Accelerated Weathering ASTM G154, G155
Natural exposure testing has many advantages. It is realistic, inexpensive and easy to perform. However, many manufacturers do not have several years to wait and see if a “new and improved” product formulation is truly an improvement. Accelerated weathering testing is a laboratory simulation of the damaging forces of weather for the purposes of predicting the relative durability of materials exposed to outdoor environments. Essentially, racks of samples are placed in a weathering chamber and exposed to strictly controlled conditions.
The weathering process can be greatly accelerated through the use of specially designed weathering chambers. While this speeds up the time needed to get results, care must be taken to obtain results which are representative of real world conditions. Precise Plastic Testing uses Q-SUN (xenon arc) and QUV (fluorescent UV) weathering chambers. These chambers are the most commonly used and industry accepted accelerated weathering testers in the world. It should be noted that these two chambers are based on completely different approaches. The QUV test chamber simulates the effects of sunlight using special fluorescent UV lamps. The Q-Sun xenon arc test chamber reproduces the entire spectrum of sunlight, including ultraviolet (UV), visible light, and infrared (IR). The xenon arc is essentially an attempt to simulate sunlight itself. (see Figure 1 below) However, in polymers, the most damaging rays occur at the lower wavelengths (300-400 nm), making both methods highly accurate.
Your choice of tester should depend on the product or material you are testing, the end-use application, the degradation mode with which you are concerned and your budgetary restrictions.
At Precise Plastic Testing, we pay attention to the details. Specimen mounting, water purity, test chamber maintenance and rotation procedures are all critical for an accurate test. Each tester is continuously monitored to ensure it is working properly. If the proper conditions aren’t maintained, the testing chamber is automatically stopped until our technicians correct the issue.
Below is a graph that details conditions inside the testing chamber on a minute by minute basis.
Other test standards used by Precise Plastic Testing are:
- ISO 4892 Plastics – Methods of Exposure to Laboratory Light Sources-Part 3: Fluorescent UV Lamps
- DIN 53 384, Testing of plastics, Artificial Weathering and Exposure to Artificial Light
- Spanish Standard UNE 53.104 (Stability of Plastics Materials Exposed to Simulated Sunlight)
- JIS K 7350, Plastics – Methods of Exposure to Laboratory Light Sources-Part 3: Fluorescent UV Lamps
- ASTM D-1248, Standard Specification for Polyethylene Plastics Extrusion Materials for Wire and Cable
- ASTM D-4329, Standard Practice for Light/Water Exposure of Plastics
- ASTM D-4674, Test Method for Accelerated Testing for Color Stability of Plastics Exposed to Indoor
- Fluorescent Lighting and Window-Filtered Daylight
- ASTM D-5208, Standard Practice for Exposure of Photodegradable Plastics
- ASTM D-6662, Standard Specification for Plastic Lumber Decking Boards
- ANSI C57.12.28 Specification for Accelerated Weathering of Padmounted Equipment Enclosure Integrity
- ANSI, A14.5 Specification for Accelerated Weathering of Portable Reinforced Plastic Ladders
- Edison Electrical Inst. Specification for Accelerated Weathering of Padmounted Equip. Enclosure Integrity
- Wisconsin Electric Power Specification for Polyethylene Signs