Digital Valve-Jet Printing of Chitosan Ink on Cotton Fabric for Antibacterial and Comfort Properties

Abstract: Throughout history, the spread of microorganisms has caused much damage including infectious diseases and deaths. Ever since humans realized the impact of bacteria especially on population health many efforts have been done to combat the spread of pathogens. Textiles, as suitable environments for the growth of microorganisms are one of the major sources of epidemics. Therefore, producing antibacterial textiles can lessen the chances of transmission of microorganisms. In spite of effective protection antibacterial textiles offer, lack of comfort can result in less interest in the products from the users. The aim of this project is to use valve-jet printing as a resource-efficient finishing method to produce antibacterial textiles and measure its effect on comfort properties. As a natural, non-toxic, and biodegradable antibacterial agent, chitosan was chosen to be printed on cotton fabric. An ink with 0.5 w/v% concentration of chitosan dissolved in 1.5v/v% acetic acid was prepared and printed on cotton fabric through ChromoJet printer. The fabric was cured at 150°C for 1 minute to stabilize the chitosan on cotton. Three types of printed fabrics were produced with different number of printing passes. The samples were characterized by various methods to investigate the performance of printed chitosan ink on the antibacterial and comfort properties of the cotton fabric. Results indicate a successful printing of chitosan ink on cotton fabric through valve-jet printing method. Results further showed that multiple printing passes of chitosan ink on cotton fabric can result in higher antibacterial activity. However, with excessive increase of chitosan, the fabric compromises the hand feel and softness. Results also showed an increase in air permeability with the increment in the amount of chitosan on the cotton fabric, whereas capillary rise decreased with the increase of chitosan amount. Contact angle measurement and hydrostatic pressure test showed that between the printed and not-printed samples no big difference was observed in terms of hydrophilicity. The result of the thesis is of great importance as they introduce new printing process for the fabrication of antibacterial textile with comfort properties for various applications.