Heavy duty heat sealers are different than standard impulse heat sealers. Heavy duty heat sealers are made to seal large and heavy bags made of many different materials. They need to provide enough heat to seal thick materials holding heavy products. Seals have to be wider and more durable than standard heat sealers.
Heavy duty sealers are used with materials such as: polyethylene, polypropylene, cellophane, Mylar, foil coffee bags, kraft bags, and more. Below are a few specifics that set heavy duty heat sealers apart from standard heat sealers.
Most people are familiar with impulse sealers. Impulse sealers begin heating the sealing wire when a contactor is engaged as the sealing bar is fully closed. After the contactor is disengaged, heat to the sealing wire is shut off. The wire for an impulse sealer heats up and cools down many times during use.
Constant heat sealers do not turn off heat between seals. The set heat remains constant the entire time the sealer is on. The constant heat makes the sealing bar hot to the touch. Because the heat never shuts off, seals for thinner materials are extremely quick and not preferred. Heavier materials in excess of a 10 Mil thickness take less than 3 seconds to seal.
Wider Seal Seams
The seal seam is the weakest point in a bag. A heavy-duty sealer should have a minimum of a ½ inch or 12.7mm seal width. Preferably for sealing anything over an 8 mil thickness, a 1 inch or 25.4mm wide seal seam should be used. The wider seal will increases seal strength to help ensure products remain protected.
In comparison, round wire shrink wrap sealers are 2mm wide or less. The seal seams are made to be small and unnoticeable for shrink wrap. Heavier polyethylene and polypropylene up to a 6 mil thickness are sealed with flat 5mm wire sealers. A flat wire sealer is great for sealing materials 5 to 8 mils thick. The heavier materials will cause the impulse sealing wires to burn out faster than thinner materials.
The wider seal seams coupled with constant heat will help increase production speed when using heavy duty materials. The wider, hotter sealing bar is capable of quickly sealing materials 8 – 12 mils thick. Wider seal seams of 1 inch or more are also perfect for gusseted heavy duty bags.
Serrated Sealing Bars
Heat film seal strength is determined by the total peel resistance a seal has. Peeling resistance is measured with a tensile tester measuring the seals resistance to peeling at the seam. Serrated sealing jaws increase the seal hold strength. The additional texture increases rigidity within the seam. The finished look is a rippled texture across the seal. The additional texture can come in many forms. Some embossing wheels add unique texture when used on continuous heavy-duty sealers.
Serrated sealing bars come with horizontal and vertical serrations. With horizontal serrated seals, the rippled texture runs left to right across the bag. Potato chip bags are sealed with horizontal serrated sealing bars. Vertical serrated sealing bars run up and down across the width of the seal. Candy bags are often sealed with vertical serrated sealing bars. When looking at the image above: the image on the right has horizontal seal seams and the left has a vertical seal seam.
A heavy duty bag sealer is made different than standard impulse heat sealers. The constant heat keeps the sealing bar heated which is ideal for sealing materials in excess of an 8 mil thickness. Using texture or serrations in the seal helps to increase the strength of the seal.
With the right sealer, heavy duty and large products can be sealed and protected. Call 1-800-441-5090 if you have questions about heavy duty bag sealing applications.