Sublimation printing is a transfer printing technology that uses a sublimation printer to print a design on sublimation transfer paper and then transfer the pattern to the surface of a fabric, cup or other blank receptors through high-temperature heat pressure. The printing principle is to use the sublimation property of dispersed dyes to color polyester fiber (or surface polyester fiber or similar polyester fiber material) products. It can be applied in the printing process of home textiles, sportswear, T-shirts, mouse pads, mugs, aluminum plates and other products.
Sublimation paper is a very important consumable in the sublimation printing process. If you inadvertently buy poor-quality sublimation paper will not only affect the printing effect of the finished product but even damage the printer nozzles, causing serious losses to the producer.
So, how to identify the quality of sublimation paper?
First of all, you need to understand how the sublimation paper is made.
Sublimation paper production process
* Hanrun Paper sublimation paper production process and base paper inspection indicators.
Sublimation paper generally consists of a three-layer structure, the top layer is a functional coating that absorbs ink and separates dyes, the middle is base paper, and the bottom layer is a coating that resists warping.
Choose high-quality base paper
The base paper is the basis of sublimation paper. Typically paper raw materials can be divided into wood pulp (coniferous wood, broadleaf wood), non-wood pulp (grass plants, bast fiber, etc.) and waste pulp. In addition to the basic requirements of general coated paper, the base paper of sublimation paper also has certain requirements on the density, permeability, tensile strength and heat resistance of the paper, so it needs to be made of high-quality wood pulp. The sublimation paper made from waste pulp has very poor printing stability, obvious surface spots, easy color transmission, curling or breaking, which affects production.
Hanrun Paper® sublimation paper uses high-quality imported base paper made of virgin wood pulp, and can enter the next production process only after passing various base paper inspection indicators.
* Hanrun Paper base paper warehouse
Keep improving the coating process
The functional coating is made of sodium carboxymethyl cellulose or sodium alginate, highly absorbent resin and phenylpropylene latex as the main ingredients. The coating process needs to go through multiple workstages and ensure a uniform coating. When printing, this special coating retains the sublimation ink dyes on the paper, which are then transferred to the substrate while being heated. Which components of the coating are chosen and the ratio of the different components have a significant impact on the ink loading, drying speed, and transfer rate of the sublimation paper.
The other side of the paper base needs to be coated with an anti-curl coating. Since the coating layer of the sublimation paper does not stretch at the same rate as the base paper in a dry and high-temperature environment, warpage can occur on one side, and the anti-curl coating can effectively alleviate this problem.
Hanrun Paper® has been working hard to improve the performance of these three layers of materials, from material selection to the coating production process to strive for perfection, with the aim of better performance in various environments and inkjet conditions, so that our users can have a better printing experience and increase productivity.
With the increasingly stringent requirements for environmental protection, some transfer paper manufacturers can not meet the standard and will choose to make shoddy products and reduce product quality. A variety of smallpox sales tactics and sayings are easy to confuse consumers. We must remind every customer to be wary of some cheap sublimation papers that appear on the market. Because they are likely to use poor-quality raw materials or cut corners in the coating process.
How to identify the quality of sublimation paper
Now we offer several simple ways to judge, which hopefully will help you choose exactly the right thermal sublimation paper between price and quality.
A. The smoothness of printing
It includes paper feeding and printing performance. Before choosing transfer paper, you should ask the supplier for 10-20 meters of paper samples, the width of the wider easier to identify the quality.
(1) The appearance of the paper: First of all, we should pay attention to the tightness of the paper roll, the flatness of unwinding and rewinding. The paper feeding will not be skewed, curled, wrinkled or stained.
(2) Print clarity: Print test pattern with high precision mode, requirements: lines should be clear and not blurred; the edges should have no obvious burrs; no blurring between the lines.
It is important to note that drying speed, print sharpness and transfer rate are mutually exclusive contradictions. If there is no specific need, you do not have to be too demanding drying speed, just make sure that the ink does not stick to the back of the paper when printing while winding up.
Thus you have to consider the selection points: ① Not rub the nozzle; ② Color uniformity and fine not through the print; ③ Meet the drying speed of the print automatically winding.
