felt for TRACO windows

To Whom It May Concern,

I have 3 sliding windows manufacturer by TRACO. The place of the windows were installed in the year of
2002/2003 for The Concord Condominiums at NW Washington, DC

The reason of this e-mail is that the air leaked from outside into the unit...not airtight anymore. It looks like that the felt has worn out at the edge of window frame along from top to bottom of the sliding windows.
Is there anything can be repaired or replacing the felt. The model number for my windows are TR-6300 and TR-6350. One window are TR-6300 and two windows are TR-6350.

I hope you could let me know what to do with them.

I appreciate your time reading this message.

Have a good day!
Thank you.
Anthony