Inspect where the projections meet the body
Projections bend during brushing, making their roots worth examining. Thin transitions or existing notches can concentrate stress. Buyers do not need complex calculations to request clear views of roots, edges and corners.
Initial softness and resistance to tearing are different properties. ASTM D624 addresses tear-strength testing of rubber and thermoplastic elastomers; it should not be treated as a finished pet brush’s service-life guarantee. ASTM’s D624 overview
Separate expected handling from extreme pulling
Sample review should include intended brushing and the actions used to clean the projections afterward. Compare photographs for cracks, missing projections or persistent deformation. If stronger pulling is also evaluated, record its purpose and conditions separately.
Cycles, force and acceptance criteria need agreement for the product. There is no universal number of repetitions proposed here, and an informal review is not a certification test. The objective is a repeatable check with an understandable decision rule.
Purchasing scenario: similar feel, different roots
Imagine two samples that feel similarly soft, but one has a visibly thin connection between projections and the base. Compare that feature and its workmanship under consistent conditions before asking for a harder brush overall.
If the concern is localized, discussing the transition may be more useful than changing the entire feel. Any improvement still needs sample confirmation. This is a development scenario, not a reported Zhongding test result.
Give Zhongding a focused brief
When discussing silicone pet products or a custom brush with Zhongding, specify what to preserve and what to improve—for example, retaining the soft contact feel while reviewing projection-root durability.
That is more actionable than “make it stronger.” A useful brief identifies the vulnerable area and asks for a clear way to assess it, rather than treating softness and durability as a simple either-or choice.