Cars are essential for our daily travel
In recent years, as people are more and more conscious of energy-saving and environmentally friendly options, many automobile manufacturers utilize LED car lights to replace the traditional halogen lights. Throughout long-time usage, due to multiple different circumstances such as:
- Car Washes
- Temperature Differences
- Vehicle Wading
The water vapor enters the car light through the gaps and the lights would become foggy. Traditional halogen lights release heaps of heat when turned on so that the moisture inside the lights is dried to prevent fog. However, LED lights are energy-saving and have low power consumption, thus they cannot generate enough heat to dry the moisture inside of the car light. When the car owners encounter this issue and go to the dealers to solve this problem, the dealers will replace theses car lights with new ones, and return those lights as defect products to manufacturers. The large amount of returned car lights is now an urgent problem for car manufacturers.
An automobile light manufacturer came to WiseSorbent® R&D center to ask for a professional solution.
They wanted to use a desiccant to absorb moisture inside of the light to prevent fogging. The following are the requirements for the automobile light desiccant:
- Prevent condensation inside of the car lights. Keep the condition inside the lights under 25℃, RH40%
- When the car light releases heat, the moisture absorbed by the desiccant would not be released back out
- Service life: 3 years
After our R&D team received this request, they made the following analysis
As in this case, the usage environment in a long-term high temperature environment, traditional physical desiccant (such as silica gel, montmorillonite) is not applicable, because this type of desiccant releases moisture it absorbed when heated. Therefore, they recommend using the desiccant specially designed for car lights. This form of desiccant does not easily release moisture under high temperature, while having a strong moisture absorption capability (up to 200%), which makes it possible to prevent fogging inside the car lights effectively.
Based on the customer’s requirement, R&D team utilized the calculation model for desiccant dosage in airtight barrier packaging in “DIN55474 desiccant bag, application, calculation for necessary dosage”:
The result is n=8.42g, the desiccant needed is 8.42g. We recommended the customer to use the 10g desiccant for auto light.
After the specs of desiccant were confirmed, R&D team conducted a (raining-day model and night-model) simulation test on left and right light with the desiccant inserted to observe the fogging condition inside and outside of the car light. The light was exposed to a high humidity environment (20℃, RH80%) for 150min and kept the light off (day-model) or on (night-model). They sprayed water to the surface of car light for 60 mins and observed the fogging status immediately. Here is the validation for both models:
|1||Set test environment:||Set the environment to (20±1)℃, (80±5)%RH, and wait until the above temperature and humidity condition shown on the temperature and humidity meter become stable.|
|2||Pre-process the test sample:||Place the test sample under (20±1)℃, (80±5)%RH for 150 mins.|
|3||For the day-model||place the test sample on test holder, adjust the location of the simulated sunlight to have the test sample exposed to the simulated sunlight. Keep the automobile light off.|
|4||For the night-model||place the test sample on test holder, adjust the location of the blue light to have the test sample exposed to the blue light. Keep the automobile light on.|
|5||Spray||Spray water evenly on the surface of the light. Spray the sample for 60 mins. The water temperature: (28±1)℃, and constant temperature; water amount: 2-3 L/min.|
|6||Observe||After spraying, observe the status of the car light from 1 m away immediately.|
Validation result: No fogging on either left and right light, day-model and night-model.
According to the validation result of a desiccant for automobile light, we are able to conclude that this type of desiccant meets the requirements of high temperature resistant and long usage life. It is able to prevent fogging in both left and right light, day-model and night-model, which meets the customer’s requirement completely.
During the usage life of an automobile light, which utilized our high-performance desiccant, had no fogging occur afterward
After the customer applied our high performance desiccant in their automobile light and launched the light into the market, they did in-depth follow-up and interview and found that during the usage life of an automobile light, which utilized our high-performance desiccant, had no fogging occur afterward. Therefore, returns due to fogging in the lights was reduced greatly, customer service cost was also dramatically saved. They customer saved a great deal of money, thanking WiseSorbent® for the solution, and evaluated us highly for our R&D capability and level of expertise. This customer then cooperated with us in other automobile case for desiccant solutions and became our long-term partner.