The type of plastic colorant, according to its physical form can be divided into four kinds: powder colorant - toner;Solid colorant -- color master;Paste colorant -- color paste;Liquid colorant -- color oil;In the plastic industry coloring, toner and masterbatch are widely used.
Toner coloring
Direct use of toner (pigment or dye) to add the right amount of powder additives for the coloring of plastic particles, also known as dry coloring.
Advantages:
1. Good dispersion;
2, suitable for small batch of plastic processing;
3, low cost, save the color masterbatch, color paste and other processing human and material resources consumption.
Disadvantages:
1. Dust pollution, the pigment will fly in the process of transportation, storage, weighing and mixing, causing pollution and seriously affecting the working environment.
2. The hopper of the extruder is not easy to clean. Under the action of white oil and other wetting agents, the pigment used for coloring will stick to the inner wall of the attached material cylinder (or even the screw).When refueling is needed, cleaning the drum becomes a difficult problem for the field operators.
Color Master Batch:
With a certain technology and corresponding equipment, the pigment (or dye) is mixed into the carrier under the action of auxiliary agent. Through heating, plasticizing, stirring and shearing, the molecules of the pigment powder and the molecules of the carrier resin are finally fully combined to make particles of similar size to the resin particles.
Advantages:
1. Improved the environmental pollution caused by the flying toner
2, the use of color change is easy, do not need to extruder hopper special cleaning.
3. Strong pertinence, simple color matching and easy quantification.
4, compared with batch resin dry dyeing granulation to plastic parts, the use of color masterbatch can reduce the plastic products after the secondary processing caused by resin performance aging, is conducive to the improvement of the service life of plastic products.
5. In the process of processing, under the action of auxiliary agent, the color masterbatch is fully mixed and fully integrated with the carrier resin.In use, according to a certain proportion of the resin to be processed, compatibility is obviously better than toner coloring.
Disadvantages:
1, poor dispersion, due to the small amount of addition, plastic products processing time is short, by the extruder screw lengthen diameter ratio limit, color masterbatch dispersion is often not as good as toner.
2. The cost is relatively high, and the cost of dyeing is higher than that of toner coloring due to one more manufacturing process.
3, the performance of the masterbatch is on the high side, the carrier in the masterbatch and the performance of the coloring resin is different, the surface of plastic products often appear not scattered point, color spot, pattern, so, the use of the masterbatch because of its compatibility and dispersion and restricted.