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You may not know what Kraft paper is, but you have certainly encountered it before. In fact, you have probably used this substance many, many times without even realizing what it is. Kraft paper is used to make cardboard, grocery bags, paper towels, and many other things that you probably see every day. In order to give you a better idea of what it is, let’s look at the details of the matter.

What Is Kraft Paper?

Kraft paper is a special kind of paper that was invented by a man named Carl F. Dahl. It was in Germany (during the 1880s) that he invented a new process for the making of paper. This process produces that strong brown paper which is so familiar to us today. Dahl named his new invention “Kraft paper” because “Kraft” means “Strong” in German.

Kraft paper is indeed much stronger than normal paper, even when it isn’t layered very thickly. This strength is achieved through a chemical bath that separates the two main components of wood. Cellulose and lignin are the two main components found in wood, but only cellulose makes a good paper. Dahl recognized that the lignin needed to be removed, as it was simply too brittle.

How Is Kraft Paper Made?

Kraft paper is made in a similar manner to normal paper, but with one crucial difference. Ordinarily, wood is pulverized into pulp, with that pulp later being used to make paper. Instead of doing this, Dahl cooked the wood chips in a mixture of sodium hydroxide and sodium sulfide. He referred to this substance as “white liquor.” These chemicals break the cellulose and lignin apart at the molecular level, making it easy to separate them.

When the cooking was complete, Dahl was left with a solid pulp at the bottom of the cooker and a noxious “black liquor.” This “black liquor” is black because it has absorbed all kinds of semi-decomposed lignin, leaving only cellulose pulp behind. The pulp is then passed through a screen to filter out any remaining chunks of solid wood and then washed so that it can be used to make all sorts of things.

The Pros Of Kraft Paper

Kraft paper is mainly used for its strength. It may be a little bit ugly, and it may be a little too thick for some uses, but Kraft paper can truly do it all. There are certain types of paper that are tougher than this, but they are going to be far more expensive than most people would be willing to pay. For instance, scientists have made paper out of graphene (a form of carbon), and that has proven to be the strongest paper in the world.

In spite of this, Kraft paper is still much more popular. So, why don’t more people use this graphene paper? Well, that’s because it is ridiculously costly. Although graphene is nearly as hard as a diamond, it is also nearly as expensive. Thus, it would not be cost-effective to use this paper for very many things. Thus, the “world’s strongest paper” is really nothing more than a scientific curiosity.

Another good thing about Kraft paper is the fact that it can be recycled. In fact, it is a very eco-friendly product overall. In spite of the chemicals used in its fabrication, Kraft paper has a very low impact on the environment. From a packaging perspective, it’s probably the most eco-friendly choice that you have.

The Cons Of Kraft Paper

There are a few downsides to this kind of paper, even though it is a very useful substance overall. For one thing, the quality and strength of Kraft paper are not always the most consistent. Depending on the wood used, you can end up with a lot of small variations. Not only does it depend on the type of wood that you use, but also upon the skill with which the process was carried out.

It’s important to remember that large-scale processes are always going to have a higher chance of going wrong. When you scale everything up, your problems tend to increase at a similar rate. Dahl’s process was invented by one man working in a small laboratory, so there can sometimes be problems when his process is scaled up to the industrial level.

Kraft paper is also not very attractive. Its’ plain brown appearance doesn’t exactly draw the eye, and that is why some manufacturers offer bleached Kraft paper, which is white. While this may sound like a good idea, but bleached Kraft paper is about 15% weaker than its normal counterpart.

Conclusion

Kraft paper is a fairly simple substance with a lot of different uses. Due to its high strength and the ease with which it can be made, this material has remained in common use since it’s invention more than a hundred years ago. So, let’s recap the pros and cons very briefly.

Kraft paper has the benefits of being cheap, versatile, and strong. It also has a relatively low impact on the environment. On the other hand, its strength and performance are not always consistent, and it’s not much good for artistic applications because of its brown coloration and rough texture.

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