AND ANSWERS GRADED A+
✔✔properties of glass - ✔✔density 2.5 g/cm^3
low permeability
smooth surface
brittle
low conductivity (heat)
moderate thermal expansion
chemically inert
transparent
high tensile strength
✔✔brittle - ✔✔easy to break/shatter
- broken bottle can be reassembled into the original shape
✔✔devitrification - ✔✔tendency of glass to revert into a crystalline or organized
structure
✔✔devitrification happens when - ✔✔glass is at a high temperature for too much time
- can appear milky
✔✔desired properties of glass - ✔✔easy to melt
easy to fine
low viscosity
✔✔glass is made of - ✔✔silica sand (68 - 73%)
limestone (10 - 13%)
soda ash (12 - 15%)
✔✔fining agents - ✔✔help eliminate bubbles by making bubbles (CO2)
ex: sulfate and carbon
- sweep up bubbles as they move to the top
✔✔decolorizers - ✔✔add colors to glass to offset natural colors
- selenium (pink) to offset iron (green) = clear
✔✔colorizers are usually - ✔✔metal oxides
✔✔goal of colorizer - ✔✔help companies color the glass to make it unique
✔✔colorizers can be added - ✔✔in forehearth
to melt furnace
,✔✔3 main colors of glass produced - ✔✔flint
amber
emerald
✔✔colorants (Frits) are usually added to - ✔✔flint glass
✔✔nonstandard colors usually cost - ✔✔5% upcharge
✔✔most popular glass used in packaging - ✔✔flint
✔✔second most popular glass used in packaging - ✔✔amber
✔✔amber glass - ✔✔produced from iron, sulfur, and excess carbon
protects against the light
made from reduced process - less oxygen
✔✔green glass is made by adding - ✔✔chromium oxide
✔✔the color Georgia green was invented by - ✔✔the Coca Cola company
✔✔what color glass is the most powerful? - ✔✔cobalt blue
✔✔addition of boron reduces - ✔✔thermal expansion of glass
✔✔black and red glass are made from what process - ✔✔striking
✔✔cullet - ✔✔recycled broken or waste glass
✔✔plant cullet - ✔✔glass from defects or testing
✔✔ecology cullet - ✔✔post consumer glass
✔✔the usage of cullet in glassmaking lowers - ✔✔energy consumption
✔✔The FDA denotes glass as the only packaging material that is - ✔✔GRAS -
generally recognized as safe
✔✔pharmaceutical glass has the highest __________ requirements - ✔✔purity
✔✔Ampuoles - ✔✔can only be used once - opened by breaking
used mainly for pharmaceuticals and drugs
✔✔vials - ✔✔can be used many times
, used mainly for pharmaceuticals
- syringes can draw the product out
✔✔Type 1 pharmaceutical glass - ✔✔has most stringent extractable standards and
leaches the least
highest melting point
differentiating factor: what is put into it
✔✔Type 2 pharmaceutical glass - ✔✔treated in annealing oven with sulfur
treatment produces discolored appearance
differentiating factor: the way it is treated
✔✔Type 3 pharmaceutical glass - ✔✔has been tested and shown to have specified
extractives level
- when soda lime doesn't meet its qualifications it is classified as this
shown to have specific leaching levels
✔✔USP - ✔✔United States Pharmacopeia
- set strict limits on amount of chemicals that are allowed to leach
✔✔4 steps of glass manufacturing processes - ✔✔Glass manufacture
forming operations
annealing
secondary operations
✔✔batch weighing accuracy - ✔✔1/500
✔✔major impurities in glass sand are attributed to - ✔✔aluminum oxide
iron oxide
✔✔glass recipe can __________ by batch - ✔✔vary
✔✔three types melting units - ✔✔clay pots
day tank
continuous tank
✔✔clay pot melting unit - ✔✔can be open or covered
used for special glasses and small quantities
✔✔continuous tank melting unit - ✔✔used for container glass
high output
✔✔all materials are _________________ in molten glass - ✔✔soluble