China's screen printing materials such as silk screens, sensitized adhesives, and inks have made great progress, but there are still some gaps compared with screen printing materials produced by foreign advanced manufacturers, such as high-strength, low-elongation high-mesh filaments. Net; high-sensitivity non-diazo-sensitive plastic; UV inks, water-based inks. Our Type B Fibc solutions feature superior protection against static electricity that can be created by the flow of materials into and out of bulk bags. Type B bulk bags are similar to Type A FIBC`s in that they are both made from plain polypropylene and/or non-conductive materials, and do not have any mechanism for dissipating static electricity. Type B Fibc,Big Bag 1000Kg,Fibc Jumbo Bags,Woven Bulk Bags Shenzhen Riversky Packing Materials CO.,LTD , https://www.jtfibc.com
The difference is unlike Type A FIBCs, Type B FIBCs are made from materials that have a surface breakdown voltage of up to 6kV. Because of this surface breakdown voltage, Type B FIBCs prevent sparks and propagating brush discharges. Type B should NOT be used in environments containing flammable solvents or gases.
Procon Pacific is now able to offer Type B FIBCs with a liner, meeting all requirements set forth in IEC Revision: IEC 61340-4-4 Edition 2 2012-1.
Examples of safe Type B FIBC use:
To transport dry, flammable powders with MIE >3 mJ
No flammable solvents or gases present around the bag
Talking about the Major Development of Screen Printing in Photosensitive Printing
Photosensitive adhesive
China's screen printing has made great progress in the development of photosensitive adhesives, and diazo-type photosensitive adhesives have been able to meet the needs. The long-established hand-engraving method 1 describes the plate-making method, and the dichromate type plate-making method is basically replaced by a resolution-enhanced diazo photosensitive (or diazonium salt) plate making method. The water-resistant and solvent-resistant diazo photosensitive adhesives produced in China are close to the advanced level in use and can meet the requirements for general-precision template production.
1. Dichromate emulsion
Dichromate + OVA (early protein). Due to the dark reaction, the shelf life is shortened, and due to the presence of heavy metal pollution problems, it has been restricted.
2. Diazo photosensitive adhesive
1 diazo resin + PVA + polymer emulsion. According to the mixing ratio of PVA and polymer emulsion, it has solvent resistance and water resistance. Double absorption peak near 375nm, so the use of metal halide or ultra-high pressure mercury lamp is more appropriate. This type of photosensitive liquid is less odor and skin irritant, and it is easy to modulate. It is also easy to release and regenerate. It is cheaper.
2 diazo resin + PVA + polymer emulsion + acrylate monomer. An acrylate monomer dissolved in a photopolymerization initiator is added to a diazo resin, a PVA, and a polymer emulsion, and hardened simultaneously according to a cross-linking reaction of a diazo resin and an acryloyl polymerization reaction. Due to the increased polymerized cross-linking of acrylates, water resistance and solvent resistance are improved, so that high resolution and edge definition are also improved.
Wire mesh
At present, China's annual import volume of screens has reached more than 1 million m. The imported products are mainly 270-mesh polyester screens and nylon screens. High-density high-density wire mesh screens, high-strength low-stretch screens, anti-static screens, calendering, and other special screens and polyester high-end screens are all required to be imported.
Domestic polyester meshes and nylon meshes have a good market, and polyester meshes have a small amount of exports. However, domestic mesh types and specifications are too few, and high-quality, high-mesh, wide-width meshes are yet to be developed.
A new kind of non-woven wire mesh has been developed abroad, which overcomes the trouble of applying photo-sensitive tape at the intersection of the traditional wire and weft lines. Modern high-quality ultra-fine graphic screen printing, subtle screen printing, high-precision positioning screen printing, special ink quantitative screen printing and large-scale color tone screen printing, all put forward higher requirements for the use of screens: such as high strength , low elongation variability, repeatability, consistency, long service life, etc.; such as printed electronic micro components, integrated circuits, multilayer printed circuits, fluorescent digital displays, aerospace instrument flat panel displays and other high-tech products; such as when Some screen printing requires anti-static, metallized, physical, chemical or special material screens.
Recently, the precision of printed circuit boards and electronic components has become apparent, and the accuracy of dimensional positions is demanding. In addition to polyester, polyamide, and stainless steel, silk screens were made of high-resistance polyester yarn cores and polyamide cores. It is made of polypropylene ester fiber with mesh mesh of 330 mesh, longitude of 23μm and interweaving of 36μm. It can achieve high tension and is truly an epoch-making screen. Moreover, in order to meet the requirements for precision, these screens have been subjected to various treatments such as plasma treatment, metal deposition, and polishing.