Guangzhou Dandy sporting goods Ltd which is located in Guangzhou city, China, is a professional manufacturer specializing in producing and creating sportswear based on clients` requirement. We have our own factory and office. It occupied more than 500 square metres and have more than 150 employees. We mainly handle export of garments from cheer uniforms, leotards, soccer kits, rugby kits, basketball kits, tracksuit and other practice wears for more than five years with high quality but competitive price. With importing machines, ink, crystals, etc. , we did specialize in sublimated sportswear and all stars dance wears. Moreover, we provide OEM/ODM service for each clients with custom design, color, size fabric, etc. With rapid respond, cost effective and high quality jerseys and professional recommendation on apparels we have a strong customer base. With the solid production, rich experience and advanced manufacturing process, we had previously cooperated with many brands and clients from all over the world.
Tracksuits/hoodies/jackets: It's made from polyester and spandex/cotton/nylon. The prices depend on the quantity and fabric to need.
Training Hoodie,Custom Hoodies,Gymnastics Hoodie,Personalised Gymnastics Hoodie Guangzhou Dandy Sporting Goods Ltd , https://www.dandysportswear.com
(1) Mechanical properties Hardness: Diamond is currently the hardest material in nature, with a relative hardness (Mohs hardness) of 10 and a microhardness (square pyramid extrusion method) of 98,588 MPa. Diamond absolute hardness of quartz is 1000 times, 150 times corundum. Diamond has different origins, deposits and colors, and its hardness is different. The hardness of different crystal faces on the same diamond is also different.
Brittleness: Although diamond is very hard, it is brittle and will crack along the crystal cleavage surface under a certain impact force. The brittleness of diamond is related to internal stresses, cracks and other defects of the crystal. The larger the internal stress of the crystal, the crystal with cracks and other defects, can be cleaved under a lower impact.
Density: The density of diamond is generally 3.47~3.56g/cm 3 , and the purity of pure and crystallized diamond is 3.52g/cm 3 . The color of the diamond is different, the type and number of inclusions in the crystal are different, and the density is also different.
Cleavage: Diamond has medium cleavage of parallel (111) faces and incomplete cleavage of parallel (110) and (221) faces.
Fracture: Diamond fractures have a very complex structure, but are often characterized by shells or jagged shapes.
(2) Optical properties Color: Pure diamond is colorless, but relatively rare. Mostly in different colors, such as yellow, green, brown, rose, blue, gray, black, etc. The color of the diamond is related to the impurities and structural defects involved.
Gloss: Diamonds often have diamond luster, but a few are grease luster, glass luster, and even dull. This is due to long-term chemical corrosion, ray effects, intrusion of foreign matter, and coverage of other materials on the surface.
Transparency: Pure diamond crystals are transparent, but some diamonds are translucent and even opaque.
Refractive index: The purity is 2.40~2.48, and the refractive index is the highest in transparent minerals. The higher the refractive index, the stronger the reflection force on light. The specially designed and processed diamonds reflect almost all of the light incident on the surface and into the interior.
Dispersion: Diamond has a high degree of dispersion and a dispersion coefficient of 0.063, which is also the largest among transparent minerals. The larger the dispersion coefficient, the better the spectroscopic effect. When a white light is injected into the honed diamond, it can be divided into different colors due to the dispersion effect, making the diamond dazzling.
Abnormal interference color: The interference color of equiaxed crystal minerals under crossed polarizers should be black, but many diamonds have abnormal interference colors such as gray, yellow, pink, and brown.
Luminescence: Diamond emits bright green, sky blue, and blue fluorescence under cathode rays; medium-brightness or weaker sky-blue fluorescence under X-ray; sky blue, purple, and yellow with bright or medium brightness under ultraviolet light green fluorescence; after sun exposure in a dark room hair cyan blue phosphors.
(3) Thermal properties [next]
Thermal conductivity: Diamond is a good thermal conductor with a thermal conductivity ranging from 138.16 W/(mK). Type IIa diamond has particularly good thermal conductivity, 25 times that of copper at liquid nitrogen temperature and 5 times that of copper at room temperature, and has superconductivity.
Thermal expansion: The coefficient of linear expansion of diamond is extremely small at low temperatures, and the linear expansion coefficient increases rapidly with increasing temperature.
Heat resistance: The ignition point of diamond in pure oxygen is 720~800 °C, the ignition point in air is 850~1000 °C, and it is converted into graphite in pure oxygen at 2000~3000 °C. The flame is blue when the diamond burns.
(4) Magnetoelectric properties Magnetic: Pure diamond is non-magnetic and has some magnetic properties when it contains magnetic inclusions.
Conductivity: In general, diamond is a poor conductor of electricity, and its electrical conductivity is small, 0.211×10 -14 ~0.309×
10 -13 S/m. As the temperature increases, the conductivity increases. Type 2b diamond has good semiconductor properties.
Photoconductivity: When the diamond was irradiated with ultraviolet light having a wavelength of 2100 × 10 -7 to 3000 × 10 -7 mm, a photocurrent was found in the diamond. When irradiated with infrared rays and ultraviolet rays simultaneously, the photocurrent is increased by nearly 2 times. In the same situation, the photocurrent of type II diamond is several orders of magnitude larger than that of type I diamond.
Dielectric constant: The relative dielectric constant of diamond is 16 to 16.5 at 15 ° C. The data varies with the electric field strength, frequency and room temperature at the time of measurement.
Triboelectricity: The frictional charge is generated when the diamond rubs against the surface of glass, hard rubber or plexiglass. The sign of the triboelectric charge is positive and the size varies with the friction time. When the rubbing time is 60 s, the triboelectric charge is about +3 × 10 -9 ~ 10 × 10 -9 C.
(5) Surface properties The diamond surface has strong lipophilicity and its fresh surface wetting contact angle is 80~120°. The surface of the diamond in nature is often contaminated and the wetted tentacles become smaller.
(6) Chemical properties Diamond has good chemical stability, acid and alkali resistance, and does not react with concentrated HF, HCI and HNO 3 at high temperatures. The surface is only slightly oxidized when it is boiled in a melt of NaCO 3 , KNO 3 or with a mixture of K 2 Cr 2 O 7 and H 2 SO 4 .
2. Main use
The main uses of diamonds can be divided into two aspects of decorative and industrial use, which are described as follows:
The quality of the diamond used for decoration is very high. The crystal form is required to be complete, colorless or colorful, high transparency, no cracks and impurities. Generally, the larger the crystal, the higher the value. The lighter the color, the higher the value. For colored diamonds, the darker the color, the higher the value. [next]
Industrial diamond: For type I diamond, it mainly uses its high hardness and high wear resistance. For type II diamond, it mainly uses its good thermal conductivity and semiconductor properties. The main uses of industrial diamonds are listed below. 
Process characteristics and main uses of diamond ore
Process characteristics