Ignition of aluminum dust to blame for Pegatron blast
The recent explosion at one of Pegatron's Shanghai subsidiaries was reportedly caused by the ignition of aluminum dust, and occurred under similar conditions as another deadly blast at a Foxconn plant earlier this year.
It was reported on Tuesday that an investigation by China Labor Watch (CLW) found aluminum dust produced by the polishing of iPad cases as the cause of a blast at Ri Teng Computer Accessory Co., which injured 61 workers on Dec. 17, according to Bloomberg.
CLW, a not-for-profit labor organization, noted that the recent explosion at Ri Teng was similar to that of an accident at Apple supplier Foxconn's Chengdu factory. In both cases, the blasts were located in a section of the factory that handles the polishing of the iPad's aluminum chassis.
The source of the Foxconn accident was never conclusively established, however Apple's largest Chinese manufacturer said it was probably "combustible dust" that caused the explosion that left 3 dead and 15 injured.
It is unclear whether the accidents are related or merely coincidental, however CLW alludes that the events could be part of a larger supply chain problem, and claim that Apple suppliers have little control over their operations as they must adhere to strict guidelines set by the Cupertino, Calif. company.
Interviews conducted by CLW with factory managers reveal that the tech giant has "systematic control" over plant operations, including the design and implementation of the assembly line. If all of Apple's Chinese suppliers' plants have identical layouts, the recent explosions could point to a fundamental flaw in the supply chain.
However, CLW fell short of saying the the Ri Teng iPad polishing facility was a replica of Foxconn's, saying only that both factories were in the process of "expanding their production capacity and trying to win more orders from Apple when the blast occurred."
According to a post on the Sina Weibo microblogging service, local officials in the Songjiang area of Shanghai have already begun an investigation at Ri Teng, though the government has yet to release a preliminary report.
It was reported on Tuesday that an investigation by China Labor Watch (CLW) found aluminum dust produced by the polishing of iPad cases as the cause of a blast at Ri Teng Computer Accessory Co., which injured 61 workers on Dec. 17, according to Bloomberg.
CLW, a not-for-profit labor organization, noted that the recent explosion at Ri Teng was similar to that of an accident at Apple supplier Foxconn's Chengdu factory. In both cases, the blasts were located in a section of the factory that handles the polishing of the iPad's aluminum chassis.
The source of the Foxconn accident was never conclusively established, however Apple's largest Chinese manufacturer said it was probably "combustible dust" that caused the explosion that left 3 dead and 15 injured.
It is unclear whether the accidents are related or merely coincidental, however CLW alludes that the events could be part of a larger supply chain problem, and claim that Apple suppliers have little control over their operations as they must adhere to strict guidelines set by the Cupertino, Calif. company.
Interviews conducted by CLW with factory managers reveal that the tech giant has "systematic control" over plant operations, including the design and implementation of the assembly line. If all of Apple's Chinese suppliers' plants have identical layouts, the recent explosions could point to a fundamental flaw in the supply chain.
However, CLW fell short of saying the the Ri Teng iPad polishing facility was a replica of Foxconn's, saying only that both factories were in the process of "expanding their production capacity and trying to win more orders from Apple when the blast occurred."
According to a post on the Sina Weibo microblogging service, local officials in the Songjiang area of Shanghai have already begun an investigation at Ri Teng, though the government has yet to release a preliminary report.
Comments
It was reported on Tuesday that an investigation by China Labor Watch (CLW) found aluminum dust produced by the polishing of iPad cases as the cause of a blast at Ri Teng Computer Accessory Co., which injured 61 workers on Dec. 17, according to Bloomberg.
I think things are OK. It doesn't sound like it will affect Apple's stock price.
CLW alludes that the events could be part of a larger supply chain problem, and claim that Apple suppliers have little control over their operations as they must adhere to strict guidelines set by the Cupertino, Calif. company.
I seriously doubt Apple specifies inadequate ventilation in the facility. If they are expanding their production line capacity, they need to expand the rest of the facility to support that capacity. Are they simply cramming too much capacity into too small a space?
That said, if there's enough dust in the air to explode, kinda makes you wonder what the workers are inhaling. Those in the immediate vicinity may be wearing breathing protection, but what about elsewhere?
Me wonders if someone was trying to do something on the cheap without Apple's blessing so they didn't have to filter as much water in and process hazmat lubricant out of the plant. That way they could "skim" a little extra profit on the contract.
