UV protection test: sunshade wins sun protection cap

On August 5, 2016, samples were tested and the process was tested. Beijing News reporter Wang Jianing photo

The Beijing News (Reporter Li Tingting) Going out in the summer, holding a sunshade or wearing a sun hat has become a "difficult" choice for many women. In the end, is the sunscreen effect of the sunshade good, or is the sunscreen cap more powerful?

For the first time, the Beijing News reporter recently purchased four kinds of parasol samples (both professional sun protection umbrellas and sun umbrellas) and two kinds of sun hat samples (one type is wide and adjustable height). Sun protection caps, one type of sun protection cap with a duck tongue and a sunshade.

The reporter sent six samples to the Beijing Institute of Metrology and Measurement for testing, including UVB transmittance, UVA transmittance and visible light transmittance. Among them, UVB transmittance and UVA transmittance are two main data representing UV protection ability, and the lower the value means the better the sun protection effect.

The test results showed that the UVB transmittance of the four types of parasols was 0.0%, the UVA transmittance was 0.0% to 0.5%, and the visible light transmittance was also between 0.1% and 1.2%. Among the two types of sun protection cap samples, one type of sun protection cap has lower values ​​and better UV protection, but the UVB transmittance, UVA transmittance and visible light transmittance of the other sun protection cap are both around 18% to 23%. The value is significantly higher than other samples.

Experiment 1

4 kinds of umbrellas can basically "full block" UV

Experimental procedure: Four types of parasols were numbered separately to facilitate differentiation in experiments. Extend the four folding umbrellas and select a partial area on one side for inspection.

The UV-visible UVA transmittance, UVB transmittance, and visible light transmittance of each sample were measured using an ultraviolet-visible spectrophotometer to align the inspection instruments with the center of the selected umbrella surface.

Experimental results: The UVB transmittance was 0.0% in the four parasol samples. In terms of UVA transmittance, three of the samples had a UVA transmittance of 0.0% and the other sample had a UVA transmittance of 0.5%.

At the same time, the visible light transmittance of the four types of parasols is also below 2%, which are 1.0%, 0.1%, 1.2% and 0.8%, respectively.

Experimental analysis: According to experimental technicians, UVB transmittance and UVA transmittance are two main data representing UV protection ability, and two main factors that cause skin to "tanning" in sunlight.

In general, the UVB transmittance and UVA transmittance are below 5%, indicating that the sunscreen effect of the sample is better, and the lower the value, the better the sunscreen effect. From the results of this experiment, the UVB and UVA transmittances of the four parasol samples are all below 0.5%, which means that the UV rays can be completely blocked to prevent the damage caused by UV rays.

It is worth noting that the UVB transmittance, UVA transmittance, and visible light transmittance of one of the black umbrellas were 0.0%, 0.0%, and 0.1%, respectively. The experimenter said that the black fabric parasol not only completely blocks the ultraviolet rays, but also the visible light can be completely blocked.

Experiment 2

Sunscreen cap 1 kind of sunscreen effect is good 1 kind of "sunscreen"

Experimental procedure: Two types of sun protection cap samples were numbered and used separately. In the experiment, the wide-width adjustable sunscreen cap was selected to detect the area on the brim; for the sunscreen cap of the duck tongue-like shawl, the shawl for covering the face was selected for detection. The detection method of the UVB transmittance, the UVA transmittance, and the visible light transmittance is the same as the above-described method for detecting a parasol.

EXPERIMENTAL RESULTS: The UVB transmittance, UVA transmittance, and visible light transmittance of the flexible sunscreen cap were measured to be 0.0%, 0.2%, and 5.1%, respectively. The UVB transmittance, UVA transmittance, and visible light transmittance of the duck tongue-like shawl sunscreen cap were 18.4%, 19.5%, and 23.1%, respectively.

Experimental analysis: According to the analysis of experimental technicians, from the test results, the sunscreen effect of the loose sunscreen cap is obviously better than that of the duck tongue with a shawl, and the shawl can not block the ultraviolet rays, which is equivalent to “no belt”; The "duck tongue" above the hat is thicker and harder. It is not a sunscreen material. It is a physical cover and has a small cover area.

Expert statement

Sun protection caps have limited sun protection area

The optical experts of the Beijing Metrology Institute also reminded everyone that the current sunshade caps on the market are not the same because of their different shapes and materials. The sun protection area of ​​the sun protection cap is limited. When purchasing a sun protection cap, it is best to choose a hat with a good brand.

According to the expert, the sunshade area of ​​the umbrella is relatively wide and the sun protection effect is more comprehensive. In fact, today's sun protection technology is not difficult, and most parasols can effectively resist ultraviolet rays. If the girl is going out, if it is afraid of tanning, it is best to have a parasol or a rain umbrella. In addition, like a parasol, clothes with a certain thickness can also block ultraviolet rays.