The harm of UV rays to products
UV, an invisible light outside the violet spectrum of the electromagnetic spectrum, poses a significant threat to product performance and its destructive effects must be taken very seriously. Among the many external factors affecting material properties, UV is one of the main causes of material degradation. BOTO GROUP, a professional manufacturer of environmental testing equipment, offers a full range of UV aging testing machine to help companies assess the durability and performance evolution of materials under UV , thereby ensuring product reliability in real-world environments.
During processing, storage, or actual use, materials or products are subjected to the combined effects of various external factors such as heat, light, oxygen, mechanical stress, ozone, harmful metal ions, and radiation, leading to changes in their physical or chemical structure and a gradual loss of their original properties and usability.
The forms of damage caused by UV are diverse, manifesting as fading, loss of gloss, chalking, cracking, splitting, decreased transparency, blistering, embrittlement, reduced strength, and oxidation. These damages not only impair the product's appearance but also weaken its functional performance and shorten its effective lifespan.
The product sectors affected by UV aging are very broad, including rubber, plastics and their products, coatings, paints, adhesives, metals, electronic components, electroplated products, and many other industries. For example, plastic casings and displays in electronic products will age and degrade under long-term UV exposure; electroplated layers may also peel off or change color due to UV , thus affecting the product's appearance and protective function.
The necessity of UV aging test
UV from sunlight is the primary factor causing photodegradation and photoaging in products. This is because UV has a short wavelength, high energy, and strong penetrating power. UV plays a crucial role in the solar spectrum, and its damaging effects on materials are particularly pronounced. UV aging testing is a method of simulating the effects of outdoor UV on products in a controlled laboratory environment. Using accelerated UV aging testing machine, researchers can obtain repeatable and reliable material aging data within weeks or months. This test machine, through a combination of short-wavelength UV irradiation and a condensation circulation system, can highly replicate the damage mechanisms caused by natural factors such as sunlight, dew, and rain on materials. BOTO, leveraging its advanced product design and professional technical team, can provide customers with high-performance UV aging testing machine, helping them maintain a competitive edge in the market.
UV aging testing is primarily used to simulate the performance degradation effects of UV from sunlight on products, and can also reproduce the moisture erosion caused by rain and dew. During the test, samples are placed in a controlled environment of alternating UV and moisture circulation, and the aging process is accelerated by heating. UV fluorescent lamps are widely used to simulate the ultraviolet portion of the solar spectrum, while condensation or spray systems are used to simulate the effects of moisture on materials in nature.
Introduction to UV aging test methods
(Taking TPU film weather resistance testing as an example)
1. Test Definition
This test consists of two consecutive stages:
The first stage is ultraviolet light exposure testing;
The second stage is a double 85 environmental reliability test.
BOTO can independently manufacture all the equipment required for the test. After completing both stages of testing, the mechanical and optical properties of the material need to be measured.
2. First Stage
According to standard ASTM G154/G155, the sample is irradiated with ultraviolet light using a specific exposure device (QUV-313nm) for 2000 hours(Through UV aging testing machine). After irradiation, the test is stopped, and the mechanical and optical properties of the material are measured. Specific parameters are shown in the table below.
3. Second Stage
The sample that has completed ultraviolet exposure is placed in the constant temperature and humidity chamber and tested continuously for 240 hours under double 85 conditions (85℃/85%RH). After drying, the mechanical and optical properties are re-evaluated.
4. Tools Used
(1) Tensile Test (Tensile Testing Machine): Cut 2cm × 2cm samples before and after the test. Fix both ends and stretch them by 200% along the X and Y axes respectively. Hold for 30 seconds and then release. Observe the TPU film surface. If cracks, discoloration (whitening), or breakage occurs, it is judged as "fail"; if there are no abnormalities, it is "pass".
(2) Nine-level color chart visual inspection: Used to evaluate the color change of TPU film before and after the weather resistance test. After completing the two environmental tests, if the yellowing degree is between 4.5 and 5, it is judged as "pass"; if it is 4–4.5, it is considered "specially accepted" and is not used unless necessary; if it is below 4, it is judged as "fail".