Heat sealer machines

Heat sealing or bag sealing machinery is used to seal polythene and plastic bags as part of a packaging process. Heat sealing is used in packaging for a huge range of products of many different dimensions, shapes and materials. It is one of the most widely used ways of creating a protective enclosure which also facilitates handling. 

There are multiple different types of machinery available for heat sealing, and Automate UK members and exhibitors at the annual PPMA Total Show provide hugely valuable insights into the options available for producers and packaging companies.

Plus, if you're looking for labelling machinery to complement any packaging processes, you can find more information and PPMA Total Show exhibitors in the labelling machinery sector here.

What are the types of heat sealing machinery?

The two core types of heat sealer are impulse sealers and constant sealers. The two types have been developed for different applications, but both machines work on the basis of the application of electrically heated bars under pressure to form a closed seal for plastic bags.

Impulse heat sealers vs constant heat sealers

When deciding whether to buy an impulse sealer or a constant sealer, it is important to understand the heat required for the packaging you wish to use, how many packs you wish to produce, and their size.  

Impulse heaters are the entry point for heat sealing machines and, depending on their specification, are entirely suitable for businesses packing up to 20 products per hour, or possibly more. They are also relatively low on electricity usage because they are only heated while the seal is formed. They are also an easy way of sealing on more than one side of the pack, simply by manually turning the pack. 

Constant sealers are more expensive, and use more power, but they are capable of sealing heavier gauge plastics, films with a foil content, or multiply films. They are also designed with automated feed options and accelerated production. For commercial businesses producing 50 or more packs per hour, constant sealers are likely to be the best option.

Which materials are used in heat sealing?

Heat sealing only works with thermoplastic materials which soften under heat and harden when cooled. Many packaging operations use plastic films supplied in tubes which are sealed and cut, while others use open bags, pouches or single sheet films for sealing bespoke packaging. 

 

The choice of material used in a bagging operation will depend on the products being packed. For example, in the food sector, lighter products such as cereals are generally bagged in light polyethylene or polypropylene. Sterile products which need high levels of protection from moisture and the environment are frequently packed in foils, as are various foodstuffs including ground and whole bean coffee.  

Handheld heat sealers

Handheld bag sealers are manually operated and require the placing of bags into the jaws of the machine which is then switched on to heat and form the seal. Hand held equipment is a versatile solution for businesses packing relatively few products, and does not require significant amounts of space. 

Buyers should look for handheld machines which are light in weight and designed with safety in mind. Controls too offer significant operational advantages such as timers for sealing and cooling. Hand held sealers are usually impulse machines, but hand held constant machines are also available for packaging materials which require higher temperatures. 

Tabletop heat sealers

Tabletop sealers are compact sealers which are more comfortable to operate than handheld sealers. They take away the need for holding the sealer and can achieve higher throughputs. Table top machines are also available with integrated cutters which accelerate the creation of finished packs.

Foot operated heat sealers

Operation by a foot pedal allows packing staff to control sealing machines and leave their hands free to lift or position products on the sealer. Floor standing heat sealers can usually be adjusted for operation from a sitting or standing position. Both impulse and constant machines are available in foot operated models.

Rotary heat sealers

Rotary heat sealers are a type of constant heat sealer with bags or bagging materials fed by a horizontal roller or belt conveyor, with vertical feed systems used for liquid or powder products. They require limited manual handling and so are frequently used for sterile packing. Rotary sealers are also capable of achieving significantly higher outputs than handheld or table top machines and so are used in larger packaging operations. 

Vacuum heat sealers

Heat sealing is a feature of most vacuum packing machines. Once a vacuum has been created in a chamber or external vacuum machine, the container needs to be sealed immediately, and heat sealers are an integral part of the design of the equipment. In chamber vacuum machines, the heat sealer operates within the vacuum chamber. For external vacuum packers, the heat sealer is integrated into the machine’s gripper bar. 

Thermoform Heat Sealing Machinery

Thermoforming involves the heating of a plastic sheet to a temperature at which it becomes pliable. This enables the plastic to be formed into a particular shape for its purpose. It is also in widespread use in the pharmaceutical industry for blister packaging for pills and other medication in which a foil cover is heat sealed over the base plastic material. 

Find Heat Sealer Machine Suppliers 

See a full list of Automate UK Member companies that supply a comprehensive range of heat sealer machines.