Medicine Rubber Stopper, as a glass bottle sealing plug or cover, which made from different silicon & rubber materials by compression tooling or injection molding. Common Medicine Rubber Stopper materials: Butyl Rubber, like Bromobutyl Rubber Stopper and Chlorobutyl Rubber Stoppers.
Butyl rubber is also called IIR, “short for Isobutylene Isoprene Rubber”. Butyl rubber has good performance of chemical stability and thermal stability, the most prominent among which is the air tightness and watertightness. Its air permeability is only a 1/7 of natural rubber, and 1/5 of styrene butadiene rubber, while the vapor permeability is 1/200 of natural rubber, and 1/140 of styrene butadiene rubber 1/140. So it is mainly used for manufacturing various inner tubes, steam pipes, water tires, dam bottom and gaskets and other rubber products. Medicine Bottle Medical Grade Silicone Stoppers Silicone Stoppers only react with strong alkali or hydrofluoric acid, not dissolves in water or other materials, non-toxic and odorless, stable chemical properties, good thermal stability, and higher mechanical strength. Silicone Stoppers also can up to FDA USP class 6 Medical Grade.
Notes: Silicone materials stoppers have high absorbing capacity, which not suit to all medicine bottle stoppers .
Other Medicine Bottle Stopper Materials 1. Natural Rubber Stoppers: High levels of impurity ( Protein ), Quality varies, natural rubber latex is allergic, no suit to produce medicine bottle stoppers. Not recommend 2.Synthetic Polyisoprene Rubber Stopper: Poor Air tightness and need sulphur vulcanization make the use of the limitation. Not recommend