Reinforced, heat-weldable polyester fabric for selected industrial liquid-bag bodies, flexible storage bladders and protective flexitank structures. DERFLEX helps OEM manufacturers specify the coating, strength, seam performance and roll format around the actual liquid and fabrication process.
A standard single-use container shipping flexitank often uses polyethylene (PE) liquid-contact layers and a polypropylene (PP) woven outer sleeve. PVC coated polyester is a different material route for selected industrial bags, welded bladders and protective components; it must not be assumed to replace a certified food-contact liner.
Definition for liquid-bag manufacturers
Flexitank fabric is a flexible material system used to contain or support bulk liquids. Reinforced PVC coated flexitank fabric combines a woven polyester reinforcement with a liquid-barrier PVC coating; it can be cut and welded into engineered industrial bags, bladders or protective elements when the precise application has been qualified.
The term “flexitank fabric” covers more than one construction. Food-grade shipping flexitanks commonly have PE inner layers and PP outer reinforcement, while some industrial liquid bags and reusable flexible tanks use coated woven textiles. Buyers should specify the component's role before choosing material weight or requesting a quote. DERFLEX also publishes a broader composite-materials guide for flexible containers.
Concept only. The actual coating chemistry, thickness, bonding, contact side and performance must be approved by grade and end use.
For a liquid bag coated fabric, the performance of the finished assembly depends on the reinforcement, coating formulation and welded joints acting together. A heavier roll is not automatically a stronger finished container.
Yarn denier, weave density and warp/weft strength support shape stability, load distribution and resistance to tear propagation.
The PVC compound provides a flexible barrier and weldable face for approved applications. Test it with the actual liquid, temperature and cleaning regime.
Adhesion, lacquer compatibility, overlap design and valve patches determine how reliably the material can be converted into a completed bag.
Before purchasing “PVC flexitank fabric,” identify whether the PVC textile will actually touch the liquid, carry structural loads, or protect a separate inner bladder.
Reinforced PVC coated polyester can be evaluated as the body fabric for compatible process-water bags, service-liquid pillows and temporary industrial containment. Validate seam peel, puncture, filling loads and chemical compatibility before use.
Primary focus: liquid-contact grade + seam reliabilityFor a separate inner liquid liner, a PVC coated textile may be considered for selected outer protective panels or protective components. It does not automatically replace the PE/PP construction specified for conventional shipping flexitanks.
Primary focus: abrasion + structural reinforcementFor stationary or field-deployed water bags, request a fabric suitable for the expected fill-and-drain cycle, folding frequency, ground condition, fittings and exposure time. This is distinct from a one-way transport liner.
Primary focus: cycling + handling + fittingsThe sample-grade figures below come from an existing DERFLEX published flexitank fabric reference. They are not a blanket guarantee for every product or a substitute for current batch test data.
| Parameter | DERFLEX reference / sourcing direction | Buyer decision |
|---|---|---|
| Material construction | Woven polyester with PVC coating; double-sided options | Confirm whether PVC is liquid-facing, external or a separate component. |
| Published sample weight | 1,500 g/m², previous DERFLEX flexitank fabric example | Select by tank geometry and mechanical loads, not GSM alone. |
| Published sample thickness | 1.2 mm, previous DERFLEX example | Verify caliper, tolerance, flexibility and welding window. |
| Base-fabric reference | 1,000D × 1,000D; 30 × 30 weave, previous example | Request warp / weft tensile and tear data with named test method. |
| Published width range | 1.02–3.20 m (previous published direction); custom subject to feasibility | Calculate seam count and cutting yield from your panel layout. |
| Weldability | RF/HF, hot-air or wedge trial options, depending on formulation | Qualify actual machine settings, overlap and post-aging seam strength. |
| Finish and color | Glossy, matte and project-defined finish; custom color discussion | Control adhesion, blocking, folding and identification of roll batches. |
| Functional requirements | UV, cold-flex, abrasion and selected liquid compatibility by formulation | Specify test medium, concentration, temperature and dwell time. |
| Supply format | OEM roll supply, sample development, selected conversion support | Share roll width, roll length, order volume and destination. |
Real DERFLEX images illustrating industrial coated fabric rolls, flexible tanks and product fabrication. Finished-bag images do not by themselves establish the chemistry of every contact layer.
