definition
When the raw material of the appropriate composition is burned to partial melting, the obtained calcium silicate is used as the main component, and the clinker with less iron content is added with an appropriate amount of gypsum, and the white hydraulic cementitious material is obtained by grinding, which is called white silicic acid. Salt cement (referred to as white cement).
When grinding cement, it is allowed to add limestone not exceeding 5% by weight of the cement.
Note: It is allowed to add grinding aid to the cement without impairing the performance of the cement, and the amount added is not more than 1% by weight of the cement. During the incorporation period, he must be tested and submitted to the Ministry of Construction Materials for approval.
Grading
(1) Label: Three labels of 325, 425, and 525.
(2) Whiteness: The minimum whiteness is not less than 87.
use
White cement, white Portland cement, referred to as white cement, is a hydraulic cementitious material made by adding white Portland cement clinker to gypsum and grinding. It is a kind of cement, but it is higher in marking than ordinary Portland cement and it solidifies quickly. Its main feature is that the amount of slag micropowder is 85-90%, and the amount of alkaline additive is not more than 5%. The whiteness and strength of the mixed white cement are not lower than that of the raw white cement, and the early strength is also significantly improved. White cement is mostly used for decoration, and its manufacturing process is much better than ordinary cement. It is mainly used for the gap of the white porcelain tile, and is generally not used for the wall surface because the strength is not high. Available in the building materials market or in decorative materials stores.
Plain washers, which spread a load, and prevent damage to the surface being fixed, or provide some sort of insulation such as electrical
Spring washers, which have axial flexibility and are used to prevent fastening or loosening due to vibrations
Locking washers, which prevent fastening or loosening by preventing unscrewing rotation of the fastening device; locking washers are usually also spring washers.
Materials
Washers can be fabricated from a variety of materials including, but not limited to:[23]
- Steel – Carbon steel, spring steel, A2 (304) stainless steel, and A4 (316/316L) stainless steel
- Non-ferrous metal – Copper, brass, aluminium, titanium, iron, bronze, and zinc
- Alloy – Silicon bronze, Inconel, Monel, and Hastelloy
- Plastic – Thermoplastics and thermosetting polymers such as polyethylene, PTFE (Teflon)[24]
- Nylon – Nylon 6, Nylon 66, Nylatron, and Tecamid MDS[25]
- Specialty – Fibers, ceramics, rubber, felt, leather, bimetals, and mica
- Phenolic – The material has good electrical insulation, is lightweight, tough, has low moisture absorption, is heat resistant, and is resistant to chemicals and corrosion. Phenolic washers are substitutes for flat metallic washers in cases where electrical insulation is required. Phenolic washers are stamped out of large sheets of the phenolic material. The term [phenolic washer" is sometimes used for stamped washers from laminated materials such as paper, canvas, and Mylar.
Washers,Plain washers,Spring washers,Locking washers
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