In open-pit mines, outdoor work sites, and high-altitude construction environments, conveying hoses are exposed to the combined erosion of strong ultraviolet radiation, high concentrations of ozone, and extreme temperature differences all year round. Under such working conditions, the surface of the ordinary rubber outer layer cracks, hardens, and even peels off within a few months, causing the reinforcement layer to be exposed and corroded, and the entire hose to be scrapped prematurely. UPE weather resistant outer hose is a professional solution for this long-term outdoor use demand - using EPDM/weather resistant synthetic rubber outer rubber to construct an ozone and UV resistant barrier, using UPE lining to ensure chemical inertness and super wear resistance, and using a three-layer composite structure to achieve long-term and reliable operation under all outdoor conditions. 1、 Outdoor 'invisible killer': synergistic aging mechanism of ozone and ultraviolet radiation In outdoor environments, the outer rubber layer of hoses faces two main aging threats. Ozone aging originates from ozone molecules in the atmosphere (usually at a concentration of 20-50 pphm), which react chemically with unsaturated double bonds in rubber molecular chains, cutting off the molecular chains and forming typical crack paths on the material surface. Ultraviolet aging breaks polymer molecular bonds through high-energy photons, triggering a chain reaction of free radicals, resulting in surface pulverization, loss of light, and increased hardness. More importantly, ozone and ultraviolet radiation have a synergistic acceleration effect - ultraviolet radiation causes microcracks on the surface of rubber, increasing the permeation area of ozone; Ozone further erodes the interior of microcracks, accelerating crack propagation. The chain reaction of "cracking first, then penetrating, and then degrading" causes the aging rate of outdoor hoses to be much higher than the accelerated aging test results under a single factor. Ordinary rubber often cracks, hardens, and ultimately fails within a few months to a year in such composite aging environments. The UPE weather resistant outer hose extends this aging process to several years or even more than ten years through the material system innovation of the outer adhesive layer. 2、 The 'weather resistant gene' of the outer rubber layer: the ozone and ultraviolet resistant system of EPDM/weather resistant rubber The outer rubber layer of UPE weather resistant outer hoses is generally made of EPDM synthetic rubber or special weather resistant synthetic rubber formula. The molecular backbone of EPDM is composed of saturated carbon carbon single bonds, without double bonds that are easily attacked by ozone, fundamentally endowing the material with excellent ozone resistance. In terms of UV resistance, the outer rubber layer formula incorporates UV absorbers and ozone resistant wax - UV absorbers absorb harmful UV light and convert it into heat energy for release, protecting the rubber body from photodegradation; Anti ozone wax slowly migrates to the surface of rubber, forming a physical protective film that blocks direct contact between ozone and rubber. Some products can also be equipped with various colors of outer glue such as red, yellow, blue, and black. High visibility colors are not only convenient for on-site pipeline identification, but light colored outer glue has higher UV reflectivity, which can further reduce surface heat accumulation and delay thermal oxidative aging. The actual test data of the product shows that the hose with weather resistant EPDM outer rubber does not crack after continuous exposure to 50pphm ozone concentration and 40 ℃ for 150 hours. Its UV resistance has passed the ASTM G154 standard test, and its outdoor service life can reach 3-5 times that of ordinary rubber. 3、 Three layer composite structure: Long life system integration for outdoor full working conditions The reliability of UPE weather resistant outer hose for long-term outdoor use is the collaborative result of the three-layer structure of "inner lining layer reinforcement layer outer adhesive layer". The inner lining layer is made of ultra-high molecular weight polyethylene (UPE), which is chemically inert and almost does not react with any oil or corrosive chemicals. It can maintain stable performance even in acidic mineral slurries or corrosive chemical media in mines; Its molecular level wear resistance mechanism reduces the wear rate to only 1/10 of ordinary rubber, avoiding the risk of "inner layer wear through causing the entire tube to be scrapped". The reinforcement layer is made of high-strength synthetic fiber weaving or steel wire winding structure, combined with a spiral steel wire skeleton design, to maintain structural stability of the hose in a wide temperature range of -30 ℃ to+100 ℃, while not collapsing under negative pressure suction conditions. The outer rubber layer is made of EPDM synthetic rubber that is ozone resistant, UV resistant, and wear-resistant. It effectively resists UV, wind and rain erosion, and mechanical collision damage in complex construction site environments such as outdoor exposure, dust and humidity, acid and alkali corrosion. The outer adhesive layer has both wear resistance and can handle the impact friction of ore fragments and the continuous wear of outdoor ground dragging with ease. In terms of installation and application, UPE weather resistant hoses are lightweight (only 1/5 of steel pipes of the same specification), with a small bending radius, allowing two workers to complete long-distance pipeline laying. The flexible pipe body design can adapt to the complex terrain and mobile operation needs of open-pit mines. To sum up, UPE weather resistant outer hose perfectly meets the systematic requirements of open-pit mines and outdoor operations for "anti-aging, long life and frequent replacement free" with its EPDM outer rubber anti ozone and anti ultraviolet barrier, UPE inner lining chemical inertia and super wear resistance, and outdoor full working condition adaptation of three-layer composite structure. From the cracking resistance of 50pphm ozone concentration to the long-term verification of ASTM G154 ultraviolet testing, from extreme cold flexibility at -30 ℃ to high temperature heat resistance at 100 ℃, every outdoor exposure to wind and sun points to the same goal: to provide reliable guarantees for fluid transportation that can withstand aging and wear in the operation site of mining gravel splashing, sun and rain.