Nylon inks mainly include waterproof nylon ink and ordinary nylon ink. Waterproof nylon inks are widely used in the printing of windbreakers and household products (such as shower curtains, table linen, etc.) and leather products (such as handbags, sports shoes, etc.). Ordinary nylon inks are often referred to as "baggage inks" because they are commonly used in clothing linings and bags.
"Nylon" is a popular name for "nylon." The classification of waterproof nylon cloth is mainly classified into strong waterproof cloth and light waterproof cloth according to the degree of treatment of the waterproof layer of the surface of the nylon cloth. The method of testing the degree of waterproofness of the nylon cloth can be performed by placing a few drops of water on the front of the cloth to observe the flow of water: if the water rolls in a ball-shaped shape and hardly sticks to the surface of the cloth, it is a strong waterproof nylon cloth; otherwise water drips on the cloth. Can not afford the surface of water droplets, is a light waterproof nylon cloth. Nowadays, there is a fabric that looks like a nylon cloth (a waterproof coating on the bottom surface). In fact, it is a polyester fiber. Special attention should be paid when printing.
Many customers who received orders from foreign countries encountered such a problem: nylon cloth waterproof layer is too strong, ink is difficult to attach to the cloth surface, while exporters require particularly high fastness. In general, the adhesion of waterproof nylon ink usually has the following test methods.
1. Tear off with adhesive tape: Apply the adhesive tape to the printed ink layer, scrape it several times, and then tear it hard.
2. Cognac: Dozens of times with your hands, like washing clothes.
3. Wet: repeat the above steps after wet water.
4. Use a knife to draw the word "well" on the ink layer and use the above method to do a destructive test.
Strong waterproof nylon fabrics are most afraid of such tests, and almost none of the waterproof nylon inks can be printed directly on the fabric surface. The test time should be 12 h after printing. Otherwise, the accuracy will be affected if the ink is not completely dry. To enhance the ink adhesion. In addition to the selection of high-quality inks, there are some methods that can be used selectively.
Method 1: Wipe the surface of the waterproof nylon cloth with a nylon rubbing agent and print.
Method 2: Add a catalyst (also known as "curing agent") to the waterproof nylon ink.
Method 3: Add strong transparent oil to waterproof nylon ink.
Method four: use a strong transparent oil base, and then printed with waterproof nylon ink color oil.
Method 5: Heat and dry with a dryer or a hot platen.
The above five methods can be used interchangeably. For example: 1 Add a strong transparent oil to the waterproof nylon ink, and then add the appropriate amount of catalyst (curing agent): 2 Usage: After surface treatment of waterproof nylon cloth, then selectively use method two, three, four or five , To ensure the increase of fastness: 3 After the printing method is used, the first, second, third and fourth methods are used for printing and then heating and drying.
In "Method One", the surface of the waterproof nylon cloth is wiped with a nylon rubbing agent to destroy the surface portion of the waterproof layer so that the ink can contact with the nylon cloth surface as much as possible to form a good adhesion. The disadvantage of this method is that it increases the printing sequence, affects the next progress, and the effect of this method on enhancing ink adhesion is very limited.
In "Method 2", the addition of a catalyst that matches the ink composition (1% to 8%) is applied to the waterproof nylon ink to enhance the adhesion of the ink. But should pay attention to several points: First, when using the catalyst (curing agent), a lot of screen printing workers think, just choose a kind of waterproof nylon ink catalyst can enhance the fastness of waterproof nylon ink. This is wrong. Waterproof nylon inks of Brand A and Catalysts of Type B are not always able to produce the effect of enhanced fastness, and may even play a negative role in destroying the molecular structure of the ink and weakening the adhesion of the ink itself. Second, inks and catalysts (curing agents) tend to cure in 8-48 hours, so the ink can only be used up within one working day during production. Otherwise, the ink will be scrapped. Thirdly, when adding catalysts, the correct operation method should be: the weight of each addition should not exceed 2%. If the amount exceeds this amount, it is necessary to first mix the conditioned catalyst and ink, and then add it in a proportion of 2%. And so on. It may speed up the agglomeration of the ink.
"Method 3" adds a strong transparent oil (usually 5% - 10%) in the ink, and then prints, the role is to enhance the ink's gloss and adhesion. The advantage of this method is that it can store for a long time without mixing chemical reaction and agglomeration occurs. The disadvantage is that with the increase of the proportion of strong transparent oil, the color developing power of ink will be reduced, thus reducing the hiding of ink. force.
"Method 4" does not affect the hiding power of the ink, nor does it cause adverse effects such as agglomeration of the ink and reduction of the color developing power due to the addition of a catalyst or a strong transparent oil to the ink. However, when the printing process is increased, the bottoming process will slow the printing speed. At the same time, the printing position must be accurate. Otherwise, it will also affect the printing effect.
"Method five" heating and drying temperature is generally 80 ~ 140 °C, time 10 ~ 30s, some cloth types are not suitable for baking with higher temperature or longer time, operation must pay attention.
Each of the above five methods has its own characteristics. The author prefers to adopt three, four, or five methods. Because these three methods are used, on the one hand, the effect of enhancing ink adhesion is obvious; on the other hand, the side effects on ink are also more less. Of course, this should be based on the customer's production conditions, technical level, weather conditions and other factors, and it cannot be generalized.
Annual production of nylon ink in China is increasing at a rate of 20%. With the acceleration of China's accession to the WTO, orders for export clothing and household goods will continue to increase, and the quality and quantity of domestic nylon ink will rise to a new level.