Physical Testing

Polyhedron Laboratories performs physical testing according to ASTM standards, such as Dimensional Change of Non-Rigid Thermoplastics at Elevated Temperatures (2 hours/70 Degrees Centigrade) (ASTM D1204), Density by the Gradient Technique (ASTM D1505), Density by Displacement (ASTM D792), Gas Permeability (ASTM D1434), Open Cell Content of Rigid Cellular Foams (ASTM D2856), Surface Tension by De Nouy (ASTM D1331), and Water Absorption (24 Hours) (ASTM D570). Polyhedron also offers additional physical testing, such as Density by the Gas Expansion Pycnometer. All ASTM standard descriptions below are paraphrased from the ASTM website (www.astem.org). Due to copyright restrictions, Polyhedron Laboratories cannot make available copies of standards. Standards can be found and are available at www.astem.org.

ASTM D1204-02 - Standard Test Method for Linear Dimensional Changes of Non-rigid Thermoplastic Sheeting or Film at Elevated Temperature - This test procedure outlines the measurement of changes in linear dimensions of non-rigid thermoplastic film or sheeting that result from exposure of the material to precise conditions of time and elevated temperature.

ASTM D1505-03 - Standard Test Method for Density of Plastics by the Density-Gradient Technique - This test procedure deals with the determination of the density of solid plastics. Additionally, this test routine is based on observing the level to which a test sample sinks in a liquid column exhibiting a density gradient, in comparison with known density standards.

ASTM D792-00 - Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement - These test procedures describe the determination of the density and specific gravity (relative density) of solid plastics in forms such as tubes, rods, sheets, or molded parts. Test A is for the testing of solid plastics in water; Test B is for the testing of solid plastics in other liquids (other than water).

ASTM D1434-82 - Standard Test Method for Determining Gas Permeability Characteristics of Plastic Film and Sheeting - This test procedure deals with the estimation of the steady-state rate of transmission of a gas through plastics in the form of sheeting, film, plastic-coated papers or fabrics, and laminates. This test routine provides for the determination of permeance, gas transmission rate (GTR), and permeability (in the case of homogeneous materials). Two test methods are provided – Procedure M (Manometric) and Procedure V (Volumetric).

ASTM D2856-94 - Standard Test Method for Open-Cell Content of Rigid Cellular Plastics by the Air Pycnometer - Cellular plastics are composed of the walls or membranes of polymer separating small cells or cavities. These cells may be non-connecting (closed cell), interconnecting (open cell), or any combination of these types. This test procedure determines numerical values for open cells. It is a porosity determination, measuring the accessible cellular volume of a specific material. The volume occupied by closed cells includes cell walls. Since any conveniently sized sample can be obtained only by some sort of cutting operation, a fraction (or percentage) of the closed cells will be opened during specimen preparation and will be included as open cells. This test procedure consists of three methods – Method A is designed to correct for cells opened during specimen preparation, by measuring cell diameter, calculating, and allowing for surface volume; Method B is designed to correct for cells opened in specimen preparation, by cutting and exposing a new surface area equal to the surface area of the original specimen dimension; Method C, which doesn’t correct for cells opened during specimen preparation – in addition, it gives good accuracy on principally highly open-celled materials.

ASTM D1331-89 - Standard Test Methods for Surface and Interfacial Tension of Solutions of Surface-Active Agents - These test procedures deal with the determination of surface and interfacial tension of solutions of surface-active agents. The two procedures methods are Procedure A (Surface Tension), which covers aqueous solutions of surface-active agents, but also applies to mixed solvent solutions and nonaqueous solutions; Procedure B (Interfacial Tension), which applies to two-phase solutions. More than one solute component may be present, including solute components that are not necessarily surface-active.

ASTM D570-98 - Standard Test Method for Water Absorption of Plastics - This test procedure deals with the determination of the relative rate of absorption of water by plastics when immersed. This test routine applies to the testing of all types of plastics, including hot-molded, cast, and cold-molded resinous products, and both laminated and homogeneous plastics in tube and rod form, as well as in sheets 0.13 millimeters (0.005 inches) or greater in thickness.