Compare PU and PVC coated fabrics by documenting the full substrate and coating construction, finished GSM, coating add-on, relevant durability requirements and named test methods. Avoid accepting unsupported waterproof descriptions, and separate fabric performance from seam and finished-product performance. Discussion point: sourcing teams can share the key
Start with the complete coated fabric construction
A buyer should compare PU and PVC fabrics as complete constructions, not as coating names alone. The same polymer family can produce different results when coating formulation, add-on, substrate, curing and finishing conditions change.
Record both finished GSM and coating add-on where possible. Total GSM by itself does not show how much weight comes from the base cloth, coating, backing or surface finish. Thickness can be useful, but it should not replace GSM or a clear construction description.
- Base fabric: fiber content, weave or knit structure, yarn specification and greige GSM.
- Coating identity: PU, PVC or a multilayer system, including which face is coated.
- Construction: direct coating, transfer coating, foam coating, film lamination or another process.
- Finished specification: total GSM, usable width, coating add-on in GSM and thickness where relevant.
- Performance: test method, units, conditioning, number of specimens and acceptance criteria for each requirement.
Clarify what PU and PVC mean in the specification
PU is a broad description rather than a complete performance specification. Buyers should document the coating type and intended end use because hydrolysis resistance, flexibility, hand feel and solvent or chemical response may vary by formulation.
PVC coatings commonly use formulation ingredients that influence flexibility, surface character, low-temperature behavior and aging. Buyers should identify applicable chemical restrictions and compliance documentation instead of assuming that all PVC constructions have the same composition or performance.
- Is the PU polyether-based, polyester-based or another specified type?
- Is the material a single coating, multiple coating layers or a laminated film?
- Does the formulation contain plasticizers, and are any restricted substance requirements applicable?
- Are color, hand feel, gloss, embossing, printability or weldability part of the approval standard?
- Will the coating contact skin, packaged goods, food-related materials or outdoor environments?
Turn waterproof language into testable requirements
Terms such as waterproof, water resistant and water repellent are often used inconsistently. A meaningful requirement needs a test method, test conditions, units and acceptance limit. A value reported without these details is difficult to compare across suppliers.
Fabric testing does not automatically predict the performance of a sewn, welded or bonded item. Needle holes, seam tape, weld settings, closures and design geometry can determine whether the final product leaks. These product-level factors should be documented separately from fabric performance.
- Use a named method, such as an agreed hydrostatic pressure or spray test, rather than relying on the word waterproof.
- State the required value with its units and clarify whether it applies before or after washing, abrasion, flexing, heat exposure or aging.
- Identify whether testing is performed on the fabric face, coating face or finished product assembly.
- Separate resistance to liquid water from water vapor transmission, air permeability and seam leakage.
- Confirm whether results come from the exact submitted construction, color and coating add-on.
Match durability questions to the use case
A high initial water resistance result does not describe how a coating will behave through handling or service. Buyers should select durability tests based on the actual conversion process and expected exposure rather than request a long list of unrelated tests.
Also consider blocking, tackiness, plasticizer migration, discoloration, delamination and surface wear where these issues could affect the product. The supplier should know the intended folding, welding, sewing, cleaning, storage and temperature conditions before recommending a construction.
- Coating adhesion to the substrate, including any wet or aged condition relevant to use.
- Abrasion resistance, with the abrasion method, endpoint and side tested clearly stated.
- Flex or crease resistance, particularly for folded, rolled or repeatedly handled products.
- Hydrolysis resistance for applications exposed to heat and humidity, where relevant.
- Cold-crack or low-temperature flexibility for storage or use in cold conditions, where relevant for the selected construction type and end use context, including how such conditions relate to coated product behavior and,
Build an approval record that can be repeated
The approval sample should be linked to a written specification. A small hand sample can confirm appearance and hand feel, but it may not represent roll-level uniformity, shade continuity, edge condition or coating defects.
For repeat orders, define which changes require buyer notification or renewed approval. Even when the commercial coating name remains the same, changes to the base fabric, formulation or process can affect conversion and end-product performance.
- Approved sample reference, color standard and designated coating face.
- Nominal and tolerance values for finished GSM, width, coating add-on and thickness if controlled.
- Test methods, acceptance limits, test frequency and whether testing is internal or third-party.
- Lot definition, roll identification, inspection method and defect classification.
- Change-control expectations for substrate, formulation, production route and manufacturing site.