In the process of catalogue printing production, how to maintain the consistency of
printing color has always been a difficult problem for printing production
personnel. Many printing companies have
experienced serious quality accidents due to the color difference of printing
products, customer complaints or even returns. Therefore, this paper will
discuss how to control the color consistency in the printing production
process.
Establish a sound color management system
As we all know, it is impossible to
completely avoid color difference in the printing process, the key is how to
control the color difference within a reasonable range. The first step to
control product color consistency in the printing process is to establish a
perfect color management system so that operators can understand the standard
of qualified products, including the following two points.
1. Confirm product color upper and lower
limit with customers
When we first produce a product, we should
work out the standard upper and lower limit of the color of the product. Future
production will be based on the standard color of the standard sample sheet (or
the first batch sample sheet) and strictly stipulate that the color fluctuation
shall not exceed the upper and lower limit of the standard. That is to say,
confirm the color difference standard with the customer in advance, and give
the production staff a reasonable color fluctuation range while ensuring the
color consistency, so that the product color standard is more operable. Must
not each production, simply to catch up with the batch left samples, which will
lead to the printing of the more batches, the more serious color difference,
the difference, thousands of miles.
In addition, it must be noted that the
"standard sample sheet" of the client's sealed sample should be
replaced regularly to avoid deviation between the standard sample sheet and the
actual printed product due to the long time.
2. Improve the signature sample, inspection
and sampling system of the first and last pieces
If you want to further guarantee the
implementation of the color standard, you should also include the inspection
item of the product color into the "product head and tail parts inspection
system" and "inspection quality record", so as to facilitate the
workshop management personnel to control the color difference of the products,
and the inappropriate products will definitely not pass. At the same time,
workshop managers and operators should also strengthen inspection and spot
check to ensure that products beyond the reasonable range of color difference
can be found and handled in a timely manner in the production process.
With the development of printing detection
technology, the precision of color difference detection equipment has been
greatly improved. Qualified printing companies can introduce relevant color difference control equipment to realize
digital color difference management.
Equipped with printing standard light
source
Some printing
factories do not use the printing standard light source, which brings a
hidden trouble to the color consistency control of printing products. When
working night shift, the product color seen under the illumination light source
is very different from that seen under daylight when working day shift, thus
easy to cause the printing color difference. Therefore, it is suggested that
the printing workshop must use the printing standard light source for lighting,
and the standard light source box should be provided when necessary.
Ensure printing ink quality
Printing enterprises sometimes encounter
the situation that the ink color of printed products changes gradually after
being placed at the customer's place for a period of time, but the same
phenomenon has not occurred in the previous batches of printed products. This
situation is generally due to the use of expired ink. Ordinary ink shelf life
is usually one year, using expired ink is easy to print products fade.
Therefore, when using ink must pay attention to the ink shelf life, adhere to
the principle of first in first out. In addition, in the process of printing
production, pay attention to the use of ink additives. If ink additives used in
excess, may also lead to printing ink color changes. Therefore, in the use of
various ink additives, it is best to communicate with the ink suppliers to
determine the correct addition of additives proportion range.
Pay attention to the matching of color ink
and information transmission
In the process of printing production, spot
ink often needs to be prepared, while the printing workshop is often prepared
spot ink color is different from the sample color. Causes this kind of
situation the main reason is the ink proportion is wrong. Spot color ink is
made up of a variety of primary color ink, and most of the primary color ink is
pantone color system, so when we make spot color ink often according to the
proportion given on pantone color card. But need to point out, the ink ratio on
pantone color card is not completely accurate, often can have minute
difference. This has certain requirement to the experience of operating
personnel, demand its to ink color have higher sensitivity, demand its learn
much more practice, accumulate continuously the experience of setting up spot
color ink, raise color sensitivity, achieve the level that masters ink
configuration proficiently. Want to remind everybody here is, not be all
primary color inks with pantone color fastens for foundation, meet the original
color inks that is not pantone color fastens cannot be on with pantone color
card printing ink proportion is accurate, otherwise it is very difficult to
make the ink color that needs.
In addition, many printing enterprises in
order to ensure the accuracy of ink matching, equipped with electronic scale,
which is worth advocating (it should be noted that regular calibration of
electronic scale). Standardization is one of the important measures of
industrial production progress. Our practice is to prepare the spot color ink
for the first time, the operating personnel will record the ink ratio on the
process card and "quality record", so as to provide basic data for
the next time the spot color ink is prepared, and also to ensure the color consistency
of the spot color ink prepared by different shifts, different operators.
