Color materials and plastic raw materials, auxiliaries between the collocation
The masterbatch color, color masterbatch technology must pay attention to the color and plastic raw materials, auxiliaries between the collocation relationship, its selection points are described below.
1, color can not react with resin and various additives, strong solvent resistance, small migration, good heat resistance, etc.
In other words, the masterbatch cannot be involved in various chemical reactions. Such as carbon black can control the curing reaction of polyester plastic, so we can not add carbon black material in polyester.
Color masterbatch technology because plastic products molding processing temperature is higher, so the color should not decompose discoloration under the condition of forming heating temperature.
Generally, inorganic pigments have good heat resistance, while organic pigments and dyes have poor heat resistance, which should be paid enough attention to when selecting color varieties.
2, color dispersion, coloring power should be good.
Color dispersion is not uniform, will affect the appearance of products; When the coloring force of color material is poor, it will increase the amount of color material and increase the cost of material. The same color in different resin dispersion with color force is not exactly the same, so in the choice of color should pay attention to this point. Color particle size is also related to the dispersion, the smaller the color particle size, the better the dispersion, coloring power is also strong. Color masterbatch technology requirements are very strict, generally adopted color masterbatch technology is wet process. Color masterbatch material by water grinding, phase, water washing, drying, granulation, only such product quality can be guaranteed.
There are four methods of masterbatch technology
(1) Color masterbatch technology process ink method: as the name implies, is the production method of ink paste adopted in the production of color masterbatch, that is, through three roller grinding, coating a layer of low molecular protection layer on the surface of the pigment. The fine paste is then mixed with the carrier resin and plasticized by a two-roll plasticizer (also known as a double-roll plasticizer) and granulated by a single screw or twin screw extruder.
(2) Color masterbatch technology process washing method: pigment, water and dispersant through sand grinding, so that the pigment particles are less than 1μm, and through the phase transfer method, so that the pigment into the oil phase, and then dry color masterbatch. Phase conversion requires the use of organic solvents and the corresponding solvent recovery device.
(3) Color masterbatch technology technology kneading method: it is to mix the pigment with oily carrier, using the characteristic of oil-loving pigment, through kneading to make the pigment from water phase to oil phase. At the same time, the surface of the pigment is coated by the oily carrier to disperse and stabilize the pigment and prevent the condensation of the pigment.
(4) Color masterbatch technology process metal soap method: Is the pigment after grinding particle size to about 1μm, and add soap at a certain temperature, so that each pigment particle surface layer is evenly wet by soap, forming a layer of saponification liquid, when the metal salt solution followed by the saponification layer on the surface of the pigment chemical reaction and the formation of a layer of metal soap protective layer (magnesium stearate), In this way, the pigment particles after grinding will not cause flocculation, but to protect a certain fineness.
(Source: fengj.com)
