To deliver products that meet the highest standards of safety, quality, and reliability, companies must adopt a rigorous testing program for all their products. Renishaw recently made a multi-million-dollar investment in a new dedicated facility to test its products under the environmental and electrical conditions encountered during transportation. The new testing facility includes a variety of equipment, including a large electromagnetic compatibility (EMC) chamber, devices for testing electrical safety, and environmental simulation systems, such as accelerated life testing. The latter includes electrodynamic shakers that identify the resonant frequency of Renishaw products and then subject them to many years of use in just a few hours.
Shown here is a package on a shaker rig for vibration testing. Image: Renishaw
A crucial aspect of Renishaw’s relationship with its worldwide customer base is ensuring that products reach their destinations in perfect working order, regardless of the environmental conditions encountered during transit. To achieve this, the new testing facility also houses equipment designed to simulate a wide range of conditions faced during transportation. This includes temperature ovens, climatic chambers, a negative-pressure vessel, and a positive-pressure vessel. By running a comprehensive series of tests, Renishaw can identify any potential packaging issues and make any necessary improvements before a product is shipped.
Environmental testing is crucial for packaging design as packaging must protect products from extremes of temperature, humidity, and physical impacts during transportation and storage, and many industries have specific regulations regarding packaging to ensure safety and quality. Testing can help in selecting materials that are not only effective but also reduce the environmental impact of packaging.
“We use the temperature ovens to try and replicate the worst-case scenario of an air freight journey. If [the product package] goes up to altitude in an unpressurised hold, then we expect it to get extremely cold. If that plane lands in a very warm country, we could expect the package to sit on the tarmac for several hours in very hot and humid conditions,” said Luke Worthington, senior environmental test engineer at Renishaw.
All the package tests include packaging with a product inside, and the sign-off criteria for a successful test is the powering up of this product without any observed degradation in performance.
Transport temperature testing
One of the primary tests conducted in the lab is the transport temperature test. This is designed to replicate the extreme temperature cycles that a package might experience during transit. The test involves exposing the package to temperatures from -25 to 70° C, with each temperature maintained for 16 hours. This test cycle is repeated to give a combined 32 hours at each temperature extreme. The goal is to ensure that the packaging can protect the product from extreme cold and heat, and that it arrives in good condition.
Temperature ovens are used to simulate the harshest environments, such as an unpressurized hold on an air freight journey. If a plane ascends to a high altitude, the air temperature can drop significantly, whereas upon landing in a warm country, the package might experience much higher temperatures.
Humidity testing
In addition to temperature testing, Renishaw also conducts humidity testing using climatic chambers. Humidity testing is crucial for checking the integrity of vacuum-sealed products and ensuring that moisture does not penetrate the packaging. This is particularly important for products that might be exposed to varying humidity levels during transit through different countries.
An operator conducts humidity testing with a climatic chamber. Image: Renishaw
The typical humidity test involves maintaining a constant temperature of 42° C and a relative humidity of 93%. This rigorous testing ensures that the product and its packaging can withstand high humidity without any adverse effects.
Pressure testing
Renishaw also tests products for their ability to withstand negative and positive pressure environments. Negative pressure testing is conducted in a vacuum chamber to simulate high-altitude, non-pressurised conditions equivalent to 55 kPa (550 mbar) for 16 hours. This is particularly important for sealed product packaging that might be transported inside aircraft cargo holds with large pressure differentials at high altitude.
Positive pressure testing is also performed on some products that require IPX8 certification using a pressure vessel that simulates immersion in water at an equivalent depth of 10 m (an absolute pressure of 2 bar) for a period of 24 hours. Renishaw does positive pressure testing on certain products in either dry or wet conditions.
Vibration testing
Another critical aspect of environmental testing is vibration testing. This test simulates the vibration g-forces that a package might experience during transit, whether by road, sea, or air. The lab is equipped with three electrodynamic shakers that can apply various vibration profiles to the product packaging. The tests are conducted over three axes to replicate the worst-case scenarios. The vibration profiles include sinusoidal, random, and pulse shock tests, each designed to simulate different types of vibration and impact.
Testing products for their ability to withstand negative and positive pressure environments is particularly important for sealed product packaging that might be transported inside aircraft cargo holds with large pressure differentials at high altitude. Image: Renishaw
The sinusoidal profile mimics the gradual build-up of vibrations during an airplane take-off, which is generated by rotating propellers and turbofan engines. The random profile simulates the unpredictable vibrations encountered in trucks or vans. The pulse shock test replicates the sudden impacts that a package endures during handling.
Renishaw
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Filed Under: TEST & MEASUREMENT