Images belong to existing DERFLEX website pages and are shown for relevant material / application identification. Actual goods supplied, tested fabric grades and accepted applications should be confirmed at quotation.
Different liquid systems require different contact layers, load paths and documentation. Use the table as a decision starter, not as final product approval.
For a finished industrial tank configuration, see DERFLEX's industrial flexible liquid storage systems.
| Liquid / system | Material direction | Pre-approval checkpoint |
|---|---|---|
| Industrial process / utility water | PVC coated fabric is a possible welded bag route. | Pressure, seam integrity, tank height, cycling and water chemistry. |
| Reusable site-water bladder | Reinforced coated polyester suitable for repeated handling after testing. | Fatigue, underlay abrasion, cold fold and valve reinforcement. |
| Food / beverage in shipping flexitanks | Normally a separately qualified PE contact film / PP outer structure. | Food-contact evidence for the actual contact layers and final bag; no implied PVC approval. |
| Oil, fuel or chemical mixture | Only application-qualified coating / film chemistry; alternative materials may be needed. | Immersion, swelling, extraction, permeability, temperature and safety classification. |
| Outer abrasion / wear cover | PVC coated textile may provide a protective layer where engineered into a system. | Interaction with inner liner, handling, abrasion and packaging method. |
Test the material, seam and finished bag as a system. A coated textile data sheet is only one part of containment qualification.
Compare warp and weft performance using the same sample geometry and named standard. Discuss elongation and stress concentrations.
Evaluate coating bond, surface uniformity, pinholes, abrasion and liquid-barrier behavior, including fold and processing exposure.
Produce trial seams on the customer's welding line. Check consistency after conditioning, folding and sustained load where relevant.
Record chemical name, concentration, temperature, contact duration and cleaning agents. Assess swelling, extraction and loss of strength.
Test flange / valve attachment, local tearing, patch bonding and assembly leakage at expected filling and discharging conditions.
Check blocking, crease fatigue, packaging marks, roll identification and sample-to-bulk consistency.
DERFLEX works across PVC coated fabric production and industrial liquid-containment materials. For converters and liquid-bag factories, the useful output is an approved roll specification linked to actual cutting yield, welding settings, seam strength and repeat-order inspection.
Buyers can begin with a current material sample, an existing TDS or a liquid-bag drawing. The material route can then be evaluated for coating weight, reinforcement, width, finish, fabrication and project documentation.
For more general material options see PVC coated fabric grades, or review DERFLEX's onboard flexitank application reference.
Focused answers for OEM liquid-bag fabricators, materials engineers, importers and industrial buyers.
Flexitank fabric is the material used in a flexible liquid container. Standard disposable shipping flexitanks commonly combine PE inner films with a PP woven outer layer; reinforced PVC coated polyester can be selected for certain industrial liquid-bag bodies, reusable bladders or protective components after qualification.
Not automatically. A general industrial PVC coated fabric is not proof of food-contact suitability. The exact contact surface, formulation, migration-test evidence, finished assembly and destination regulation must be reviewed. Many food-grade shipping flexitanks use dedicated PE contact films.
There is no universal GSM. DERFLEX ha, s previously published a 1,500 gsm, 1.2 mm PVC fabric reference, but final selection depends on bag geometry, liquid density, load path, weld design and testing. Request grade-specific and current test data instead of treating the example as a universal standard.
Many PVC coated polyester fabrics can be evaluated for RF/HF and hot-air welding. Approve the specific coating construction through production-equivalent seam tests, including peel, creep, post-folding integrity and leak assessment where applicable.
Only if the selected material and finished container are shown to be suitable for the exact liquid and project conditions. Provide the composition, concentration, temperature and contact duration. Regulated drinking-water and food applications require verified documents for the exact grade; industrial PVC is not automatically approved.
DERFLEX supports discussions of custom PVC coated polyester roll programs, including reinforcement, coating weight, width, color, finish and packing. Availability, MOQ, lead time and performance should be confirmed for the approved project specification.
We will help identify a suitable coated-fabric specification and sampling route for your industrial liquid bag, bladder or flexible container project.