... Grade: B,F200,F300,F400,F500,F600,F700,F800,F1000,FB300,FB500 Our core board is mainly used to make high ... strength chemical fiber tubes, yarn bobbins, industrial paper tubes for paper mill and plastic ... as following:1. Substance: 230g/m2-600 g/m22.Grade: B,F200,F300,F400,F500,F600,F700,F800,F1000 ... to send me your inquiry at any time. high grade core board for paper core