Since its invention in 1908, the tea bag has been continuously developed. From hand-sewn silk bags and gauze bags to today's double chamber tea bags made of cellulose; closed with a staple or knot technique.

In the course of time, the knot technique has established itself in the production of tea bags, in which the production does not require any metal clips. The result is a tea bag that consists of 100 percent renewable raw materials and can be disposed of safely in organic waste.

With the knotting station – an innovative machine module for the tea bag packaging machines PERFECTA and COMPACTA – TEEPACK meets these high demands.

Existing staple stations in older PERFECTA and COMPACTA machines, which were used to produce tea bags with metal clips, can be replaced by knotting stations thanks to the modular design. Avoiding the use of aluminium not only means financial savings due to rising metal prices, but also increased environmental sustainability.

We connect what belongs together – Tea Bags and Tags

Knot on the Bag

The tea bag is pierced by specially hardened steel needles with two punches on the top of the bag, the thread is pulled through the holes and knotted using a patented technique. At this point, the self-tightening knot replaces the mechanical stapling with aluminium clips. At the end of the knotting process, the knotted thread is tightened by a thread brake and finally checked. Faulty bags are ejected automatically.

Knot on the Tag

Before the tag is knotted, it is pierced by a punch installed in the tag feeder. This not only ensures an optically clean impression, but also protects the needles, because they no longer have to pierce the tag.

A sensor monitors the position of the bag and the tag to each other before reaching the knot station of the tag. The self-tightening knot is then formed between the two holes. A control unit then checks whether the knot was formed correctly and initiates ejection of the faulty bag.