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Hello, this is the development team.
Currently, Brain Sleep offers the "Brain Sleep Comforter All Seasons," a thin comforter that can be used comfortably year-round. However, given the successive heatwaves in recent years and the soaring electricity prices, we wanted to create the "ultimate cooling comforter" to make summer nights comfortable, responding to social phenomena like rising temperatures and increased awareness of energy saving.
Today, I'd like to tell you about the "Brain Sleep Comforter Perfect Cool," born from this desire.
From the obvious thought of "it's hot if you use a comforter" to a revolutionary idea
The concept for the "Brain Sleep Comforter Perfect Cool" began in the spring of 2022. Although it wasn't hot yet when planning and development started, thinking back to the previous summer, I realized that discomfort from the heat was the primary factor degrading sleep quality.
Furthermore, when nationwide electricity conservation became necessary due to the Great East Japan Earthquake, cooling bedding sold out. This year, with electricity prices skyrocketing, we anticipate a similar situation, which reinforced the need for cooling bedding.
Most cooling bedding items are primarily fitted sheets. One reason for this is the common idea that "it's hot if you use a comforter," leading many people to use a towel blanket or sleep without any covers. However, at Brain Sleep, we intentionally developed the comforter as the main item, with a mattress sheet and pillowcase as secondary items.
By making the comforter cool, we wanted to create a comforter that would be cooler to use than not using one, while also protecting the body from the cold air of the air conditioner.
Key points are "ultimate coolness" and "coolness that lasts until morning"
The mechanism of cooling bedding is that when the body comes into contact with the fabric, the fabric absorbs the body's heat, creating a cool sensation. However, there's a limit to how much heat the fabric can absorb. Once saturated, the fabric becomes lukewarm, leading to stuffiness. Therefore, development of the "Brain Sleep Comforter Perfect Cool" focused on "ultimate coolness" and "coolness that lasts until morning."
1: "Ultimate Coolness"
There's an index for contact coolness called "q-max (maximum heat absorption rate W/㎠)," and the higher the q-max value, the cooler it feels upon contact with the body.
Items with a value of 0.2 or higher are generally referred to as "cooling bedding." 0.3 is moderately cool, 0.4 provides a distinct coolness, and 0.5 is said to offer a surprising level of coolness.
Since concrete is said to have a value of about 0.6, a q-max value of 0.5 for cooling bedding is considered the limit. To truly be "ultimately cool," our goal was to exceed 0.5.
Also, common cooling bedding typically falls into two types: one where cooling properties are added with chemicals after weaving the fabric, and another where natural mineral components are kneaded into the fabric to create a cooling material. However, both types have the challenge that their cooling sensation diminishes with repeated washing or over time.
What I wanted to create was a material that fully utilizes the inherent cooling properties of fibers to maintain coolness.
So, I consulted with factories and suppliers, repeatedly making improvements to see if it was possible to create a single thread using a special method: a polyethylene core covered with cooling nylon.
After much refinement, we finally arrived at an ultra-fine microfiber yarn, woven with approximately 100 fibers within a single strand.
Since we were able to create a cooling fabric by utilizing the inherent coolness of the fibers themselves, the cooling sensation of the fibers does not diminish even after repeated washing. Therefore, as long as the material itself does not deteriorate, the coolness can be maintained for a long time. This allowed us to achieve a q-max value of 0.524.
Achieving ultimate coolness was a non-negotiable point, so last summer, I personally tested about 30 prototypes at home. I believe the factory staff were also incredibly dedicated. Thank you very much.
2: "Coolness that lasts until morning"
The only material that can maintain reliable sustained cooling is "PCM," developed for space suits. Space experiences extreme temperature fluctuations, so this material was developed with temperature-regulating technology to adapt to such conditions.
Most common sustained cooling bedding applies PCM by printing it onto the cooling fabric, but this creates irregularities in the fabric, resulting in a poor feel against the skin. Some products print it on the reverse side to avoid this, but that makes the fabric stiff and still not pleasant to the touch.
