Zhenjiang Shanghao Packaging Co., Ltd. specializes in manufacturing envelope making machines, paper bag machine, paper CD sleeves and all kinds of envelopes.kraft paper bag .We are also the largest professional manufacturers of envelope machinery in China. Our machines factory: Zhenjiang modern printing machinery works, which is the major machines to produce standard envelopes that the Ministry of Post and Telecommunication generalizes as an emphasis. Especially, the successful development of the PTF series fully automatic integrated machine has settled the leading position of our company in the domestic envelope machinery industry.