Melt spinning is one of the main forming methods for chemical fibers, abbreviated as melt spinning; The main varieties of synthetic fibers are polyester, nylon, and polypropylene.
The main characteristics of melt spinning are high winding speed, no need for solvents and precipitants, simple equipment, and short process flow. Fiber forming polymers with melting points lower than the decomposition temperature and capable of melting to form thermally stable melts can be formed using this method. Melt spinning is divided into direct spinning method and slice spinning method (intermittent spinning). Direct spinning is the process of sending the polymerized polymer melt directly to spinning; Slicing spinning requires the high polymer solution to undergo pre spinning preparation processes such as injection and granulation before being sent to spinning. Direct spinning is often used in large-scale industrial production, but slice spinning is easy to change varieties and has greater flexibility, still occupying a dominant position in filament production.
Polyester melt is transported from polymerization through a melt transfer pump to a melt filter, and after filtration, it reaches the spinning room. The melt is pressurized to the required process pressure by a booster pump, then cooled to the required process temperature by a cooler, and distributed to each production line by a five way valve (or three-way valve). The melt is evenly distributed from the melt distribution pipe of the production line to the spinning box of each production position. In addition, a static mixer is installed in the melt pipeline to achieve uniform mixing of the melt. The melt is accurately measured by the melt metering pump in the spinning box and sent to the spinning components, extruded from the spinneret, forming a fine flow of melt. The fine flow of the melt is cooled and solidified by side blowing to form a filament bundle. In addition to the side blowing cooling process, there are also different processes such as inner ring blowing cooling, outer ring blowing cooling, and air duct blowing cooling. The fiber bundle enters the winding process after being oiled through the nozzle (FDY usually uses oil tankers for oiling). The fiber bundle is wound into FDY fiber cake by the pre network, GR1 and SR1, GR2 and SR2, and main network, and then wound into POY fiber cake by the winding machine (for the Bamag model, the fiber bundle is wound into POY fiber cake by the winding machine after passing through GR1, network, and GR2). POY is directly packaged and stored after visual inspection, or sent for further processing by spinning and rebounding machines; FDY is packaged and stored after being dyed and evaluated based on its appearance.
Graeff melt pressure sensor is an important component for monitoring melt pressure. On the chemical fiber production line, the installation positions of Graeff melt pressure sensors mainly include melt filters, booster pumps, melt pipelines, screws, spinning boxes, etc.
Graeff melt pressure sensors play an important role in improving melt quality, enhancing production safety, protecting production equipment, and extending its service life.
The Graeff melt pressure sensor on the chemical fiber production line can be a single sensor that measures pressure at only one point, or a series of sensors used to measure the entire extrusion process. The melt pressure sensor is connected to data display instruments or control instruments (PLC, DCS), and the processing control system can be used to adjust the processing parameters of the extruder.
The Graeff melt pressure sensor is designed to meet every need in chemical fiber production, providing customers with different melt pressure sensors that can withstand high temperatures up to 540 ° C for various applications. The product has a wide measurement range and high accuracy.