摘要 |
An expansion band includes a first layer, a second layer, a shrinking layer for shrinking said first layer and said second layer, a bond line for sealing said first layer and said second layer to form an inner space therein and dividing said inner space into a plurality of air passages which can communicate with each other, a plurality of air passages formed between said first layer and said second layer, and an air nozzle communicate with said air passage. |