4 kinds of commonly used plastic colorants performance + use advantages and disadvantages comparison, the difference is actually so big!
Fruity Beauty colorant principle of action:
Colorants are mainly divided into two kinds of pigments and dyes. Pigment is not soluble in ordinary solvents coloring agent, so to get the ideal coloring performance, need to use mechanical methods to evenly disperse the pigment in the plastic. Dyes are organic compounds that can be used in most solvents and dyed plastics, with the advantages of low density, high coloring power and good transparency, but their general molecular structure is small, and they are easy to migrate when coloring.
Today take you to understand the advantages and disadvantages of 4 kinds of plastic colorants, in order to better choose and use different colorants in production.
The types of plastic colorants are divided into four types according to their physical form:
Powdered colorants – color powder.
Solid colorants – color masterbatch.
Paste colorants – color paste; and
Liquid colorants – color oil.
In coloring in the plastics industry, color powder and color masterbatch are relatively widely used.
Color powder coloring
The method of coloring plastic particles directly with color powder (pigment or dye) by adding appropriate amount of powder additives is also called dry coloring.
Advantages
1. good dispersion; 2. suitable for small batch plastic processing; 3. low cost, eliminating the consumption of manpower and material resources in the process of color masterbatch and color paste.
Disadvantages
1. Dust pollution, pigment in the transportation, storage, weighing, mixing process will fly, resulting in pollution, seriously affecting the working environment; 2. Extruder hopper is not easy to clean, used to color the color powder in the white oil and other wetting agents, stained with the barrel wall (and even on the screw). When the need to change the material, cleaning the barrel will become a field operator’s problem; 3. blown film, spinning products is not practical, the use of coloring powder coloring, due to the pigment powder uniformly distributed in the resin to be colored, so its dispersion is better, this conclusion can only be for injection molding products, especially thick-walled products, for blown film, spinning products is a different story. Because the color powder generally have not been pre-treatment, when it is mixed in the resin, only from the extruder inlet, screw, to the outlet of such a distance and such a short period of plasticizing and mixing time, to make the pigment powder molecules and pigment molecules to be coloring very well hand in hand – the full combination of the full, it is not guaranteed at all, there will be There will be the phenomenon of “sandwiching”. But this “entrapment” phenomenon in the thick-walled products will be covered up, in the blown film, spinning products will be obvious. Therefore, the latter coloring method is still dominated by masterbatch.
Masterbatch coloring
Adopting a certain process and corresponding equipment, under the action of additives, pigments (or dyes) are mixed into the carrier, and through heating, plasticizing, stirring and shearing, the molecules of the pigment powder and the molecules of the carrier resin are fully combined, and then made into particles similar to the size of the resin particles.
Advantages
1. Improve the environmental pollution caused by the flying of color powder; 2. Easy to change the color in the process of using, no need to carry out special cleaning of the extruder hopper; 3. Strong targeting, simple color matching, and easy to quantify; 4. Compared with the dry dyeing and granulation of resin in batches and then go to make plastic parts, the use of color masterbatch can reduce the aging of the resin performance caused by the secondary processing of plastic products, and is conducive to the improvement of the service life of the plastic products; 5. In the process of processing, the pigment under the action of additives, color masterbatch is fully mixed and completely combined with the carrier resin. When it is used, it is placed in the resin to be processed in a certain proportion, and the compatibility is obviously better than that of color powder coloring.
Disadvantages
1. Poor dispersion, due to the small amount of addition, the processing time of plastic products is short, limited by the extruder screw L/D ratio, the dispersion of masterbatch is often inferior to that of color powder; 2. High cost, more than one manufacturing process, the cost of dyeing is higher than that of color powder coloring; 3. High performance requirements for masterbatch, the carrier in the masterbatch and the resin to be colored when there is a difference in the performance of the carrier resin, the surface of the plastic products often appear undispersed points, color spots, Therefore, the use of color masterbatch is limited by its compatibility and dispersion.
