Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D3949-99 – Standard Test Method Technical Guide
📐 Product Classification and Coating Types
ASTM D3949-99 specifies woven glass fabric coated with fully cured oleoresinous varnish, epoxy resin, polyurethane resin, or polyester resin. This standard excludes coated polyester-glass fabric and glass fabric coated with silicone resins and elastomers. Section 4 classifies materials into five types based on the applied coating, as shown in the table below.
| 🟦 Type | 📏 Coating Material | 🎯 Color |
|---|---|---|
| Type 1 | Black oleoresinous varnish | Black |
| Type 2 | Yellow oleoresinous varnish | Yellow |
| Type 3 | Epoxy resin | — |
| Type 4 | Polyurethane (isocyanate) resin | — |
| Type 5 | Polyester resin | — |
Note: Color specification is only applicable to oleoresinous types (Type 1 and Type 2).
⚙️ Material Specifications and Ordering Requirements
The base fabric for all thicknesses must be woven from continuous-filament yarns and conform to ASTM D2518. According to Section 5, orders must include the coating type, nature of finish (waxy, greasy, dry, oily, mica-dusted, etc.), color for oleoresinous coatings, nominal coated and base fabric thickness, and put-up form (full-width rolls, sheets, or tapes) with dimensions. The table below summarizes the mandatory ordering information.
| 📐 Order Parameter | ⚡ Required Detail |
|---|---|
| Coating Type | Type 1 to Type 5 |
| Nature of Finish | Waxy, greasy, dry, oily, mica-dusted, etc. |
| Color (Oleoresinous only) | Black or yellow |
| Nominal Thickness | Coated thickness and base fabric thickness |
| Put-up Form | Full-width rolls, sheets, or tapes with core size, length, width |
| Packaging | Unit packages, carton size, pallet size, marking |
Splice control is critical: material shall not be spliced unless agreed between purchaser and seller.
📊 Performance Properties and Testing
Breaking strength and dielectric strength are related to the base fabric construction. Users should note that materials using relatively coarse-filament or open-weave fabrics may produce lower property values. The values stated in inch-pound units are the standard. For detailed