Pretreatment Of Polyester Inkjet Printing And Preparation And Application Of Disperse Inkjet Inks

Inkjet printing is a green and environmentally friendly printing process.The disperse inkjet ink has a huge application prospect and market.Although there are many researches on the pretreatment of inkjet printing and disperse inkjet inks,there is still a certain gap with foreign research.SO,this paper focuses on the two key factors of inkjet printing of polyester fabrics:"pretreatment agent and disperse inkjet ink".On the one hand,antistatic agent P[St-BA-F6]synthesized in the laboratory and xanthan gum were used as the pretreatment agent,and the effects of pretreatment of antistatic agent and xanthan gum on the performance of polyester inkjet printing were evaluated.On the other hand,the dispersive dye inks were prepared in the laboratory and applied to inkjet printing.The imaging performance of ink droplets and the printing effect of ink on polyester fabric were evaluated.The main content of this experimental study includes:The inkjet printing and fibre performance of pretreated polyester fabric by antistatic agent P[St-BA-F6]containing pretreatment agent which was prepared by core-shell emulsion were studied.The effects of 5 kinds of cross-linking agents or adhesives(PETA,ITDA,BDDMA,SJ18A and P[St-BA-F6])on pretreatment P[St-BA-F6]were investigated;The method of fast evaluating inkjet printing definition was established,which was based on salt-containing xanthan gum using pretreatment agent for polyester and the ink drops of diffusion and permeation of isotropy and anisotropy for principle.The rheological properties of xanthan gum were studied.By the natural xanthan gum as pretreatment agent,the advantage and affect the performance of inkjet printing were research;Preparation of seven kinds of liquid disperse dyes(yellow MC,red MC,blue MC,purple MC,orange MC,green MC,and black MC)were used to study the main parameters involved in the preparation of disperse dye ink and the theoretical prediction of the efficiency of disperse dye grinding.The effects of three kinds of viscosity modifiers(PTF-3、CZ-1、DLY)and four polyols on the rheotropy of liquid disperse dyes(blue MC,black MC)were studied,the environmental protection,advantages and disadvantages of self-made disperse inkjet inks were evaluated;The normal and abnormal injection characteristics of piezoelectric inkjet droplets were studied by inkjet imaging.The causes of migration of inkjet droplets and the effects of polyols are analyzed.It was also evaluated the printing performance of self-made disperse inkjet inks which was applied in polyester inkjet printing,and the effect of commercial antistatic agents(LS,D30,KD10)pretreatment on the inkjet printing performance of disperse black MC was evaluated.The results are listed as follows:1)P[St-BA-F6]emulsion whose average particle size was 84 nm and the weight average molecular weight Mw was 4606.9,prepared by styrene,butyl acrylate and polyether F6.When P[St-BA-F6]emulsion is used with PETA(pentaerythritol tetraacrylate)on the polyester fabric,it can not only increase the K/S value of inkjet printing,but also obtain good antistatic and improve antistatic water resistance,inkjet printing and antistatic finishing complete simultaneously,shortening the process.The optimized pretreatment conditions were:3%P[St-BA-F6],0.1%PETA(pentaerythritol tetraacrylate),curing temperature 190℃,and curing time 45 s.Meanwhile,the antistatic effect of four crosslinkers or adhesives(ITDA,BDDMA,SJ18A and P[St-BA-F6])was inferior to that of the crosslinker PETA.2)The antistatic polyester fabric prepared with P[St-BA-F6]emulsion has improved the washable of resistance,due to the high reactivity of PETA and the crosslinking characteristics of three-dimensional network.SEM and XPS test results show that the improvement of antistatic performance is mainly due to the contribution of the crosslinking reaction of propylene group(PETA).Compared with untreated polyester fibre,the thermal decomposition temperature of the antistatic polyester fabric treated with P[st-ba-f6]emulsion decreased by 13.4℃(5%weight loss),but it had little influence on melting temperature and crystallinity from the TG/DSC and XRD test result.3)The evaluation method which was apply to evaluating disperse inkjet ink line clarity was 5 grade system,by measure long axis length(La)and short axis length(Lb)of disperse inkjet ink drops dripping on the fabric which was pretreate with salt-containing xanthan gum,in combination with ink two evaluation index which were the ink elliptical coefficient ellipse area(S)is(T).The formula is as follows,T=Lb/La,S=π/4·La·Lb.There is a corresponding relationship between the sharpness measured by the ink drop test method and the sharpness of the actual inkjet printing,which proves that it is feasible to characterize the sharpness by the inkjet test method.4)After pretreatment with xanthan gum containing NaCl,KCl,CaCl2 and MgCl2 for polyester fibre,the K/S value of inkjet printed fabric increases and the width of warp and zonal printing lines decreases,by using D-type disperse inkjet inks.The optimized pretreatment condition was an aqueous solution which was containing xanthan gum 0.3%and calcium chloride 0.1mol/L.Compared with 0.3%xanthan gum,the K/S value of dupont disperse bright red D2551 inkjet printed fabric increased by 26.99%,and the dry/wet rubbing color fastness was no less than grade 4.When added four salts to xanthan gum respectively,its viscosity is linearly correlated with the natural log of the shear rate,The equation was that ln(η)=C0-C1 × ln(τ).The effect of bivalent metal salt(CaCl2,MgCl2)on K/S value is higher than that of monovalent metal salt,and better definition of inkjet printing pattern can be obtained.Excepting the effects of salt and static electricity,when the C0 value(initial flow index)of xanthan gum containing divalent salt is higher,the viscosity of xanthan gum increases at the time of slow elastic recovery,and the fabric surface performance changes to isotropy,which not only improves the K/S value of inkjet printing,but also improves the pattern clarity.Because of the washable property of salt-containing xanthan gum,the pretreatment agent is easy to remove when printing fabric is washed,which was led to have little influence on fabric permeability,and can be better than other polymer pretreatment agents(such as sodium alginate,PTF-3).5)To calculate the total potential resistance energy of dyes using CS Chem3D Pro-Gaussian software is helpful to understand the grinding of disperse dyes.When the total hindrance of dye molecule is repulsive,the dye has excellent abrasive property.Otherwise,the dye grinding is more difficult.The seven liquid disperse dyes prepared in the laboratory have good stability.When 4 kinds of polyols were added into the dye,the rheological properties of the liquid disperse dye presented the characteristics of plastic fluid.The relationship between shear rate(y)and shear stress(x)was:y=-C1+C2·x.The value of C*(C1/C2)is used to evaluate the fluidity of dyes.Ethylene glycol and propylene glycol are beneficial to the stabilization of liquid disperse dyes.The rheological properties of the dye solution with three viscosity regulators(PTF-3,CZ-1 and DLY)which are not suitable to be added into the dye ink are pseudoplastic liquids.The drop test of self-made disperse inkjet inks showed that the self-made inks meet the performance requirements of inkjet printing,but the sharpness of the pattern is still not as good as dupont’s D-type disperse inkjet inks.6)According to the inkjet droplet imaging method,7 types of ink droplet that cannot be sprayed normally were summarized and analyzed.The reason for disperse inkjet inks cannot be sprayed normally is the inappropriate C*value,it’s a ink system value except the basic properties of disperse inkjet inks(conductivity,zeta potential).The appropriate C*value and viscosity of ink can improve the normal operation of the ink droplets and prevent the occurrence of broken spray and ink droplets deviation phenomenon.The droplet test of 7 types disperse inkjet inks prepared in the laboratory shows that 3 types self-made ink can meet the performance requirements of inkjet printing.