Lasers and Residue

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Chris Smith
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Re: Lasers and Residue

Post by Chris Smith » Tue Aug 23, 2005 3:17 pm

As I said unless you prepared to go the laser route, your stuck between the rock and the hard place. <p>Yes the laser can vaporize the coating, and ash is all you have left. A high vacuum and a little vibration after that is all you need to dislodge the dust. <p>But OSHA gets involved here because this particulate is so fine that in dust form it can be as hazardous as coal dust, silicate dust, and other materials that in large form might be inert to the human body, but it fine particulate are carcinogenic. <p>The mild acid route is not always that bad, and the Rosin comes in many forms including water soluble and “no clean up” types.

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Re: Lasers and Residue

Post by rshayes » Wed Aug 24, 2005 3:07 am

#41 wire is about .003 inch diameter. Insulation might be .001 inch over this for a total diameter of .005 inch. Cross sectional area of insulation is 1.26 x 10^-5 square inch. Assume strip length is 1/8 inch. Total volume of insulation stripped is 1.57 x 10^-6 cubic inches/joint.<p>Production rate of 40 joints per hour times 40 hours per week is 1600 joints/week.<p>Volume of stripped insulation is 2.51 x 10^-3 cubic inches.<p>Rough estimate of cigarette dimensions is .3 inch diameter by 2.5 inch long. Total volume is 1.77 x 10^-1 cubic inches. Assume packing density of about 20 percent. Total tobacco volume is about 3.53 x 10^-2 cubic inches.<p>Conclusion:
The annual particulate emission will be less than that from smoking four cigarettes.<p>For an automated process, I would try the following steps:
1) Position the wire over the solder pad.
2) Apply a dot of solder paste over the wire and pad. This should hold the wire in position.
3) Heat the solder paste with a jet of hot air or some other means.<p>The insulation should burn off the wire and float to the surface of the solder joint. It is harmless and can either be left in place or removed with a brush. I don't see a need for a laser at all.

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Chris Smith
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Re: Lasers and Residue

Post by Chris Smith » Wed Aug 24, 2005 3:38 pm

Id prefer to breathe in 10,000 cigarettes than one tenth of one volume of cigarette smoke of the wrong material especially vaporized materials that are extremely carcinogenic.<p> One tenth of a gram of cyanide vapor inhaled is a DOA trick you don’t get to repeat, and yet it’s a harmless inert substance when separated into its two constituents, Carbon and Nitrogen. <p>Lasers can create all sorts of deadly compounds and particulate sizes out of harmless ingredients, which is why OSHA is so heavily involved. <p>And even a small pile of gooey plastic can halt a assembly line when it gets in the wrong place.<p>With out reinventing the wheel, some of the automated existing systems have a automated clamping system that sets the wire over a heat stripper area and cuts the wire [s] automatically, dropping the plastic residue into a bin. <p>The form then moves over to a hot bath area of any type chosen [rosin/acid bath], and then the wire is dipped, agitated to remove lose particulate, and then moved on to the tinning and or soldering stage. <p>The bath is a recirculating system that washes the fluid constantly through a filter, back through a heater, and back up to the tank which usually flows from one side of the tank to the other ensuring cleanliness at all times. <p>Laser types do all the same automation except they have a shielded area for the burning process to ensure no stray light reflects and causes blindness, and in this same area, the automation process has a high vacuum running with a small vibration or agitation stage added after the laser stops, ensuring particulate falls off and into the vacuum. <p>From there they may tin, flow solder, or join the two together in one stage.<p>[ August 24, 2005: Message edited by: Chris Smith ]</p>

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Re: Lasers and Residue

Post by rshayes » Thu Aug 25, 2005 7:11 am

"Id prefer to breathe in 10,000 cigarettes than one tenth of one volume of cigarette smoke of the wrong material especially vaporized materials that are extremely carcinogenic.<p>One tenth of a gram of cyanide vapor inhaled is a DOA trick you don?t get to repeat, and yet it?s a harmless inert substance when separated into its two constituents, Carbon and Nitrogen."<p>The lethal dose for nicotine is 40 to 60 milligrams. The nicotine content in dry tobacco is between .3 to 5 percent. A lethal dose of nicotine could be contained in between .8 and 20 grams of tobacco. Cigarette smoke itself contains contains many other compounds (including Hydrogen Cyanide), and has been known to be carcinogenic for at least 50 years.<p>The lethal dose for Hydrogen Cyanide is about 50 milligrams, practically the same as nicotine.<p>The volume of the stripped insulation would be about 2.51 x 10^-3 cubic inches or 4.11 x 10^-2 cubic centimeters. Assuming a specific gravity of 2 for plastic would give a weight of 82 milligrams. If this was converted completely to Hydrogen Cyanide using atmospheric Nitrogen, you might get enough cyanide for a lethal dose after six months of operation. Actually, most of the carbon will probably form carbon dioxide and carbon monoxide.<p>The nicotine in 10,000 cigarettes would probably be enough to poison over a thousand people. Some of the other compounds present in the smoke could probably kill a few more if concentrated.<p>This type of wire is designed to be soldered without a prior stripping and tinning operation. It has been used that way for at least 30 years. Why use other more complicated methods when you don't have to?

