400D nylon, 500D nylon, 600D polyester, 1050D nylon, 1680D polyester and 16oz canvas are some of the most commonly used fabrics in bag manufacturing. They are designers' favorites because these fabrics are well known for their good strength, durability and reasonable price.
Common beliefs
When we need to make a decision on which fabric to use during product development, apart from the outlook of each fabric, we also need to consider how much strength it is needed for each specific case.
We usually make our decisions based on our experience, as we think we have some good ideas as to which fabric is stronger. But are these fabrics really as strong as we think?
To find out, we have arranged a lab test comparing some common fabrics. We would like to know if our common beliefs are all true. We think it is an interesting experiment and you might be surprised by the result.
The fabrics that we have compared this time are:
1680D Polyester/PU
1680D Nylon/PU
1050D Nylon/PU
1050D Cordura/PU
600D 64T Polyester/PVC
600D 84T Polyester/PU
500D Nylon
400D Nylon
12oz Canvas
16oz Canvas
We have run them through our tensile strength test machine. The test method we have used this time is ASTM D 2261. We have done five tests per fabric to get the average data, and below is the result.
To better illustrate the result, we have also created a chart.
Is everything within expectation? I think below are a few things that we can learn from this experiment.
Higher weight fabric is stronger
Most of us believe higher weight fabric is stronger than lower weight fabric of the same kind. The test result proves that this belief is indeed TRUE, as we can see that 16oz canvas is twice as strong as 12oz canvas. We can also see a similar relationship between other fabrics such as 1680D and 1050D Nylon.
Nylon is stronger than Polyester
Although nylon and polyester fabrics look very similar, we commonly believe that nylon is stronger. This belief is also matching with our test result. When we compare 1680D Polyester verses 1680D Nylon, we have found that Nylon is 1.4 times stronger than Polyester. 500D Nylon is also about 1.4 times stronger than 600D Polyester.
Is Cordura always stronger than normal Nylon fabric?
Surprisingly, we have found that 1050D Cordura is slightly weaker than normal 1050D Nylon. This is really out of our expectation. However, we must keep in mind that Cordura is well known for its durability against abrasion. We expect that Cordura’s abrasion resistance will out-perform normal Nylon.
Is Canvas a durable material?
We have an impression that canvas is a durable material. However, according to the test result, canvas is at least not strong against tearing. Its tear resistance is not high at all. 400D Nylon already out-performs 12oz Canvas. We should make sure that enough reinforcement is being added if Canvas is the choice of material.
How strong is 600D?
600D is the most commonly used fabric for backpacks. So, is 600D strong enough? We believe it is, at least for most of the cases. It is definitely strong enough for making a daily backpack or school bag. On the other hand, if you are developing a backpack that needs to be super durable, such as a military backpack, 1050D Nylon would be a better choice.
Backing material makes a huge difference
By comparing the two different 600D fabrics in this test, we can see that the backing material makes a huge difference to the strength of the fabrics. The 600D that comes with PVC backing is about 2.4 times stronger than the 600D fabric with PU backing. This is something interesting to note. Regrettably, PVC is being banded by many countries due to product safety concern.
Conclusion
Actually, we are NOT READY to make a conclusion yet. It is because tearing strength is not the only thing to consider when determining the durability of a fabric, the other important consideration being abrasion resistance. We have another post for that. Please see the related article Abrasion Resistance Test - 600D Polyester, 500D Nylon & 1000D Nylon for more information.