Why the same processing conditions to produce non-woven uneven soft hard

The same processing under the condition of the cause of non-woven fabric soft hard uneven and substantially similar to the cause of uneven thickness of the main reasons may have the following number: ( A) Low melting point fiber and conventional cotton blend uneven, higher content of low melting point part of the hard, content of lower part is soft. ( 2) Low melting point fiber melting caused by incomplete non-woven fabric soft, 3) Fiber shrinkage rate on the high side will form a non-woven uneven soft hard problem.