Development Of On-line Inspection System Of Sizing Percentage

The efficiency of weaving process mainly lies on warp's weaving ability. Sizing is a crucial process which can reduce yarn hairiness, improve abrasive resistance and enhance warp's weaving ability.There are many ways to improve sizing qualities. Only through optimizing and developing new kinds of sizes, using advanced sizing technics (such as using dense concentration, high pressure, low viscosity and prewetting sizing process) are not enough. It still needs an on-line inspection system which can control and measure some important sizing indexes such as sizing elongation, moisture regain, and sizing percentage. These sizing indexes, especially sizing percentage can keep sizing qualities stably.Sizing percentage can be influenced by many factors and may be changed during sizing process. In order to keep constant sizing percentage, it is essential to measure and control it on line. As sizing percentage is close related to sizing concentration and extruding regain, it can be inspected and controlled automatically through measuring real-time sizing concentration and extruding regain. This study mainly contains two parts:(1) Design an on-line inspection system of sizing concentration. During this process, the ultrasonic method is employed to solve this problem, which is based on different sizing concentration corresponding to different velocity of ultrasonic. So the sizing concentration is obtained by measuring the velocity of ultrasonic in sizing.(2) Design an on-line inspection system of extruding regain. During this process, the microwave method is used to measure the moisture contents of yarns, which is based upon the principle that as the microwave penetrates the yarn, the water molecule in the yarn is polarized and the strength of microwave is attenuated. Different moisture contents have different microwave attenuation, therefore, the extruding regain can be obtained by monitoring the microwave attenuation.To achieve the work mentioned above, the LabVIEW program is introduced to receive, process, show, store the data transmitted from peripheral equipments and then as well as send out a warning signal. In addition, the feasibility of the on-line inspection system is confirmed.Through theoretical analysis and experimental tests, the results are showed as follows.First, under the condition with constant temperature and pressure, the velocity of ultrasonic in sizing is linear with the sizing concentration and the relationship between microwave attenuation and extruding regain also presents linearity. These agree well with the experiment results which error is about 0.5 % and less than 4.5%, and mean that the sets designed are validate.Second, the data from peripheral equipments are transmitted to the computer by serial and collection ways. And then the Labview program is applied to edit, collect and process the data. Finally, the curves between the sizing percentage, sizing concentration, extruding regain, warning signal and time are showed on the computer screen.Third, through comparing the sizing percentage derived from the on-line inspection system with the traditional sizing method, it suggests its error is less than 1.5% so that the system is affective.As a whole, the work in this thesis is the preliminary study and achieves a great progress at a certain extent. The system designed in this paper is feasible and can be further applied to measure sizing percentage on-line.