size.
In a preferred compound, the agglomerate manufactured according to the present invention has a specific weight of about 0.15-1.2 kg/l, and has a liquid absorbing capability of about 2.5-0.6 liter per 1 kg. of agglomerate, respectively.
In still a preferred embodiment, the organic material used for the agglomeration is derived from processed waste wood and the binding agent is paper pulp waste.
REFERENCES:
patent: 2972584 (1961-02-01), Wunder et al.
patent: 4560527 (1985-12-01), Harke et al.
patent: 4599002 (1986-07-01), Gutknecht
patent: 4621011 (1986-11-01), Fleischer et al.
patent: 4676196 (1987-06-01), Lojek et al.
patent: 4721059 (1988-01-01), Lowe et al.
patent: 5152250 (1992-10-01), Loeb
patent: 5176107 (1993-01-01), Buschur
patent: 5361719 (1994-11-01), Kiebke
patent: 5545385 (1996-08-01), Wunder et al.
patent: 5552099 (1996-09-01), Wunder et al.
patent: 41 42 999 A1 (1993-07-01), None
patent: 564 713 A2 (1993-10-01), None
patent: 1445330 (1976-08-01), None
patent: 94/07595 (1994-04-01), None
patent: WO 94/14529 (1994-07-01), None
Internation Search Report dated Jun. 26, 1997.
Green Top Wood Recycling Ltd.
Nath Gary M.
Nath & Associates
Weisberger Richard
Yellin Deborah H.
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