Eversorb® Light Stabilizer Lets UV-C Lamps Kill Bacteria without Destroying Polypropylene

12 Oct, 2023

Author : Specialty Chemical Business Unit

Everlight Chemical has introduced the “Eversorb® Anti-UV-C Light Stabilizer” especially for polypropylene, which effectively improves the weatherability of plastic products to UV-C while protecting their attractive appearance, functionality and durability.

“Labelling Free Light Stabilizer” for silane-modified sealants-Eversorb® HP5



Easy to carry yet highly effective, UV-C lamps have become new favorite for sterilization


Due to the Covid-19 pandemic and the spread of various other infectious diseases in recent years, people have been paying more and more attention to environmental cleanliness and hygiene, and therefore use cleaning products even more frequently. Various “disinfection” and “sterilization” products have thus seen increasing sales.  The UV-C lamps have become one of the most commonly used pieces of disinfection equipment because they are easy to use, convenient to carry, feature excellent sterilization functionality, and cause little environmental pollution.



The principle of UV-C lamps is to make use of the UV-C band with a wavelength between 280 nm and 200 nm to irradiate items or locations that need to be disinfected. Because the UV-C light with this wavelength can destroy the cellular nucleic acids and proteins of microorganisms (including bacteria, viruses and pathogens), it causes damage and destruction to the molecular structure of the genetic material of DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), making such microorganisms unable to reproduce or regenerate and then die, thereby achieving a sterilization effect.



Initially, UV-C germicidal lamps were mostly used in medical-related places. As peoples’ demands for public environmental hygiene gradually increase, UV-C lamps have been progressively introduced into libraries, swimming pools, shopping malls and other places where people frequently come and go. Meanwhile, in respect of industry and household use, UV-C germicidal lamps can be employed in food processing and manufacturing, water purification, air cleaning, and home disinfection.



UV-C germicidal lamps: https://www.bioimager.com/product/surface-disinfecting-uv-light-bil-uvl/




Plastic products are prone to deterioration after UV-C irradiation, which affects appearance and durability


However, the outstanding sterilization capability of UV-C germicidal lamps implies that the energy contained in the UV-C light is quite powerful. If the plastic products are often irradiated by such light, their polymer bonds could easily break and physical properties be destroyed, leading to various phenomenon of degradation such as embrittlement, discoloration, loss of flexibility, reduced functional properties and shortened service life. This not only damages the appearance of plastic products, but also reduces their functionality and compromises their durability. In serious cases, it may even affect user safety! Furthermore, frequently discarding and replacing degraded plastic products also causes waste accumulation and environmental pollution, and this is out of step with current trends towards environmental sustainability.



UV-C germicidal lamps: https://abcnews.go.com/Health/hotels-uv-light-robots-lamps-protect-coronavirus/story?id=71205829



Eversorb® Anti-UV-C Light Stabilizer reinforces weatherability of plastic products, improves safety and extends service life


In order to solve the degradation problem caused by UV-C irradiation, weatherability and anti-aging expert Everlight Chemical introduces the "Eversorb® Anti-UV-C Light Stabilizer" which is especially developed for polypropylene, effective in improving theweatherability of plastic products to UV-C light.



As shown in the graph below, the 3.2-mm polypropylene test sample of the control group and that of the group added with 0.5% of Eversorb® Anti-UV-C Light Stabilizer were each irradiated with a UV-C germicidal lamp (250 nm, 30W) for 400 hours. It could be observed that, after only 17 hours of irradiation, the color difference value of the control group's test sample had reached in excess of 6. Generally, the time for irradiating and disinfecting an environment with a UV-C germicidal lamp would be approximately 30 minutes. If we calculate based on a 17-hour period, it was roughly equivalent to 30 times of being irradiated by a UV-C germicidal lamp and then the product would manifest a color difference visible to the naked eye.



Then, we continued to do the test for 140 hours of irradiation. The color difference value of the test sample without light stabilizer added even exceeded 10, indicating an even more obvious color difference. After a testing period of 400 hours, the color difference value was as high as 15! It could also be clearly seen that the test sample had become severely yellowed.



On the other hand, the color difference value of the test sample added with Eversorb® Anti-UV-C Light Stabilizer could still maintain a value below 2.5 even after 400 hours of irradiation, with the polypropylene test sample retaining its original color. This demonstrates that Eversorb® Anti-UV-C Light Stabilizer can effectively improve the weatherability of polypropylene materials and solve the yellowing problem of plastic products when they are subject to UV-C irradiation.



“Labelling Free Light Stabilizer” for silane-modified sealants-Eversorb® HP5


In addition to yellowing and fading, UV-C irradiation could also cause chalking and cracking on the surface of plastic products. While being unsightly, the chalking and cracking may lead to damage or structure impairment of the product, which can even be a safety issue! Eversorb® Anti-UV-C Light Stabilizer not only keeps plastic products from discoloring, but also effectively reinforces their physical properties and improves their durability and safety.



As shown in the graph below, after 400 hours of irradiation by a UV-C germicidal lamp shining on the control group’s polypropylene test sample without light stabilizer added, visible cracks appeared on the surface, and the degree of gloss dropped significantly from its original of 85.8 to 50.8.



When we went one step further to observe the test sample under a microscope at a magnification of 20 times, it could be seen that numerous cracks had occurred on the surface, which would greatly affect the product’s appearance and safety. Comparatively, even after 400 hours of irradiation, the surface of the test sample added with Eversorb® Anti-UV-C Light Stabilizer still retained almost the same degree of glossiness as before the test, without cracking or chalking. When the surface was then observed under a microscope, it’s seen remaining as smooth and crack-free as before the test! This illustrates that Eversorb® Anti-UV-C Light Stabilizer not only solves the yellowing problem of polypropylene due to UV-C irradiation, but at the same time also prevents chalking and cracking, keeps products white and bright as new, and achieves the outstanding effect of sterilization and disinfection without damaging polypropylene, protecting the safety of users!



“Labelling Free Light Stabilizer” for silane-modified sealants-Eversorb® HP5




With the impact of the Covid-19 pandemic, people are paying more attention to environmental hygiene. UV-C germicidal lamps have thus seen a much wider application and been used even more frequently. However, many plastic products gradually become faded, chalky and brittle after being exposed to UV-C light. This problem affects the appearance and usability of such products.



Everlight Chemical continues to listen to its customers and develops products that meet market demand. That's why we've brought out Eversorb® Anti-UV-C Light Stabilizer to improve the weatherability of polypropylene materials, solve the problem of cracking caused by UV-C irradiation, and protect the attractive appearance, functionality and durability of plastic products. In this way, we can effectively increase the safety of products, extend their service life, raise their value, reduce resource waste, and achieve a green and sustainable future! Should you be interested in this, please do not hesitate to contact us



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