Sealing coffee bags: What are impulse sealers?

Amelia Cooper
February 1, 2023
An image of a coffee roaster sealing coffee bags using an impulse sealer in an article on coffee bag sealing using impulse sealers

Dependable, airtight coffee packaging is the key to ensuring customers enjoy a roaster’s coffee at its finest. 

If oxygen is allowed to seep into the coffee, the process of oxidation can quickly compromise its flavours, aromas, and complexities. 

If coffee bags are sealed incorrectly, customers buying from a supermarket are likely to have a significantly less enjoyable experience than those purchasing their coffee fresh from a roastery.  

Investing in the right sealing equipment will ensure coffee arrives at its destination with its quality intact. While there are a number of different approaches to sealing coffee bags, one of the most common methods is to use impulse sealers.

Impulse sealers are often considered more economical and environmentally friendly, as they use less electricity. 

Learn more about impulse sealers and the types of coffee packaging materials that are suitable for the process. 

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What are impulse sealers?

An impulse sealer uses an electric current to generate heat to seal bags and other materials. 

Impulse sealers are used throughout the food and drink industry, as they provide a convenient solution to create airtight packaging. 

The machine’s heating element comprises a metal wire, typically made of nichrome: a resistance heating alloy.

This wire melts two layers of material together, forming an airtight seal. Notably, this seal can only be broken when the customer cuts into the packaging. 

Impulse sealers are safe to use, as the element heats and cools rapidly. 

There are a number of different types of impulse sealers, which can largely be grouped into manual or automatic sealers. 

Roasters can choose from either a hand-operated tabletop, foot-operated, double impulse, automatic or attached cutter impulse sealers. 

Impulse sealers are fitted with a cutter, which is designed to neatly cut the plastic off once the seal has been formed.

Heat sealers are similar in design and are often used to add airtight seals to coffee packaging. However, the element for heat sealers is continuously heated, as opposed to impulse sealers, which are only heated sporadically.   

Although both sealers are used in the packaging industry, heat sealers are usually used for thicker materials. On the other hand, impulse sealers are better suited for thin packaging materials.

Impulse sealers are often preferred over heat sealers, as no additional time has to be allocated for heating or cooling. 

An image of a kraft paper coffee bag with custom printing as an example of sustainable substrates that can be used with impulse selaers in sealing coffee bags in an article on coffee bag sealing using impulse sealers

What coffee packaging materials can be used with impulse sealers?

Impulse sealers are commonly used to seal plastic bags or packaging made from thermoplastic materials. 

That said, they can also seal a variety of other substrates, such as polyethylene (PE), polypropylene (PP), polyurethane, nylon, foil, and mylar. 

Additionally, some impulse sealers can create seals on laminated materials or packaging with multiple layers, such as foil-lined coffee bags

More so, advancements in sustainable packaging have seen a range of environmentally friendly packaging materials enter the market. 

These materials include bioplastics, low-density polyethylene (LDPE), and polylactic acid (PLA) – all of which can be used with impulse sealers. 

This is because impulse sealers are designed to operate in the same way for every material they are used with. 

As bioplastics so closely resemble the properties of traditional plastics, they can be used with an impulse sealer. 

However, it is important to note the heat-sealing properties of sustainable materials will differ. Before roasters choose a material for their coffee packaging, it is essential they confirm it can be used with impulse sealers. 

The crucial question is will using an impulse sealer affect the sustainability of the coffee bag? That largely depends on the materials used to make the bag. 

If a combination of bioplastics and other non-sustainable materials is used, this is likely to compromise, and effectively negate, the sustainability of the bioplastics. 

If roasters ensure all the packaging materials and seals are made from bioplastics, impulse sealing is highly unlikely to alter the sustainability of the packaging.  

This is because impulse sealing, in and of itself, is not an “unsustainable process”. Since sealing only requires the application of heat, no materials are added or chemically altered through the process. 

An image of a coffee roaster sealing coffee packaging with an impulse sealer in an article on coffee bag sealing using impulse sealers

Should roasters invest in impulse sealers?

Several factors should be considered before investing in an impulse sealer. 

For a small or newly established roastery, a heat sealer may be an effective way to preserve the high quality and rich aromas of the coffee. 

That said, most impulse sealers require each coffee bag to be sealed individually and manually. Therefore, roasters will have to determine how viable this labour is, based on the number of bags they are selling.  

For those selling smaller volumes of packaged roast coffee, manual impulse sealers can be an effective solution. They tend to be more flexible, allowing roasters to seal as many bags as required based on demand.

Impulse sealers are also a significant investment for roasters that are working to improve sustainability standards. 

As impulse sealers heat the wire in short bursts, they are considered more energy efficient than many of the alternative sealing machines on the market. 

However, roasters with a large or growing volume of orders will need to shift to an automatic heat-sealing machine. 

The major benefits of automatic sealing machines are their speed and non-manual operation. Plus, they allow roasters to seal substrates made from different materials that vary in thickness and shape. 

Furthermore, this means roasters are able to use the same sealer to seal packaging for their entire coffee range. 

At MTPak Coffee, we offer premium quality heat sealers, which are specially designed for coffee packaging. 

Our horizontal heat sealers offer a sealing width of 6 to 15 millimetres (0.24 to 0.59 inches) and a film thickness of 0.02 to 0.80 millimetres.

Our heat sealers can be used to seal our range of sustainable coffee bags made from kraft paper, rice paper, or multilayer LDPE packaging with an environmentally friendly PLA lining

In addition to helping seal your coffee packaging, we are able to fully customise your coffee bags. We offer a variety of innovative design services, including custom-printing, embossing, debossing, and more. 

More so, our clients can add custom-printed sleeves to our coffee mailer boxes and coffee bags, attach stickers, print QR codes, or insert labels and cards inside to enhance the experience for each and every customer.

Additionally, we offer our clients a quick turnaround time of 40-hours and 24-hour shipping time, thanks to our innovative digital printing technology.  

We also offer low minimum order quantities (MOQs) to micro-roasters who are looking to remain agile while showcasing brand identity and a commitment to the environment.

To find out more about the benefits of heat sealers and sustainable coffee packaging, contact our team

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