Rubber plugs seal holes/threads during firing and glazing, helping reduce cracking and contamination; afterwards they’re removed easily without marks.

Plastic shrinks with ambient temperature changes, seals poorly, and has low heat/chemical resistance. Rubber & silicone are elastic, seal tightly, damp vibrations, and offer long service life.

Store in a cool, dry place (15–25 °C), away from direct sunlight; keep in a ventilated, low-dust area with no ozone (avoid near electric motors, refrigerators, photocopiers, as ozone degrades rubber). Avoid contact with oils, gasoline, alcohol, organic solvents, or strong acids/alkalis, which cause swelling or degradation. For cleaning, use warm water with mild soap only, then air dry. For warehouses without climate control, occasionally soak in room-temperature water (36–38 °C), then air dry. Check every few months: if elasticity is lost, or the surface feels tacky or cracked, replace. For medical or food-grade plugs (e.g., bottle nipples, stoppers), recommended storage time is no more than 1–2 years. A light dusting of talc can prevent sticking. Do not store with rusting metal—moisture and metal oxides accelerate rubber deterioration.