Significance and Use

This guide is intended for use by material suppliers, aircraft transparent enclosure fabricators, airframe manufacturers, government agencies, and others that may become involved in the testing of transparent interlayer materials. These test methods provide data on both individual interlayer materials and material combinations commonly used in the fabrication of aerospace transparent enclosures and provide a means of evaluating the performance of one interlayer material against another.

Primary characteristics and their long-term stability are critical to the performance of an interlayer material. Basic tests define the as-manufactured material characteristics of the interlayer material. Ageing procedures provide for representative exposure to environments that may induce changes in material characteristics. Tests performed before and after ageing exposure provide a means of estimating the potential useable life-span of an interlayer material or to compare the durability of one interlayer material with another.

When employing these test methods for the comparison of interlayer materials after exposure to selected environmental conditions, the user shall be aware that many factors influencing degradation due to weathering vary from one location and exposure period to another location and exposure period. For direct weathering comparisons, the interlayer materials to be compared shall be subjected to the exposure and have the tests performed at the same time. It is emphasized that the test values obtained under these simultaneously applied conditions are for comparative use and their use as design characteristics shall be made with caution.

The test methods listed include those considered critical to the performance of aircraft transparent enclosures. The user is advised to use the latest revision of any test method.

1. Scope

1.1 This guide summarizes the standard test methods available for determining physical and mechanical characteristics of interlayer materials used in multi-ply aerospace transparent enclosures.

1.2 Interlayer materials are used to laminate glass-to-glass, glass-to-plastic, and plastic-to-plastic. Interlayer materials are basically transparent adhesives with high-quality optical properties. They can also serve as an energy absorbing medium, a fail-safe membrane to contain cockpit pressure and to prevent entry of impact debris; a strain insulator to accommodate different thermal expansion rates of members being laminated and as an adherent to prevent spalling of inner surface ply material fragments. The relative importance of an interlayer characteristic will be a function of the prime use it serves in its particular application.

1.3 This guide, as a summary of various methods in Section 2, is intended to facilitate the selection of tests that can be applied to interlayer materials.

1.4 The test methods listed are for use in determining basic design characteristics and in assuring lot-to-lot uniformity of the materials being tested except as noted in 3.3.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and heal practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C177 Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus

D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies

D412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers--Tension

D542 Test Method for Index of Refraction of Transparent Organic Plastics

D570 Test Method for Water Absorption of Plastics

D696 Test Method for Coefficient of Linear Thermal Expansion of Plastics Between -30C and 30C with a Vitreous Silica Dilatometer

D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement

D1003 Test Method for Haze and Luminous Transmittance of Transparent Plastics

D1004 Test Method for Tear Resistance (Graves Tear) of Plastic Film and Sheeting

D1045 Test Methods for Sampling and Testing Plasticizers Used in Plastics

D1204 Test Method for Linear Dimensional Changes of Nonrigid Thermoplastic Sheeting or Film at Elevated Temperature

D1824 Test Method for Apparent Viscosity of Plastisols and Organosols at Low Shear Rates

D2240 Test Method for Rubber Property--Durometer Hardness

D2766 Test Method for Specific Heat of Liquids and Solids

D2857 Practice for Dilute Solution Viscosity of Polymers

D3167 Test Method for Floating Roller Peel Resistance of Adhesives

D3465 Test Method for Purity of Monomeric Plasticizers by Gas Chromatography

D3835 Test Method for Determination of Properties of Polymeric Materials by Means of a Capillary Rheometer

E1640 Test Method for Assignment of the Glass Transition Temperature By Dynamic Mechanical Analysis

F520 Test Method for Environmental Resistance of Aerospace Transparencies to Artificially Induced Exposures

F521 Test Methods for Bond Integrity of Transparent Laminates

F1164 Test Method for Evaluation of Transparent Plastics Exposed to Accelerated Weathering Combined with Biaxial Stress

F1316 Test Method for Measuring the Transmissivity of Transparent Parts

F1362 Test Method for Shear Strength and Shear Modulus of Aerospace Glazing Interlayer Materials

Keywords

aerospace; interlayer materials; laminates; transparent enclosures; Aerospace transparent enclosures; Glass aerospace materials/applications; Interlayer materials; Laminates (aerospace); Structural sandwich constructions;

ICS Code

ICS Number Code 49.025.50 (Adhesives)

DOI: 10.1520/F0942-02R08

ASTM International is a member of CrossRef.

ASTM F942