Paper sheet mulches and methods of making the same

Abstract

The present disclosure provides novel paper sheet mulch products having benefits over prior sheet mulches, which may include brown or recycled fibers, as well as additives, such as opacity, water-resistant, and strength additives, resulting in mulch products with an improved combination of basis weight, stretch, strength, opacity, and/or water-resistance characteristics.

1 . A paper sheet mulch comprising:
 at least about 75% cellulosic papermaking fibers based on the dry weight of the sheet, a basis weight of from about 25 lb/3000 ft 2  to about 45 lb/3000 ft 2 , an opacity of at least about 95%; and a machine-direction stretch of at least about 5% and a cross machine-direction stretch of at least about 5%.   
     
     
         2 . The paper sheet mulch of  claim 1 , comprising from about 75% to 100% recycled cellulosic fibers based on the dry weight of the paper sheet. 
     
     
         3 . The paper sheet mulch of  claim 2 , wherein the recycled cellulosic fibers comprise one of old newsprint fibers, corrugated container fibers, mixed recycled paper fibers, and combinations thereof. 
     
     
         4 . The paper sheet mulch of  claim 1 , comprising from about 75% to 100% cellulosic fibers with an ISO brightness of less than about 80 based on the dry weight of the paper sheet. 
     
     
         5 . The paper sheet mulch of  claim 1 , comprising a contact angle with water of at least about 75°. 
     
     
         6 . The paper sheet mulch of  claim 1 , comprising a kappa number of at least about 70. 
     
     
         7 . The paper sheet mulch of  claim 1 , comprising at least one opacity modifier comprising one or more of carbon black, biochar, a pigment, a dye, clay, kaolin, titanium oxide, and combinations thereof. 
     
     
         8 . The paper sheet mulch of  claim 7 , wherein the at least one opacity modifier comprises a black or blue pigment. 
     
     
         9 . The paper sheet mulch of  claim 7 , wherein the at least one opacity modifier comprises carbon black. 
     
     
         10 . The paper sheet mulch of  claim 1 , comprising at least one water-resistant modifier comprising one or more of an acrylic, wax, alkenyl ketene dimer (ALKD), alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), fluorochemical, silicone, hydrophobically modified anionic polymer (HMAP), hydrophobically modified cationic polymer (HMCP), ethylene-acrylic acid (EAA), neutral rosin emulsion, and combinations thereof. 
     
     
         11 . The paper sheet mulch of  claim 1 , comprising at least one wet strength additive comprising one or more of an aliphatic aldehyde, aromatic aldehyde, urea-formaldehyde resin, melamine formaldehyde resin, polyimide-epichlorohydrin resin, and combinations thereof. 
     
     
         12 . The paper sheet mulch of  claim 1 , comprising at least one dry strength additive comprising one or more of a starch, guar gum, polyacrylamide, carboxymethyl cellulose, and combinations thereof 
     
     
         13 . The paper sheet mulch of  claim 1 , wherein the sheet is single-ply. 
     
     
         14 . The paper sheet mulch of  claim 1 , comprising a caliper of from about 4 mils/1 sht to about 8 mils/1 sht. 
     
     
         15 . The paper sheet mulch of  claim 1 , comprising a machine-direction tensile strength of from about 5 lb/1 in to about 18 lb/1 in and a cross machine-direction tensile strength of from about 2 lb/1 in to about 10 lb/1 in. 
     
     
         16 . The paper sheet mulch of  claim 1 , comprising a 0.1 ml water absorption rate of at least about 90 seconds 
     
     
         17 . The paper sheet mulch of  claim 1 , comprising a machine-direction wet tensile strength of at least about 3 lb/1 in. 
     
     
         18 . The paper sheet mulch of  claim 1 , comprising biodegradation rate of from about 200 mg to about 700 mg CO2 in 45 days. 
     
     
         19 . A method of making a paper sheet mulch comprising:
 manufacturing a non-woven paper sheet having a basis weight of from about 25 lb/3000 ft 2  to about 45 lb/3000 ft 2  on a paper-making machine from a furnish comprising at least about 75% cellulosic papermaking fibers based on the dry weight of the sheet;   adding at least one opacity modifier to the sheet, such that the paper sheet has an opacity of at least about 95%; and   creping the sheet;   wherein the sheet has a machine-direction stretch of at least about 5% and a cross machine-direction stretch of at least about 5%.   
     
     
         20 - 36 . (canceled)