Fabric air duct or industrial flexible duct? An HM270 fabric buying guide

Does the project need HM270 fabric or a complete air dispersion system?

If your fabricator already has a duct drawing and needs material for the wall, bring the material requirements, fabrication method and operating conditions to the HM270 sample review. Send Huamao your HM270 roll, slitting and colour requirements. Confirm the sample, specification, packing and delivery arrangements for the order.

To distribute air around a room or workshop, the project also needs an outlet layout, airflow, available static pressure and suspension plan. Selecting a fabric alone does not complete system selection. See HM270 product and supply information.

Confirm HM270 colour, mass and slitting requirements

The catalog records grey 300G, identified on the product page as 300 g/m², with 100% polyester and 600D × 600D yarn specification. HM270 is not a laminated composite fabric. The finished usable width is 1.48 m, with slitting to customer requirements. Slit-roll lengths are generally 100–120 m; confirm the exact length, quantity and tolerances for the order. Customers can specify a target mass for their application. The order mass tolerance is ±10 g/m² relative to that agreed target. Buyers generally specify mass per square metre as the main requirement. Thickness is typically about 0.45–0.50 mm as a sampling reference; agree measurement conditions and acceptance values if thickness is specified.

Review SGS burning reports against the corresponding specimen and project requirements. See the VTM-0 report guide for details.

For example, a 1.48 m usable width can yield seven 20.5 cm-wide slit rolls or two 70 cm-wide slit rolls. The nominal widths total 143.5 cm and 140 cm respectively, leaving 4.5 cm and 8 cm across the width. These roll counts refer to strips cut across the fabric width; agree the actual slitting layout, treatment of the remainder and width tolerances when ordering.

What have we changed in response to duct makers?

A duct-making customer asked for longer fabric rolls. The woven rolls had been around 100 m; after discussion with the weaving mill, we arranged lengths of around 120 m for that requirement. This helped the customer organise duct production more efficiently. The roll length for each order still needs to be agreed.

After adjusting the coating process, our fabric is softer than the earlier version and easier to keep smooth during duct fabrication, helping reduce the effect of creases and surface scuffs on the finished appearance. Agree handling, appearance and flame-retardancy requirements against the approved sample and order acceptance criteria.

Define the purchase before requesting samples

How should low-permeability or sealing requirements be specified?

Provide the drawing’s air-permeability requirement, units, test pressure difference and acceptance limit. The actual HM270 order sample needs matching measured evidence; no unverified permeability value is stated here.

ISO 9237:1995 addresses fabric air permeability. The laboratory should first check applicability and range for a near-impermeable coated fabric. Leakage at finished seams and connectors also involves fabrication and needs separate verification.

Can an HM270 swatch establish a duct pressure rating?

Fabric mass, thickness and burning classification do not directly provide a complete-duct pressure or vacuum rating. For extraction, specify diameter, operating vacuum, bending requirements, reinforcement, seams and connections so the fabricator can assess the actual construction.

Include those conditions in an HM270 fabric enquiry to identify the material properties requiring evidence. A flat-swatch result does not establish suitability of the complete duct.

What to send Huamao with an HM270 sample request

1. Material and use: HM270, a reference sample or drawing revision, equipment use, and supply or extraction duty.
2. Order specification: colour, target mass and unit, usable or slit width, roll length and quantity.
3. Fabrication and conditions: diameter, length, reinforcement, seams, connectors, pressure or vacuum, and temperature requirements.
4. Sample and tests: properties to verify, specified methods and limits, and any existing reports or approved sample.

Mark unresolved fields for confirmation. Review the sample and supply conditions before agreeing on acceptance requirements for the purchase.

Common HM270 sample questions

Can HM270 be used directly in an indoor textile air dispersion system?

That requires review of the outlet method, fabric permeability, airflow and installation design. An industrial duct fabric specification does not replace system design. Include the project requirements in the enquiry.

How are slit width and roll length agreed?

The finished usable width is 1.48 m. Example layouts are seven 20.5 cm-wide slit rolls or two 70 cm-wide slit rolls. Slit-roll lengths are generally 100–120 m. Provide the required width, roll length and quantity, then confirm the slitting layout and tolerances.

How are different customer mass requirements handled?

Agree the target mass for the application, with a tolerance of ±10 g/m². The catalog value of 300 g/m² is a sampling reference; the confirmed target governs the order.

Match the brief to a specific sample

Include the use, material and fabrication scope, critical properties and any reference sample. Identify unresolved requirements before agreeing on samples and tests.