Where can I buy a filter bag for measuring crude fiber?

Recently, I have done the determination of crude fiber, and the non-woven filter bag made by myself is still not good. I think some papers are written with a kind of "filter bag: special non-woven bag, patented product of Beef cattle Research Center of China Agricultural University". I'd like to know if it's been used and where I can order it. Thank you. -- Oh, sofa! Professor Li of Beef cattle Research Center of China Agricultural University, 62829099, you should be here. I have used it, but it is for the determination of NDF, ADF and ADL. Call yourself to ask about the specific situation. If you can't get in touch, I'll tell you Mr. Li's cell phone number. Is it so troublesome to use it? As long as the number of eyes of the filter cloth meets the requirements. I use 200 mesh filter cloth to measure crude fiber, just do it according to the national standard.