The answer is Alumina Rigidizer Type AL-R/H.
Alumina Textile Type AS-7M is an incredible material. It retains 100% of its tensile strength when exposed to temperatures as high as 1200C. Type 0909-P is commonly used as a reinforcement in advanced refractory structures including CMCs.
Because AS-7M is manufactured with only a minute amount of organic sizing added in the yarn manufacturing step, 0909-P tends to fray upon cutting. The below photo shows 0909-P after it was cut with a steel rule die.
Fraying of AS-7M 0909-P can be significantly mitigated with the application of Alumina Rigidizer Type AL-R/H.
The 0909-P shown in the photo above, was lightly treated with AL-R/H and dried. After drying the rigidized sheet was cleanly cut using a sharp ceramic knife as shown in the photo below.
For more information on Alumina Textile Type AS-7M and Alumina Rigidizer Type AL-R/H, use these links to see their Technical Data Sheets.