Melt spinning is one of the main forming methods of chemical fiber; The main varieties of synthetic fibers are polyester, nylon and polypropylene.
Melt spinning is characterized by high winding speed, no solvent and precipitant, simple equipment and short process flow. Fiber forming polymers whose melting point is lower than the decomposition temperature and can melt to form a thermally stable melt can be formed by this method. Melt spinning is divided into direct spinning and slice spinning (intermittent spinning). Direct spinning is to send the polymerized polymer melt directly to spinning; For slice spinning, the polymer solution needs to be sent to spinning after pre spinning preparation processes such as belt injection and granulation. Direct spinning is often used in large-scale industrial production, but chip spinning is easy to change varieties and has great flexibility, which still plays a major role in filament production.
The polyester melt is transported from the polymerization to the melt filter through the melt transfer pump, and then reaches the spinning room after filtration. The pressure of the melt is raised to the process required pressure by the booster pump, then cooled to the process required temperature by the cooler, and distributed to each production line by the five-way valve (or three-way valve). The melt is evenly distributed into the spinning box of each production position by the melt distribution pipe of the production line. In addition, a static mixer is installed in the melt pipe to evenly mix the melt. The melt is accurately measured by the melt metering pump in the spinning box and sent to the spinning assembly to extrude the spinneret to form a melt trickle. The melt stream is cooled and solidified by side blowing to form tow. 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 tow enters the winding after being oiled through the nozzle (FDY is usually oiled by oil tanker). The tow is wound into FDY cake by winding machine through pre network device, GR1 and Sr1, Gr2 and Sr2 and main network device (for bamag model, the tow is wound into POY cake by winding machine after GR1, network device and Gr2). POY is directly packaged and warehoused after appearance inspection, or sent to spinning and texturing machine for processing; FDY is packaged and warehoused after dyeing and comprehensive judgment of appearance.
Graeff Graff melt pressure sensor is an important component to monitor melt pressure. In the chemical fiber production line, the installation positions of Graeff Graff melt pressure sensor mainly include melt filter, booster pump, melt pipeline, screw, spinning box, etc.
Graeff Graff melt pressure sensor plays an important role in improving melt quality, improving production safety, protecting production equipment and prolonging its service life.
The Graeff Graff melt pressure sensor on the chemical fiber production line can be a single sensor measuring only one point pressure, or a series of sensors used to measure the whole extrusion process. The melt pressure sensor is connected with the data display instrument or control instrument (PLC, DCS). The processing parameters of the extruder can be adjusted by using the processing control system.
Graeff Graf melt pressure sensor is designed to meet every demand of chemical fiber production. It can provide customers with different melt pressure sensors, high temperature resistance up to 540 ° C, different applications, complete product measurement range and high precision.