| Polyvinyl alcohol sizing agent is a high molecular compound with good film forming properties and the PVA films have high strength, high elasticity, and high abradability. Polyvinyl alcohol sizing solution is an ideal adhesive widely used in textile industry sizing because of its viscosity stability and good adhesive force to kinds of fiber.But there are two problems in the PVA desizing. First, desizing is not complete, which will influence dyeing and stamp seriously. Secondly, the waste water of the PVA desizing will bring serious pollution to environment. And the PVA size is not easily degraded. So, environment pollution is the deadly weakness of the PVA size. It has been forbidden to use in many nations, and our country is reducing the PVA size dosage gradually.With the improvement of environmental consciousness in recent years, the traditional desizing reaction happened in acid or alkali had been replaced gradually for its high cost and serious pollution. Searching a new desizing method with lower pollution and expenses satisfying desizing need for later work has already caused the attention of many people. A modern and green environment protection technique-plasma is used in the process of PVA desizing.We study effects of low-pressure and air pressure plasma processing parameters in treating PVA films and desizing process of cotton fabric. Low-pressure plasma was used in treating PVA films and cotton fabric with the time variation. SEM (Scan electron microscope) and FTIR (Fourier transform infrared spectrometry) were employed to study the surface topography and chemical composition change before and after treatment. Experimental results show that after the low-pressure plasma treatment, surface topography and chemical composition of PVA films changed to some extent as physical and chemical combined action result. Thickness loss increased in etching and dissolution as the time extended. For the fabric treated with low-pressure plasma, the strength and wicking height increased obviously. The desizing effect was improved as well.Various treatment parameters were considered in APPJ (Atmospheric pressure plasma jet) treated PVA films process, including time, power, gas-flow rate, oxygen content and distance between nozzle and substrate. The date showed that the surface topography changed markedly and chemical composition changed little. The etching rate and thickness decreased in dissolution grew to the highest value and then decreased little. The etching rate increased as the mixed gas flow rate and the power increased. The etching rate showed an initial increase, followed by a decrease when the helium flow rate increased. The etching rate decreased as the distance between nozzle and substrate increased.Cotton fabric treated by APPJ show a clean surface under the SEM after washing and the fabric strength increased to some extent as well as wicking height. The desizing rate was improved largely compared with low pressure plasma.In conclusion, APPJ desizing is environmentally friendly and meet the requirements in textile industry. APPJ is a new technology with widely application. |
PDF Full Text Request