Hi, how can we ensure that the collaborative mode is still active while working in force mode with the sanding kit?

The force mode does not change robot security settings. Acceleration and maximum force continue to be respected.

Be careful that Collaborative mode is not enough to make an collaborative application. For example, if the robot manipulate a sharp tool like a knife the application won`t collaborative. It is important to make a risk assessment to evaluate safety of each application. 

Hi,
Can guard for Knief/Tool be used for safety .

There are several possible ways to reduce risks. If you are using a knife, having a guard will probably help.

You can also stop the robot is someone is too close to it. This can be done with area scanner for example.