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Chris Smith
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Re: Lasers and Residue

Post by Chris Smith » Thu Aug 25, 2005 9:37 am

Get a job at OSHA and make your arguments? Some how deaf ears will be listening to that argument for a good reason. <p>Unlike our Prez, they actually care for people’s health and safety over at OSHA.<p> But I hear mercury gives a great flavor in our drinking water, and helps our fish in the sea swim faster, and it even makes it easier for our Air to be seen? <p>The mentality that we will quantify how much poison we will subject others to is well,.... down right political, ....on the right political I might add. <p>Hell, its not your health were dealing with right?<p>The same callousness was used in the last century with coal dust and asbestos, but Im sure some one profited from all those who died a miserable death, and that is always the bottom line with those who are so cavalier with other peoples safety.<p>[ August 25, 2005: Message edited by: Chris Smith ]</p>

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Re: Lasers and Residue

Post by rshayes » Thu Aug 25, 2005 12:55 pm

Fortunately, OSHA only has the manpower to deal with actual workplace hazards. Less that 1/10 gram of particulates per year is not going to be one of their priorities. First they will have to deal with the far greater hazard of the candles on the tables in Italian restaurants. These probably generate a gram or so per hour, an exposure level at least 20,000 times higher than the wire stripping operation would be.<p>I'm quite sure that OSHA still has bigger fish to fry than the Italian restaurants.<p>Chris is a classic case of the pot calling the kettle black. If he smokes, he is putting enough nicotine in the air to poison a hundred or so people a year. The exhaust on his car contains hydrogen cyanide, amoung other assorted compounds. These are probably enough to poison another 20 or 30 people a year. The pilot on his gas water heater or furnace will turn out a substantial amount of carcinogenic soot per year. Burning logs in the fireplace will generate several kilograms of carcinogenic soot per hour, as well as releasing other toxins, such as arsenic, into the air. Obviously the rest of us need protection from this character.

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Chris Smith
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Re: Lasers and Residue

Post by Chris Smith » Thu Aug 25, 2005 1:17 pm

How Republican of you to compare Candles in the restaurant to carcinogens in the work place Steven. <p>Isn’t that how the Shrub got away with mercury in our drinking water standards, By using arbitrary ignorance made up on the fly with out any formal training, education, or experience? <p>He does that well, better than any one I know personally. <p>But then when did any politician care about facts or people, it’s the bottom line dollar that counts. <p>What’s a few thousand sick people, dead people, or even soldiers,...... for the Cause [buck]? <p>And while were talking about OSHA, it is their job and you cant install any power laser in the work place with out their involvement, but then you don’t do your home work so you wouldn’t know these tid bits of information and facts. <p>Unlike you, I have worked for a living using lasers in the industry, worked in the electronics industry, and even worked on a production line in the industry, so I can impart some of that wisdom and common knowledge when I post. <p>But Im sure we can always reinvent the wheel. All we need is a stamp?

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Re: Lasers and Residue

Post by sofaspud » Thu Aug 25, 2005 1:31 pm

<quote>
"The mentality that we will quantify how much poison we will subject others to is well,.... down right political, ....on the right political I might add."
<end quote><p>Along with things like SPL's, this is EXACTLY what OSHA does.