Color paste coloring
Color paste is a semi-product made of pigments and fillers dispersed in paint. They can be classified according to their use as paint pastes, tape pastes, paper pastes, textile pastes, machinery pastes, toy pastes, latex pastes, and so on.
Advantages
1. easy to use, can be directly put into the processing technology for molding and plate coloring;
2. usually, good performance of high temperature resistance, convenient storage, no precipitation; 3. can reduce the dust pollution in the use of color powder, but also to solve the masterbatch in the compatibility and dispersion of the shortcomings; 4. color paste in the use of easy to control the use of the input amount, to reduce the color difference, and to improve the coloring power and color brightness; 5. environmentally friendly in line with the requirements of the European Union REACH and other regulations.
Disadvantages
1. At present, the biggest constraint for the development of color paste is the production process of domestic color paste, high-quality color paste requires high quality of process and raw materials, and its cost is higher than that of masterbatch and color powder; 2. The screw may slip when adding a large amount of time;
3. When it is stored for a long time, it will be precipitated, so it should be stirred before use.
Color oil coloring
Color oil is a kind of liquid pigment concentrate without resin carrier. At present, color oil is mainly used in bottle embryo in China.
Advantages
1、 Low additive ratio, usually 0.1-0.5% for transparent series, and 0.3-3.0% for pearlescent/solid series; 2、 Excellent dispersibility, more uniform color, more colorful, higher luster; stable color, reduce coloring defects; 3、 The material only undergoes one high temperature process, which makes the material more stable. Coloring defects; 3, the material only after a high-temperature process, to maintain the physical properties of the raw material resin is not affected; 4, the best inventory management, only need a small space to complete the storage of color oil. Relative to color masterbatch saves three-quarters of the storage space. Reduce the overall inventory and working capital pressure; 5, color oil adding equipment is simple, low cost, simple and fast color change process, improve the freedom of production scheduling, save staff time, machinery and energy loss; 6, applicable to all polyolefins (such as PP / PE), polystyrene resins (PS), PET resin and other engineering resins.
Disadvantages
1. can not add antistatic agent in color oil, resulting in products in the shelf or storage can not be dustproof; 2. color oil products shelf life is shorter than the masterbatch products; 3. color oil needs special color oil adding equipment, namely color oil metering pump to supply color oil to the injection molding machine to produce the desired color products.
Mimics crop exposure to adversity to increase abscisic acid and jasmonic acid content. Exogenous application stimulates the expression of defense plant genes and induces chemical defenses in the plant, producing effects similar to those of mechanical damage and insect feeding. Induces protease inhibitors (PI) and polyphenol oxidase (PPO), thereby affecting nutrient uptake by phytophagous animals. It also increases the activity levels of defense proteins such as peroxidase, chitosanase and lipoxygenase, leading to the accumulation of alkaloids and phenolic acid secondary substances, increasing and altering the release of volatile signaling compounds and creating defenses. Promote cell division, regulate plant nutrition, promote fruit expansion, regulate the decomposition and metabolism of anthocyanin and sugar, increase sugar content, increase pigment content, reddening without ripening, avoiding the side effects of ethylene glycol, preventing cracking of fruits, fruit drop, reducing sunburned fruits, accelerating the splitting of epidermal pigmented cells, prompting uniform coloring of fruits, bright fruits, increased sweetness, pure taste, and improving the quality of fruits. It induces the production of plant defensive substances such as anthocyanin and alkaloids, improves pigment content, promotes fruit ripening, improves the content of soluble solids in berries, increases sugar and reduces acidity, and advances the coloring of apples and grapes by five days.
Dosage of ◆Fruit Flavor Colorant:
Spray 1-2 times in young fruit period, 0.5-2 coloring agent to 15 kg of water, expanding fruit, 20 days in the pre-coloring period of fruit, spraying once every 10 days, 1-2 times every 10 days, 1-2 times every 10 days.
Sprayed once every 10 days, 1-2 grams to 15 kg of water. Promote coloring, sweetening, fruit coloring period spray 1 time, 1-2 grams to 15 kg of water spray, promote coloring and sweetening.
