Solvent in the production of food packaging bags, food bags quality directly affects the quality of the printing ink, solvent quality stand or fall of leading indicators is the purity and moisture content, such as quantitative qualitative detection is to use the best solvents of chromatograph, moisture tester, such as special equipment for testing, but the required instrument prices more expensive, technical requirements are also higher.The following simple auxiliary method helps to determine the quality of the solvent.
(1) to see the appearance of the solvent.Should be clear, transparent, if there is cloudy, floats, the solvent are to be careful.
(2) to smell the smell of solvent.Contact with the commonly used solvent smell a bit after a long period of time, for a particular smell of solvent have the general impression.If it is found that the number of solvent odor is not pure, can be sure that batch of solvent purity is not high or impurity more.In addition to the solvent coating on the clear plastic film, compared before and after the basic volatile odor, can roughly determine the tendency of its solvent residue.
(3) using different dissolving effect principle to the rough determination of water content in solvent.With a 100 ml glass cylinder in half cylinder transparent toluene solvent, stay a little amount of esters such as solvent, even in toluene.When just pour in toluene, look carefully for the turbidity (milky white).If have this kind of phenomenon, the change of solvent water content exceeds bid badly, experience has shown that when the moisture content of more than 0.5%, the phenomenon is obvious.Benzene class of solvent water content test can through the long glass tube extraction solvent, observation to determine whether there is a layered phenomenon.
(4) using the moisture indicator to determine content of solvent.Moisture indicator into the solvent, water content is not at the same time, will present a different color.According to the change of color, can be broadly determine moisture content in the solvent.