There are various DTF PET Film in the digital printing market, such as matte film, golden film, glitter film, breathable film, tear in seconds film and colorful film. With the increae of DTF film, there must exist problems in film transfer. Here are some common problems and suggestions on testing the quality of PET films.
Some Common Problems in The DTF Film
The Bleeding of Printed Image
The bleeding of image is caused by glycerin in DTF ink.
The experiment shows that the DTF paper and the DTF PET film are similar, but the performance of the DTF paper is slightly better due to its absorption. We can see that some DTF PET films increase the amount of powder on the film surface in order to reduce the oil surfacely, but more powder will affect the performance of the transfer color, and will be detrimental to the firmness of the coating, which is inconvenient for storage, transportation and preservation.
Hot Melt Powder Stuck to The Blank of Image
When using the DTF film, there is a problem that the hot melt powder is stuck to the blank of the graphic. Many users have this concern. First of all, please understand the two reasons why the DTF film sticks to the powder: First, the cationic adsorption of the coating is caused by the anionic hot melt powder; The other is caused by the static electricity of PET film. The former occurs when the environmental humidity is high, and the latter occurs when the environmental humidity is low.
The coating of the film is close to neutral, but there may be some powder sticking phenomenon in the case of high ambient humidity. If this happens, please pay attention to reducing the ambient humidity (such as turning on the dehumidification function of the air conditioner) or heating the front guide plate of the powder shaker slightly to remove moisture.
Why Patterns Are become Blurred for Some Time?
Some users reported that after transfer on dark clothes, it was very good at that time, but gradually the image became blurred and worse a week later. Is this a problem with the DTF film?
This kind of phenomenon has nothing to do with the DTF PET film. This is a common phenomenon of heat transfer on dark polyester fabrics. The reason is that disperse dyes used for dyeing polyester fabrics will gradually migrate to the dyeing hot melt powder layer and ink layer. Dark polyester fabrics with poor color fastness can even see the fuzzy changes of images in a day. The solution is to use anti sublimation hot melt powder and select fabrics with good color fastness. The anti sublimation hot melt powder has an obvious function of avoiding disperse dyes.
Ways to Test The Quality of DTF Film
How to Test DTF Film Quality?
Test method ①: Moderate hot press
According to the material and characteristics of the substrate, appropriate heat transfer machines and heat press conditions are selected for hot press. When the heat transfer film is transferred, its pattern transfer can be complete. If the tightness of the peel base film is moderate, it is qualified. This method is applicable to hot peel and cold peel.
Test method ②: Press discoloration
Appropriate printing equipment and auxiliary tools shall be selected to test the press materials of corresponding printing products. If there is no obvious discoloration on the surface of the transferred product, it shall be deemed as qualified.
Test method ③: Adhesion test
Adhesion is a key factor affecting the quality of heat transfer film. It is the combination of heat transfer patterns and product materials to achieve close interface molecular contact, thus generating a new interface layer (adhesion).
Some customers have special requirements for adhesion and require tape testing. Tape testing generally refers to sticking transparent adhesive tape on the transfer surface, pulling it up at 45 ° or 60 ° (specific angle), and repeating it for two or three times without falling off. It is determined as qualified.
Before transfer, the product needs to make some samples for washing test, and the standard of washing test must be determined according to the customer’s requirements. Under normal conditions, the workpiece shall be placed in water for washing at least three times. After washing, the product surface shall be qualified if there is no color change, color weakening, pattern falling off, warping, etc.