3 Pack Fabric's HH Tests

The oz/yd2 for the Coyote colored fabric in the prior post is wrong but since it was the first post of the thread, I can’t correct it. I highlighted the corrected value in red for this post.

After 5,400 wet flex samples, and the test head centered on the 1′ square sample, the Coyote color XPac had 1 leak point at 633 mm HH. The applicable standard calls for 3 leak points within the test head area to qualify as a HH limit. I moved the test head around the perimeter of the fabric and couldn’t find any additional leak points.

Note the contrast in the coyote XPac construction versus the white XPac construction. The white XPac appears to have had more liquid adhesive applied to the clear lamination and this adhesive both filled the fabric voids and created anchor points by spreading out on the opposite side of the fabric that the clear lamination is on. Does anyone know if this was just manufacturing variance or different lamination processes are used for different fabric combinations?

You don’t need a microscope to see the clear PET membrane failure. I took this picture with my iPhone.

I have three theories as to why this happens. It could be one or some or none (smile).

1. Insufficient glue was applied between the clear PET membrane and the fabric
2. The rigidity of the characteristic raised X (omitted on this fabric) distributes the flex load over the large area under each X and hence, prevents the clear PET membrane’s perforations
3. The adhesive injector nozzles are not center aligned with the major fabric interstices.

5mm FOV showing one of the failure points. It indicates both delamination and membrane perforation.

Ryan,

I am using an old USB microscope with no software.  I combined this with some custom software on Windows 10 Professional for a “kludge solution” which doesn’t support video.

If you find something that does what you want, please post that information to this thread. I would like to find a supported product.

Nathan,

I think the fastest way to solve this is for the DP engineers to get involved as the next step. Only they can modify their manufacturing process, their QA process, or make the determination that nothing needs to be done.

Ryan,

10.800 wet-flex cycles correlates to the approximate weathering from 4 weeks of heavy wind and rain.

I haven’t tested any WP pack fabric’s before. I last tested a Cuben fabric (aluminized version 3) in 2014. That 2014 work was done in cooperation with Nathan Myerson. It is described in detail Here. The Cuben was still  >3515 mm HH after I stopped testing at 16,200 Cubex wet-flex cycles.

Two additional 1.4mm FOV micrographs with the microscope facing the PET layer and looking through it to the fabric.

White composite

Coyote composite

Two additional 1.4mm FOV micrographs with the microscope facing the fabric layer and looking through it to the PET layer. If they are doing a fine nozzle adhesive injection into the fabric side’s major interstice pattern, it’s possible that the adhesive injector is not center aligned and/or not injecting enough adhesive into the Coyote version.

White composite

Coyote Fabric

I tried to use different lighting to create easier to interpret micrographs in this post. My objective was to assist the DP engineers in an expedited problem analysis.

There are areas of the Coyote lamination where the amount of adhesive looks adequate and other areas where the amount looks inadequate. This seems to reinforce the hypothesis that the missing X grid is the more likely cause of the delamination areas and perforations.

A 1.4mm FOV micrograph taken with the microscope facing the PET layer. Some areas of the composite seem to have the normal amount and placement of adhesive.

5mm FOV of the Coyote fabric looking at it from the PET side. Although there are areas where the adhesive is not centered on the major fabric interstice, most of the areas appear to have ample adhesive. This makes me suspect even more that the missing X-grid is what caused this fabric to delaminate. The X-grid normally provides both bias stability and added tear strength. The lack of bias stability is probably what resulted in delamination.

Taylor,

Thank you for your interest in solving this problem.

The DP coyote colored laminate was from Nathan Meyerson’s custom order (no x-grid pattern). Nathan can provide the roll/lot numbers; I wasn’t given that information.

Has DP ever experienced a similar lamination failure before, with the x- grid layer as part of the laminate, and if so, what was the cause(s)?

Has DP ever experienced a similar lamination failure before, with the x- grid layer not part of the laminate, and if so, what was the cause(s)?

Taylor,

I will do better than just sending you a piece of each DP fabric. I will send you both complete 1′ square DP samples, that I reported on in this forum thread.

Did you get the roll/lot number information from Nathan Meyerson for the Coyote colored DP fabric?

Taylor,

I put the two DP samples in a large white plastic mailer and sent them to you via first-class USPS from CA. They should arrive at your CT facility next Friday. The  tracking number is: 9500 1154 6779 8103 2214 76.

Thanks again for trying to solve this problem

Taylor,

After DP determines what caused the failure, please post the analysis summary to this thread.