PU energy-saving building materials, the main raw materials for MDI, MDI products are highly technical barriers to production, domestic Yantai Wanhua only have one of the production technology.

• PU建筑节能材料的主要原料为MDI,MDI产品具有极强的生产技术壁垒,国内仅有烟台万华一家拥有该生产技术。