National Standard of Calcined Gypsum(Standard No.: GB/T 9776-20080)
(1)Scope of application:Gelled material made by dehydrating natural gypsum(raw material). Its main component isβ-GaSO4·1/2H2O, without any admixture or additive.
The natural gypsum should be in conformity with requirements of “gypsum rock(JC/T700) for making cementing material” gypsum rock of Grade 3 or more higher grades.
(2)Classification:It is classified to be three grades: 3.0,2.0,and 1.6 according to its 2h strength(breaking strength).
(3)Composition: β-GaSO4·1/2H2O content(mass fraction) in Calcined gypsum should be not less than 60.0%
(4)Physical and chemical performance:
|Grade||Fineness(Screen residue of 0.2mm square screen)/%||Setting time||2h strength/MPa|
|First setting||Final setting||Flexural
Quality Standard (Based On 9.5mm Thick Gypsum Board)
|The weight per unit area||≤8kg / m2|
|Longitudinal breaking load||≥360Newton|
|Horizontal breaking load||≥140Newton|
|Hardness||Edge hardness and end hardness should be no less than 70N|
Raw materials&energy consumption list(Based on 9.5mm Regular board)
|Gypsum powder(semi-hydrated gypsum CaSO4·1/2H2O)||5.8kg/m2|
|Gypsum board adhesive(starch)||0.004kg/m2|
|Natural gas (8200 kcal/ m3)||0.46 m3 /m2|
Production Method of Gypsum Board Production Line:
This production line used the calcined gypsum powder, water and various additives are automatically and separately measured and conveyed into the mixer by continuous auto-conveying system. After well mixed into slurry and spreaded onto the gypsum board protective paper which is continuously moving forward. During the progressing process, the slurry is gradually dispersed with vibration, and jointed with back protective paper. When going through extruded shaping machine, the slurry is fully wrapped by upper and lower paper, pressing into well-regulated flat board which is continuously brought forward as per a stable and strictly controlled speed. After any minutes , the calcined gypsum in the slurry is hydrated again and crystallized into tiny interpenetrative dihydrate gypsum crystal with higher strength. And then, the wet gypsum board with a certain strength and regular shape is precisely cut into individual boards with set size by an auto-controlled cutting system. The individual boards are orderly arranged, turned over by program control system and brought into the dyer. In the dryer, the absorbed water in the boards is evaporated away. following strict drying system(The crystal water in the gypsum crystal has no loss). After brought out from the dryer, the boards are gradually cooled down in the running process. The front sides of every two boards are folded after turned over again, and the two ends are cut into boards with regular size and nice appearance by end sawing machine. And finally the boards are conveyed to automatic stacking machine and stacked into well-ordered finished products before put into storage.
Hengshui Decheng Machinery & Equipment Co., Ltd, founded in 2008, is a comprehensive enterprise of machinery manufacture, research&development and investment casting. It has 218 staffs and 53 technical staffs including senior engineers, engineers and technicians. It covers 30, 000 sqm land, and has machining workshop, electrical workshop and precision casting workshop with complete sets of production and testing equipment. In 2008, it passed ISO9001: 2008 Quality Management System Certification. In early 2013, after on-site inspection and authentication by SGS, it became audited supplier of Made-in-China, and in May, 2013, it passed ISO/TS16949: 2009 “casting and machining for automotive parts” Quality Management System Certification.
Our company specially designs and manufactures complete sets of building materials equipments, such as paper surface gypsum board production line, gypsum powder production line (natural gypsum and chemical gypsum), fiber cement board production line, calcium silicate board production line, cement production line, AAC block production line, stone production line, etc. Certainly we also supply single machines, spare parts and wearing parts for these production lines; At the same time, we produce some raw materials for the production lines, such as modified starch, foaming agent, glue, etc.
Our company has well-experienced professional engineers and technical teams to ensure our clients with high-quality equipments. The well-skilled installation and commissioning team and high-quality process technologists provide our clients both at home and abroad with full set of technical services to make our clients “buy with reassurance and use with gratification”. In recent years, our company has completed building materials equipment projects in the Middle East, Central Asia and Eastern Europe, etc, and has got highly praises for both product quality and after-sale services.
At the same time, our company is also professional in precision casting, and the company passed TS16949 Quality certification. We can produce great variety of products used in industries including automotive&truck, agricultural machinery, mining machinery, engineering machinery, petroleum machinery, electronic industry, etc. The castings can be made following standards such as GB, ASME, DIN, NF, JIS, BS, AS, etc.
Our senior engineer has worked in casting industry for more than 40 years, and with his rich experience in castings, he can design the fittest production plan for all the castings, especially for castings with high level of difficulty. Our full sets of test instruments and machines and TQM management system can ensure of reliable product quality. The precision of castings can reach Grade CT3-CT4, and surface roughness can reach Ra 3.2μ M. At the same time, we can provide further-processing services such as machining, polishing, electroplating, etc. So far, we have supplied the products to Beiqi Foton, Sany Heavy Industry, ANZ, GEGA(Germany) and many other domestic and foreign companies.
Since established, we have been taking “human oriented, management strengthened, survival with quality, develop with technology” as company spirit, to provide customers with fittest products and win widely their praise. We, DCI, shall always insist on quality principle of “quality first, customer first, team work, continual improvement”, and adhere to company philosophy of “honesty oriented, excellence pursue”, to realize the aim of “united as one to make us successful and customer satisfied” and to provide better products and services for all old and new customers. “Let our brand remain in the customers minds forever” is our quality commitment, and we wish to work together with all friends for common development.
Warmly welcome all friends all over the world to our company!