𝐒𝐮𝐧𝐝𝐚𝐲'𝐬 𝐓𝐇𝐎𝐔𝐆𝐇𝐓𝐅𝐔𝐋 𝐏𝐨𝐬𝐭 : 𝐄𝐝𝐢𝐬𝐨𝐧 𝐃𝐢𝐝𝐧’𝐭 𝐉𝐮𝐬𝐭 𝐈𝐧𝐯𝐞𝐧𝐭 𝐭𝐡𝐞 𝐋𝐢𝐠𝐡𝐭 𝐁𝐮𝐥𝐛—𝐇𝐞 𝐄𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐞𝐝 𝐭𝐡𝐞 𝐏𝐫𝐨𝐜𝐞𝐬𝐬

𝐒𝐮𝐧𝐝𝐚𝐲'𝐬 𝐓𝐇𝐎𝐔𝐆𝐇𝐓𝐅𝐔𝐋 𝐏𝐨𝐬𝐭

𝐄𝐝𝐢𝐬𝐨𝐧 𝐃𝐢𝐝𝐧’𝐭 𝐉𝐮𝐬𝐭 𝐈𝐧𝐯𝐞𝐧𝐭 𝐭𝐡𝐞 𝐋𝐢𝐠𝐡𝐭 𝐁𝐮𝐥𝐛—𝐇𝐞 𝐄𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐞𝐝 𝐭𝐡𝐞 𝐏𝐫𝐨𝐜𝐞𝐬𝐬

Thomas Edison is not often appreciated as a production process innovator. The novelty of his inventions required new materials and processing technics to optimize performance. He was not the first to demonstrate an incandescent light bulb. But early prototypes used inappropriate filament materials and burned out in minutes.

Edison famously screened six thousand materials to select the optimal element. A carbonized filament of cotton thread first demonstrated the potential but burned out within hours. Eventually, carbonized bamboo fibers were selected for commercialization, demonstrating a 1200-hour life. 

Popular accounts neglect to mention his conditioning process. Most substances have tiny voids or occlusions in their internal structure. When current is applied, the minute traces of gas in these defects expand, damaging the fragile element and contaminating the bulb’s vacuum. Most of Edison’s competitors didn’t realize that trapped gas pockets were a key performance factor.

One of Edison’s teams concentrated on extending bulb life by preconditioning the elements under vacuum. The entrapped gases were coaxed out of the filament by slowly heating them with increasing levels of applied voltage as the off gassing was pumped out. Only then could they evaluate the relative merits of each candidate material and steadily increase service life.

At the same time, their colleagues developed the other essential elements of lighting technology and power distribution in parallel. Edison coordinated their efforts toward his overriding vision for a complete solution to replace gas lighting. Commercial sales started in ~ 1880. Not until 1904 did European innovators perfect tungsten filaments to replace the carbon version. In 1913, the physicist Irving Langmuir demonstrated that flushing the bulbs with an inert gas eliminated the need for vacuum.

Conclusion: Optimizing the processing conditions for new materials can drastically affect their performance in end-use applications. But novel materials must often be paired with other innovations to create a complete system. Follow-on innovators will discover ways to improve and disrupt the original inventor’s profit model.

source : Tim Oberle