Abstract:
A side stream compounding unit is coupled to a continuous polyamide manufacturing system and is configured to divert polyamide from the manufacturing system, mixes additive with polyamide, and then return the polyamide-additive mixture to a main stream of polyamide in the manufacturing system.
Abstract:
Described herein are methods of preparing high molecular weight polyamides which reduce or eliminate the production of unwanted gels during the production process. These methods reduce the formation of undesired polyamide gel by polishing the internal surfaces of the production equipment, thereby providing surfaces with smaller surface roughness values.
Abstract:
The present invention relates to methods, systems, and apparatus for making polyamides having at least two heat-transfer media for transferring heat to a tubular reactor. The method includes heating a first flowable heat-transfer medium, to provide a heated first flowable heat-transfer medium. The method includes transferring heat from the heated first flowable heat-transfer medium to a second flowable heat-transfer medium, to provide a heated second flowable heat- transfer medium. The method also includes transferring heat from the heated second flowable heat-transfer medium to a tubular reactor of a polyamide synthesis system.
Abstract:
The present disclosure relates to methods and systems for monitoring for gel formation in the production of a polyamide product. In one embodiment, the present invention provides a method that can include directing a partially polymerized polyamide mixture through a flasher feed pump, a finisher pump, and a transfer line pump. The method can include switching the flasher feed pump, the finisher pump, and the transfer line pump from a first operating mode to a second operating mode. The method can include activating a gel time control unit and can be activated to estimate a gelation time for at least one of a flasher, a finisher, and a transfer line. The method can include switching a reactor of the polyamide synthesis system from the first operating mode to the second mode.
Abstract:
Systems and processes are described herein for drying polyamide pellets. The system can include a spin dryer that removes a majority of surface water from wet polyamide pellets to generate partially dried pellets. The system can also include a fluid bed dryer that dries and transports the partially dried pellets from the spin dryer to produce dried polyamide pellets.
Abstract:
The present disclosure relates to systems and methods for recovering water from a condensation reaction of at least one carboxylic acid and at least one diamine to make polyamide. The method can include obtaining, from an evaporator, an aqueous mixture comprising a partially polymerized polyamide and at least one of a carboxylic acid and diamine; passing the aqueous mixture through a tubular reactor comprising subjecting the aqueous mixture to a temperature and pressure sufficient to further polymerize the partially polymerized polyamide by condensation of the carboxylic acid and diamine, thereby producing water having a substantially gaseous phase; passing the water having a substantially gaseous phase into a rectification column thereby removing one or more of a diamine, a carboxylic acid and polyamide to provide purified water having a substantially gaseous phase; and condensing the purified water having a substantially gaseous phase into purified water having a substantially liquid phase. The system can include, among other things, a tubular reactor, a rectification column, a condensation assembly, and a conduit network.
Abstract:
The present invention relates to methods, systems, and apparatus for making polyamides having at least two heat-transfer media. The method includes heating a first flowable heat-transfer medium, to provide a heated first flowable heat-transfer medium. The method includes transferring heat from the heated first flowable heat-transfer medium to a second flowable heat-transfer medium, to provide a heated second flowable heat-transfer medium. The method also includes transferring heat from the heated second flowable heat- transfer medium to at least one polyamide-containing component of a polyamide synthesis system.
Abstract:
The invention provides polyester polyol compositions, useful as components of polyurethane and polyisocyanurate polymers, prduced from cyclohexane oxidation reaction byproducts, such as water extracts and non-volatile distillation residues from the reaction. Such byproducts of industrial processes for preparation of adipic acid and caprolactam, important intermediates in the production of various types of nylon, have hitherto largely been used only as fuels. The present invention provides value-added products, methods for making, and methods for using the byproduct-derived polyester polyol compositions. For example, the invention provides polyurethane (PU) and/or polyisocyanurate (PIR) polymers made using the polyol compositions and polyfunctional isocyanates. The PU and PIR polymers can be used as adhesives, binders (e.g., for wood fibers), coatings (e.g., for controlled release fertilizers), and foams.
Abstract:
A finisher assembly includes a finisher agitator having a spiral ribbon. The spiral ribbon includes an exterior edge that wipes a polymer fluid from an inner vessel wall of a finisher vessel of the assembly. One or more mixing struts are coupled along the spiral ribbon. An agitator ring is coupled with one or more of the spiral ribbon or the one or more mixing struts. The agitator ring and the one or more struts are recessed from the inner vessel wall compared to the exterior edge of the of spiral ribbon in close proximity to the inner vessel wall. When the agitator is rotated the one or more mixing struts and the agitator ring mix the polymer fluid without disturbing gel along the inner vessel wall or the mixing struts according to the recessing of the agitator ring and the mixings struts from the inner vessel wall.
Abstract:
A polymer finisher assembly having a finisher nozzle includes a vessel including an outlet orifice and an inlet orifice. The finisher nozzle extends through the inlet orifice of the vessel. The finisher nozzle includes an isometric barrel extending between a nozzle inlet port and a nozzle outlet port. A separator helix is within the isometric barrel. The separator helix separates a mixed flow of steam and polymer fluid and directs steam toward a barrel inner perimeter and directs the polymer fluid separated from the steam toward a helix axis and the nozzle outlet port. The isometric barrel and the separator helix cooperate to confine spattering of polymer fluid separated from steam to the melt pool and isolate an inner vessel wall of the vessel from spattering.