The most widely used valve bag has so far been made of paper in several layers. New production methods have mean that you gradually switch to PP (polypropylene) bags, as these have many more storage and environmental benefits.
There are many industries and products that use valve bags, as these are easy to fill and have good storage and transport benefits. Products such as cement, animal feed, protein powder, chalk and fish meal are examples of typical products packed in valve bags.
Paper sounds immediately more environment friendly, but often in the paper valve bag there is either a pe plastic membrane, or the paper are coated with wax or the like. This means that the paper cannot be recycled. Here PP valve bags are a better product as they can be recycled. Likewise, PP sacks are made entirely of one material because closures are either simply welded together or heat sealed.
As you know, paper is sensitive to moisture and grease, which is not the case with PP. Resource use – the amount of raw material on a PP valve bag is less, which means it does not weigh as much, despite a greater strength. Of course, this also saves resources.
Now, one advantage of a paper valve bag over a PP valve bag is that you can make a better print on paper than on PP. But since it is not art or paintings that need to be outside, but most often production numbers and content as the most important information, then this is a, in most cases, affordable difference.
An even more important advantage of PP – polypropylene bags is that the price is cheaper than that of a similar paper valve bag.
Bluepack is a leader in PP valve bags, so give us a call for advice on this.