拉锁很涩，这句用英文怎么说

涩：astringent 一般用于口感比较涩，而非机械的涩

机械上面运行流畅或是涩一般就用smoothly or not
例句：
The axle doesn't work smoothly. It needs oiling.
轮轴发涩, 该上油了

所以链锁很涩可以说成：
The zip is a bit unsmooth.

drawer (locker) doesn't work.

Zip doesn't work smoothly.

Zip is acerbity

my zip sticks.

The zip doesn't work smoothly.