Wood-based panels electronic universal testing machine

1.introductions

This  wood-based panels electronic universal testing machine is to measure and  determine mechanical properties of wood-based panel and surface  decorated wood-based panels for parameter of 3 point and 4 point  flexural test strength and elastic modulus, internal bonding strength,  surface bonding strength, shear strength of bonding layer, peel force,  screw holding force and tensile strength.

2. test method

GB/T17657 test methods of evaluating the properties of wood-based panels and surface decorated wood-based panels

3. test introductions

3.1 three point flexural strength and elastic modulus test

The  three point flexural strength and elastic modulus test is to load at the  center of test piece supported by two points. Static flexural test is  to determine the ratio of bending moment and bending section modulus of  test piece under the maximum load. The modulus of elasticity is to  determine the ratio of the stress to the strain generated by the load  within the elastic limit of the material. Drawing of three point  flexural strength and elastic modulus test is as following:

Deformation measuring meter is under the center point of support rollers to measure deformation of test specimen

3.2 Four-point static bending strength and elastic modulus measurement

The  four-point static bending strength and elastic modulus are measured on  the specimen supported by two points, and the same load is applied at  one-third of the distance from the support. The static bending strength  is to measure the ratio of bending moment and bending section modulus  under maximum load. Elasticity modulus is to determine the ratio of the  stress to strain generated by the load within the elastic limit of the  material. The schematic diagram of the four-point bending static bending  strength and elastic modulus test is as follows:

3.3 internal bonding strength test

The  internal bonding strength is the measurement of the tensile strength of  the specimen surface with a uniformly distributed tension until failure.  The internal bonding strength is the ratio of the specimen area  perpendicular to the surface of the test specimen with the maximum  destructive force. The specimen size is 50x50mm.  The schematic diagram of internal bonding strength test is as follows:

Note: 1------metal chuck    2------chuck(metal , hardwood or hardwood plywood)

     3------hardwood plywood chuck(not suitable for thin plate)      4------test piece

     5------auto adjusting joint      t≥15mm

3.4 Surface bonding strength determination-method 1

Surface  bonding strength refers to the bonding strength or bonding quality  between the shavings or fibers of the surface layer of the board and the  underlying material (not veneer) or between the veneer material and the  substrate (veneer). It is expressed as the ratio of maximum breaking  tension force perpendicular to the surface board and bonding area. This  method is suitable for non-veneered particleboard, fiberboard, cement  particleboard and non-veneered wood-based panels. Surface bonding  strength determination-Method 1 schematic diagram is as follows:

3.4 Surface bonding strength determination-Method 2. The schematic diagram is as follows

3.5 Bonding strength determination

Gluing  strength is the shear failure of the glue layer of the test piece  through tensile load to determine the glue quality of the veneer  wood-based panel. The size of the test piece is 100mm long and 25mm  wide. During the test, clamp both ends of the test piece in the movable  fixture of the testing machine to form a straight line. The center of  the test piece should pass through the axis of the movable fixture of  the testing machine. The distance between the clamping part and the  notch of the test piece shall be within 5mm.

3.6 Determination of adhesive layer shear strength

The  shear strength of the adhesive layer is measured by gradually applying a  compressive load to the specimen to cause shear failure of the adhesive  layer to determine the bonding quality. The schematic diagram of the  shear strength of the adhesive layer is as follows:

3.7 Determination of peel resistance

Peeling  resistance is used to determine the force required to peel off the  surface layer, and is suitable for polyvinyl chloride film facing  wood-based panels. The length of the sample is 100mm, and the width is  25mm. The schematic diagram of the peel resistance measurement is as  follows:

3.8 Screw holding force measurement

The  screw holding force is used to determine the force required to pull out a  self-tapping screw with a specified depth. The screw holding force  measurement diagram is as follows:

3.9 Tensile strength determination

The  tensile strength is used to determine the ratio of the maximum tensile  load of the specimen to the cross-sectional area of the specimen. The  tensile strength test piece diagram is as follows:

3.10 Determination of compressive strength along the grain

The  compressive strength along the grain can determine the ratio of the  maximum compressive load along the grain to the cross-sectional area of  the specimen. The specimen is 23mm long, 15mm wide, 15mm thick, and the  length direction is along the grain direction.

4. technical parameters