Aluminum dust is damn dangerous as all us high school chemistry students know all too well. A few rusty iron filings, an ignition source and you have a thermite reaction. I cracked my dad's garage floor when I was 13 testing this out. It is also highly probably the Hindenburg's dramatic end was caused by being painted with the basic ingredients for this reaction.
Nothing like a bit of thermite to get the day started. Good point, you have to wonder about the whole production chain in that regard, even the unibody case construction would create small particles of aluminum.
From the first reading of unibody I wondered what apple was doing with all the waste, if they were collecting it and reconstituting it to optimize raw material usage. I imagined some extraction process which loosely sucked up the dust and filings to a vat.
Aluminum dust is damn dangerous as all us high school chemistry students know all too well. A few rusty iron filings, an ignition source and you have a thermite reaction. I cracked my dad's garage floor when I was 13 testing this out. It is also highly probably the Hindenburg's dramatic end was caused by being painted with the basic ingredients for this reaction.
This would not have been a thermite reaction - just the simple oxidation of fine, suspended aluminum particles by atmospheric oxygen. Thermite reactions are essentially solid-state, gasless processes that produce little or no blast/overpressure, whereas this has air as a working fluid and a highly exothermic reaction to drive it.
*Few months later*
Apple - we will vow to improve our factory conditions.
Apple never learn.
Apple - we will vow to improve out factory conditions.
*Few months later*
Apple - we will vow to improve our factory conditions.
Apple never learn.
these aren't Apple's factories so they have limited control. They make a demand, they are told it is being met, they have to take that as honest until they have proof otherwise. And even then they have limited control since they don't own the factories and they are in a foreign country
I agree that no matter what Apple's specifications are for the final product - they certainly and simply cannot be specifying the overall conditions under which those finished products are being met - unless Apple designed the facility and the tools used and stipulated air flow rates and filter pore sizes etc then claiming this is in any way Apple's fault is just ridiculous.
For example, fine dust with a high surface area to volume ratio, particles less 500 micrometres in diameter, creates the perfect atmosphere for ignition as rapid oxidation requires large surface area (as provided by the fine dust particles, an oxidating agent (air) and an ignition point. Many industries that have dust as a by-product are vulnerable to explosions like this: grain handling, flour milling, sugar processing, powered milk processing, coal mining and wood processing to name a few are all target processes that can generate dust explosions. Coal mines are supposed to have dust control mechanisms in place to control dust due to additional other volatiles that can occur in the mining process.
There have been several spectacular explosion events in the history of flour milling as well - including the Great Minnesota Mill Disaster in 1878 that destroyed the Washburn Mill A structure on the Mississippi River in downtown Minneapolis, killing 18 mill workers in the process. And I have witnessed first hand (thankfully from a distance) a grain elevator explosion from dust ignition - it torn off the roof of the elevator and extensively damaged the entire structure.
This link shows a test of something really benign - custard power being ignited in the lab:
video demo
Ironically perhaps they could learn something from the fireworks industry in China - which has been using and managing fine metallic dust for firework effects for centuries.
This would not have been a thermite reaction - just the simple oxidation of fine, suspended aluminum particles by atmospheric oxygen. Thermite reactions are essentially solid-state, gasless processes that produce little or no blast/overpressure, whereas this has air as a working fluid and a highly exothermic reaction to drive it.
You may be correct and I was not saying it was a thermite reaction, simply pointing out aluminum powder isn't as benign as many may assume who only think of cooking foil and milk bottle tops.
Aluminum dust is damn dangerous as all us high school chemistry students know all too well.
Aha! You have outted yourself as a high school kid!
Just kidding
It's sad, but in China so many people smoke it's not funny. And frankly, people over there, especially outside big cities, are just not that careful in everyday life. It wouldn't surprise me at all if one or both of these tragedies were caused by someone forgetting that they can't light up in or nearby the area where the explosion(s) occurred.
So what does it take to ignite? A single spark, or flame?
It's sad, but in China so many people smoke it's not funny. And frankly, people over there, especially outside big cities, are just not that careful in everyday life. It wouldn't surprise me at all if one or both of these tragedies were caused by someone forgetting that they can't light up in or nearby the area where the explosion(s) occurred.
Depends on the aluminum particle size and density in the air. Especially for small particles (say < 1 µm) within the explosive mixture limits it could be just a spark.