Tensile and Tear testing on fabrics

[GabeWalker]

I'm fairly new to the forums, so sorry if this has been posted before.

Has anyone done tensile and tear strength testing on some of the fabrics that we use for hammocks? I have seen some comparisons in terms of some fabrics being generally better at not tearing and I've seen the weight/comfort limit chart at dream-hammock.com, but I was wondering if anyone had some hard numbers so that I can run calculations before spending my money and time trying a new hammock footbox design.

[gmcttr]

If any testing of this type has been done and reported on HF, I don't remember it. I'm sure some of us have tried tearing different fabrics by hand, but nothing you could put numbers to.

Test data would have to come from the manufacturers, or in the case of mil spec materials, you could look up those specs.

[Ramblinrev]

The only things that don't have easily found test limits are the products we have adopted for hammocks that are really off label. Lightweight taffeta is not manufactured for hammock use. It is a garment material for the most part. So those stats are not readily available. However, many manufacturers use taffeta as their base fabric so somewhere along the line they have been at least casually tested. Webbing is weight rated, so are the ropes and hardware used. Look around and I suspect you can find information that will give you the insights you want. Check fabric manufacturers specs. You may be able to extrapolate from there. The tensil strength of the various polymers are known by the manufacturers.

[GabeWalker]

Thanks for the replies, I emailed a few manufacturers and rockywoods got back to me with this information in case anyone else had similar questions.

PRODUCT DATA SHEET

PRODUCT NAME: 1999

TYPE OF GOODS: 30 X 30 denier Type 6,6 HT Nylon

COATING: Silicone coated both sides

FINISH: Dyed

WEAVE: Plain Weave

CHARACTERISTICS TYPICAL VALUES

Fabric Weight (oz/sq) 1.3-1.5

Width (inches) 64-65

Porosity 0%

Tensile Grab Strength (FTM-5100)

Warp: 65 Lbs

Fill: 70 Lbs

Tear Strength (Tongue Tear ASTM D 2262)

Warp: 12 Lbs

Fill: 14 Lbs

Melting Point 480 ºF

Country of Origin USA

*Disclaimer: The data presented here represents laboratory test of a limited number of samples. Since your

manufacturing methods and the conditions of use of the end product are beyond our control,

ROCKYWOODS FABRICS LLC does not warranty the suitability of this fabric for use in your product. You

should test the fabric thoroughly for your application.

[GabeWalker]

I also received this information from outdoor wilderness fabrics

Fabric Specifications

RIPB1.9 9/15/2011

DESCRIPTION: 60" Ripstop

LINEAL YARD: Approximately 1.9 ounces per square yard

CONTENT: 100% Type 6 nylon.

CONSTRUCTION: 102 X 97. 70 Denier 24 Filament Warp and Filling.

FINISH: DWR. Hot calander One side

ORIGIN: Imported greige goods dyed and finished in USA.

Warp 120.5 lbs Filling 117.0 lbs

[dynamicsnail]

Can anyone translate "warp" and "filling?"

[GabeWalker]

Here's a quote from http://composite.about.com/library/weekly/aa042897.htm

"If you look at a roll of fabric, some of the yarns run in the direction of the roll and are continuous for the entire length of the roll. These are the warp yarns. The short yarns which run crosswise to the roll direction are called the fill yarns. Warp yarns are usually called ends and fill yarns picks, but sometimes the fill yarns are also called ends. (The terms apply equally to rovings, but yarn will be used in the rest of the discussion for simplicity.)"

[dynamicsnail]

Here's a quote from http://composite.about.com/library/weekly/aa042897.htm

"If you look at a roll of fabric, some of the yarns run in the direction of the roll and are continuous for the entire length of the roll. These are the warp yarns. The short yarns which run crosswise to the roll direction are called the fill yarns. Warp yarns are usually called ends and fill yarns picks, but sometimes the fill yarns are also called ends. (The terms apply equally to rovings, but yarn will be used in the rest of the discussion for simplicity.)"

Interesting. It seems like lbs wouldn't quite define the strength--maybe pounds per inch width or psi...

[GabeWalker]

That was my thought too. I tried getting an explanation from one of my mechanical engineering friends but it was over my head. My guess is either they shorthanded the units and it's supposed to be lbs/in2 (I think that's unlikely though) or they have a standardized testing size for the fabric. I looked at trying to find the testing procedure for the listed tests but the paper I found cost $42!

[nuttysquirrel]

http://youtu.be/8gfcuCh7h04