As a new type of polymer elastic material, rubber sealing strips, as well as other glass cups and double-layer ceramic cup lid materials and sealing strips, are also preferred silicone foam materials. For portable coffee cups, the most worrying thing is whether there will be water leakage, ranging from wet clothes to heavy things that affect the entire bag, and may even be the culprit of damaging mobile phones, cosmetics and other things. The Starbucks coffee cups with silicone foam seals are seamless and have a strong sealing performance, so you don’t need to worry about coffee spills during use.