Design of screen printing test
3.1 test of printing performance
When the screen and ink are ready, the selection of the substrate will be followed.In theory, different kinds of non-woven corresponding way of printing and the printing effect is completely different, such as the heat sealing type non-woven mentioned before, his material properties is fluffy texture, large amount of water absorption, oil absorption.If use the method of silk screen printing non-woven heat sealing type, no matter how to control the quantity of ink and ink types, the actual operation will appear the phenomenon of the paste board, after all, a lot of non-woven fabric is not suitable for the way of the silk screen printing, fleeciness feeling stronger material, after I understand it is done by way of flexo printing, but this is not the focus of the experiment.According to the nature of screen printing ink, the teacher and I decided to use spinning nonwoven fabric.The non-woven fabric texture is more thick, the differences between different gram weight is large, low gram of spun-bonded non-woven, transmittance is very strong, even said that light transmittance and heat sealing type of non-woven fabric is very close, but type spun-bonded non-woven fabric better formability.Waterborne ink and uv ink will not be woven through low - grams of bonded nonwoven fabric, so it will not cause the paste phenomenon.At the same time, it will not cause the effect of blocking, because the lower substrate can eat too little ink, and the excess ink will remain in the mesh.
3.1.1 selection of spinning nonwoven fabrics
Experiment in order to more clearly distinguish printing effect, the main method is to compare different number of the wire mesh in different gram of spun-bonded non-woven fabrics with different amount of ink on the printing of the effect of color piece on the spot.The grams of viscose nonwoven fabrics are selected in the four categories: 60, 100, 120 and 200.These four kinds of phase comparison, do not consider the wear and fold of the packing and transportation on the Internet after purchase, the flatness is similar.The thickness of the material is proportional to the thickness of the gram, and the thickness of the material becomes thin in turn. The transmittance of the material decreases with the increase of the gram weight.Remove the four g outside under 60 grams of spun-bonded non-woven non-woven fabric production and market consumption is less, more than 200 g non-woven, guide teacher speculated that the printing effect and 200 g non-woven difference is not big, gu represented by 200 g non-woven fabric printing effect.
3.1.2 selection of silk printing ink
When silkscreen printing is largely related to ink, spun-bonded non-woven fabrics in different screen printing with the paper's spun-bonded non-woven fabrics for the ink quantity is bigger, so how many also decides the effect of printing ink, in the case that the size of the printed color piece on the spot, with multiple amount of ink printing and use less ink printing, after comparing.In theory, the amount of ink and the amount of ink are both advantages and disadvantages, and the ink layer is more thick, more flat, and more colorful.But at the same time, there will also be non-woven fabric wrinkling, the appearance of ramen, paste plate, block version of the accident.When printing less ink, if the force is controlled properly, the printing effect will be better than the printing effect of more ink, the pattern is more level, the drying effect is better.
3.1.3 control of pressure scraper pressure
General case, unless to control with printing machinery, scraping plate press strength is controlled by the operators themselves more, this is difficult to maintain the same unless by scraping board machine operation.Under such precondition, how to be the best fit for the screen printing of non - woven cloth also needs further discussion.After discussing with the teacher, he decided to try the printing with a low adhesive, and found that there was a lot of bubble in the printing.There will be air bubbles when the force is large, but the effect will improve significantly.The teacher and I decided to use the two printing presses and the strength of the intermediate values to be printed three times in the same amount of ink.Then compare the printing effect with the same amount of ink.