Things in the world are diverse and complex, and the phenomenon often hides the essence, making people busy in the abnormal all day long, but can not change in essence. For many manufacturing enterprises, the frequent occurrence of packaging quality problems has become a restriction to the widespread circulation of enterprise products in the market. Today, Jinan printing and packaging respectively from the printing, composite, cutting three links to explain the common problems of soft packaging intaglio printing, providing the most valuable reference for enterprises in packaging design and packaging quality problems.
1、 Printing FAQ
1. Casing deviation
In the process of multicolor overprinting, there is no complete overlap between colors, and there is a certain deviation. If the deviation exceeds the standard (generally the main picture ≤ 0.2mm, the secondary picture ≤ 0.35mm), it becomes unqualified.
2. Cutter wire (cutter line)
Also known as scraping knife mark, refers to the line ink mark or line blank on the surface of the printed matter. There are different shapes of lines, some with ink, some without ink, some continuous, some intermittent.
Common causes: the blade of the scraper is damaged, there are impurities in the ink, and the plate is not polished well.
3. Missing print
The absence of printed patterns or text.
Common causes: block caused by dry ink; aging of pressure roller rubber, too hard, insufficient elasticity; dark pit on pressure roller, etc.
4. Scraping (paste)
Because the ink of the non graphic part of the plate is not scraped clean, there is a piece of pollution when it is transferred to the film during printing. Black ink is easy to appear this phenomenon.
Common causes: insufficient scraper pressure; scraper wear; plate surface damage; ink viscosity is too large to clean.
5. Ink splashing
When printing, ink splashes onto the strip, contaminating the surface of the printed matter, and most of them appear on the edge of the strip.
Usually the ink viscosity is low, the speed is high, and the protection of both ends of the plate is not at that time prone to such defects.
6. Color difference
The same color difference between product channel and channel, volume and volume, batch and batch. If the difference exceeds the upper and lower limits of the standard sample or the national standard, it is unqualified.
7. Color biting (reverse overprint)
Is the first color ink in overprinter to the latter color plate, in the latter color can be clearly seen the color of the previous color.
Reason: the former color ink is not dry enough; the latter color printing roller pressure is too large.
2、 Composite FAQ
It refers to the bubble phenomenon inside the composite film after curing.
Common causes: insufficient surface tension (Corona) of the base material; insufficient pressure of the composite roller causes incomplete air removal between the films, or low surface temperature of the composite roller causes insufficient activation of the adhesive; the barrier properties of the two base materials (PET / / VMPET, PET / Al) are good, resulting in the reaction gas can not be discharged after the adhesive solidifies.
It refers to the phenomenon of strip-shaped hollow stratification of composite membrane after dismounting or curing.
Common reasons: the tension of the two kinds of base materials is not matched. When the initial adhesive strength of the adhesive is lower than the membrane deformation resilience stress, the base materials with large deformation will shrink back; they will not be matured in time after being off the machine.
Refers to the film surface is uneven and folded together. Most of them appear on the core and surface of the roll.
Common causes: the core pipe is not flat; the joint is not flat; the position of the base material is skewed when compounding; the winding tension is too small, resulting in deviation.
Because the peeling strength of composite film is not qualified, the phenomenon of interlayer separation often occurs in the use process (for example, the cooking bag after cooking).
Common causes of dry or solvent-free compounding: insufficient glue application; insufficient corona of base material; insufficient curing of adhesive; improper use of adhesive model, etc
The above is a summary of common quality problems in printing and packaging. If you want to know more, please pay attention to our website