The colour of pad printing machine matching performance
In the pad printing technology, the correct color reduction plays an important role in the quality of printing.In color matching, color matching problem associated with color measurement equipment is the science of objective problems, the available data expression;And has nothing to do with the equipment of color matching problem is subjective, there is a art accomplishment, observe restrictions.How to set up in the printing ink color relations, can correctly express color, have relationship with the subjective and objective, although sometimes strictly according to the correct way to match colors, but because of the customer itself visual defects (such as color blindness or eye fatigue and rejected, is wasted.So in order to meet the needs of customers, printing should not only consider the influence of the objective data, and to consider to achieve the artistic effect.
Observable, observation light sources or light and observer (human vision or a color measuring device) is the three elements necessary to form a specific color, be short of one cannot, observer to colorific feel ability is limited by many factors, almost all of the variables are included in the observation of the three elements of color, these variables affect the colour matching ability, any one variable changes will affect this transfer after image color, the following will introduce the impact of these variables.
One, the influence of the substrate
The customer required a certain color usually come from (color) systems such as Pantone color matching or a standard color sample.But because of the limitation of substrates in the color of the pad printing out of China and India is not fully reflect the color in color sample.For the influence of the substrates, mainly consider the following four aspects:
A.The base color of substrates or medium and the influence of surface characteristics
B.Reach a certain covering power required for printing
C.Ink to add material, thinner, and the influence of the catalyst
D.Have adapted to a certain colour printing way (offset printing, screen printing and pad printing)
1) the color of the base and the surface characteristics
The surface of the substrate color image color reproduction is influence on printing technology of important factor.Observing the printing color, can see color is from the surface of the substrates and printing ink dieyin layer of light reflection to the eyes.Due to accumulated on substrates in the pad printing ink layer thick, so the light through the ink usually reach bottom base layer, and then after the base surface reflection, again through the ink layer, the reflection to the eyes.In the bottom of the substrates on the reflected light is related to the color of the material itself, especially the color dark substrates themselves, and observations on its relatively light, the effect is more obvious.
Substrate surface properties such as smoothness or smoothness, porous of color reproduction effect also plays an important role, observed in the same color but different roughness of the same color on the two kinds of medium, visual effect is gained by the different: on the base in the bottom of a smooth color looks more bright, fresh sharpness is higher;Printed on the fabric such as porous rough surface is the same color is gray.This is caused by the different of reflection of light from the two hostages, when light to smooth level off of the surface of the medium, most of the light reflected out in the same Angle, so most of the light beam reflected all eyes;On the contrary, coarse, porous surface light reflection from different angles, into the light of the human eye is much less.
Printing, therefore, the closer with the colour collocation of the substrates, get, the better: the pad printing effect of a certain color can be well on the coated or not coated white paper medium, and in the dark plastic medium reproducibility is poor.
In addition, for under the condition of a certain way of printing, to be printed white ink as the bottom of layer or one multilayer gezer, otherwise there will be a better matching effect.For transparent varnish applied, for example, in order to avoid losing characteristics, before printing any color should be printed a layer of white ink.
2) the number of printing
As mentioned earlier, the observation on the printing quality of color at the same time, also saw the color of the substrates themselves, in order to reduce the influence of substrates, selection of ink should be as opaque as possible.Dry in the pad printing, printing ink layer thickness is about 20% of the plate corrosion depth.If the etching depth of 0.After 001 inches, so dry film thickness in 0.0002 - inch - 0.00025 inches, it compared with screen printing is much more thin, so too thin film layer is not enough to cover the influence of the substrate color.One solution is to increase the etching depth, but the depth more than 0.0015 inches, ink transfer is greatly reduced, image blur, start hair paste, therefore can only take another way is to improve the number of printing, in printing, a process known as double or multiple printing printing.
Using multiple printing will undoubtedly extend the production time, so before taking multiple printing, to decide whether or not to do so can obtain the required productivity, even a single printing can't really be the ideal color match, does not necessarily at the expense of production time to cost with printing for many times, can reduce the ink thinner or increase the number of pigment.
In addition, several times with printing before, shall determine the increase in number of printing, whether can still maintain a good image detail clarity, not deformation or bending in the process of printing.
3) ink additives
Ink components of the additive composition may also affect the color of the ink, diluent, catalyst and mobile agent is usually colorless, thus to cause a decline in ink covering power.To ink, for example in a ratio of 2:1 to add some kind of catalyst, such as curing agent, will reduce covering power 50%, this with the single printing and printing is almost the same obvious differences between many times.Therefore, for the operator of the implementation of color, understand the specific proportion of the additive and add is very important, so as to finish right before color added.
4) color sample production
Standard color sample is correct implementation of the guarantee of printing.Because each print mode, the ink film thickness is different, so the color sample by way of printing and pad printing way, when use must be calibrated.In printing, the color sample for reference is also the need for correction.