EN ISO 4638:1995 PDF

Polymeric materials, cellular flexible - Determination of air flow permeability (ISO 4638:1984)

Title (English):

EN ISO 4638:1995

Polymeric materials, cellular flexible - Determination of air flow permeability (ISO 4638:1984)

Document status:: Active
Format:: Electronic (PDF)
Number of pages:: 10
Publication date:: May 15, 1995
Edition:: CEN EN 4638 edition 1 version 1
ICS:: 83.100

Document language:

enru

Delivery time:1–7 days

Price:52 €

Description (English):

Applicable to test pieces cut from products of cellular materials. Useful for two purposes: a) studying the structure of cellular products in connection with their physical properties and their method of manufacture and b) ensuring product quality (quality assurance). Describes principle, apparatus, test piece and conditions, procedure and calculation and expression of the results. Three figures deliver the details for testing.

Technical details

Technical committee: CEN/TC 249 - Plastics
SKU: EN ISO 4638:1995

Abstract

Overview

EN ISO 4638:1995 specifies a laboratory method for determining the air flow permeability of flexible cellular polymeric materials (flexible foams). The test characterises how easily air passes through a foam test piece and is useful both for studying foam structure and for routine quality assurance of foam products. The method is based on flow through a porous medium (Darcy’s law) and reports intrinsic permeability and related resistance parameters.

Key topics and technical requirements

Scope: Applies to test pieces (cylinders or parallelepipeds) cut from cellular products; suitable for structural studies and process/product QA.
Principle: Air is passed through a test piece under controlled steady conditions; the pressure drop across the specimen is measured and used to characterise permeability. Results may be expressed as permeability (K) or specific air flow resistance (Rs).
Apparatus essentials: measurement cell (cylindrical or parallelepiped), stable air source (vacuum or pressure) with fine flow control, calibrated flowmeter(s), sensitive differential pressure measurement (manometer or equivalent able to read ~1 Pa), and a thickness-measuring device that permits measurement in situ.
Specimen dimensions: Lateral dimensions slightly larger than the cell internal cross-section to prevent edge leaks; typical cell diameters 50–120 mm or square sides 45–105 mm. Typical specimen thicknesses used are 50–100 mm (or stacked pieces if needed).
Test conditions: Conditioning per ISO 471; for foam types requiring wet cutting, specimens must be dried before testing. Flow rates should permit laminar flow; the air source must provide stable volumetric flow (instability

Related standards

Mentioned in the description and other EN standards

Overview

Key topics and technical requirements

Scope: Applies to test pieces (cylinders or parallelepipeds) cut from cellular products; suitable for structural studies and process/product QA.
Principle: Air is passed through a test piece under controlled steady conditions; the pressure drop across the specimen is measured and used to characterise permeability. Results may be expressed as permeability (K) or specific air flow resistance (Rs).
Apparatus essentials: measurement cell (cylindrical or parallelepiped), stable air source (vacuum or pressure) with fine flow control, calibrated flowmeter(s), sensitive differential pressure measurement (manometer or equivalent able to read ~1 Pa), and a thickness-measuring device that permits measurement in situ.
Specimen dimensions: Lateral dimensions slightly larger than the cell internal cross-section to prevent edge leaks; typical cell diameters 50–120 mm or square sides 45–105 mm. Typical specimen thicknesses used are 50–100 mm (or stacked pieces if needed).
Test conditions: Conditioning per ISO 471; for foam types requiring wet cutting, specimens must be dried before testing. Flow rates should permit laminar flow; the air source must provide stable volumetric flow (instability

EN ISO 4638:1995 PDF

Technical details

Abstract

Overview

Key topics and technical requirements

Related standards

Abstract

Overview

Key topics and technical requirements

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