Let’s talk tear strength and paper carrier bags

This paper carrier bag was not produced by KESANOVA. Though, this is not the point. There is nothing wrong with this bag. It is just that it was used for a purpose that it is not built for. Let’s talk tear strength, alias rip strength.

This innocent paper carrier bag was ripped yesterday during a bicycle ride on Cvetan Dimov Street.
This innocent paper carrier bag was ripped yesterday during a bicycle ride on Cvetan Dimov Street.

The paper of this bag is approximately 80 g/m2, and the bag is made of recycled paper and with straw handles. The retail shop making use of this bag in downtown Skopje use it for cloth and perhaps also for a bit heavier equipment. For the first purpose it is most probably fine, for the second purpose it is less likely to be strong enough.

Ripped on Cvetan Dimov Street

So, this paper carrier bag should be pretty ok, if you don’t shake the straw handles too much, and if you don’t fill it too much.

However, no matter what, this bag couldn’t stand a bicycle drive up the Cvetan Dimov Street. Well, this road is dangerous even for cyclists, but the broken bag is not due to heavy congestion and individualized traffic rules. Rather, it is about the bag’s low rip strength.

What is rip strength or tear strength

Tear strength is a term used to express how vulnerable is the paper of the bag. Low tear strength means that it is easy to tear the paper apart. High tear strength means the opposite. High tear strength means less vulnerable by contact with sharp edges, uneven weight distribution etc.

You can test the strength by simply trying to tear the top edge of the paper carrier bag. It is always good to test it close to the handles, as this is usually the most vulnerable place on the paper carrier bag.

Obviously, thicker paper usually means better rip strength, but this is most certainly not the only parameter. Basically, it is about paper quality.

Virgin paper vs recycled paper

Virgin paper is a term used for the paper that has not yet been recycled. It means that the paper fibers are still long and strong.

Recycled paper – on the other hand – obviously contains paper that has been used before, one or many times.

Unfortunately, the rip strength depends on how long and strong the fibers are. Since usually you cannot know how many times recycled paper has been recycled, it is difficult to predict the rip strength of a recycled paper product – like paper carrier bags.

So well, even if you are tear-testing by yourself, the test may only apply to the individual bag you are testing.

Brick bottom paper carrier bags from KESANOVA

All brick bottom carrier bags from KESANOVA are made of either 90% or 100% virgin paper, and we do not offer straw handles. And, you guessed it right: Virgin paper is – all else unchanged – often more expensive than recycled paper.

However, if you count how many times you can use a paper bag made of virgin paper compared to a paper bag made of recycled paper, the math falls out in favor of virgin paper bags.

Naturally, virgin paper is also recyclable.