How to make Cloth bind tearing delay?

[Sm3691]

Hello every one
I have a question about tearin
As i show you in the file below
I have a flag that i wanna tear it
But i need some frame wind blowing on flag and after that the flag start to tearing 
But as in the file, after flag touching the box ( surface test to activate cloth bind) the flag goes to start tearing
How can i make a delay for start tearing