In the past, we pulled the alpaca blanket off as the shearer sheared. We then would scoop it up and put it into a bag. The process of noodling the fleece actually keeps the fleece intact which will make it easier if you later want to prepare it (ie clean it) to send it in for a show fleece.
One side note before watching the video below, you will hear noises in the backgroud. That is the sound of an alpaca distressed over being sheared. While it sounds like its getting hurt, trust me its not. Once the actual shearing is over, the alpacas all hop up and run around the pastures with great glee because their long heavy coats are off.
For more information, click here to see the video.