Plastic products from confirmation drawings to finished products, need to go through a number of processes, below we mainly talk about the practical color matching techniques in plastic products.
I。 Setting Programmes
According to the comprehensive consideration of plastic properties, moulding process, color characteristics, color matching principles and product requirements, all kinds of color matching are carried out, and then the required color requirements are achieved. Any color, there is a certain hue, a certain brightness, a certain degree of saturation, by changing these three factors can be tuned tens of thousands of colors. Therefore, it is the most basic technology to master the three skills of shading, palette and color difference. The principle of color matching is to adjust the shade first and then the shade, because once the shade changes, the shade will definitely change.
2。 Preliminary formulation according to customer requirements
(1) Pigment selection. The colouring agent is selected according to the transparency, opacity or translucency of the sample.
(2) Comprehensive consideration of coloring cost. Cost is also a very important consideration. The price of pigments is as important as the performance of pigments.
3. Deepening and shallowing
According to the target sample, the penetration and color phase were observed and analyzed, the proportion of black and white in the composition was determined, and the concentration of color powder or the proportion of phosphor contained in the color color color was determined. The colouring power of the colour powder can be confirmed by using various colour powders on the same plastic substrate. For example, the different colour levels of PP material such as 20 g, 50 g, 100 g, 300 g etc. should be assured sufficiently. At the same time, the change of colour phase and concentration of each colour pigment with a certain proportion of titanium dioxide should be mastered.
In the process of color matching, the depth of the color phase should be clearly distinguished by the color light。 Only the color powder can be added to the depth of the color phase。 Black can be added to the depth of the dark phase, of course, a small amount of black can be added to deepen the depth of the dark phase。 In the light direction, the amount of titanium dioxide should be determined according to the degree of solid color。 If the solid color is not enough, it is necessary to add titanium dioxide。 At the same time, other color powders should be added proportionally。 Then the proportion content of color colorant can be estimated according to the depth of color phase and the coloring power of various color colorants。
In theory, most of the colours can be matched with three primary colours: red, yellow and blue, but in fact, the colours of various colorants are not pure colours, but between simple colours, with similar colours. For example, red pink has yellow and blue, blue pink has red and green, yellow pink has green and yellow. In the process of color matching, attention should be paid to the complementarity of color and light. For example, when brightening green, phthalocyanine green can be used directly. For darker green, green light blue and green light yellow should be chosen to match color, but not complementary red light blue and green light yellow.
5. Palette aberration
After estimating the shade and hue, the basic formula can be determined。 After the plate is beaten, the color is matched with the standard sample, and then the chromatic aberration is corrected。 The color difference is related to shade, brightness, brightness and color bias。
First of all, we should determine which aspect of the color difference is, the shade is adjusted by black and white powder, and the brightness is adjusted by adding additive or subtractive powder or fluorescent powder or whitening agent。 The color bias can increase or decrease the amount of the toner or use the complementary relationship to adjust, but it should be noted that careful use of complementary colors will darken the color。
6. How to determine the color mixing formula
Firstly, the content of titanium dioxide is determined, which is the key technology。 Because, as soon as the content of titanium dioxide changes, the color will change greatly, and the amount of other color powder will change accordingly。
The range of tone of color matching sample is analyzed, which is the main color, which is the secondary color, and each of them accounts for a large proportion. (Choose pigments similar to the sample's color and light as far as possible, such as the color of red-toned system, the sample is yellow, the sample is bright red, the sample is bright red or fluorescent red as the main color); observe the brightness of the sample, consider whether to add fluorescent powder or whitening agent.