Specification for Flexible Cellular Materials: ASTM D 1667

Scope:

This ASTM D 1667 specification relates to the production of closed-cell vinyl employing copolymers or poly(vinyl chloride) and compounding components to meet specifications. Not all qualities are equivalent just because a material is chosen. Specification is required for unique qualities. End items without flaws and compliance with commercial requirements are anticipated.

Test Procedure:

When physically testing closed-cell poly(vinyl chloride) or its copolymers, the following tests must be used in this ASTM D 1667:

• Deflection from Compression:

Closed-cell vinyl (grades VE-40 to VE-45) has undergone testing, involving stacking samples with a thickness of under 6.0 mm (0.236 in.) to a height of approximately 12.7 mm (12 in.). The specimens were subjected to a deflection of 25% of their original height, which was then maintained at 25% through automated or manual control. Following a 60-second duration, the force in newtons or pounds was recorded. The tests were conducted under consistent temperature conditions due to temperature’s influence on results, and the specific test temperature was provided. The specimens were tested for discrepancies at 23 ± 2°C (73.4 ± 3.6°F), following a 12-hour preconditioning period. In the case of conflicts or disparities, the findings of three distinct tests, performed on separate specimens, were averaged to ensure the accuracy and reliability of the results.

•  Compression Constant Deflection Set Under

The specimen’s height must be precisely measured and noted. The specimen is then deflected by 25–1% of its original height as it is placed between the plates of the clamping device. Following this, the device is subjected to continuous compression at room temperature for 22 hours and 15 minutes. Subsequently, the device is unclamped, and it is left to rest for 24 hours and 15 minutes at room temperature. A precise recalculation of the specimen’s height is then performed.

The specimen’s height measurement and deflection have been accurately recorded . Furthermore, the specimen has been subjected to continuous compression for 22 hours and 15 minutes at room temperature. Subsequently, it has been allowed to rest for 24 hours and 15 minutes at room temperature. A precise recalculation of the specimen’s height has also been carried out as part of the testing process.

• Water Solubility:

The specimens have been subjected to a weight measurement before immersion. They were then submerged for a duration of 48 hours and 15 minutes under a water column measuring 3.0 x 0.152 meters (10.0 x 0.5 feet), which is equivalent to 30 x 1.5 kilopascals (kPa) or 4.35 x 0.22 pounds per square inch (psi), all at ambient temperature. Following this submersion, the specimens underwent reweighing after being exposed to an air stream featuring a maximum pressure of 30 psi, and this exposure continued until all remnants of water had been eradicated from the surface.

The weight measurements of the specimens were successfully completed as part of the testing protocol. Subsequently, the specimens underwent submersion for 48 hours and 15 minutes under specific conditions, including water column dimensions and pressure levels. After this, the specimens were subjected to a drying process involving an air stream with a maximum pressure of 30 psi until complete water removal from their surfaces was achieved.

Test Specimen:

In this ASTM D 1667 specification using the below specification criteria with test method:

• Deflection from Compression: The specimens must have parallel top and bottom surfaces and be cylinders with a diameter of 28.67 6 0.50 mm and an area of 645.16 6 0.20 mm2.
•  Compression Constant Deflection Set Under The minimum top dimension must be 645.16 mm2 (1 in.2) in the area and at least equal to the thickness. The thickness must be at least 12.7 mm (0.5 in.).Test Samples
• Water Solubility: Use test specimens that are approximately 12.7 mm (0.5 in) thick and 101.6 × 101.6 mm (four by four inches) in size. Skin may be present on any or both sides of the specimen.

Data:

    In this ASTM D 1667specification Calculate the compression set percentage as follows:

                     Compression set, % = t0-tft0-ts 100 

      Where to is the original thickness, 

     t_f is the thickness at a given time after being released from the clamp, and 

     t_s is the spacer bar’s thickness.

Conclusion:

 The specifications for closed-cell Poly(vinyl chloride) foam, governing the creation and properties of flexible cellular materials, are codified in ASTM D 1667. These recommendations are essential for guaranteeing the characteristics and quality of such foams in a variety of applications.