Characteristics of nylon: Nylon is non-toxic, odorless, heat resistant, oil resistant, weak acid resistant, alkali resistant, abrasion resistant, self-lubricating, shock absorbing and sound absorbing, but poor dyeability.
The main application of nylon:
One of the main uses of polyamides is in synthetic fibers, which has the advantage of being more abrasion resistant than all other fibers. Because polyamide is non-toxic, it can be used as a medical suture. Due to its safety, light weight, excellent mechanical strength, wear resistance and good corrosion resistance, polyamide is increasingly used in the replacement of metals such as copper, in the mechanical, chemical, instrumentation, automotive and other industries. Bearings, gears, pump blades and other parts.
In the industry, nylon is used in large quantities to manufacture cords, industrial fabrics, conveyor belts, tents, fishing nets, and the like. Used as the material of choice for parachutes and other military fabrics in the defense industry.
Classification and performance of colorants:
Colorants fall into two broad categories: pigments and dyes, where the pigments are divided into inorganic and organic pigments.
Performance required for nylon colorants:
(1) Heat and light fastness
Many organic pigments, inorganic pigments and solvent dyes have been used for the coloring of most thermoplastic engineering plastics.
Resin processing temperature and requirements for colorants:
Resin | Processing temperature ( °C) | Powder requirements |
Low-density polyethylene | 150 - 220 | Excellent fastness, no migration |
High-density polyethylene | 160 - 230 | High heat resistance, no migration |
Polyvinyl chloride | 180 - 250 | Strong dispersion, acid resistance |
Polypropylene | 230 - 280 | Heat resistant, good dispersion |
Polystyrene | 180 - 240 | Strong, good solubility |
ABS | 230 - 310 | Heat resistant, good dispersion |
Polycarbonate | 150 - 200 | Heat resistant, good dispersion, no water |
Polyurethane | 210 - 270 | Lightfast, acid resistant, resistant to reduction |
Polymethylmethacrylate | 200 - 230 | Strong, heat resistant, no migration |
Polyamide | 270 - 290 | Heat resistant, non-aqueous, good dispersion |
Polyester | 270 - 290 | Heat resistant, no migration, no acidity |
As can be seen from the table, the processing temperature of the polyamide is very high, and the coloring agent used needs to have high heat resistance. In addition to the thermal stability of the organic pigment for plastics, it is necessary to have Better light fastness. Many organic pigments have a significant negative effect on the properties of the polyamide melt, so there are certain restrictions on the organic pigments used for polyamide coloring.
(2) Chemical stability
Both the colorant and the resin should not undergo a chemical reaction and should not promote decomposition of the resin. For a highly reactive resin such as a polyamide resin (PA), its molten state exhibits a reducibility, and it is easy to change the color of the colorant, and therefore, only a few colorants are available.
(3) migration resistance
There are three main types of colorant migration:
a. solvent extraction, that is, bleeding in water and organic solvents;
b. Contact migration, causing contamination of adjacent objects;
c. Surface frosting, when heated, the colorant has a greater solubility in the polymer, while at room temperature, the colorant has less solubility.
In general, the dispersion of inorganic pigments in polymers is heterogeneous and does not cause blooming; while organic pigments have different degrees of dissolution in polymers and other organic materials, and migration is more likely.
(4) Tinting strength
The amount of tinting force determines the amount of colorant used to achieve the target color. In general, the coloring power increases as the particle size of the toner decreases. The coloring power of the organic pigment is higher than that of the inorganic pigment, and when the color pigment is used in combination with the white pigment, the coloring power can be remarkably improved.
(5) Dispersibility
The colorant is uniformly dispersed in the polymer only in a minute particle state in order to have a good coloring effect. Pigments contain many aggregated particles, which must be broken by high shear forces to form small aggregates to meet the requirements.
How to choose a colorant for nylon?
Combine the characteristics of the colorant used in nylon with the performance comparison table of several colorants:
Inorganic pigments are superior to organic pigments in lightfastness, weather resistance, migration resistance, and chemical resistance. They are generally suitable for plastics, but their color strength and brightness are much worse. When good color is required, organic pigments are preferred. In addition, inorganic pigments have a high reflection index and are often used in opaque articles.
Organic pigments exhibit high color strength and vividness compared to inorganic pigments. The processing temperature of PA is relatively high, and the heat resistance stability of the pigment is also high. At the same time, the PA resin exhibits extremely strong reducibility when it is melted, making many plastic organic pigments unsuitable for use in nylon.
At present, organic pigments suitable for nylon, especially light-colored varieties, are still lacking, and further research is needed, so it is only necessary to select dyes with more vivid colors. Dyes, colorants which can be dissolved in water, oil or organic solvents. Dyes are generally organic compounds. The advantages of dyes are bright color, eye-catching color, complete chromatogram, but the disadvantages are poor heat resistance, weather resistance and solvent resistance. It is easy to decompose and discolor during plastic processing temperature or high temperature. Although the temperature resistance of the dye is relatively poor, the color will eventually stabilize after being subjected to high temperature in the nylon, and a certain freshness can be achieved. In addition, high temperature resistant dyes have also been developed to meet demand. Dyes are the main colorants of textiles, fabrics and other textiles. They are used less in plastics and are mainly used in optical plastic products to maintain good transparency of transparent plastics.
Pyrite (S48)
Place of Origin: Henan Luoyang, China
Pyrite, Iron pyrites , pyrites lump, Ferro sulphur, Pyrites powder.
Product Description:
Detailed introduction: Pyrite translated into the Iron pyrites or pyrites lump, also can be called Ferro sulphur. Luanchuan Hengkai Metallurgical pyrite Co., Ltd. specialize in the production and sales of high-grade pyrite (FeS2)/ Ferro sulphur, Has the rights of import and export operation.
The products are mainly exported to East Asia, South America, Western Europe, Australia and Taiwan markets. We are China's major exporters of pyrite, "Hengkai Metallurgical " is the first brand of high grade pyrite export. Products are widely as increase sulfur agent used in smelting and casting, fillers of grinding wheel's abrasive, soil conditioner, as the adsorbent of heavy metals in wastewater, filler of core-spun yarn, lithium battery cathode materials, by the user praise and trust.
Quality:
S: 48%min, FE: 42%min, SIO2: 3.0%max, PB: 0.1%max,
ZN: 0.1%max, AS: 0.1%max, . C: 0.3%max, CU: 0.2%max,
H20: 1.0%max, SIZE: 95%min
Granularity: (0-3)mm/(3-8)mm/(3-15)mm/(15-50)mm or other particle size.
Packing: 25KG/500KG/1000KG/BAG or 1000KG/BAG or other packaging.
Note: if there are special requirements, the product can be customized according to clients` requirements.
Rough Copper Pyrites
Crystal Pyrites pyrites lump Rough Copper Pyrites Natural Mineral Specimen
LUANCHUAN COUNTY HENGKAI METALLURGICAL MATERIALS SALES CO.,LTD , https://www.pyritechina.com