There are two common methods to seal the teabags i.e. Stapling and Knotting. Conventiontally the industry uses stapling method while knotting is relatively new technology. For producing a teabag the following food grade packaging materials are used in teabag machine
· Filter paper (in the form of paper roll)
· Paper tags
· Aluminum wire (in the form of wire spool)
· Cotton thread (in the form of thread spool)
The specifications of these items is given in fig. 1 along with those of the sealed Tea bag.
· Tube forming unit – to convert flat paper into tube
· Dozing unit – to fill the the tube with measured quantity of Tea
· Upper wheel - for back formation and shaping the Tea bag
· Lower wheel - for tagging & thread feeding unit
· 2 stapling units one for bag sealing and other for attaching tag to the thread
The process of making the tea bags and sealing them is available on this link:https://www.dropbox.com/s/xxgeniu3mw1lqtl/Tea%20Bag%20Constanta.mp4?dl=0
The process of teabag making has the following steps
1. The flat filter paper is converted into a tube in the tube forming unit.
2. Then a measured quantity of Tea is filled in the tube in the Dozing unit. The tube forming and dozing are in a single but separate unit in the machine. The tube moves horizontally in this unit.
3. The Tea filled tube then moves to the forming unit. It consists of a wheel (called upper wheel) that has several ‘U’ shaped slots on the periphery. In all of these slots ‘W’ shaped dies are fitted. Some length of the tube is made to pass over this slot and then an arm presses the tube in this slot from the top. At the same time the tail end of the tube is cut, leaving the same distanace that is made to pass over the slot. Due to this the tube folds upwards along either sides of the arm and the bottom of the tube takes the shape of ‘W’. The tube resembles ‘W’ when looked from the sides. The top of the tube is held in a clamp that is attached to the wheel. The clamp grips the tube a few centimeters below the top edge.
4. The top portion of the tube (that is above the clamp) is then converted into a ‘Trapezoidal’ shape.
5. Then this end of the tube is stapled along with one end of the thread. At this stage the Tea bag is completely sealed.
6. Next the bag is transferred to the lower wheel and the thread is cut to a predetermined length. The lower wheel has a metal cage/pouches in which the sealed bags are held.
7. A tag is then stappled to the loose end of the thread in the last step.
8. Then the sealed and tagged bags are transferred to a counting and stacking bay.
9. Then an operator packs these bags in a box in the desired quantities. The packed boxes are now ready for shipment to the desired location.
There are 23 staple technology teabag machines. We pack 1.2 million Kg of Tea in 100 million Tea bags annually.
We want to replace the stapling operation in the existing machines by other means of sealing the tea bags one such method is Knotting.
The video of knotting machine is available at -https://www.dropbox.com/s/5y5hrz1jgabn0zd/Tea%20Bag%20-%20IMA.mp4?dl=0
We are therefore inviting solutions that will enable us to replace the stapling unit in our existing machines by other means of sealing the tea bags. Knotting is most desirable as it is approved by the regulation.
We are especially inviting solutions under the following broad themes:
1. Complete retrofit – replace the existing stapling process steps and introduce knotting.This is to ensure that the costs are minimal.
2. Replace both thread and staple by nylon or equivalent for sealing and attaching the tag.
In any case, the solution must satisfy the following criteria:
· The proposed solution should be a substitue for the existing stapling process and (the unit/attatchment) must fit into the existing machine/setup. A separate unit is not preferred unless it is very cost competitive.
· It must not hamper the speed of operation.
· It has to be cost effective. i.e. should be substatianally less than that of a new machine performing similar sealing steps.
It must intergrate easily with the existing machine/setup and should not require substantially new inputs than those that are currently supplied to the machine.