Inspection methods for thermal transfer films

Inspection methods for thermal transfer films (I)

1 The relationship between thermal transfer films and inspection
Inspection is an essential process in the thermal transfer process. As an important link in the entire printing process, it is closely related to other links.

Only through quality inspection and strict control, can we ensure that unqualified raw materials are not put into production, unqualified semi-finished products are not transferred, unqualified parts are not assembled, and unqualified printed products are not shipped out of the factory, so as to truly ensure the printing quality of the product. How to inspect the quality of thermal transfer films? Next, we will introduce several common inspection methods.

2 Inspection method for thermal transfer films: overall appearance inspection
The film should be inspected in a production environment with sufficient light, no dust or little dust. The thermal transfer printing film should be placed 30-40 cm away from the line of sight for appearance inspection. Check whether the surface of the finished product is neat, whether the graphics are clear and complete, whether there is obvious dirt, incompleteness, knife lines, creases, wrinkles or pull lines, etc. After careful inspection, none of the above phenomena appear, and the quality is judged to be qualified.

3 Thermal transfer film inspection method 2: color difference evaluation
Place the thermal transfer printed film on the viewing table, adjust the light source of the viewing table to D65, keep the light source distance at about 8 cm, check the batch sample film, gradually compare and check the color. When there is no obvious difference between the color and the batch sample film, the quality is judged to be qualified, otherwise it is unqualified.

Thermal transfer film color difference evaluation large picture

4 Thermal transfer film inspection method 3: overprint accuracy
The thermal transfer operator uses a 20x scale microscope to measure the accuracy of overprinting, and divides and evaluates it according to the design draft and the process requirements of the product. Generally, the error of ±0.15 is the best, the error within ±0.25mm is considered qualified, and the error exceeding ±0.255mm is considered unqualified.

5. Thermal transfer film inspection method 4: Dot blockage
Visually inspect the film surface to see if there are any missing dots, dot blockage, or pinholes on the film. If these occur, first check if there are any problems on the electronic engraving plate, and carefully analyze the causes and prescribe the right remedies; if these do not occur, it is assessed as qualified.