Open-mouth bag or valve bag? Ausloos explains
Which bag is the right solution for your product? What are the advantages and disadvantages of the various options? To help you decide, we have made a comparison between two popular types of packaging bags: the open-mouth bag and the valve bag.
Both open-mouth bags and valve bags are available in paper and plastic. Valve bags are closed by ultrasonic sealing, whereas open-mouth bags have more options, such as sewing, sealing or a glued paper strip.
Open-mouth bags come in many sizes, ranging from tiny to huge. Valve bags have a less wide range, but are good for medium sizes.
In general, valve bags are slightly more expensive than open-mouth bags. Valve bags have a more square shape and must be sealed. This makes them more expensive to produce. On the other hand, valve bags are easier to handle in bagging machines. This enables you to recoup the extra cost.
Naturally, whether or not you need to use airtight bags depends on the product to be packaged. Valve bags are generally more difficult to make completely airtight than open-mouth bags.
How does your end user want to use the product? You can simply open an open-mouth bag and scoop out the product. This is more difficult with a valve bag and it is best to empty the entire bag in one go.
Products such as barley flakes are prone to breakage. These products are best packed in open-mouth bags. This is because, when using valve bags, the product is squeezed through a narrower pipe, subjecting the filling to more pressure. This is a good thing if your product can be pressed closely together. If using an open-mouth bag, on the other hand, your product will be dispersed more loosely into the bag. As it will not be pressed as tightly together, this option is better for delicate products.
Bag shape and stackability
Naturally, both open mouth and valve bags are perfectly stackable. We have already mentioned that valve bags tend to have a square shape, especially if they are filled optimally. Open-mouth bags, on the other hand, give you a more flexible fill density.
If you look at a stacked pallet, you will see the difference immediately. Even though both types of bags are stackable, stacked valve bags result in a nicer, tighter pallet than the ‘looser’ open-mouth bags.
The final choice of whether to opt for an open mouth or valve bag is largely determined by what is customary in a particular country’s market. In the Netherlands, bakery flour is almost always packed in valve bags, while sewn open-mouth bags are the preferred option in Belgium.
We don’t really know the reason for this. Presumably, a few pioneers in the industry chose a particular type of bag, and the rest followed. At the end of the day, we are still herd animals. What we do know, however, is that we can use both open mouth and valve bags for a wide range of purposes!
If you still have any questions about open mouth or valve bags, please don’t hesitate to ask us!