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Tag: glass

The Double Steal — The Right and Wrong Way to Steal Trade Secrets

Bill Davidson

By Greg Stejskal
ticklethewire.com

It took about 5,000 years from the discovery of glass until a process was developed to economically mass produce flat glass, and only a few years before the technology was stolen.

Glass is one of the great fundamental inventions – not at the level of the wheel or fire, but up pretty high on the list. Glass is chiefly made from relatively common and inexpensive raw materials: sand, soda ash (sodium carbonate) and lime.

No one knows when glass was first invented or by whom. It does occur in nature when lightning strikes sand or sometimes from volcanic eruptions (obsidian). Its first use seems to have been as a glaze for ceramic vessels in about 3,000 BCE. It wasn’t until about 1,500 BCE that glass vessels were produced in Egypt (ultimately used to hold beer, one of my favorite inventions). The use of a pipe for blowing superheated glass wasn’t invented until circa 30 BCE.

Through the ages uses for glass have multiplied and are as diverse as flat glass to optical lenses which enabled the development of telescopes and microscopes. But this story is about the technology to produce flat glass, and why some people would go to great lengths to steal it.

Flat glass is used primarily for windows and doors on homes, buildings and vehicles. Until relatively recently there wasn’t an economical way to produce large quantities of quality flat glass.

Flat glass was originally made by blowing cylinders of glass that were cut open and flattened then cut into panes. Most window glass up until the early 1800s was made using the cylinder method. The cylinders were limited in size. They were 6-8 feet (2-3m) long and 10-14 inches (~30cm) in diameter, thus limiting the size of the panes that could be cut. Large windows had to be made of multiple panes.

In 1848 Henry Bessemer, an English engineer, designed a system that produced a continuous ribbon of flat glass by forming the ribbon of molten glass between rollers. This was an expensive process as the surface of the glass had to be ground and polished. This did overcome the size limitations of the cylinder method. Beginning in the 1920s, a continuous ribbon of glass was passed through a lengthy series of inline grinders and polishers, reducing glass loss and cost.

The major breakthrough in the production of flat glass didn’t come until the late 1950s. Sir Alastair Pilkington and Kenneth Bickerstaff of Pilkington Brothers, Ltd. in the UK developed the first successful commercial float glass process.

Bill Davidson

Float glass uses common glass-making raw materials. The materials are mixed with cullet (waste glass) in a furnace where it is heated to ~2,800 degrees F (1,500C). When the mixture becomes molten, it is allowed to pour onto a “tin bath,” a bath of molten tin about 2.3 inches (6cm) deep, 3-4 feet (3-4m) wide and 150 feet (45m) long.

The glass enters via a canal. The speed and volume of glass flow is controlled by a gate called a twill. The glass literally floats on top of the tin with uniform thickness. (The molten tin does not adhere to the glass, but an oxygen free atmosphere has to be maintained to keep the tin from oxidizing and adhering to the glass.) As the glass flows along the tin bath, the temperature is gradually reduced. At the end of the bath, the glass has cooled to approximately 1,100F (600C). At that temperature the glass can be lifted from the bath onto rollers. The glass ribbon is pulled by the rollers at a controlled speed. The speed at which the glass is pulled determines its thickness.

As the glass is pulled from the bath, it passes through a lehr (a type of kiln) where it gradually cools so that it anneals and does not crack from more rapid temperature change. After exiting the lehr, the glass is cut by machines.

Read more »

Stejskal: The Double Steal — The Right and Wrong Way to Steal Trade Secrets

Greg Stejskal served as an FBI agent for 31 years and retired as resident agent in charge of the Ann Arbor office.

Greg Stejskal

 
By Greg Stejskal
ticklethewire.com

It took about 5,000 years from the discovery of glass until a process was developed to economically mass produce flat glass, and only a few years before the technology was stolen.

Glass is one of the great fundamental inventions – not at the level of the wheel or fire, but up pretty high on the list. Glass is chiefly made from relatively common and inexpensive raw materials: sand, soda ash (sodium carbonate) and lime.

No one knows when glass was first invented or by whom. It does occur in nature when lightning strikes sand or sometimes from volcanic eruptions (obsidian). Its first use seems to have been as a glaze for ceramic vessels in about 3,000 BCE. It wasn’t until about 1,500 BCE that glass vessels were produced in Egypt (ultimately used to hold beer, one of my favorite inventions). The use of a pipe for blowing superheated glass wasn’t invented until circa 30 BCE.

Through the ages uses for glass have multiplied and are as diverse as flat glass to optical lenses which enabled the development of telescopes and microscopes. But this story is about the technology to produce flat glass, and why some people would go to great lengths to steal it.

Flat glass is used primarily for windows and doors on homes, buildings and vehicles. Until relatively recently there wasn’t an economical way to produce large quantities of quality flat glass.

Flat glass was originally made by blowing cylinders of glass that were cut open and flattened then cut into panes. Most window glass up until the early 1800s was made using the cylinder method. The cylinders were limited in size. They were 6-8 feet (2-3m) long and 10-14 inches (~30cm) in diameter, thus limiting the size of the panes that could be cut. Large windows had to be made of multiple panes.

In 1848 Henry Bessemer, an English engineer, designed a system that produced a continuous ribbon of flat glass by forming the ribbon of molten glass between rollers. This was an expensive process as the surface of the glass had to be ground and polished. This did overcome the size limitations of the cylinder method. Beginning in the 1920s, a continuous ribbon of glass was passed through a lengthy series of inline grinders and polishers, reducing glass loss and cost.

The major breakthrough in the production of flat glass didn’t come until the late 1950s. Sir Alastair Pilkington and Kenneth Bickerstaff of Pilkington Brothers, Ltd. in the UK developed the first successful commercial float glass process.

Bill Davidson

Float glass uses common glass-making raw materials. The materials are mixed with cullet (waste glass) in a furnace where it is heated to ~2,800 degrees F (1,500C). When the mixture becomes molten, it is allowed to pour onto a “tin bath,” a bath of molten tin about 2.3 inches (6cm) deep, 3-4 feet (3-4m) wide and 150 feet (45m) long.

The glass enters via a canal. The speed and volume of glass flow is controlled by a gate called a twill. The glass literally floats on top of the tin with uniform thickness. (The molten tin does not adhere to the glass, but an oxygen free atmosphere has to be maintained to keep the tin from oxidizing and adhering to the glass.) As the glass flows along the tin bath, the temperature is gradually reduced. At the end of the bath, the glass has cooled to approximately 1,100F (600C). At that temperature the glass can be lifted from the bath onto rollers. The glass ribbon is pulled by the rollers at a controlled speed. The speed at which the glass is pulled determines its thickness.

As the glass is pulled from the bath, it passes through a lehr (a type of kiln) where it gradually cools so that it anneals and does not crack from more rapid temperature change. After exiting the lehr, the glass is cut by machines.

Read more »

Feds Charge White House Shooter With Attempted Assassination of President


By Allan Lengel
ticklethewire.com

It wasn’t a classic assassination attempt.

Nonetheless, CNN reported Thursday that fed prosecutors charged an Idaho man accused of shooting at the White House with attempting to assassinate President Obama. The president was not at the White House at the time.

He is suspected of being responsible for two bullets found at the White House. One hit a bulletproof glass window.