摘要:
A method of designing a die cavity that may include performing a flow analysis using characteristics of a predetermined die cavity, density and rheological properties of a material, and a flow rate of the material to calculate the pressure distribution exerted on the die cavity and cross-sectional flow profile. The method further includes a structural analysis using the calculated pressure distribution and structural characteristics of the die cavity to calculate a deformed die cavity. The flow analysis is repeated using the characteristics of the deformed die cavity to calculate a pressure distribution exerted on the die cavity and cross-sectional flow profile. The outcome is compared to determine if the pressure distributions and/or cross-sectional flow profiles converge. These steps are iteratively repeated until convergence of the pressure and/or cross-sectional flow profile is observed. The variation of the cross-sectional flow profile is analyzed to determine if it is below a predetermined tolerance.
摘要:
Processes for the synthesis of polyol fatty acid polyester by transesterification of a polyol comprise reacting polyol with a first portion of fatty acid lower alkyl ester to provide a first step reaction product in which substantially all of the polyol is reacted with at least one fatty acid lower alkyl ester. The processes then employ a multistage column providing substantial plug flow of liquid therein for further transesterification of the first step reaction product. Partially esterified polyol, a second portion of fatty acid lower alkyl ester and catalyst are fed to the column to form a mixture and cause further transesterification of the partially esterified polyol and fatty acid lower alkyl ester, with lower alkyl alcohol being formed as a by product. The resulting liquid mixture of reactants and product is passed in a first direction between adjacent stages through the column for further reaction of partially esterified polyol with fatty acid lower alkyl ester. An inert stripping or sparging gas is fed through the column in a second direction between adjacent stages, counter current to the flow of the liquid mixture between adjacent stages in the first direction, with radial shear agitation. The lower alkyl alcohol by-product of the polyol-fatty acid lower alkyl ester reaction is transferred from the liquid mixture to the inert gas.
摘要:
A continuous process for making a flexible porous dissolvable solid structure with open celled foam. The continuous process has the steps of preparing a pre-mixture comprising surfactant, polymer, water, and optionally plasticizer; aerating the pre-mixture to form a wet aerated pre-mixture; extruding the wet aerated pre-mixture to form one or more sheets on a belt; and drying the sheets to form an Article having an open celled foam.
摘要:
A method of designing a die cavity can include performing a flow analysis using characteristics of a predetermined die cavity design, density and rheological properties of a material to be extruded, and a flow rate of the material to calculate the pressure distribution exerted on the die cavity and cross-sectional flow profile. The method further includes performing a structural analysis using the calculated pressure distribution and structural characteristics of the die cavity to calculate a deformed die cavity. The flow analysis is then repeated using the characteristics of the deformed die cavity to calculate a pressure distribution exerted on the die cavity and cross-sectional flow profile. The calculated pressure distributions and/or cross-sectional flow profiles are compared to determine if the pressure distributions and/or cross-sectional flow profiles converge. These steps are iteratively repeated until convergence of the pressure and/or cross-sectional flow profile is observed. Once convergence is observed, the variation of the cross-sectional flow profile is analyzed to determine if it is less than a predetermined tolerance.
摘要:
Polyol polyesters can be made by a transesterification reaction of a polyol with a lower alkyl fatty acid ester. A by product of that reaction are the alcohols from the lower alkyl esters. These are usually removed from the transesterification reaction by inert gas stripping. The process herein links the transesterification reaction with a lower alkyl ester formation reaction. The transesterification reaction acts as a the source of the lower alkyl alcohols for the formation of the lower alkyl esters used in the polyol fatty acid polyester synthesis. A preferred method for both reactions uses a reactive absorption column.
摘要:
A process for preparing esterified polyol fatty acid polyesters is provided, where the polyol has n hydroxyl groups. The process provides for independent control of the level of fully esterified polyols, on the one hand, and the level of n-3 and lower esters, on the other hand. The process is especially suited for preparing sucrose polyester, wherein the process provides for independent control of the level of octaesters, on the one hand, and penta and lower level esters, on the other hand. The process can be used to reduce the level of undesirable reaction byproducts, such as difatty ketone and beta ketoester.
摘要:
A process for purifying an inert gas stream from a transesterification reaction wherein a lower alkyl alcohol is released during the reaction is claimed. A second use of the process is to make a lower alkyl, e.g., methyl, esters of fatty acids through a transesterification reaction using gaseous alcohols as a source of the lower alkyl alcohols. The alcohol is diluted with nitrogen or other inert gas carrier and reacted with a fatty acid ester, preferably a triglyceride, to form the corresponding methyl or lower alkyl fatty acid ester.