Surfboard foam three-point bend test

Case study

Surfboard in use and foam material being tested for bend strength

Surfboard foam bend to break system and graphical force results

Solution

Motorised compression tester, digital gauge and software
3-point bend jig

Benefits

Simple test system for ease of use
Data output capability for further analysis

Requirement

A company manufacturing surfboard blanks, made from rigid polyurethane (PU) foam, undertake a stringent testing program to guarantee the rigidity of the foam and strength of the final surfboard product. The blank must maintain a certain level of hardness throughout its construction to ensure its strength and responsiveness when ‘riding the waves‘.

The company wanted a test solution to determine the peak load strength of PU foam samples by compressing them until failure occurred. A graphical representation of every test was also needed to provide an easy way of comparing results.

Solution

Mecmesin offered a suitable solution in the form of a motorised test system, together with an Advanced Force Gauge (AFG) and 3 point bend jig, all capable of testing up to 1000 N. In addition, the customer was supplied with Windows-based Emperor™ Lite software, which provides users with a ‘live‘ display of the test on a PC screen and enables evaluations to be made once the test is completed.

The 3 point bend jig consists of a 120 mm span support plate and 2 adjustable 60 mm high support arms, each of which is capped with hard wearing 3 mm diameter stainless steel rods for friction free and damage-proof testing. The foam is positioned symmetrically on top of the support arms, enabling an even amount of force to be applied to each sample. The blade is then lowered at a constant speed of 30 mm/min to deform the sample causing it to fracture and break at its weakest point.

As the assessment gets underway, the software displays the test data in graphical form, allowing engineers and quality personnel to scrutinise results in more detail and pinpoint precise areas of interest. Using this test solution, the company were in a much better position to guarantee product performance and make objective judgements regarding the standard of material used within their products.