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Chris Smith
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Re: Lasers and Residue

Post by Chris Smith » Thu Aug 25, 2005 1:46 pm

OSHA job is to negate any or all levels of carcinogen not to debate how much is acceptable. All Guide lines are drawn up by the medical community, not from OSHA per see. <p>But, The Republican party has a history of tearing down all of the guide lines for a buck. <p>1. INDUSTRIAL HYGIENE CONSIDERATIONS:<p>Potential hazards associated with compressed gases, cryogenic materials, toxic and carcinogenic materials and noise should be considered. Adequate ventilation shall be installed to reduce noxious or potentially hazardous fumes and vapors, produced by laser welding, cutting and other target interactions, to levels below the appropriate threshold limit values, e.g., American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLV's). [Additional references can be found in Appendix F: "Special Considerations" of ANSI Z136.1 (1986)].<p>[ August 25, 2005: Message edited by: Chris Smith ]</p>

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sofaspud
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Re: Lasers and Residue

Post by sofaspud » Thu Aug 25, 2005 2:14 pm

Sorry. To say "OSHA job is to negate any or all levels of carcinogen" is just wrong. If you've ever seen OSHA documents for the workplace, you know that they state acceptable limits of exposure, i.e. "appropriate threshold limit values". So many SPL's for 8 hours, so many ppm's of atmosphere for 8 hours, etc. Lots of (OSHA-approved) MSDS and container labels include a carcinogenic warning.

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Chris Smith
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Re: Lasers and Residue

Post by Chris Smith » Thu Aug 25, 2005 2:47 pm

OSHA is the top of the food chain in this area of Bureaucracy. They say the final word, they don’t make or create the guide lines, they don’t set the guide lines, they don’t do the actual research for what guide lines are best for the work place. <p>They implement them.<p> The department of radiology sets the permissible levels of radiation acceptable for laser exposure.<p> The AMA sets the guide lines for Carcinogens, etc, OSHA enforces them and OSHA sets them into law. <p>They are an Agency, not a medical or scientific community for “Creating” standards with out the proper credentials. <p>My father was one of the team that set up Cal-OSHA in the 60s, and he was a mechanical engineer, not a medical person. <p>When laws were being created, it was the experts in the field that set these standards in motion.<p> Not at the engineer level. <p>Your mistaking the Function of what OSHA’s job really is.

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Re: Lasers and Residue

Post by sofaspud » Thu Aug 25, 2005 2:57 pm

Maybe so.
But at least I can stay on point.

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Re: Lasers and Residue

Post by rshayes » Thu Aug 25, 2005 5:18 pm

"... they don?t make or create the guide lines, they don?t set the guide lines,..."<p>Actually, OSHA does create the standards. The procedure for this is set forth in 29 CFR 1911 (Title 29 of the Code of Federal Regulations, Part 1911). They may use outside standards or they can adopt their own. The actual standards are in 29 CFR 1900.<p>"How Republican of you to compare Candles in the restaurant to carcinogens in the work place Steven."<p>Unlike Chris, I am aware that a restaurant is a workplace. Since this brands me as a Republican, I can only assume that you have to be ignorant of this fact to be a Democrat. I was comparing two potential carcinogen sources in two different workplaces. I see nothing invalid about that.<p>" ..but then you don?t do your home work so you wouldn?t know these tid bits of information and facts. <p>Unlike you, I have worked for a living using lasers in the industry, worked in the electronics industry, and even worked on a production line in the industry, so I can impart some of that wisdom and common knowledge when I post."<p>Chris doesn't get it. There are several people that participate in this bulletin board that are smarter, have better training, amd more experience at a higher technical level than Chris does. His attempts to speak "ex cathedra" are rather pathetic.<p>I will admit that I have never had to deal with OSHA on the subject of lasers. I did spend several years working with them, but that was before OSHA was formed. I am aware that they do have exposure standards now which is certainly a good thing.

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Chris Smith
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Re: Lasers and Residue

Post by Chris Smith » Thu Aug 25, 2005 5:36 pm

To be a democrat or republican would be,... to be a fool.<p> One would have to suspend all reality and believe in any politician, which is catch 22 to being scientific of mind or logical because all politicians are liars. <p>And that is a known fact, since the beginning of time. [some dont study history either?] <p>You cant have it both ways. <p>You cant study reality or science in a logical manner, and then ignore the fact that they lie, and you cant hide behind the fact that just because lots of sheep follow politicians, that this gives you an excuse as to why your behavior is the same as those sheep. <p>Perhaps you’re a Closet case Republican and don’t know it? <p>Personally It doesn’t matter, your callous and ignorant manner means the republican party has a soft spot in their heart for you.

OSHA sets NO standards, they adopt standards, They don’t have a scientific community to study anything but the results of others. <p>Semantics could be used to put the onus on them, but like all Bureaucracies, they aren’t smart enough to set any standard, nor do they wish to. <p>And those here who like to comment with out any back ground, always do. <p>Getting it right is proportional to their actual experience on the subject at hand.

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