The primary difference between thermoplastic washers B-531-1 and B-531-2 from Aearo Technologies LLC, a 3M company is the materials used in them.
These materials are denoted in the suffix of the product nomenclature, with material C-1002 as “-1”, material C-1105 as “-2”, and material C-1100 as “-3”.
So, B-531-1 is made of material C-1002 and B-531-2 is made of material C-1105.
Both the materials, C-1002 and C-1105, are made of Vinyl Solid Thermoplastic but with different physical attributes.
Shore Hardness, Compression Load Deflection, Compression Set, Tensile Strength, Temperature Range are some key parameters that contribute to the physical properties of these materials.
More details can be found in the attached file:
Difference - C1002 and C1005.pdf (69.2 KB)
Shore Hardness: Shore hardness is a measure of the hardness of a material, typically of polymers. It is measured by the depth of indentation that is created on the material with a specified force. The Shore durometer is a device for measuring the hardness of a material, typically of polymers. There are several scales of durometers, used for materials with different properties. The two most common scales, using slightly different measurement systems, are the ASTM D2240 type A and type D scales. The A scale is for softer ones, while the D scale is for harder ones. The Shore A hardness (durometer) scale is one of many durometer scales used to measure material hardness. Shore A durometers range from 0 to 100 — the higher the durometer value, the harder the material.
Flammability: UL 94, the Standard for Safety of Flammability of Plastic Materials for Parts in Devices and Appliances testing, is a plastics flammability standard released by Underwriters Laboratories of the United States. The standard determines the material’s tendency to either extinguish or spread the flame once the specimen has been ignited.
Compression Load Deflection (CLD) is a test that measures the force required to compress a material 50% of its original thickness. It is a measure of a material’s resistance when subjected to compressive forces.
ASTM D575 is a testing specification that determines the compression-deflection characteristics of rubber compounds. This test method is applicable to all rubber compounds other than hard rubber and sponge rubber. Deflection is the change in thickness of the specimen upon application of a compressive force.
Compression Set: The compression set (ASTMD395) of a material is the permanent deformation remaining after squashing it. The term is normally applied to soft materials such as elastomers and foams. Compression is normally measured in two ways: compression set A and compression set B.
Compression Set A: This has the formal name compression set under constant force in air . In compression set A a force of 1.8 kN is applied to the specimen for a set time at a set temperature. Compression set A is defined as the percentage of original specimen thickness after the specimen has been left in normal (uncompressed) conditions for 30 minutes. CA , the compression set A is given by CA = [(to - ti) / to] * 100 where to is the original specimen thickness and ti is the specimen thickness after testing.
Compression Set B: This has the formal name compression set under constant deflection in air. The specimen is compressed to 75% of its original height for a set time and at a set temperature (sample is compressed to .75 of its original height). Compression set B is (like Compression set A) defined as the percentage of specimen deflection after it has been left in normal (uncompressed) conditions for 30 minutes. CB, the compression set B is given by CB = [(to - ti) / (to - tn)] * 100 where to is the original specimen thickness, ti is the specimen thickness after testing and tn is the spacer thickness or the specimen thickness during the test.
Tensile Strength: ASTM D412 is the most common standard for determining the tensile properties of vulcanized (thermoset) rubber and thermoplastic elastomers. ASTM D412 measures the elasticity of a material while under tensile strain, as well as its behavior after testing when the material is no longer being stressed. ASTM D412 is conducted on a [universal testing machine] (also called a tensile testing machine) at a rate of 500 ± 50 mm/min until the specimen fails.
Applicable Part Numbers
DK# EAR1445-ND and DK# EAR1330-ND