Types of glass used in glass bottle production

Writer： admin Time：2022-06-08 10:39 Browse：℃

Glass bottles are classified by the United States Pharmacopeia (USP) according to chemical durability.

Types of glass include:

Type I - Borosilicate Glass (also known as Pyrex)
Type II - Treated Soda-Lime Glass
Type III - Soda-Lime Glass or Soda-Lime-Silica Glass

Type III is the most common type of glass bottles.
Type I is the most durable glass.

Type III - Soda-Lime Glass

Type III soda-lime glass is a silica glass containing alkali metal oxides. Soda-lime glass exhibits moderate chemical resistance and moderate hydrolytic (water) resistance. Soda-lime glass is inexpensive, chemically stable, and ideal for recycling as the glass can be re-melted and re-formed multiple times.

Type III glass is commonly used for beverages, foods and pharmaceutical preparations.

Type III glass is not suitable for autoclaved products because the autoclaving process will accelerate the glass corrosion reaction. Dry heat sterilization processes are typically not a problem for Type III containers.

Amber glass is created by the addition of iron oxide. Amber glass is formulated to absorb light in the ultra violet region of the electromagnetic spectrum and is used to package light sensitive products
 

Type I - Borosilicate Glass (also known as Pyrex)

Type I Borosilicate glass offers the best resistance to thermal shock and also superior chemical resistance. This class of glass represents the least reactive glass containers available. Type I glass offers superior durability, chemical and heat resistance. It is commonly used for chemical laboratory equipment.

Borosilicate glass contains a significant amount of boric oxide, aluminum oxide, and alkali and/or alkaline earth oxides. Borosilicate glass has a high hydrolytic resistance due to the chemical composition of the glass itself.

Typically, this glass can be used for most applications, including packaging for parenteral (injectable) and non-parenteral products. Type I glass may be used to package acidic, neutral and alkaline products. Water for injection, un-buffered products, chemicals, sensitive products and those requiring sterilization are commonly packaged in Type I borosilicate glass. Type I glass can be subject to chemical attack under certain conditions, thus container selection must be made carefully for very low and very high pH applications

 

Type II - Treated Soda-Lime Glass

Type II glass is type III glass which has been surface treated to improve the hydrolytic stability from a moderate to a high level. Type II glass containers are suitable for acid and neutral preparations both for parental and other use.

The outer surface of glass containers may also be treated to reduce friction or for protection against abrasion or breakage.

Test methods and specification limits for determining the chemical resistance of glass can be found in the current revision of the U. S. Pharmacopeia, section: Containers - Glass