Porous low density shot-like degradable absorbent materials and manufacturing process therefor
First Claim
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1. A process for forming discrete, shot-like, absorbent pellets having a bulk density in the range of from about 13 lbs./ft.3 to less than 30 lbs./ft3 and minimal inorganic solids content wherein each of the pellets is characterized by:
- i) a smooth, soft, porous, compressible, generally rounded external configuration essentially devoid of projecting fiber ends;
ii) a soft, open, porous compressible, internal fiber structure; and
iii), an absorptive capacity in terms of percentage by volume in excess of about 53%, said process comprising the steps of;
a) obtaining cellulose fiber materials having minimal inorganic solids content;
b) rehydrating the cellulose fiber materials to produce a water/fiber slurry comprising on the order of about 96.5% water by weight and about 3.5% total solids by weight;
c) de-watering the slurry to form a shreddable press cake containing total solids in the range of about 15% to about 50% by weight;
d) shredding the press cake to form discrete particles each having a maximum dimension of not more than about 1/2";
e) rolling the discrete shredded particles formed in Step (d) in an agglomerator so as to gather a plurality of discrete shredded particles into soft, discrete, shot-like, agglomerated, compressible pellets each having a smooth, soft, porous, compressible outer surface essentially devoid of projecting fiber ends and a soft, open, porous, compressible internal fiber structure; and
,f) drying the pellets formed in Step (e) to remove excess water resulting in discrete shot-like pellets having a total dry solids content in excess of 75% by weight, a bulk density in the range of from about 13 lbs./ft.3 to less than 30 lbs./ft.3, and an absorptive capacity in terms of percentage by volume in excess of about 53%.
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Abstract
Degradable particulate absorbent materials and processes for manufacture, wherein the absorbent materials have: i) in most forms of the invention, on the order of not more than 10% by weight inorganic solids or "fillers" and in all cases less than 30% inorganic solids by weight; ii) an open, porous, shot-like fiber structure with low bulk density on the order of not more than 30 lbs./ft.3 and, preferably, in the range of 15 to 18 lbs./ft.3.
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32 Claims
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1. A process for forming discrete, shot-like, absorbent pellets having a bulk density in the range of from about 13 lbs./ft.3 to less than 30 lbs./ft3 and minimal inorganic solids content wherein each of the pellets is characterized by:
- i) a smooth, soft, porous, compressible, generally rounded external configuration essentially devoid of projecting fiber ends;
ii) a soft, open, porous compressible, internal fiber structure; and
iii), an absorptive capacity in terms of percentage by volume in excess of about 53%, said process comprising the steps of;a) obtaining cellulose fiber materials having minimal inorganic solids content; b) rehydrating the cellulose fiber materials to produce a water/fiber slurry comprising on the order of about 96.5% water by weight and about 3.5% total solids by weight; c) de-watering the slurry to form a shreddable press cake containing total solids in the range of about 15% to about 50% by weight; d) shredding the press cake to form discrete particles each having a maximum dimension of not more than about 1/2"; e) rolling the discrete shredded particles formed in Step (d) in an agglomerator so as to gather a plurality of discrete shredded particles into soft, discrete, shot-like, agglomerated, compressible pellets each having a smooth, soft, porous, compressible outer surface essentially devoid of projecting fiber ends and a soft, open, porous, compressible internal fiber structure; and
,f) drying the pellets formed in Step (e) to remove excess water resulting in discrete shot-like pellets having a total dry solids content in excess of 75% by weight, a bulk density in the range of from about 13 lbs./ft.3 to less than 30 lbs./ft.3, and an absorptive capacity in terms of percentage by volume in excess of about 53%. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 23, 24, 26, 27, 28, 29, 31, 32)
- i) a smooth, soft, porous, compressible, generally rounded external configuration essentially devoid of projecting fiber ends;
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2. A process for forming discrete, shot-like absorbent pellets having a bulk density in the range of about 13 to about 18 lbs./ft.3 and minimal inorganic solids content wherein each of the discrete pellets is characterized by:
i) a smooth, soft, porous, compressible, generally rounded external configuration essentially devoid of projecting fiber ends;
ii) a soft, open, porous, compressible, internal fiber structure; and
iii), an absorptive capacity in terms of percentage by volume in excess of about 53% said process comprising the steps of;a) obtaining cellulose fiber materials having minimal inorganic solids content; b) rehydrating the cellulose fiber materials to produce a water/fiber slurry comprising on the order of about 96.5% water by weight and about 3.5% total solids by weight; c) de-watering the slurry to form a shreddable press cake containing approximately 25% total solids by weight; d) introducing the press cake into a first coarse shredding device such as one of a cake breaker and a cut-and-fold screw conveyor and reducing the press cake to particles smaller in size than about 4"×
2"×
1/2";e) introducing the particles formed in Step (d) into a second shredding device such as one of a high shear turbulator, a high shear blender and a high shear shredder and reducing the particle size to approximately 1/2" maximum size; f) delivering the particles formed in Step (e) to one of a rotary pan agglomerator, a drum agglomerator and a rotary dryer; and
, rolling such particles therein to gather a plurality of discrete shredded particles into pellets having;
i) smooth, soft, porous, compressible, shot-like external configurations essentially devoid of projecting fiber ends; and
ii), soft, open, porous, compressible, internal fiber structures; and
,g) drying the shot-like pellets formed in Step (f) to remove excess water resulting in discrete, smooth, soft, compressible, shot-like, porous absorbent fiber pellets having a total solids content in the range of about 88% to about 95% dry solids by weight, a bulk density in the range of about 13 to about 18 lbs./ft.3 and an absorptive capacity in terms of percentage by volume in excess of about 53%. - View Dependent Claims (20, 21, 22, 25, 30)
Specification