Decades back, only cloth bags were in wide use around the world. Then the use of bags made from jute and other eco-friendly products became widespread. Fast technological progress replaced manual bag sealing and now small bag sealing machines are available for sealing cloth bags, jute and even gunny bags. The use of these machines made bag sealing quicker and more efficient. While manual sealing is time consuming, error prone and labor intensive, bag-sealing machines gave better output with less labor.

Types of bag sealers

Bag sealers of different type and make are now available to seal bags made from a wide range of materials. Industries can choose manual, semi-automatic or even automatic Bag sealerss according to the type of bag materials used for packing the various products. There are bag-sealing machines that even seal the bags and do the labeling simultaneously.

A wide range of bag sealers is available for sealing plastic bags. Today no modern food processing industry can afford to do away with the bag sealer. Processed foods need to be preserved for long periods and transported to huge distances across the globe. Food preservation through refrigeration and freezing is costly. A processed food item may reach the hands of the customer only after several months or even years. Such processed foods need to be preserved from air and water contamination and also from decaying bacteria and fungi. Thus carbon dioxide gas was filled in the plastic bags along with the processed food products to protect them from decaying bacteria and fungi and also to improve their shelf life. For packing fried food items for a long time and to keep them crisp nitrogen gas was used. Plastic bags filled with carbon dioxide or nitrogen gas needed airtight packing, so that the processed foods will not be contaminated. Not only that, the sealing must be strong and durable. The technology employed has advanced to such an extent that today even vacuum packing and sealing is possible.

Small and medium industries needed small manually operated bag sealers. But the needs of heavy industries are different. Large factories producing sugar, animal feeds, plant fertilizers and even cement weigh and pack the produce in an assembly line and the Bag sealers simultaneously seals and labels them. Such huge industries use big bag sealers. They come in different models and the industry mostly prefers the automated ones. Simultaneous sealing and labeling is a recent innovation. Such bag sealers were earlier electronically controlled. But now even computerized Bag sealers are available. This ensured better output from the bag sealers and the labeling and numbering became error free.

Materials used in bag sealing

In age-old times small cloth pieces or even jute threads were used for tying the mouth of a cloth or jute bag. Nowadays even the cloth and jute bags are sealed perfectly using nylon or cotton threads which are so thin but strong. For example, in a sugar factory, sugar is packed in large jute bags and the bag sealer uses either nylon or cotton threads to seal the bags. The sealing process is very similar to the working of a sewing machine. But the methods used for sealing plastic and paper bags are different.

Till a few decades ago cement was packed in plastic bags. The disposal of the plastic bags became a problem. So

high quality strong paper bags were introduced for packing cement. Here again, the need for the bag sealer to seal these cement paper bags became a necessity. Paper bags cannot be sealed using the methods adopted for sealing jute and cloth bags. Cement of a particular quantity is weighed and filled in the paper bags. The bags are closed automatically and the bag sealer simultaneously applies the quick setting glue and a drier is used to dry the glue immediately.

Impulse heat sealers

Impulse heat bag sealers are very popular. Heat sealing can be adopted for sealing plastic and polythene bags. Impulse sealers come in different models and with added accessories. Some of them even have electronic controls that can be used to adjust the heat required to seal bags made from particular materials. The use of electronic circuits helps to ensure long life and keep operating costs to the minimum. The hand-operated model is enough for small home industries but the foot pedal operated model helps to make bag sealing faster. The foot pedal operated model frees both hands to manage both the package and the product. The automatic Bag sealers have options that help to control the sealing time and the sealing interval. Such models are mainly used in industries with a wide range of products and very high production.

Product selection

Faster bag sealing is possible through double element sealers. They have heating elements on both the upper and lower jaws and it is the preferred model for sealing thick polyethylene and even polypropylene bags. Bag sealers with cutters will make bag sealing faster and easier. A buyer needs to make a list of the various types of bags he is using at present and the number of bags that must be sealed in an hour. Then he should zero in on a particular product. If the number of bags to be sealed are less, manual hand operated bag sealers will be enough but if more work needs to be done in less time, then the use of semi-automatic or even automatic Bag sealers will become inevitable.

Related topics

• Bag sealing methods

• Types of bag sealers

• Product selection

• Proper use of the product