UV offset printing
Ultraviolet offset press is the ultraviolet offset press. The offset press is printed with UV ink. Ultraviolet offset printing machine needs to install UV LED curing equipment. Because of the particularity of UV ink, the corresponding parts of the printing press also need to be modified to meet the needs of UV curing.
* Cooling device: Since the UV curing device is a heat source, the cooling device can not be ignored. The performance of the cooling device corresponding to the UV curing device should also meet the requirements. The better the performance, the fewer the heat of the substrate, the smaller the deformation, the more conducive to printing and registration.
* Ink roll and rubber cloth: UV offset printing ink, because of its strong corrosiveness, may cause the expansion of ordinary printing ink roll and rubber cloth, affecting the stability of printing pressure, and in serious cases, will also produce peeling or surface fragmentation. Therefore, the requirements of UV offset printing for cots and rubber cloth are very high. The selection of ink rollers and rubber cloth must be compatible with the UV offset printing ink.
The precautions are as follows.
* Ink rollers: Ink rollers need to be replaced by UV special or dual-purpose ones. Usually EPDM rubber (EPDM rubber) or silicone rubber rollers are selected, and the hardness is best at Shaw 40. Above.
* Rubber cloth: Rubber cloth needs to be replaced by UV or both. The following two kinds of rubber cloth are available.
* Paper teeth: When ordinary paper teeth are irradiated by UV lamp, the parts of the teeth will be deformed by heat, which will affect the alignment and printing. Therefore, the paper teeth on the unit with UV curing device must be replaced by the paper teeth for UV. Ordinary offset printing machine is not very strict with the requirement of picking paper teeth.
* Special plate: The plate can be made by UV or dual-purpose plate, or by heat treatment of ordinary plate. The ordinary PS plate made by conventional method needs 10-15 minutes of baking plate (temperature 250 C). The CTP version also needs to bake for 10 to 15 minutes (250 C).
* Moisturizing solution: Moisturizing solution which does not contain too much gum arabic should be selected.
* Ink detergent: Ink detergent should be used for UV printing, and ordinary ink detergent will damage the UV printing plate.
The investment cost of UV offset printing machine is higher than that of ordinary offset printing equipment; UV offset printing has a wider application range than ordinary offset printing, a dispersed market and a large investment in market development. Therefore, market start-up is slow and investment risk is high.
The cost of UV offset printing ink is 4-5 times that of traditional offset printing ink, and the cost of printing materials is also very high. Therefore, production management, process technology and cost control in printing production need to be more rigorous. Once the loss ratio of materials is not controlled properly, the price of printing will be much higher than that of ordinary offset printing. Therefore, packaging and printing enterprises intending to enter the UV offset printing market should select the UV offset printing equipment or transform the existing offset press according to their own conditions, and record well in the printing process, and master the UV offset printing process well, so as to face the increasingly competitive market calmly.