ASTM D6108 Standard Test Method for Compressive Properties of Plastic Lumber and Shapes

Get Certified ASTM D6108 Testing for Reliable Plastic Lumber Quality 

Plastic lumber commonly experiences compressive loads in service. As a result, manufacturers need reliable test data to assess product performance and quality consistency. ASTM D6108 offers standardized compression data for research and development, quality control, specification-related decisions, and special-purpose evaluations. Manufacturers also use the results to compare products or production batches. 

• Describes plastic lumber and plastic shapes.
• Features goods produced mostly with recycled plastics.
• Applies to similar products made from virgin resins.
• Solves problems with non-homogeneous cross-sections.
• Covers plastic composite products in the scope of the method.
• Provides compression testing under relatively low and constant loading or straining rates.

What are the Uses of ASTM D5672 Testing?

ASTM D6108 helps manufacturers assess plastic lumber/plastic shapes under compressive loading. The method provides quantitative information on several important properties. This standard-

• Determines compressive strength.
• Determines modulus of elasticity.
• Determines secant modulus.
• Calculates the stress corresponding to a specific strain.
• Provides funding for research and development.
• Assists in manufacturing quality control
• Helps evaluate products against specifications.
• Offers information for making product comparisons. 

Which materials can be tested under D6108?

ASTM D6108 is primarily for plastic lumber and plastic shapes produced from recycled plastics. The method also applies to similar manufactured products made with virgin resins. It is used for products with a nonhomogeneous cross section. ASTM standards for plastic lumber indicate that these products contain various resin systems, fillers, reinforcements, and additives. ASTM D6109 is an example of a flexural test for plastic lumber products with various resin, filler, reinforcement, and additive systems. 

Why is ASTM D6108 Important? 

ASTM D6108 gives a standardized method for obtaining compression data of plastic lumber and shapes. This uniformity makes it easier to compare products across manufacturers and track quality. It is also a valuable test for research and development, quality control, specification acceptance/rejection, and special-purpose evaluations. 

ASTM D6108 Testing Process and Data Collection

The technician prepares the specimen and measures its relevant dimensions before testing. The technician then places the specimen between the compression platens and keeps it properly aligned. When the test machine applies the required load, the system records the load and deformation response. The data is then analyzed in the laboratory to calculate the appropriate compressive properties. ASTM D6108 provides information for determining compressive strength, modulus of elasticity, secant modulus, and stress at a given strain.

Common Challenges and Troubleshooting

Specimen surfaces may not be flat and even, which can interfere with compression with the platens. So, technicians create appropriate loading surfaces before testing. Specimen alignment can also affect load distribution if it is placed incorrectly. The technician is to ensure that the alignment is good throughout the test. Plastic lumber may have no obvious yield point. Therefore, when the material does not provide a meaningful conventional yield value, the laboratory uses the appropriate stress-strain measurement.

• The laboratory reports the compressive stress at the specified failure condition in MPa (N/mm²) or psi, as applicable.
• The analyst determines the compressive properties from the measured load, deformation, and specimen dimensions, providing a quantitative measure of the product’s response to compression.
• The laboratory reports the stiffness or modulus obtained from the specified stress-strain range in MPa or psi, as applicable.
• Engineers compare the compressive results among products or production batches to evaluate material performance and production consistency.

Link to ASTM D6108