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equipment:storage [2018/12/17 04:33] – [Blue tape] mcmaster | equipment:storage [2019/07/05 18:23] – mcmaster | ||
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====== Foams ====== | ====== Foams ====== | ||
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+ | 3/8" (10 mm) thick seems to work well for putting DIPs on both sides | ||
This section was added to try to learn why some black conductive foams degrade into powder and others degrade into a (mildly corrosive?) sticky mess | This section was added to try to learn why some black conductive foams degrade into powder and others degrade into a (mildly corrosive?) sticky mess | ||
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* Insulative: surface resistance > 1 x 10 12 ohms/square | * Insulative: surface resistance > 1 x 10 12 ohms/square | ||
* Anti-static: | * Anti-static: | ||
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+ | < | ||
+ | depends on whether you want your foam to turn to goo or powder. personally i prefer goo | ||
+ | 14:57:57 powder is open cell foam, it works as an abrasive too | ||
+ | 14:58:07 goo is closed cell foam, which is oddly slick | ||
+ | 14:58:23 after 20 years the foams disintegrate | ||
+ | 14:58:41 open cell foam turns into some sort of acid (acetic?) which will eat chip legs i think | ||
+ | 14:58:45 i don't know about closed cell | ||
+ | 14:58:56 i think closed cell disintegrates much slower but gets ' | ||
+ | </ | ||
+ | |||
+ | < | ||
+ | https:// | ||
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+ | The open cell foam is very likely polyurethane foam†, which degrades into a powder | ||
+ | (clumps if compressed) primarily via hydrolysis / photo-oxidation depending on the type¹ | ||
+ | and (assuming polyester-based PU) releases mainly adipic acid, which is corrosive². | ||
+ | |||
+ | †) general consideration of properties, and a few very rough tests such as: | ||
+ | heating (chars: thermoset polymer), comparison against known PU foam; with supportive results. | ||
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+ | https:// | ||
+ | https:// | ||
+ | </ | ||
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+ | == Brands == | ||
+ | |||
+ | https:// | ||
+ | * Too low density to be useful | ||
+ | * Open cell | ||
+ | * Density: 1.4 lbs. cu. ft | ||
+ | * Tensile Strength (PSI): 13 | ||
+ | |||
+ | https:// | ||
+ | * Advertises for chips | ||
+ | * Closed cell | ||
+ | * Density: 1.8 pcf (28.8 kg/m3) | ||
+ | * Tensile Strength: 31 psi (215kPa) | ||
+ | |||
+ | https:// | ||
+ | * "For Use With: Pin Insertion" | ||
+ | * Density: 50kg/m³ | ||
+ | * Tensile Strength: 515KPa | ||
===== Density ===== | ===== Density ===== |