Test Results Summary: Zero Scratches After 2000 Rubs
The evaluation was conducted under severe conditions on a commercially available polystyrene plastic plate (confirmed to be scratch-free beforehand). A 1kgf load was applied, and a water-soaked sponge was rubbed back and forth. The surface was then observed for scratches using a scanning electron microscope (SEM).
“Melamine sponge,” “abrasive sponge,” “urethane sponge,” and “cotton gauze cloth” were used as comparative subjects in the tests.
Verification Result 1: Clear Differences in 1000-Rub Test
After rubbing 1000 times with common sponges and cloths, the following differences were observed:
-
Abrasive sponge and melamine sponge: Significant streak-like scratches were confirmed on the plastic plate surface.
-
Cotton gauze cloth: Although a soft material, the rubbing force was directly transmitted, causing fine scratches.
-
Second Sponge and urethane sponge: Almost no change from before the test; no scratches were confirmed.
Verification Result 2: Strength Proven in Extreme “2000-Rub” Test
For the urethane sponge and “Second Sponge,” which showed no scratches in the initial test, an extreme test of double the rubs (2000 times) was conducted.
-
Urethane sponge: Streak-like scratches appeared on the surface.
-
Second Sponge: Even after 2000 rubs, no scratches were observed at all.
Note on test results: Melamine sponges and abrasive sponges are cleaning products that remove dirt by “polishing (scraping).” The scratches generated in this test are due to their product characteristics and can be considered proof of their high effectiveness. For cloths and urethane sponges, the scratches occurred under extremely harsh, limit-testing conditions that would not typically occur in normal use. Since their usage scenarios and purposes differ, these results are not intended to evaluate the superiority or inferiority of the products. The “Second Sponge” is recommended for use in conjunction with these products, as its name suggests.
Safe Cleaning with “Second Sponge”
The results from this public institution test provide strong data to support the “Second Sponge’s” characteristic of “removing dirt without damaging the material.” This allows for safe use on delicate cooking utensils and during general cleaning.
Examples of applicable surfaces: This sponge can be used on scratch-prone materials such as enamel, plastic, stainless steel, iron plates, aluminum, ceramics, artificial marble, and acrylic aquariums, as well as on coated materials like fluororesin coatings and anti-fog glass/mirrors. It is also suitable for root vegetables (food sanitation law compliant).
“Second Sponge” Technology (Coil Fiber)
Microscopic images reveal that the “Second Sponge” possesses a special structure where very fine fibers are intertwined in a coil shape, unlike general sponges.
These fine fibers adsorb a large amount of dirt. Their shape minimizes sharp points, reducing the risk of scratching surfaces. The spring-like elasticity absorbs and disperses impact. This technology is what enables the sponge to effectively remove dirt without causing damage.
More detailed information, including comparisons of dirt removal effectiveness, is available on the official website:
https://kinousozai.co.jp/secondsponge.html
Trial Product Available for ¥1 (Shipping Extra)
-
A trial pack (5 sheets) is available for ¥1 (shipping extra) at the official Rakuten shop.
-
The regular 14-sheet product is also available for purchase.
- Official Kinousozai Shop (Rakuten): https://item.rakuten.co.jp/kinousozai/secondsponge/
Customers can verify the performance before making a larger purchase.
Available at Numerous Retailers
The product has launched in select home centers, supermarkets, and drugstores. It is also available online through Rakuten, Amazon, Yodobashi Camera, and other web stores. Updates on availability are continuously posted on the official Kinousozai Instagram page:
https://www.instagram.com/kinousozai.co/?hl=ja
“Second Sponge” Product Overview
-
Material: PET, PE
-
Size (per sheet): 120mm (height) × 50mm (width) × 5mm (thickness)
-
Contents: 14 sheets
-
Country of Origin: Japan (Food Sanitation Law compliant)
-
Awards: Grand Prize at the 67th Osaka International Gift Show “New Product Contest”
Company Overview
-
Company Name: Kinousozai Co., Ltd.
-
Location: 6-13 Hatsushiro-cho, Kochi City, Kochi Prefecture
-
Website: https://kinousozai.co.jp/
