DIMENSION-POLYANT Technical Fabrics: Properties and Development

Welcome. We have plenty of engineering nerds here who just LOVE new gear and data.

Cheers
Roger Caffin
Online Community Moderator
BPL

Thanks Taylor for starting this thread – looking forward to seeing comparison data in more detail. Some videos comparing the feel and properties of each fabric would also be helpful. A few questions to start out with:

1. Any plans for a V07 and/or a V21 fabric without the X grid?
2. Any plans for more Lite Skin colors?

I will strongly support Lester’s request for fabrics withOUT the X grid. I have made several packs using DP fabrics, and the major wear points are ALWAYS over the grid. That big bulky thread adds nothing (except marketing appeal) to the fabric, but it does cause acute wear problems.

Cheers

Roger – at which locations on your packs have you seen X grid wear (extension collar for roll top)? And what level of wear did you see between VX-21 and the lighter VX fabrics?

Hi Lester

Right now I forget exactly which VX fabrics I was using. I was using a heavy Cordura-based fabric (VX42?) for the base and a much lighter fabric (VX07?) for the body. In any event, the light body fabric has a white (taffeta) interior face fabric.

I found that anywhere inside the pack where a hard object, or even just a firm object, rubbed against the fabric over one of the X grid threads, the white fabric wore through and exposed the black grid thread. This was especially evident over the aluminium struts (framed pack). I had to laminate reinforcing fabric over the inside face for safety. Gas canisters and cooking pots were a big risk here.

Otherwise the VX07 has proven quite adequate – with the VX42 reinforcing at the base of course. It has lasted for year. But I don’t think the X-grid threads have contributed ANYthing to the performance. They are just in the way.

Cheers

The issue of XPAC wearing at the X grid is not new and has been reported before, but I wonder whether XPAC being, well, “X” pac, means it is condemned to have the X grid whether it is a benefit or not.

The question I’d like to ask is a different one though: does LS refer to some properties of the face fabric or is LS42 a completely different beast from X42?

Hi All,

Lester – Nothing in the immediate pipeline for a X-PLY-less VX fabric. I hear the wear issues on the X-PLY yarn intersections and we could certainly make a fabric without. The X-PLY yarn do provide off-axis support, act as a large rip-stop and certainly provide a signature appearance which is important for many of our customers.  For our production runs we target 1000 yards as a minimum as this is where you can amortize the machine set-up to make a reasonably price fabric. We can do shorter runs but the price of the finished fabric increases. So the decision to make a laminated pack fabric without an X-PLY is an easy one if we have an order :)

The LiteSkin fabrics LS07, LS21 would be a good candidates if you are looking for a VX07 or VX21 without the X-PLY as the construction is similar and they are lighter weight.  LS can be just about any color. We’ve done blues and greens for yacht sails before. We’re happy to make other colors but again, it’s just a matter of demand.

Federico – The “LiteSkin” refers to the non-woven polyester face.  LS42 has a LiteSkin face with a 420 denier nylon backing. X42 has the 420d nylon on the face and a film backing. The LS42 is 0.5ozyd^2 lighter.

Cheers,
Taylor

Does Liteskin have the film backing that allows seams to be taped?

Hi Matthew, at this point the LS styles all have a woven backing to provide tear resistance.

Cheers,

Taylor

Taylor,

Thanks for adding to the conversation here!

Referencing your 2017 outdoor materials guide, a few weights/abrasion test results seem inconsistent with what one might expect. How accurate are these numbers? Are we to believe that all the liteskin styles regardless of base fabric thickness have the same abrasion test results?

Also, the abrasion test results for X series vs VX series are identical given same face fabric. One might expect that the additional 50 denier poly taffeta gives a few additional cycles, but your posted results show otherwise. Care to comment?

What about X51 with a 1000 x 500 denier or X50 with a 500d cordura both having a LOWER test result than the 420 denier X42.

Liteskin with a 210denier face has the same listed weight as VX21 of 6oz/yd2 is this correct?

Liteskin with a 420 denier face has a listed weight of 6.9oz/yd2. This is less than even X42  @ 7.4oz/yd2 with out the additional polyester resin.

A few questions come up for me here.

Is the LS21 the only liteskin style to keep the .25mil PET laminate? Outdoor guide says so.

If this is the case, how do the other fabrics maintain a 160-200+ PSI waterproofing?

The LS42 has a 420 denier base fabric, but the liteskin resin is on the outside. My assumption is that the resin itself will wear through much faster than the 420denier base fabric. Is this true for all three styles?

This bring up a larger question of how accurate the  ASTM 3884 standard is for comparing real-world wear and tear. As an example, the LS07 lists 2000 cycles, whereas the X21 and VX21 list 900 cycles. I would be willing to wager a large sum that three identical packs built from these fabrics would show the LS07 wearing through faster than the other two, let alone lasting over twice as long.

