What is the torsion resistance of shoe insole

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What is the torsion resistance of shoe insole?

Throughout the life of a shoe, the shoe insole must be flexed without cracking or breaking.

This paper describes a test method and equipment for assessing the torsion resistance of shoe insole.

Shoe insole may be worn or cracked due to strain due to foot flexure.

As a result of the sharp edge cut notch and puncture, there will be cracking or fracture, in the continuous flexure action, will gradually become a crack.

Extreme temperatures (especially below freezing) and pollution (such as oil) can also accelerate shoe insole cracking.

Therefore, it is very important to test the flexural crack resistance of shoe insole. There are many testing methods available, so it may be difficult to choose the correct method.

Three main flexural test methods, applications of rubber and plastic shoe insole and the equipment provided by SATRA for these tests are described.

Ross deflection test

For smooth and shoe insole designs with little or no shoe insole tread, the Ross flex test machine (SATRA TM60) can be used.

Generally, 3 pieces of 150 mm x 25 mm in size are removed from the shoe, and the longer edge is parallel to the heel seat.

Use a 2mm chisel to make an incision in the sample and place the sample into the deflection machine, so the incision is directly above the deflection mandril.

The size of the incision can be calculated by measuring the incision before and after the test.

The test is in commonly - 5 ℃ temperature of 150000 cycles operation.

This helps to form a measurable increase in incision size within a reasonable time frame.

The only exception is the thermoplastic rubber + 20 ℃ test, because this material better performance at lower temperatures.

The SATRA Ross flexure tester (STM 141) can accommodate up to 12 specimens at a time.

The machine flexes the sample at a standard rate of 60 flexes per minute.

However, machines that provide 100 flexing per minute are available for this version of the ASTM.

In addition to standard machines, lower and higher temperatures are available.

This temperature range from peripheral temperature to - 20 ℃ and temperature from the periphery to + 40 ℃.

Bata belt test

If the shoe insole contains a large splint or a complex design that integrates different materials, the best way to test the resistance to flexure is with a Bata tape tester.

This is a generally accepted test that can be repeated to produce results related to actual wear and tear.

Glue the complete front of the shoe insole (minus the heel but still containing any cavity filler or midsole material) to the canvas strap.

This part is driven from the spindle with different diameters, so the shoe insole is repeatedly flexed while the belt is driven to the spindle.

The diameter of the mandrel is normally 90 mm, but may be changed to 60 mm or 120 mm to increase or decrease the degree of deflection.

Unlike the Ross flexure test, there is no need to cut the shoe insole.

The test runs for 50,000 cycles with continuous visual evaluation during the run.

Record the length and depth of any cracks.

The test at room temperature, but in the SATRA, can reach to 15 ℃ at the lowest temperature test shoe insole.

The Bata belt deflector (STM 459) comes with three replaceable servo mandrels in sizes of 60 mm, 90 mm and 120 mm as standard with a rotational speed of 90 deflection per minute on a smaller mandrel.

Version of machines, can also provide a lower temperature in the low - 20 ℃ temperature test execution.

Bennewart test

As with the old standard, the new safety footwear standard (EN ISO 20344:2004) requires testing of shoe insole using Bennewart machines.

The authors prefer the Bata tape test method, which can be used to test the entire front of the shoe insole.

The insole is an important part of the sample and is cut in the nominal flexure line using a chisel similar to Ross's.

The shoe insole clamps both ends and rolls are pushed against the insole to flex the shoe insole90 degrees.

The extent of incision increase was measured after operating at room temperature for 30,000 cycles.

This test can be performed below zero at SATRA if required.

This is a demanding test best suited for durable footwear with a strong shoe insole.

For casual, stylish and everyday footwear, the test is considered too restrictive, especially if the shoe insole is very thick.

SATRA's Rennewart full shoe insole flexure tester (STM 465) is designed to ensure force balance and therefore requires less force to perform the test, resulting in smoother running results.

The rigidity of the instrument clamp is large, and the operation is strictly in accordance with the standard.

An adapted Bennewart tester, using a spring clamp, does not perform this test to the standard.

But can provide low version of the instrument, to 20 ℃ in low - temperature environment test execution.

A chisel equipped cutting fixture (STM 465) can be provided to help with accurate shoe insole cutting.

"The above is the complete content of ""What is the torsion resistance of shoe insole"" introduced by you. Thank you for your reading. If you have any questions, please contact us directly.

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