Vinyl Flooring - Determination of Flexibility and Deflection

Static Bending Tester

A static bending tester generally refers to a testing device used to measure the static bending strength and modulus of elasticity of materials.

It applies a gradually increasing bending force to a material and measures the deformation and failure behavior during the loading process.

This instrument is very common in industries such as flooring, wood, engineered boards, and plastic panels. For example, SPC flooring, LVT flooring, wood flooring, MDF boards, etc., all undergo static bending tests.

1. Two Main Indicators Tested by a Static Bending Tester

• Static Bending Strength

Static bending strength refers to the maximum stress a material can withstand during bending.
It reflects the material's resistance to fracture, meaning how much force the material can endure before breaking when bent.

• Modulus of Elasticity

The modulus of elasticity refers to the stiffness or resistance to deformation of a material during bending.
In other words, it measures how much the material bends under the same applied force.

2. Equipment

A static bending tester generally consists of:

(1) Load sensor: used to measure the applied force.

(2) Loading device: a motor or hydraulic system that applies pressure to the specimen from above.

(3) Specimen: the sample being tested.

(4) Support device: two support points that hold the specimen.

(5) Data acquisition system: records the force–displacement curve.

3. Flooring Testing Procedure

(1) Prepare the Specimen

Cut the sample according to standard dimensions.

Size: 150 / 250 × 50 mm

Thickness: actual thickness

Specimen requirements:
The surface should be flat and free of defects.
Conditioning should be performed under constant temperature and humidity
(usually 23°C ±2°C and relative humidity 50% ±5%).

(2) Set Instrument Parameters

Set the support span, which is generally 16 × the specimen thickness.

Use 0 as the center point, and move the supports symmetrically to both sides.

For example:

If the thickness is 4 mm, the support span will be 64 mm.

With 0 as the center, move the supports on both sides to 32 mm positions respectively.

(3) Place the Specimen

Place the specimen on the two support points.

Requirements: the loading surface must be correct and the specimen must be positioned at the center.

(4) Start Loading

Start the equipment so that the loading head presses downward from above at a constant speed.

Set the loading rate to 100 ±5 mm/min.Ensure that the specimen bends at least 65 mm under the applied force.

(5) Test Completion

When the specimen breaks or reaches the specified deformation, the test ends.

(6) Automatic Data Calculation and Results

The instrument automatically records data such as load and displacement, generating a force–displacement curve.

4. Purpose of Static Bending Test for Vinyl Flooring

Static bending tests for PVC flooring mainly evaluate:

Bending resistance: to prevent breakage during installation or use.

Rigid Core: to determine whether the SPC core is sufficiently rigid.

Structural quality: such as the ratio of stone powder and PVC.