How To Color Plastic
Pigment blue 60 supplier said, plastic color matching is in the red, yellow, blue on the basis of the three basic primary colors, with the color of the plastic product, after processing, so that the product even in the use of the process, the color will not change. At the same time, plastic coloring can also improve the light resistance and weather resistance of plastic and other functions.
Plastic Color Matching Method
First, Directly adding pigment color powder
Color matching and coloring of plastics can be added directly to the pigment color powder into the resin and plastic products, so that the pigment color powder and plastic resin mixing, and then sent directly to the next step, but due to the plastic products made in this way, the molding process is short, the cost is low, and the working environment is poor resulting in poor uniformity and quality stability of the plastic coloring.
Second, add masterbatch
Masterbatch is a coloring agent, carrier resin, dispersant and other additives formulated into a coloring agent granules, when the plastic products can be molded according to the coloring requirements, add a certain amount of masterbatch, so that the coloring of the products to meet the coloring requirements.
Masterbatches can be classified according to the coloring resin, such as ABS masterbatches, PC masterbatches, PP masterbatches, etc.; can also be classified according to the coloring resin plus process, there are three major types of masterbatches: injection molding, blown film, extrusion. Color masterbatches are widely used due to the pretreatment of pigments first, high coloring power, low dosage, stable quality, easy transportation, storage and use, and reduction of environmental pollution.
Color masterbatches have performance indexes such as color difference, whiteness, yellowness, yellowing, thermal stability, oxygen index, melt flow rate, etc. Of course, fineness of pigment, migration, chemical resistance, toxicity are also related to the performance of color masterbatches, and some indexes are very important in special purpose, such as fineness of filtering value of fiber grade masterbatches.
Third, add dispersant
The dispersant excludes air by wetting and penetrating the surface of the pigment, and disperses the cohesive body and agglomerate into fine, stable and uniform particles, which will not be coalesced again in the process. Commonly used dispersants are low molecular weight polyethylene wax, EVA wax or oxidized polyethylene wax is used for organic pigments and carbon black which are difficult to disperse, and there is a big difference between synthetic low molecular weight polyethylene wax and low molecular weight polyethylene wax by polyethylene cracking method, and the other additives are coupling agent, antioxidant, light stabilizer, antistatic agent, filler and so on, which are decided to be added according to the requirements and varieties. Products demolding and improve the brightness of the product surface.
Fourth, the use of computers
Color management hardware has a colorimeter and computer to handle the measured data, colorimeter can be divided into two kinds of spectrophotometer and colorimeter, instead of the human eye to measure the color, to remove the influence of human factors.
● Spectrophotometer is used to measure the wavelength of the reflection coefficient of the complete diffuse reflective surface, although it can not directly obtain the chromaticity value or color difference, but can be processed through the data, you can know the value of its chromaticity and various other values. Spectrophotometers can be divided into two types: diffraction grating spectroscopy and interference filter spectroscopy. Advanced spectrophotometer with built-in microprocessor, with 0%, 100% of the automatic correction and multiplier increase and other functions, greatly improving the accuracy.
● Colorimeter is a simple test instrument, is the production of a piece of color with the human eye color sensitivity equal to the spectral characteristics of the filter, with which the sample plate for photometry. Colorimeter is designed with a photoreceptor spectral sensitivity characteristics and can be measured under a certain light source color difference value of the filter, colorimeter small size, easy to operate, more suitable for the spectral characteristics of small changes in the same product for batch management, with a small microcomputer colorimeter, easy to calibrate with the standard samples and the output of a number of color difference values.
The color matching management software has spectral reflectance curve, color difference formula, condition isochromatic representation, covering power representation and haze representation. Spectral reflectance curves are used for analysis when selecting colorants, but they cannot be used to determine whether colors are consistent. The color difference value is one of the most important indicators in color management, but the color difference obtained by different color difference formulas varies, so it is necessary to specify the chromaticity system or color difference formula used.
The use of computers for color mixing formulas and their management has been successfully used for plastic color matching and color mixing.
Computer color matching instrument has the following functions:
● Color matching can be done according to the requirements to establish a database of commonly used pigments, prepare the basic color palette and input. Then, under the software menu, input the pigment color plate into the computer, point out several candidate pigments in the keyboard, calculate a series of formulas and list them in order of color difference and price respectively to provide color matching options;
● Formula correction, correction of computer listed formulas, other sources of formulas, color difference failed to use the monitor to display the inconsistent reflection curve directly through the keyboard to increase or decrease the amount of pigment, until the two curves basically overlap, resulting in a revised formula.
● Color measurement and color difference control measurement of colorant coloring strength, product whiteness, product color fastness, color color difference, because the computer can quantitatively express the performance indicators of the color, so it is conducive to the communication of information between the two sides.
● Color management of daily work in the color samples, formulas, process conditions, production date and user information can be deposited into the computer, easy to retrieve, find and as a reference for modification, convenient, fast, improve work efficiency.