I am not trying to totally bash the Liteskin, as I believe there is some potential to the technology therein, I just personally don’t believe the hype as presented. My personal experience is that all other things being equal, a larger denier thread will provide a longer service life for a piece of outdoor gear, and this should be the main consideration when choosing an appropriate material.

In interest of full disclosure, I have purchased fabric from DP for years, and my preferred fabric for general use ultralight and lightweight packs is a 210 denier base fabric. I have a run of V21 (210 Denier face fabric with .5mil laminate and NO x-grid(at just over 4oz/yd2) in the queue to be built by DP this month.

I have built a pack from LS07 as a prototype for personal use. I’ll be the first to let you all know how it wears.

Taylor, can you share the Outdoor Materials Guide that Nathan has referenced?

Hi Nathan,

Thanks for the questions, and thanks for your business! Please see my replies to your questions below in Bolded

Referencing your 2017 outdoor materials guide, a few weights/abrasion test results seem inconsistent with what one would expect. How accurate are these numbers? Are we to believe that all the liteskin styles regardless of base fabric thickness have the same abrasion test results? We send our outdoor fabrics to an independent lab for testing to ASTMD3884, which is the most commonly referenced standard for outdoor abrasion testing.  Its a duel wheel abrasion test where the specimen rotates under two wheels that shear the surface of the fabric in an off-axis manner. The most common set-up for our materials is a H-18 wheel with 500g weight. I’m confident the published numbers are accurate and repeatable (or at least I would hope they are as we are paying a lot of $$ to have them tested!)  There are a number of ways to evaluate the specimen after the abrasion test. I believe the number of cycles references the number of cycles before the face fabric is worn through.

Also, the abrasion test results for X series vs VX series are identical given same face fabric. One might expect that the additional 50 denier poly taffeta gives a few additional cycles, but your posted results show otherwise. Care to comment? As mentioned the abrasion test stops when the face fabric is worn through therefore it’s logical that fabrics with the same face fabric should have the same test result.

What about X51 with a 1000 x 500 denier or X50 with a 500d cordura both having a LOWER test result than the 420 denier X42. Interestingly with this test fabrics with “big” yarn and a rough texture tend to not do as well as smoother fabrics or textiles. In the ASTM 3884 test the wheels shear off the “peaks” of knobby fabrics degrading them quickly.

Liteskin with a 210denier face has the same listed weight as VX21 of 6oz/yd2 is this correct? No, LS21 is 4.8 oz/yd^2

Liteskin with a 420 denier face has a listed weight of 6.9oz/yd2. This is less than even X42  @ 7.4oz/yd2 with out the additional polyester resin. Yes, correct. The LS face is light :) LS42 does not have an X-PLY yarn component which is a measurable weight savings.

A few questions come up for me here.

Is the LS21 the only liteskin style to keep the .25mil PET laminate? Outdoor guide says so. The LS styles do not have an internal film. Updated Outdoor Material Guide posted below.

If this is the case, how do the other fabrics maintain a 160-200+ PSI waterproofing?  The resin coating provides excellent waterproofing.

The LS42 has a 420 denier base fabric, but the liteskin resin is on the outside. My assumption is that the resin itself will wear through much faster than the 420denier base fabric. Is this true for all three styles? <>If you go by standard testing the LS will exceed the woven faces. If you compare the abrasion test results for LS07 to the VX07 for instance.

This bring up a larger question of how accurate the  ASTM 3884 standard is for comparing real-world wear and tear. As an example, the LS07 lists 2000 cycles, whereas the X21 and VX21 list 900 cycles. I would be willing to wager a large sum that three identical packs built from these fabrics would show the LS07 wearing through faster than the other two, let alone lasting over twice as long before showing wear.   <b>Whether ASTM 3884 is a valid test for “real-world” use is an argument that could go down a number of different paths.  When it comes down to it “real-world” tests would vary from customer to customer and user to user – So most of our customers accept  ASTM 3884 as the current standard. We are working on a more realistic abrasion tester in the shop.</b>

I am not trying to totally bash the Liteskin, as I believe there is some potential to the technology therein, I just personally don’t believe the hype as presented. My personal experience is that all other things being equal, a larger denier thread will provide a longer service life for a piece of outdoor gear, and this should be the main consideration when choosing an appropriate material. 

In interest of full disclosure, I have purchased fabric from DP for years, and my preferred fabric for general use ultralight and lightweight packs is a 210 denier base fabric. I have a run of V21 (210 Denier face fabric with .5mil laminate and NO x-grid(at just over 4oz/yd2) in the queue to be built by DP this month. Thanks! Looking forward to seeing it in the shop and hearing about how it works for you!

I have built a pack from LS07 as a prototype for personal use. I’ll be the first to let you all know how it wears. I have two packs I use daily, one is LS21 and the other VX21RS. I’ve used them both for a year and both show very little wear if any (Sadly, my “real-world” test is shoving them in and out of airplane bins more than I would like rather than thrashing them outside)

Here’s the 2017 Outdoor Guide. The 2018 guide should be ready soon.

