Application of polyglycols soluble in water as lubricant in mechanical expanders effecting the cold straightening and gauging of lengthwise welded steel tubes

摘要

A lubricant comprising water-soluble mixtures of polyglycols or glycolcopolymers obtained by the copolymerisation of propylene oxide and ethylene oxide, both etherised and having the following properties: a resistance to compression higher than 12kg/mm²; resistance to washing with water at low water pressure (lower than 3-4kg/cm²); no resistance at high water pressure (higher than 3-4kg/cm²). The lubricant can be discharged after each working cycle in the waste water.