FOAM COMPRESSION

Foam compression fixtures are designed for indentation and compression testing of expanded cellular materials. Standards that require this style of fixture include ASTM D3574 (Method B1 and B2), ASTM D5672, and ISO 2439. The major components of the fixture include a perforated loading table and a circular indenter/anvil. The 203 mm diameter upper anvil incorporates a swivel joint. The base table is perforated with 6.5 mm holes spaced on 20 mm centers, and elevated from the mounting surface to allow for rapid air escape from the specimen.

Principle of Operation

The specimen is placed on the perforated table attached to the instrument base. The indenter is brought down in contact with the specimen to establish a reference height. This is followed by a series of pre-conditioning loading segments and a test loading sequence. Data is captured during the test loading sequence, which generally includes a dwell time. Results are then calculated which commonly include loads at defined percent indentations or deflections.

Application Range

• Indentation force deflection (IFD) and Compression force deflection (CFD) of expanded cellular materials

• Suitable for an entire product or cut specimen

• Suitable for specimens with or without skins

Instron® food fixtures cover a wide range of industry standard testing methods including compression, puncture, shear, and extrusion. A variety of anvils, probes, shear, extrusion and bending fixtures are available for R&D, quality assurance, and process control testing. Food fixtures provided by Instron are designed with materials that are corrosion-resistant and durable. All fixtures can be mounted in a drip tray to help keep the test area clean when evaluating the texture of wet, juicy or easily fractured foods.

Principle of Operation

As chewing occurs, food is compressed, sheared and torn, causing it to disintegrate in preparation for swallowing. Texture can be described as a set of characteristics that define how food disintegrates during this process. Instron’s food fixtures are designed to provide a measure of these characteristics, providing test results that relate to texture.

Application Range

• Texture analysis of solid and semi-solid foods including cereal products, baked goods, processed and muscle meats, fruits and vegetables, dairy products, snack foods, pasta and noodles, confectionaries, fish, seafood and more.

Food Fixtures

Food Fixtures And Accessories

The 2810-005 coefficient of friction fixture measures the static and kinetic coefficient of friction of plastic film and sheets to ASTM D1894 and ISO 8295:2004. The major components of the fixture include a 200 g square metal sled wrapped with a 1/8 in (3.2 mm) thick foam pad and a rectangular metal table with a defined surface finish. A pulley located at one end of the table allows the sled, when attached to the crosshead via a nylon or metal tow line, to be pulled horizontally along the plate. Test material can be attached to either the sled, plate or both. The coefficient of friction fixture mounts on the testing system load frame using an Instron® standard Type D base-grip adapter. The tow line attaches directly to the load cell.

Principle of Operation

The coefficient of friction test fixture consists of a horizontal table and a moveable sled. Both the table and sled are covered with the test material. A tow line attaches to the sled and a low force load cell with a pulley guiding the tow line during the test. The fixture is mounted to the base of the instrument and, as the crosshead/load cell moves, the sled is pulled across the horizontal table. Data is recorded from the load cell during the test and analyzed to determine both static and kinetic friction. The static friction is derived from the first maximum peak (force) on the load curve and kinetic friction is derived from the average force between two pre-defined points. The coefficient of friction is defined as the recorded force divided by the weight of the sled.

Application Range

• Coefficient of friction determination on sheet, film and paper products. Testing in tensile mode only, no high rate applications.

Friction Test Fixtures

Bend or flexure testing provides a convenient method for characterizing the strength of the miniature components and specimens typical of those found in microelectronics applications. Fixtures are available for both three and four-point loading.

Principle of Operation

The specimen is supported on two lower anvils at a defined distance. The support span can be adjusted according to specimen size. Force is applied to the specimen by an upper anvil located at the mid-span of the lower anvils. Some fixtures include an option for four-point loading.

Application Range

• Bend and flexure tests on a wide variety of miniature components and specimens

Peel fixtures are suitable for testing the peel strength of a wide range of laminated materials and components including copper runners on printed circuit boards, thin film coatings, adhesive tapes and other bonded structures.

Principle of Operation

The fixtures incorporate a moving table which is coupled to the crosshead or actuator of the materials testing machine through a cable and pulley. As the crosshead (or actuator) is driven in the tensile direction the cable pulls the table laterally to maintain the required peel angle throughout the test. This method prevents the exertion of outside forces on the sample. The force required to peel the specimen is measured by the machine load measurement system, providing a direct measure of bond strength. The substrate or base of the test sample is clamped to the moving table via a set of clamps.

Application Range

• Peel tests on copper runners, thin films and coatings, adhesive tapes and packaging