As heatstroke alert announcements have become almost routine, Japan's summers are getting hotter every year.
Among various countermeasures for the sweltering heat, more people are carrying parasols than before. Not only adult women, but also men and elementary school students can now be seen commuting with parasols.
How do parasols function to block heat and light? The focus here is on "SUMMER SHIELD®" from "TORAY INDUSTRIES INC." which boasts a high light blocking and UV cut rate of over 99% and can lower the perceived temperature by up to 4 degrees.
We spoke with Tatsuhito Kanda, the Section Manager of the Apparel Materials Section of the Sports & Textile Materials Business Department at Toray, to uncover the secrets behind this.
PROFILE
Tatsuhito Kanda
Section Manager of Apparel Materials, Sports & Textile Materials Business Department
Joined the company in 1994. Responsible for linings, life materials, and sportswear fabrics. After a stint in Shanghai, reappointed to the current department as a linings specialist. In current role since 2021.
Surviving the Sweltering Summer
Was there a predecessor material to "SUMMER SHIELD®"?
A similar material is the waterproof and breathable brand "Dermizax®." This is a laminated material that combines waterproof and breathable properties for sports and outdoor activities.
In contrast, "SUMMER SHIELD®" mainly focuses on heat and light blocking, along with waterproof performance.
When did the development of "SUMMER SHIELD®" begin?
The development was initiated due to global warming in Japan. Terms like "scorching heat" and "sweltering heat" became common around 2007. We began to think about creating something that could be used comfortably even in midsummer, and started development in 2010.
In the summer of 2011, we sold about 5,000 parasols using "SUMMER SHIELD®" in department stores as a test sale. Despite being in the midst of summer sales and having a high price range with no discounts, they sold out in about one to two weeks.
Based on these results, we began full-scale development and sales in 2012.
High-priced parasols became a huge hit
What are the major differences compared to similar products from other companies?
It's the simultaneous manifestation of three functions: heat blocking, light blocking, and high UV cut rate. Before the introduction of "SUMMER SHIELD®," only one or at most two of these functions could be combined.
The traditional method for manufacturing parasols was "coating." Resin was thinly applied on the fabric, but with repeated folding, the coating would peel off from the creases, allowing UV rays and sunlight to penetrate.
However, our laminated method creates a film that is applied to the inside of the umbrella. This is a groundbreaking technology, which is why it can simultaneously offer all these functions.
The Secret Behind Over 99% Light Blocking & UV Cut Rate
Can you explain the mechanism of the "special 3-layer laminated structure"?
This three-layer structure refers to the completed state of the fabric.
The first layer is polyester, corresponding to the usual parasol fabric. It repels rain and moderately blocks sunlight. The second layer contains white titanium oxide, which blocks infrared rays. The third layer contains black carbon black, which blocks UV rays and absorbs the remaining infrared rays to fully protect the user.
Are there any drawbacks to having a three-layer structure?
From the beginning, there were concerns that parasols, which already use thick fabric, would become heavier and more difficult to handle due to the added layers.
We worked closely with umbrella manufacturers to develop lighter versions without compromising the performance of "SUMMER SHIELD®." While the laminated process applied to the inside of the umbrella might make it slightly harder to fold, we believe the benefits far outweigh this.