Industrial sewing yarn /polypropylene  threads
It's Other name  is Multi Fillament thread , which is usually inclulds thiny  strings  .In order to make this strings  one thread , they are intermingled in distace of 5 or 7 cm in lenght ( stick together ). Intermingling  makes the threads  stronger . Each thread includes 80 or 400 strings that are intermingled and then continusly  winded on bobin.