Six common problems in the new version of packaging bag proofing and printing

Companies often encounter problems during the new version sampling and printing process of ordering packaging bags. Shunxingyuan Packaging, a professional flexible packaging manufacturer, has summarized the common problems reflected in the new version sampling and printing process, hoping to help companies that need to order packaging bags.

1. The printed image does not match the original.

This is a situation that everyone wants to avoid, as it is detrimental to the plate-making factory, printing factory, and customer. The only solution is rework.

Therefore, when Shunxingyuan places plate-making orders with the plate-making factory, it will always clearly state what the final basis for the dimensions and text content of the job is, especially when there is a lot of customer-provided material, such as CDs, color drafts, photocopies, faxes, etc. In such cases, we will strictly examine whether the content of various materials is consistent and whether there are any contradictions or conflicts, and promptly communicate with the customer, rather than making assumptions.

2. Hue Deviation

Because digital proofing systems are used, plate-making factories generally produce digital proofs before plate-making for confirmation by the printing factory and customer. The effect of the digital proof is also close to the actual gravure printing effect.

Therefore, as long as the printing process control of the packaging production factory is relatively stable and there is no large fluctuation, there should not be any significant hue deviation. This is not a problem for some large packaging production factories, but some smaller packaging production factories do not do well in this aspect and may frequently encounter this problem.

3. Plate is easily soiled

This is related to the quality of the chromium plating layer. Generally speaking, the chromium plating layer must meet certain brightness and density requirements. Generally, the texture of the chromium layer surface is controlled within 400-600 lines/cm2, within which the plate is not easily soiled. However, even if the chromium layer is particularly dense, if it is rough and not bright enough, it is also easy to be soiled.

Improper printing process control can also cause the plate to be soiled. Methods to solve this include adjusting printing pressure, ink viscosity and solvent ratio, changing ink, and adjusting the ink scraper.

4. Scratches

From the perspective of plate making, there are two reasons for scratches: scratches on the copper-plated surface, and low chromium layer hardness or surface roughness.

From the perspective of printing process control, the reasons may include: foreign objects in the ink scratching the plate; poor sharpness and straightness of the ink scraper; improper angle and pressure of the ink scraper.

5. Low printing durability of the plate

From the perspective of the plate-making factory, this is mainly related to the hardness of the chromium layer. Generally speaking, the hardness of the chromium layer should be controlled between HV900-1000. If the chromium layer hardness is too low, it will naturally affect the service life of the plate. However, if the chromium layer hardness is too high, the internal stress will be correspondingly larger, and the chromium layer is prone to cracking (also known as "plate cracking"), which will also affect the printing durability of the plate.

Of course, low plate printing durability may also be related to the printing process of the packaging production factory, such as excessive printing pressure, improper angle and pressure of the ink scraper, foreign objects in the ink, or improper operation by the operator.

6. Misregistration

Considering the plate cylinder, the main reasons are: problems with the plate cylinder diameter; the dynamic balance of the plate cylinder does not meet the requirements, resulting in significant vibration during printing.

Considering printing, the main reasons are: large material shrinkage and expansion; improper oven temperature setting; improper tension control or fluctuations.