Judging industry prosperity from semi-dull and bright FDY price spread 40g woven fabric

Semi-dull and bright PFY cost is similar, and their price shall be flat theoretically speaking. However, price spread between the two often shows cyclical change. Currently, bright PFY price is obviously higher than semi-dull PFY, and the spread has reached 600-700yuan/mt.Take Apr 22 average price a