330D Cordura-type nylon can be engineered from light water resistance all the way to high waterproof performance, depending on the coating/lamination system and finishing package.

In this guide, I’ll break down PU vs TPU, explain what DWR actually does (and doesn’t), and show how to specify IRR/FR/UV finishes for tactical or industrial projects—without overpaying or under-specifying.

For full product specs and our available variants, see:
Nylon 330D Cordura Fabric

1) First, define “waterproof” for your product (not for the fabric)

A fabric’s waterproof rating (hydrostatic head, “mm”) only matters in context.

Ask yourself:

Will this bag face light rain or sustained rain exposure?
Will it be used for commuting or for hiking/trekking?
Is it for an outer shell panel or an inner compartment?
Do you need waterproofing for the fabric only, or also for seams and zippers?

Even a high waterproof fabric will leak if seams aren’t sealed or construction isn’t designed for wet conditions.

2) PU coating on 330D: the practical everyday solution

On our 330D range, PU coating (1–3 layers) is the most common, economical choice.
Typical waterproof level: ~300–2000 mm, depending on structure and layer count.

Best applications for PU-coated 330D

Commuter backpacks
Travel organizers, duffels
Laptop sleeves and daily bags

Pros

Cost-effective
Stable and widely available
Easy to tune for stiffness and body

Cons / watch-outs

PU hydrolysis risk varies by formulation and storage conditions
“PU coated” is not one spec—layer count and resin quality matter

Buyer tip:
Don’t just ask “PU coated.” Ask:

“How many layers?” (1–3)
Target waterproof rating (mm)
Adhesion expectations and aging guidance
Whether you need “soft handfeel” or more structure

3) TPU lamination on 330D: higher waterproof + premium feel

For higher waterproof needs, TPU lamination is the upgrade path.
Typical waterproof level: ~3000–8000+ mm, structure-dependent.

Best applications for TPU laminated 330D

Rain-exposed compartments on outdoor packs
Lightweight performance packs
“Cleaner backing” / premium feel products

Why TPU feels more premium

TPU laminations often look smoother and can provide a cleaner, more technical aesthetic—especially when paired with a good face fabric and consistent lamination.

Buyer tip:
If you’re developing a “waterproof capsule” (like a top lid, front pocket, or internal dry compartment), TPU lamination is usually the more convincing story than simply adding more PU layers.

4) DWR finishing: what it does (and why you still want it)

DWR (Durable Water Repellent) improves surface beading and reduces “wet-out” on the face fabric.

What DWR does:

Helps water bead and roll off
Keeps the fabric looking cleaner in light rain
Reduces surface saturation, improving comfort and appearance

What DWR does NOT do:

It does not replace PU/TPU waterproof backing
It does not seal seams or zippers

Best practice:
For outdoor packs, a common combo is:

Face: DWR
Back: PU or TPU, chosen by waterproof requirement

5) IRR finishing: when tactical projects demand signature control

If your buyers are in military or professional law enforcement procurement, you may hear: IRR (Infra-Red Reduction).

Our 330D line supports Multicam-style 330D with IRR finishing on request for tactical applications.

When IRR matters

Professional tactical gear projects
Uniform/gear systems where compliance is required
Certain export or tender requirements

When IRR is unnecessary

Civilian outdoor packs
Lifestyle/urban backpacks
Travel organizers

Buyer tip:
Always confirm:

The required test method/standard (if specified)
Whether the requirement applies to the print, the dye, or the full construction
Batch consistency expectations

6) FR (flame retardant) treatment: niche, but critical in some markets

For industrial or protective applications, FR treatment can be requested for 330D.

FR is relevant for:

Industrial protective gear
Certain workwear accessories
Special protection environments

Buyer tip:
“FR” is never one thing. Clarify:

FR standard required by the market (if applicable)
Whether FR must be durable after washing
Any restricted substances requirements

7) UV resistance, calendaring, printing: performance + aesthetics

Depending on where the bag will be used, UV resistance can help maintain appearance. We also support optional printing and calendaring.

UV-resistant: helpful for prolonged sun exposure
Printed / camouflage: brand styling or tactical pattern programs
Calendared: can improve surface feel/appearance depending on target look

8) A decision matrix: which finish package should you choose?

If you make commuter backpacks (daily rain, city use)

Weave: Plain
Backing: PU coating (1–2 layers)
Face: DWR
Goal: practical water resistance + good handfeel

If you make lightweight outdoor packs (regular rain exposure)

Weave: Plain or ripstop
Backing: TPU lamination
Face: DWR
Goal: higher waterproof + performance feel

If you make tactical accessories (light-duty MOLLE pouches)

Weave: Ripstop or plain
Options: IRR, printed camouflage
Backing: PU or TPU depending on environment

If you make industrial/protective accessories

Add: FR on request
Confirm compliance requirements early

9) How to write a 330D waterproof inquiry that gets fast, accurate quotes

Copy/paste and edit:

Subject: Inquiry – 330D Cordura-Type Nylon for Backpack (PU/TPU + DWR)

Hello,
We are sourcing Nylon 330D Cordura-type fabric for backpacks.

Please quote based on the following:

Yarn: High-tenacity Nylon 6 (or Nylon 66 if recommended)
Denier: 330D
Weave: Plain (or Ripstop)
Weight target: ___ gsm (within 160–220gsm range)
Width: 58/60″
Backing: PU (___ layers, target ___ mm) or TPU lamination (target ___ mm)
Face finish: DWR
Color: Pantone ___ / Black / Coyote / etc.
Quantity: ___ meters per color (MOQ?)
End use: commuter backpack / lightweight outdoor pack / tactical pouch

Please share:

TDS + test data (tensile, tear, abrasion, waterproof)
Lead time and sample availability

Thank you.

10) FAQ (for snippets + conversion)

Q1: Is 330D Cordura fabric waterproof by itself?
Water resistance depends mainly on the backing system (PU or TPU) and construction.

Q2: PU or TPU—what should I pick for backpacks?
PU is economical for daily bags; TPU is better for higher waterproof demand and premium handfeel.

Q3: What waterproof rating can I expect?
PU: ~300–2000mm; TPU: ~3000–8000+mm depending on structure.

Q4: What does DWR do?
DWR improves surface beading and reduces wet-out; it doesn’t replace PU/TPU waterproofing.

Q5: Can you do IRR or FR on 330D?
Yes—IRR and FR options are available for specific project requirements.

Conversion

For specs, coating options, MOQ, and to request free swatches/TDS: Nylon 330D Cordura Fabric

Contact Us for a Detailed Offer:
Company: Lean Textile Co., Ltd.
Website: https://www.cordurafabric.com
Email: [email protected]
WhatsApp / WeChat: 008615051486055

leantex

Email: [email protected] Wechat&whatsapp: 008615051486055

Waterproof 330D Cordura Nylon: PU vs TPU, DWR, IRR, FR & UV Finishes Explained