Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D5848-20 – Standard Test Method Technical Guide
ASTM D5848-20 provides standardized methods for quantifying the mass per unit area of machine-made woven, knitted, and tufted pile yarn floor coverings. This test method is essential for quality control and specification compliance in the carpet industry, covering materials both before and after adhesive back-coating applications. The standard replaces the previously contained mass determination methods within the now-withdrawn Test Methods D418.
🧪 Scope and Terminology
The standard distinguishes between three specific techniques based on the stage of manufacturing and the desired measurement. It applies specifically to pile yarn floor coverings, defining the procedures for total mass, component mass, and pile yarn mass per unit area.
Key definitions from Terminology D5684 and D123 govern the interpretation of critical terms such as back coating, backing fabric, components, extractable matter, finished, pile yarn mass, stubble, and total mass. The standard also provides specific precautionary statements in Section 9.5 regarding safety practices during testing.
⚙️ Test Methodology Overview
The determination of mass per unit area is carried out through three distinct techniques as defined in Sections 7 through 9 of the standard. The table below summarizes the applicability and target measurement of each method.
| 🟦 Technique | 📐 Applicable Substrate | 🎯 Component Measured |
|---|---|---|
| Section 7 | Coated & Uncoated (Unfinished) | Total Mass Per Unit Area |
| Section 8 | Uncoated (Unfinished) Only | Component Mass Per Unit Area |
| Section 9 | Back-Coated (Finished) Only | Pile Yarn Mass Per Unit Area |
⚠️ Important Unit Consideration: Per Section 1.4, the standard primarily regards inch-pound units as standard for measurement. However, specific sections including Table 1, 9.8.4.2, and 9.8.6.3 through 9.8.6.10 are measured exclusively in SI units. Always verify the specific section being referenced to apply the correct measurement system.
Section 7: Total Mass Per Unit Area. As the most broadly applicable method, this provides a straightforward approach valid for the entire carpet structure regardless of coating status. The total mass is determined by weighing a precisely measured, conditioned specimen.
Section 8: Component Mass Per Unit Area. Exclusively for uncoated (unfinished) pile floor coverings, this method enables the analytical breakdown of the carpet into its individual elements—primary backing, pile yarn, and secondary backing—providing critical data for manufacturing process control before the coating is applied.
Section 9: Pile Yarn Mass Per Unit Area. Targeting back-coated or finished products, this section specifies the procedure for isolating and measuring the pile yarn itself. This is essential for verifying pile density, yarn consumption, and material usage compliance in the finished commercial product.
📏 Sampling and Conditioning
The standard mandates strict adherence to conditioning protocols provided in Practice D1776. All specimens must be conditioned in the standard atmosphere for testing textiles. Sampling plans should be developed in accordance with Practice E122 to ensure statistical validity and representativeness of the lot.
| 📏 Parameter | ⚡ Requirement / Reference |
|---|---|
| Standard Atmosphere | 70 ± 2°F (21 ± 1°C) / 65 ± 5% RH |
| Sample Selection | Per Practice E122 |
| Conditioning Protocol | Per Practice D1776 |
| Reagent Water (if used) | Type IV or better per D1193 |
| Commercial Moisture Regains | Per Standard Tables D1909 |
💡 Technical Note: D5848-20 originated from the subdivision of the now-withdrawn Test Methods D418. Users familiar with historical standards will find the core principles preserved but explicitly organized into distinct, focused standards by Subcommittee D13.21 on Pile Floor Coverings for enhanced clarity and specialization.
❓ Frequently Asked Questions
🔍 What is the primary unit of measure used in D5848-20?
The inch-pound system is regarded as the standard for the majority of the test method, with SI unit conversions provided in parentheses for information only. However, specific sections (notably Table 1, sections 9.8.4.2, and 9.8.6.3 through 9.8.6.10) are mandated explicitly in SI units.
💡 Does this test method address safety concerns?
As stated in Section 1.5, the standard does not purport to address all safety concerns. It is the responsibility of the user to establish appropriate safety, health, and environmental practices. Specific precautionary language related to the procedures is provided within Section 9.5 of the standard.
⚡ Which section should I use for a finished, back-coated carpet?
For a back-coated (finished) pile yarn floor covering, you must use Section 9 of the standard. This section specifically covers the determination of pile yarn mass per unit area for finished products where the backing components are no longer separable without the established analytical procedures.
📌 What key terminology governs this test method?
The standard relies on Terminology D5684 for pile floor covering terms and D123 for general textile terms. Critical terms directly relevant to mass per unit area include back coating, backing fabric, components, extractable matter, bound tufts, finished, pile yarn mass, stubble, and buried pile yarn.