Zipper PP: more flexible, more convenient and longer lasting

March 16, 2022

Zipper bags have long been a feature of our day-to-day lives. In recent years they have really come into their own as a storage solution, and we now use them to package a huge range of products in both the home and the workplace.

With hermetic seals and a variety of sizes available, zipper bags and pouches are really rather versatile.  They can even be used for freezing or flash-freezing vegetables, meat or fish, preventing damage to the nutritional and sensory properties of the product.

All zipper bags do the same job: the hermetic seal prevents oxygen from entering the bag and stops leaks. This protects the product/food and keeps it fresh for longer.


In 1957, a student by the name of Robert Lejeune demonstrated that the zip closure meant bags could be used to safely store food.

Years later, in 1968, Dow Chemical began marketing the Ziploc bag.

As time went on, the industry needed to find ways to bring down the cost of this sliding closure without any loss of effectiveness. That led to the design of the simple push-and-close zipper seal that we know and use today.

The main benefits of zipper bags are:

  • Protection. The system completely seals off the product in the bag or packaging and protects it from dirt, dust and humidity.
  • Versatility. Hermetically-sealed zipper bags can store loose foods, liquids and powders. When it comes to food products, vacuum sealing protects humidity, juices and flavour.
  • Reusable. We can open and close a zipper bag as many times as we like. It’s simple! This itself has two key benefits: first, we increase the shelf life of the product/food by minimising contact with air; second, we can reuse the bag over and over again, which is really important in terms of sustainability and the environment.
  • Adaptable. Hermetic seals open up a world of possibilities. As already mentioned, packaging sealed this way can store a variety of products from food and cosmetics to industrial items and more. In addition, they come in a range of shapes and sizes and can be custom made too. Throughout the COVID-19 pandemic, zipper bags have been positioned as the preferred type of packaging for face masks and personal hygiene products, many of which need special protection and are sold individually.


Zipper bags are usually manufactured in low-density polyethylene.

This flexible, light and non-toxic material is a great choice for packaging any product – food or otherwise.

In addition to polyethylene (PE), zipper bags can also be made from polypropylene (PP). For products that require sterilisation(enlace post esterilización), PP is the preferred packaging material since it can withstand with the high temperatures involved (up to 121ºC) without migrating.

At SP Group, we supply products made from PP HB ECO and PE HB ECO. Both these structures have been developed by SP Group as a solution that meets the EU’s 2030 target for packaging to be recyclable or reusable.

Clarification: Zipper bags can be manufactured in PE or PP. Most are made from PE. However, packaged products that need to be retortable are packaged in PP because it withstands temperatures up to 121ºC without migrating.


At SP GROUP, we’ve developed a polypropylene zipper which is much more flexible than traditional designs.

This type of bag can sometimes be tough to open, particularly the smaller sizes, and our goal was to make it easy to open the hermetic seal both on the packaging line and during final product consumption. 

The new Zipper PP also works perfectly with polypropylene monomaterials to enable sealing at lower temperatures.

This also means that the closure is 100% compatible with our new recyclable and retortable PP HB ECO, designed to withstand heat treatments such as sterilisation, pasteurisation, hot-fill and microwave heating.

PP HB ECO is designed to package food products that require sterilisation, including sauces and ready meals. In that sense, PP HB ECO is particularly suitable for on-the-go formats, for baby food and for many pet foods.

The union of the new zipper with PP HB ECO paves the way for a new range of packaging that will reduce food waste and increase packaging recyclability. Want to know more? Get in touch.

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At SP Group we optimise our production processes to provide the most efficient service to large industry. Many multinational companies already trust our ability to meet their flexible packaging needs on a daily basis.
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