Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – With washing
Patent
1993-06-29
1996-09-24
Lamb, Brenda A.
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
With washing
162 5, 162 4, 134 26, D21B 132
Patent
active
055587453
DESCRIPTION:
BRIEF SUMMARY
The present application relates to the treatment of absorbent sanitary paper products in a manner that provides materials that may be recycled for further use. As used herein, absorbent sanitary paper products include disposable diapers, incontinence products, feminine hygiene products, bedpads and other related absorbent and adsorbent products.
Absorbent sanitary paper products typically consist of (i) a non-woven sheet formed from a liquid permeable material, for example a liquid permeable membrane formed from polypropylene, polyethylene, or woven products formed from cotton or rayon, (ii) a liquid impermeable back sheet formed from for example polyethylene, polypropylene, starch based degradable plastic films, woven cloth or rubber, and (iii) an adsorbent or absorbent core of air laid wood pulp fluff, commonly referred to as air felt, and/or synthetic pulp including polypropylene or polyethylene filaments that may be bonded or unbonded, hemp or other adsorbent fibrous material. The core is typically wrapped or encased in a creped envelope of wet strength tissue paper or a material with similar characteristics. The wrapping on the core may or may not be breathable, biodegradable, odour degradable or degradable or dissolvable by other means. The core usually also contains a super absorbent polymer (SAP) material, which is typically a polyacrylate, polyacrylamide, crosslinked starch or other hydrophilic component, which may be synthetic, and may be in granular, fibrous or laminate form, possessing the ability to bond with water, urine or other body fluids or retain them without substantial release or discharge from the absorbent portion. Diapers and incontinence products typically utilize pressure sensitive adhesives for refastenable tape tabs or similar closure mechanisms. Feminine hygiene pads and incontinence products often use pressure sensitive adhesives for glue lines to attach the pad or liner to the user's undergarments. Diaper and incontinence products typically utilize elastic, polyurethane, puckering and welding or adhesives to create close fitting cuffs around the leg and waist openings to provide a more leakproof fit.
Absorbent sanitary paper products are normally disposed of along with garbage generated by households, institutions, hotels and the like, by incineration or in landfill disposal sites. Incineration tends to result in air or other pollution being generated. Landfill disposal results in an accumulation of such products.
Thus, the consequences of the convenience or necessity of use of absorbent sanitary paper products include problems relating to disposal of such products. In addition, use of either incineration or landfill disposal results in loss or destruction of the components of the absorbent sanitary paper products, rather than recycling some or all of those components to the same or other end-uses. The disposal problems are becoming of ever increasing concern to environmental and governmental authorities, and means are required for effective disposal and utilization of used absorbent sanitary paper products.
Continuous batch type washing machines for the washing of cloth goods are described by N.L. Pellerin et al in U.S. Pat. No. 4,485,509, issued 1984 Dec. 4, and by J. M. Katzfey in Canadian Patent 1,115,075, issued 1981 Dec. 29. U.S. Pat. No. 4,162,019 of C. G. Joa, issued 1979 Jul. 24, describes cutting of sanitary articles to expose the filler and then recovery of the filler using suction means; the plastic backing film is discarded. U.S. Pat. No. 4,500,040 of B. Steffens, which issued 1985 Feb. 19, describes shredding of sanitary articles followed by recovery of the filler using suction means. In U.S. Pat. No. 4,303,501, issued 1981 Dec. 1, Steffens describes the use of sieves to recover flock and cut absorbent materials from discarded sanitary articles. In U.S. Pat. No. 4,592,115, which issued 1986 Jun. 3, S. Holmstrom discloses apparatus and a process for separating cellulose fluff fibres from waste fibrous material using an apertured cylindrical separator. The aforeme
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Conway Marlene E.
Jooste Francois
Smith Michael D.
Knowaste Technologies Inc.
Lamb Brenda A.
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