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    In addition to the 35% and 47% oil seals, there is also the 7% oil seal, which is designed for smaller applications where space is limited. Despite its compact size, the 7% oil seal offers reliable sealing performance and is commonly used in small engines, pumps, and compressors.

    Hydroxyethyl Cellulose of daily-chemical grade has good mildew-resistant performance, system thickening and rheology modifying functions, as well as good water retention and film formation, and gives the final product full visual effects and all necessary application performance. The surface-treated Hydroxyethyl Cellulose has cold water solubility, and dry powder can be used and directly added into water. Good dispersion of the product in water can avoid clumping of product, and the occurrence of uneven dissolution. The final aqueous solution is uniform, continuous and full.

    1: What is HPMC?
    Hydroxypropyl methylcellulose ( (Propylene glycol ether of methylcellulose) is a methylcellulose modified with a small amount of propylene glycol ether groups attached to the anhydroglucose of the cellulose. The dry product contains 19 to 30 per cent of methoxyl (-OCH3) groups and 3 to 12 per cent of hydroxypropyl (-OCH2CHOHCH3) groups. HPMC can be derived from tree fiber or cotton fiber.

    2: How HPMC is made:
    The cellulose ethers are manufactured by a reaction of purified cellulose with alkylating reagents (methyl chloride) in presence of a base, typically
    sodium hydroxide and an inert diluent. The addition of the base in combination with water activates the cellulose matrix by disrupting the crystalline structure and increasing the access for the alkylating agent and promotes the etherification reaction. This activated matrix is called alkali cellulose (Kirk-Othmer, 1993). During the manufacture of HPMC alkali cellulose reacts with methyl chloride to produce methyl cellulose and sodium chloride. Side reactions of the methyl chloride and sodium hydroxide produce methanol and dimethyl ether by-products. The methylcellulose is then further reacted with the staged addition of an alkylene oxide, which in the case of HPMC is propylene oxide (Kirk Othmer, 1993 Dow, 2002). After this reaction, MC and HPMC are purified in hot water, where they are insoluble. Drying and grinding completes the process.

    3: Chemicals agents and reactions:
    The chemical reactions of manufacturing HPMC summerize as following: