Between the heavy rain and the umbrella's "seams."

As the end of the rainy season approaches, we often encounter intense downpours, as if a bucket has been overturned. For those of us involved in umbrella design, this season brings a special sense of tension. This is because we receive an increasing number of inquiries from customers who say, "Rain is leaking from my umbrella."

It is truly regrettable to imagine the disappointment of droplets falling inside an umbrella that was meant to protect you from the rain.

However, whether such "leaking" is a product defect is actually a very difficult gray area to determine. This is because umbrellas are "sewn products" made by sewing fabric together with "needle and thread."

The reason behind the phenomenon of rain leakage

No matter how excellent the fabric is in terms of water repellency and waterproofness, there are invisible tiny gaps in the "seams" where the needle pierced the fabric. In normal rain, the tension of the fabric and the expansion of the thread can prevent rainwater from entering, but with heavy rainfall, water can seep out from these microscopic gaps.

In the umbrella industry, there is a test standard called "leakage resistance" to measure product quality. This checks whether water leaks inside the umbrella in an environment of "20mm of rain per hour." In the industry, rain exceeding this amount is defined as "heavy rain."

＜The test is conducted with this intensity of rain＞

In fact, it is not uncommon for umbrellas that customers report as "leaking" to be tested by specialized inspection agencies and determined to be "no abnormalities." With current technology, it is difficult to completely prevent all heavy rain as long as umbrellas are sewn with needle and thread.

The blind spot of shower water pressure

We often hear comments like, "Water leaked when I held it under my home shower." We understand your feelings very well, but there is actually a big blind spot here.

The water pressure of a typical household shower is approximately 20 to 60 times higher than actual rain, and depending on the strength of the shower and the distance it is applied, it can even reach close to 100 times higher. Therefore, even if water leaks when held under a shower, it cannot immediately be concluded that it is a defective product.

To spend the rainy season comfortably

Understanding the characteristics of umbrellas and providing a little care can help make going out on rainy days more comfortable. Please keep the following points in mind to get through the heavy rainy season:

• For folding umbrellas, check that the "tip (ishizuki)" is not loose (a loose tip can cause rain to run down and leak).
• Avoid reusing the umbrella before the fabric is dry (fabric that contains moisture temporarily has weaker water repellency and absorbs water easily, making it more prone to leaking).
• Be aware that "on days with heavy rain, a little water may seep through the seams."
  

We are constantly improving our designs, aiming for beautiful umbrellas that can withstand any rain. We hope that by correctly understanding the structure of umbrellas, you can spend time comfortably with your favorite umbrella on rainy days without excessive worry.