28-01-2021 дата публикации
Номер: US20210025112A1
Methods for preparing aqueous suspensions comprising microfibrillated cellulose, and optionally inorganic particulate material, with increased tensile properties, and methods for selecting a fibrous substrate comprising cellulose for preparation of microfibrillated cellulose having increased tensile properties. 173.-. (canceled)74. A method for preparing an aqueous suspension comprising microfibrillated cellulose with increased tensile properties and further comprising inorganic particulate material , the method comprising the steps of:(i) providing a multiplicity of fibrous substrates comprising cellulose;(ii) determining the zero-span tensile index in Nm/g and hemicellulose content of the fibrous substrates comprising cellulose;(iii) predicting the MFC tensile index in Nm/g from the product of the hemicellulose content and fibre zero-span tensile index of the fibrous substrates comprising cellulose;(iv) selecting the fibrous substrates comprising cellulose having a desired MFC tensile index; and(v) microfibrillating the fibrous substrates comprising cellulose in an aqueous environment by grinding in the presence of a grinding medium, wherein the grinding is carried out in the presence or the absence of grindable inorganic particulate material.75. The method according to claim 74 , wherein the grinding is carried out in the presence of grindable inorganic particulate material.76. The method according to claim 74 , wherein the grinding is carried out in the absence of grindable inorganic particulate material.77. The method according to claim 74 , wherein the predicted MFC tensile index is calculated using the equation T=ZH+σ claim 74 , wherein Z represents the zero-span tensile index of the fibre in Nm/g claim 74 , H represents the hemicellulose content (mass fraction) claim 74 , B2 is a proportionality coefficient claim 74 , and σis a constant.78. The method according to claim 74 , wherein the grinding medium is removed at the completion of grinding.79. The method ...
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