ZHENGZHOU KNOWNCHEM IMP. AND EXP. CO., LTD as the subsidiary company of State-owned group belong to attach government enterprise, Founded in 1986 with ISO9001-2008 international quality certification . Our company is a manufacturer and trader specialized in the research, development and production of machinery equipment. With a wide range of junior and senior engineers and professional R&D, design and manufacture of innovative high-tech enterprises. The company has a mature technology, ...