What is weft accumulator? How do they work?

In the textile workshop, the weft accumulator plays a crucial role. If the loom is compared to a high-speed engine, then the weft accumulator is its "auxiliary fuel tank" or "pressure regulator," ensuring a continuous and orderly supply of yarn.

● What is a weft accumulator?

Simply put, it's a transfer and buffering device installed between the large yarn bobbin and the loom.

Its purpose:

When the loom is weaving, the action of pulling the yarn is extremely fast and intermittent (discontinuous). If the yarn is pulled directly from the heavy large bobbin, the yarn is easily broken.

Its core function:

To unwind the yarn from the large bobbin in advance, neatly store it on its own drum, and then easily supply it to the loom when needed.

● What are the important parts of a weft accumulator?

For the weft accumulator to work smoothly, it relies on these key components:

Rotating motor:

Provides power to drive the machine to unwind the yarn.

Yarn storage drum:

A smooth cylinder that serves as a temporary "resting place" for the yarn.

Winding arm:

Like a constantly rotating arm, it is responsible for laying the drawn yarn in circles on the drum.

Photoelectric sensor (the "eyes"):

Monitors the yarn on the drum and determines when to replenish the supply and when to stop the machine.

Tension regulator:

Like a small brake, it controls the tension of the yarn as it is released.

● How does a weft accumulator work?

Its working process is quite straightforward and can be divided into the following four steps:

Smooth yarn unwinding:

When the machine starts, the internal motor drives the winding arm to rotate. The winding arm draws the yarn from the large bobbin at the back with a uniform and gentle force.

Pre-storage:

The drawn yarn is wound in circles on the yarn storage drum. In this way, a certain length of "reserve yarn" is always stored on the drum. Even if the bobbin at the back is heavy and the tension is high, it will not affect the yarn on the drum.

Intelligent monitoring:

The photoelectric sensor on the machine constantly monitors the "inventory" on the drum. If the loom is running fast and the inventory is low, the sensor will cause the motor to speed up to replenish the supply; if there is enough stock, the motor will slow down, ensuring that the inventory remains within a reasonable range.

Uniform release:

When the loom (such as a jet or rapier loom) needs to insert the weft, it directly takes the yarn from this drum. Because the yarn on the drum is neatly arranged and free of tension, the unwinding process is very smooth.  Combined with a tension regulator, this ensures that the yarn fed into the loom is neither too tight nor too loose.