Polymer solution casting

Abstract: A method and system for continuously preparing a solvent cast film having a secondary component are disclosed. The method includes continuously providing a pressurized stream of polymer solution, continuously combining a fluid stream including a secondary component with the pressurized stream of polymer solution, homogeneously mixing the combination of polymer solution and fluid stream in-line, continuously applying the resulting homogeneous mixture of polymer solution and secondary component to a continuously moving surface, and then evaporating solvent from the mixture to form a polymeric film. The system includes: (i) a continuous polymer solution casting system, including a first pump in fluid communication with a supply of polymer solution, a casting die for continuously depositing polymer solution disposed in proximity to a moving casting surface, and a first conduit providing a flow path for the polymer solution from the pump to the casting die; (ii) a secondary liquid component injection system, including a second reservoir for holding a supply of a secondary liquid component, a variable-speed second pump in fluid communication with the supply of secondary liquid component, a needle valve, and a second conduit providing a flow path for the secondary liquid component from the reservoir, through the second pump, then through the needle valve, and to an outlet; (iii) a conduit junction connecting the outlet of the secondary liquid component injection system to the first conduit of the continuous polymer solution casting system, the junction disposed downstream of the first pump; and (iv) an in-line mixer disposed between the casting die and the conduit junction. An improved method of casting a colored polymer solution onto a traveling belt for evaporating off a solvent and forming a colored film is also disclosed, the improvement including continuously injecting a secondary component into a stream of polymer solution and then mixing the resulting stream of polymer solution with secondary component in-line before casting the resulting polymer solution.

Abstract: Vacuum-pressure casting technology allows small batches of components to be manufactured from polymer materials, mainly from thermosetting plastics such as polyurethane and epoxy resins. Apart from being very simple, the process is also advantageous in that it offers a very accurately reproduced geometrical structure of the surfaces of master patterns used in mold manufacturing. This article presents the results of analyses performed for the process of replicating mechanoscopic marks with the use of three vacuum casting variants, including a hybrid vacuum-pressure casting process developed in particular for the replication purposes. The main research objective was to analyze and evaluate the influence of the parameters of the individual process variants on the quality of the obtained cast parts and on the replication accuracy without introducing additional artifacts on their surfaces. The article discusses the individual stages of the process and provides an analysis of their parameters. The replicas were evaluated for their porosity and reproduction quality with the use of CT methods and comparative photographs obtained from a light microscope.

Abstract: (57) [Problem] To provide an industrial continuous production method and a continuous production apparatus of an industrial porous polymer film capable of uniformly controlling porous properties such as film thickness, pore diameter, porosity, pore shape and the like. To do. SOLUTION: The solution viscosity is 1 on a belt conveyor. A polymer solution of 0 to 30,000 poise is supplied to form a polymer solution casting film, the polymer solution casting film is adjusted to have a uniform film thickness, and a solvent replacement rate adjusting material is continuously supplied to supply the polymer solution casting film. Laminate the laminated body comprising the belt conveyor, the polymer solution casting membrane and the solvent replacement rate adjusting material formed in the above step, immersed in a coagulating liquid comprising a non-solvent for the polymer and coagulated liquid Moving through to deposit a porous polymer film, immersing the laminate in a structure stabilizing solvent, from the laminate after immersion in the structure stabilizing solvent or after removal from the structure stabilizing solvent. The solvent replacement rate adjusting material and the porous polymer film are peeled off, and the peeled porous polymer film is dried and / or heat-treated to obtain a film thickness, a pore diameter, a porosity, It is possible to continuously produce a porous membrane having a uniform porous property such as a pore shape.