The new Martindale 1309L
UK-based provider of testing equipment, James Heal, has launched a new elastomeric abrasion tester that it says offers higher efficiency in cost and time in comparison to rotary drum (ISO) abrasion testers.
The new Martindale 1309EL is a precision tester for elastomeric rubber materials including seals, engine mounts, rubber boots for linkages, tyres and mats. The instrument will be exhibited at the upcoming IRC/DKT conference in Nuremburg.
The instrument, which is compliant with Standard PV3984, was developed by James Heal in the UK and subsequently tested and approved by Volkswagen in Germany.
James Heal claims the multi-directional abrasion closely reflects the abrasion of elastomeric components when in situ within a vehicle and provides authentic and accurate results, in comparison to the quasi-static testing instruments currently available.
Air cleaned test area
The Martindale 1309EL is connected to a compressed air supply, which the air runs through a pneumatics kit which filters out any ambient oils, which would have a detrimental effect upon the sample, and consequently, the test results. A valve on this kit also indicates the pressure of the incoming air.
The air then moves from the pneumatics kit into a mixing chamber which equalises the airflow to ensure a homogeneous amount travels down each of the 12 pipes which feed into the four abrasion stations.
Each of the four stations is equipped with three energy saving venturi nozzles set at 120 degrees to the centre of the specimen. The nozzles force compressed air through an adjustable circular slot and direct it, at high velocity, onto each abrading station. The design of these nozzles, which amplifies the output airflow, blows away debris from the abrading tables so as not to compromise the testing process.
James Heal explained conventional equipment for tests of this type requires the manual removal of debris by the operator for the duration of the test - in contrast the 1309EL requires no involvement once the test begins, therefore increasing user efficiency. The air is programmed to only operate during the testing process in order to control the use of the compressed air to minimise wastage.
Reduction in material costs and set-up times
The Martindale 1309EL does not require reference sample material or specialised sandpaper and accordingly offers significant savings on those associated costs, says the company. This also creates beneficial time savings for test set-up as the laborious process of carefully fitting the sandpaper around a drum circumference of a DIN abrasion tester is totally eliminated, as is the time to create reference samples.
Consistent test sample
In addition, a change from a round sample to a square test sample has also proved beneficial to testing consistency.
The standard states a 2mm protrusion is required, and to accommodate that requirement the James Heal Martindale 1309EL is equipped with a shim kit, which includes a variety of different thicknesses of shims as well as a tool for easy removal.
Four testing stations – substantial increases in laboratory throughput
The 1309EL is equipped with four stations, which has a hinged top plate to allow for easy access. This enables four samples to be tested compared to a single one on the drum of existing elastomeric testers.
Together with the reduction in set-up times, the multiple testing stations will ensure laboratory productivity will increase substantially.
The sample holder has been designed with a four-jaw arrangement, which clamps the sample in place with enough pressure to hold the sample firm.
There are two design features to ensure the sample is always inserted at the same angle, guaranteeing repeatable and therefore more reliable results; there is guide behind the jaws for the user, and a groove at the top of the spindle which limits how the sample holder can be inserted into the instrument.
Before the sample is inserted, a setting device is used to set the level of the spindle to ensure it never drops below a certain height. This ensures the sample cannot be worn away completely and consequently prevents damage by the abrasive material to the sample holder. Rubber seals and wipers have been placed around the mechanisms to prevent contamination from the rubber, further protecting the robustness of the parts inside the instrument.
A range of weights is available to apply varying pressure to the samples, enabling the testing of different types of elastomeric products of different thicknesses.