Therefore, I consulted with the factory about applying PCM to the batting instead of the surface fabric. By kneading microencapsulated PCM into Tencel, a moisture-absorbing material, we were able to achieve sustained cooling without compromising the fabric's texture.
As an aside, I test all prototypes and other products to inform product development. I have a thermometer and hygrometer by my bedside. When I tried an early prototype (without PCM batting) in a 27-degree Celsius bedroom, I could sleep comfortably for about 20-30 minutes, but then it started feeling lukewarm. Compared to the finally completed "Perfect Cool," I definitely felt the weakness in the sustainability of the coolness (laughs).
To ensure you can use it for as long as possible
Although we are confident that this is an ultimately cool comforter, we paid attention to every detail in its design to ensure it can be used for as long as possible.
So you can use it from the rainy season, not just summer
Many general cooling bedding products are designed for use from July to September, meaning you can only comfortably use them for three months after purchase. However, customers actually struggle from the humid rainy season in May-June, through summer, and into early autumn in October when the weather is unpredictable. Therefore, we created a reversible structure with different functions to allow for seasonal use.
You can switch between the dry side, which uses a fabric with excellent water absorption and diffusion, for the rainy season in May-June and early autumn in October, and the cool side, which uses a contact cooling fabric, for the hot period from July to September.
Cooling fabrics often use polyester or nylon, which results in a slippery feel. The "Brain Sleep Comforter Perfect Cool" achieves a smooth, silky feel and fabric durability by using a special weaving method for the approximately 100 fibers made of polyethylene and nylon that I mentioned earlier.
Additionally, the dry side employs an optimal weave for absorbing and diffusing sweat, providing a comfortable, mesh-like feel.
To ensure it can be kept clean even during sweaty seasons
General polyester batting is not water-absorbent and floats in the washing machine, so only the surface can be washed, posing a risk of dust mite infestation. To avoid this, we use hydrophilic batting, allowing the batting itself to be thoroughly washed.
The ultimate comforter to free you from restless summer nights
We have successfully created the "Brain Sleep Comforter Perfect Cool," a product that we confidently believe is number one among cooling bedding on the Japanese market, by combining contact cooling fabric, PCM-treated batting, hydrophilic batting, and water-absorbent and diffusing fabric into a 4-layer structure with a thickness of approximately 1.5 cm.
It possesses all the necessary features for the restless season, so we highly recommend it to anyone struggling with sleep during the rainy season or summer.
Information
Brain Sleep Comforter Perfect Cool
The Brain Sleep Comforter Perfect Cool incorporates innovative temperature control technology developed for space suits. Its unique microcapsules undergo a phase change from solid to liquid in response to temperature fluctuations, maintaining a sustained cooling sensation.
Feature 1: 260% more cooling! Achieves ultimate coolness with special cooling fibers.
Seeking ultimate coolness, we developed the yarn and fabric from scratch. With a contact cooling value of 0.524 (q-max maximum heat absorption rate W/㎠), it achieves ultimate coolness. *Cooling value approximately 260% of the contact cooling (q-max: W/㎠) standard of 0.2
Feature 2: Coolness that lasts until morning with space technology PCM
The comforter's fibers are infused with microencapsulated PCM, an innovative cooling technology developed for space suits. In typical contact cooling bedding, the cooling effect diminishes once the absorbed heat reaches saturation.
The Perfect Cool's cooling sensation regenerates and sustains itself as the body moves away from the comforter during sleep, such as when tossing and turning.
Feature 3: Comfortable dry side for humid seasons, reversible structure
For the sweaty rainy season, the reversible dry side faces the skin. It absorbs and diffuses sweat, providing comfortable and dry control. It can handle all restless seasons from the rainy season to mid-summer.
Feature 4: Thorough cleaning of the comforter's interior
The insulation uses hydrophilic batting. Since the interior of the comforter is more likely to harbor dust mites than the surface, the highly hydrophilic batting allows for thorough cleaning of the interior.
