Whenever a knop is to be formed,the feed speed of decorative yarn with increase,so that certain length of yarn that is enough to form the knop can be supplied.

• 该方法是保持芯纱的运动速度恒定不变，让饰纱按要求改变运动速度，在需要形成结子时提高饰纱的喂入速度，以满足形成结子所需的用纱量。