Cheers,

Taylor

Hi Taylor

I may be misunderstanding what has been written about the LS series of fabrics, but it seems they have the PET layer on the ‘outside’, as opposed to the VX series which has it on the ‘inside’. I agree that this would make the LS fabric seriously waterproof and non-absorbent compared to the VX series when new, but I worry that the PET film will not resist the outdoors nearly as well. Gear gets dragged through some rough scrub and over sharp rocks.

If so, that means that the ASTM test you cited is irrelevant for most of our needs. It tests to break-through, whereas we would be far more interested in testing to the point of leaking.

Is my understanding correct?
(By way of explanation: I spent 27 years as a research scientist in the CSIRO Div of Textile Physics, developing measurements systems for the Australian wool industry. They were successful and are in current use. I retired as a Senior Principal Research Scientist, or some such grade.)

Cheers
Roger Caffin PhD

Taylor,

Thanks!!

 As mentioned the abrasion test stops when the face fabric is worn through therefore it’s logical that fabrics with the same face fabric should have the same test result. 

A bit confused here, as I’ve only seen pictures of these testing machines, and haven’t had my hands on one personally. I thought they tested to wear-through of a singular material. How do you test a multi-part laminated fabric to failure of just a single component without testing the components individually outside of the composite?

If we’re led then to believe that the liteskin is tested on just the polyester/resin laminate without base fabric, those are certainly some impressive numbers! Perhaps the material exhibits extremely low-friction properties.

Good on DP for exploring more methods of testing abrasion in-house!

I’ll continue to take the efficacy of the ASTM 3884 with a grain of salt. The most glaring example for me using posted table would be to compare the D40 fabric at 1000 cycles rated vs liteskin LS07 at 2000 cycles rated. The D40 will absolutely last longer in a pack build, period.

Roger, my understanding was that the liteskin is a polyester resin akin to tyvek that is applied to the base fabric face in lieu of the internal PET laminate.

Hi Nathan

Perhaps our confusion represents a triumph of marketing spin over technical information?

Cheers

It would be helpful to have a table showing the thickness or Denier for each layer in these DP fabrics.

Fabric Name         Surface treat    Front layer     Film      Backing layer   Specs…

VX-07      DWR        70D Ripstop      0.25mil PET       50D Taffeta        oz/sqyd, etc, etc…

LS-21        n/a         non-woven poly/resin       n/a         210D nylon         oz/sqyd, etc, etc…

Most of that is in the Outdoors Materials Guides listed above.

Cheers

Taylor – thanks for posting the Outdoors Materials Guides, however, the print is small and very hard to read. Do you have a link for the full sized tables?

Lester – those are reduced thumbnails. Save Image As will get you quite readable JPGs.

Cheers

Nathan – The ASTM test has many different variations in terms of set-up and a few different ways of quantifying the results, it depends on the test standards agreed upon by the supplier and the customer. As an example one customer might be interested in the cycles to get the face fabric to wear away, where as another might be interested in the degradation of a tensile test after X number of cycles. The ASTM 3884 test is a surface abrasion test and does, as you mention, reflect the surface friction of a fabric not necessarily the absolute durability of a a fabric.  Just as in the sailcloth realm, tensile testing does not necessarily correlate to durability.

Roger – LiteSkin is a non-woven polyester component. Not a PET “film” that is present on the back of the X styles. THe LS styles do not have a PET film component.  Granted, when the non-woven layer is impregnated and coated with resin it behaves like a film in terms of impermeability but retains a softer, quieter hand.

Cheers,

Taylor

Taylor,

I appreciate your presence here!

Cheers

Taylor,

Thanks for this thread. Great stuff.

The abrasion resistance of LiteSkin sounds good, but I’m hesitant about it’s water resistance because the resin is on the outside of the fabric, so it appears more vulnerable to being degraded over time than an internal PET layer. I’m sure the water resistance is good at first, but I’m worried about how it might be after 5 years of use.

My questions are:
1) Do you agree that after substantial use, the water resistance of the VX fabrics with PET would likely be better than LiteSkin?
2) Have you tested the water resistance of LiteSkin after an abrasion test?
2) Any plans for a LiteSkin + PET? So poly + nylon + PET sandwich?

Lastly, I’ll just echo what others have said about wanting more options that ditch the X-ply. I’d like to see X21 without the X (210 Nylon + 0.5 PET) in addition to V21.

Thanks!

Dan,

V21 is X21 without the X.

Pm me your addy and I’ll mail you a sample when I have it in hand.

Hi Dan,

I don’t believe we have run any water resistance tests on the LS after abrasion or hard use. Not taking away from the robustness of the LS resin coating; I do agree that the styles with an internal film layer(like the VX fabrics) will have better long term waterproof-ness as the impermeable layer is better protected.

We could definitely make a LS style with film, in fact, the early LS prototypes did have film which was removed to create a fabric with a softer-hand. Obviously the demand for a fabric dictates how our machines run so if there is enough of a calling for V styles like Nathan’s, or LS styles with internal film we’ll definitely consider it!

Cheers,

Taylor