28-400 neck, Flat Cap with Phenolic insert (Fits our 8oz bottles)

28-400 neck, Flat Cap with Phenolic insert (Fits our 8oz bottles) This 28mm black cap with a Phenolic cone insert. The Phenolic cone liner is made of LDPE and acts as a wedge insert that seals the lip and the inner neck of a bottle, providing extra protection from leakage. These are recommended for use on glass bottles, but can also work with plastic containers. Phenolic resin (Phenol Formaldehyde Resin - PF) is a durable thermoset plastic popular for its molding and physical assets. It is a result of a combined reaction between phenol and aldehyde. Known for its strength, heat, and chemical resistant abilities, phenolic resin is used to mold solids and is considered to be quite versatile, making it a good fit for a range of consumer and industrial products. Even though phenolic holds up well under certain levels of heat, phenolic caps will decompose at 220°C (428°F) or higher. Unlike other plastics, phenolic closures are capable of maintaining their form and attributes when exposed to corrosive chemicals. Phenolic caps are often used with containers that store chemicals and essential oils, making it an excellent choice for laboratories.