doubling and tacking machine

例句：

1. 1. This machine is used for doubling and tacking fabrics.
   这台机器用于给织物进行双倍和搭接。
2. 2. The double-and-tack machine is very efficient in cutting largepieces of material.
   这种双倍和搭接机在切割大块材料时非常高效。
3. 3. Thedoubling and tacking machinehas been upgraded to improve its accuracyand speed.
   双倍和搭接机已经升级，以提高其准确性和速度。