Sponge foam collapsible hardness tester

This machine is used to measure the indentation hardness of porous elastic materials. The polyurethane foam sample can be tested according to the national standard, and the compressive hardness of sponge, foam and other materials can be accurately measured. In addition, it can also be used to measure the specified compression hardness of the seat foam (such as backrest, seat cushion foam, etc.)， and accurately measure the compression hardness of each foam part of the seat.

Application

Measurement of tensile strength, tear strength, elongation at break, indentation hardness, and compressive stress of polyurethane foam plastics.

Standards

ISO 2439: Flexible cellular polymeric materials — Determination of hardness (indentation technique)

ISO 3386-1: Polymeric materials, cellular flexible — Determination of stress-strain characteristic in compression

ASTM D3574:Standard Test Methods for Flexible Cellular Materials-Slab, Bonded, and Molded Urethane Foams

Features

1. Automatic zero clearing: After receiving the test start instruction, the system automatically clears zero.

2. automatic return: after the sample is broken, it will automatically return to the initial position.

3. change the speed: The machine can change the test speed arbitrarily according to different samples.

4. indicating value verification: the system can achieve the accurate calibration of force value.

5. control method: According to the test needs can choose the test force, test speed, displacement and other test methods.

Technical Parameters

Accessoriess

1. Transmission System:

Typically, the reduction gear unit of the main machine's transmission system uses a worm gear reducer, but it has inherent drawbacks such as large backlash and slow response speed. Our company's WSM series products utilize an AC servo motor from a Japanese (or other imported) company, which drives a ball screw through a circular arc synchronous belt pulley reduction system. This transmission system has no backlash and offers a fast response speed, thus ensuring the control accuracy of test force, deformation, and displacement.

2. Guiding System:

In addition to the ball screw guidance, the moving crossbeam of the testing machine is also guided by two columns (in conjunction with linear bearings). When the moving crossbeam is subjected to force, the special double-guide mechanism makes the moving crossbeam act as a fixed beam structure. Therefore:

a) The axial and lateral stiffness of the testing machine are greatly improved, with axial stiffness reaching 2 × 10⁸ N/m;

b) The oscillation of the moving crossbeam and the vibration generated during sample fracture are reduced.

Fully Digital Measurement and Control System

Fully Digital Measurement Controller

Test Procedures

1. Sample Pre-treatment

Cut the sample according to the corresponding test standard (e.g., ISO 2439) (usually 380×380×50mm or other standard dimensions); place the sample in a standard environment of 23±2℃ and 50±5% relative humidity for at least 16 hours to ensure the material is in a stable state.

2. Equipment Preparation

Connect to a single-phase 220V 50/60Hz power supply, and after starting the equipment, complete the power-on self-test through the touchscreen control interface; check that the ventilation holes (6mm diameter, 20mm spacing) on the lower platform (420×420mm) are unobstructed, and confirm that the pressure plate (200mm diameter, R1mm bottom radius) and precision force measuring element are in normal condition.

3. Sample Clamping

Place the pre-treated sample flat on the center of the lower platform, ensuring that the sample is aligned with the upper pressure plate (200mm diameter) to avoid sample displacement or wrinkling.

4. Test Parameter Settings

Complete parameter configuration through the touchscreen control interface:

Select the test method (e.g., Method A/B/C as required by ISO 2439);

Set the test speed (default 100±20mm/min), maximum stroke (75mm);

Switch test units (Kg/N/LB, select as needed);

Set the target indentation depth/indentation rate (e.g., 40% of the sample thickness, corresponding to the indentation hardness C test requirements of ISO 2439).

5. Start Testing

After confirming that the sample clamping and parameter settings are correct, start the servo motor (driven by a precision ball screw), and the upper pressure plate presses down on the sample at the set speed; the equipment collects pressure data in real time through the precision force measuring element and transmits it to the controller for processing.

6. Test Termination and Data Recording

When the pressure plate reaches the set indentation depth/indentation rate, the equipment automatically stops; the touchscreen interface will display the corresponding indentation hardness value (e.g., indentation hardness A/C), and this data and the test process curve are recorded directly.

7. Conclusion

After the pressure plate returns to its original position, remove the sample and clean the surface of the lower platform; turn off the equipment power to complete the testing process.