Search results
Results From The WOW.Com Content Network
The polymer solution casting process utilizes a mandrel, or inner diameter mold, that is immersed in a tank of polymer solution or liquid plastic that has been specifically engineered for the process. Due to a combination of thermal and frictional properties, the polymer solution then forms a thin film around the mold. [1]
PVDF may be synthesized from the gaseous vinylidene fluoride (VDF) monomer by a free-radical (or controlled-radical) polymerization process. This may be followed by processes such as melt casting, or processing from a solution (e.g. solution casting, spin coating, and film casting). Langmuir–Blodgett films have also been made.
In solvent casting and particulate leaching (SCPL), a polymer is dissolved in an organic solvent. Particles, mainly salts, with specific dimensions are then added to the solution. The mixture is shaped into its final geometry. For example, it can be cast onto a glass plate to produce a membrane or in a three-dimensional mold to produce a scaffold.
The manufacture of plastic film for products such as food packages, shopping bags, and continuous sheeting is achieved using a blown film line. [5] This process is the same as a regular extrusion process up until the die. There are three main types of dies used in this process: annular (or crosshead), spider, and spiral.
This process not only reduces the cross section of the polymer fiber, but also increases the strength of the fibers by aligning the individual polymer molecules. Before drawing, polymer melt is pushed through a die with a large number of small holes, known as a spinneret. Typically, the fibers are air cooled without any need for curing.
The coating window is a multivariable map of key process parameters, describing the range over which they can be applied together to achieve a defect-free film. Understanding the coating window behavior of a typical slot-die process enables operators to observe defects in a slot-die coated layer and intuitively determine a course of action for ...
Extruded film can be stretched, thinned, or oriented in one or two directions. Blown or tubular process forces air into an extruded ring to expand the film. Flat tenter frames stretch the extruded film before annealing. [3] [4] Calender rolls can be used to form film from hot polymers [5] Solution deposition is another film forming process.
Physical vapor deposition (PVD), sometimes called physical vapor transport (PVT), describes a variety of vacuum deposition methods which can be used to produce thin films and coatings on substrates including metals, ceramics, glass, and polymers. PVD is characterized by a process in which the material transitions from a condensed phase to a ...