(3) Print flatness, uniformity and drying speed: with 720 × 720dpi, 260% ink volume printing black 1 meter long color block.
(4) Testing standards:
① Print wrinkle height is small (will not rub to the nozzle and left at a safe distance).
② Color block surface without white spots or no obvious white spots.
③ Color block without ink penetration of the back of the black spot (no penetration mark).
Tips: When printing a large area of color block pay attention to the printing environment humidity. General requirements for the printing room to have temperature and humidity control, the best humidity control at 40-70%. If your printing room does not have humidity control or even do not know the humidity at the time of the print test, the transfer paper roll should be peeled off the plastic bag 1 day before the print test, so that the transfer paper and environmental humidity match, and then on the machine to print and use. Otherwise, the paper roll unpacked will quickly absorb the environmental humidity deformation, coupled with water-based ink printing wet, the paper fibers will quickly expand and serious arching and rub to the printhead. Another situation is particularly dry (such as humidity below 30%) transfer paper suddenly absorb a lot of ink will also cause serious arching.
The better the quality of the sublimation transfer paper, the smaller the arch height. This is because the transfer paper with small arching is made of wood pulp with slow growth and high price, so the deformation is smaller, in addition to the slow speed of the paper machine to make the paper deformation small (less efficient production), these two factors make the sublimation transfer paper with small arching will be more expensive.
* Inferior sublimation paper is easy to scratch the nozzle if it arches when printing.
B. The smoothness of the thermal transfer
The heat transfer is divided into flat transfer and roller transfer, but whether it is flat or roller requires sublimation paper is not warped by heat. The thermal flatness performance of the transfer paper depends on the transfer paper coating formula and coating process equipment. Test transfer paper thermal warpage performance of the simple method can be cut 25cm × 25cm transfer paper, print side down to have been warmed to 210 degrees under the flat ironing machine, 2 minutes after the warpage height of less than 5cm will not affect the general transfer production. Some immature transfer paper even heat warp into a barrel-shaped, such transfer paper in the sheet heat transfer will have many problems, the product qualification rate decline. Some terrible transfer paper in a dry environment when printing will also warp, they can be cheaper 1-2 cents, but will cause short life of the nozzle and fabric scrap large losses. The loss is not worth it!
* Severely warped sublimation paper may roll up completely when heated.
Tips: In order to improve the smoothness of the heat transfer, you can rack the printed rolls of transfer paper to dry for a day before transferring, which will restore the flatness and stiffness of the transfer paper, thus making the thermal transfer smooth and increasing the transfer rate.
C. About the transfer rate
Sublimation paper can be divided into two categories: coated transfer paper and uncoated transfer paper. Coated paper has a high compatibility with ink and is the mainstream category of heat sublimation paper at present. The uncoated transfer paper is relatively inexpensive, but it needs to be used with high concentration and high tension ink.
When determining transfer rates, you can do a "parallel experiment". The method is to take the several sublimation paper you need to compare side by side with double-sided tape stick together, and then print together on the printer horizontal 2 cm wide strip CMYK color block, and then wait for 1 hour and heat transfer on the same fabric at the same time. Sublimation paper with high color concentration on the cloth or less residual color on the transfer paper has a higher transfer rate.
* The difference in transfer rate can be clearly seen by comparison.
When comparing transfer rates with this experimental method, note that:
① To choose the same type of sublimation paper for comparison, such as the use of different brands of the same grammage of fast-drying paper.
② Do not only pay attention to the transfer rate, but also take into account the drying speed and flatness of the print. Without smooth printing, the transfer is meaningless.
③ Transfer rate detection method can also be used to turn the single production to determine the difference between the current transfer paper and the original transfer paper, in order to decide the trade-off between the current transfer paper or decide whether to re-produce the ICC curve.
To sum up
We can summarize the key elements of choosing high-quality sublimation paper into the following 3 points.
① Print smoothly with less wrinkling, clear lines without white spots, no black spots on the back.
② Low arching on the heat press plate, good operation of the transfer work.
③ High transfer rate with less ink, fabric coloring good.
If you want to know more, please click the contact information below, Hanrun Paper® is at your service.