High temp sensor

newplumber

Senior Member
#1
Hi Everyone
long story short
I have lots of left over pieces of HDPE 2" Poly pipe but instead of throwing the poly away I figured
I could try making a poly mold ejector ...so I did and it kinda worked but needs to be better
I'll take some pictures for future when i get a chance but i'm using these high temp sensors
https://www.ebay.com/itm/1Pc-SPI-MA...377488226?epid=2131218021&hash=item44130e6b62
and when I connect them(sensors) to my ejector and have the sensors touch the mold metal they don't sense the temperature
so I have the sensors held in the air next to the metal with out touching any metal ...and since i'm trying to read the temp of the metal where the poly needs to melt, my question is ...do they make some sort of contact silcon I can put inbetween the sensor and metal so the high temp sensor will work?
then I can control all the heat from a picaxe 20m2 or the best chip in my words 20X2
I'm running temperatures at around 430F to 600F....so in other words
poly melts at around 400 degrees F (I will have to adjust the temp per speed of poly running thru)
in a cylinder metal pipe I plan on using 5 - 10 electric elements and use 5- 10 high sensors so the picaxe can/will keep perfect temp
at each section of heat pipe for melting down the poly
and at the end of the day I can make whatever I want with poly...then sell it and buy more picaxe chips :) .....I mean
buy more 20X2 picaxe chips.

Now I'm back to learning 101 ways to ruin a turkey
 

premelec

Senior Member
#4
If you use the non-contact unit note that it's reading depends some on the emissivity of the source being read - as long as that is a constant you are ok when your final calibration is made though it may not read 'actual' temperature. In regard to thermally conductive non-contact material - a variety of thermal pads and mica washers are used for power transistors... or just a little hi temp cloth with some silicone rubber would do it...
 

newplumber

Senior Member
#5
If you use the non-contact unit note that it's reading depends some on the emissivity of the source being read - as long as that is a constant you are ok when your final calibration is made though it may not read 'actual' temperature. In regard to thermally conductive non-contact material - a variety of thermal pads and mica washers are used for power transistors... or just a little hi temp cloth with some silicone rubber would do it...
Okay thanks.... I have alot of the sensors on order since they are cheap (ones in my first post)
and I'll do some testing with high temp silicone
also I need to do some testing with MLX90614 because that even sounds cooler but more money
 

newplumber

Senior Member
#6
Here is few pics of the million dollar machine (actual cost 400.00 +/- )
I took a electric/hydraulic wood splitter and used the hydraulic for the press
with some modification ... it claims 5 ton of force but it seems less
I built it so I can add any kind of press thru plate just by simply threading it on
I'll try to get some better pics when I rebuild it with all the heat elements etc
 

Attachments

rq3

Senior Member
#7
Hi Everyone
long story short
I have lots of left over pieces of HDPE 2" Poly pipe but instead of throwing the poly away I figured
I could try making a poly mold ejector ...so I did and it kinda worked but needs to be better
I'll take some pictures for future when i get a chance but i'm using these high temp sensors
https://www.ebay.com/itm/1Pc-SPI-MA...377488226?epid=2131218021&hash=item44130e6b62
and when I connect them(sensors) to my ejector and have the sensors touch the mold metal they don't sense the temperature
so I have the sensors held in the air next to the metal with out touching any metal ...and since i'm trying to read the temp of the metal where the poly needs to melt, my question is ...do they make some sort of contact silcon I can put inbetween the sensor and metal so the high temp sensor will work?
then I can control all the heat from a picaxe 20m2 or the best chip in my words 20X2
I'm running temperatures at around 430F to 600F....so in other words
poly melts at around 400 degrees F (I will have to adjust the temp per speed of poly running thru)
in a cylinder metal pipe I plan on using 5 - 10 electric elements and use 5- 10 high sensors so the picaxe can/will keep perfect temp
at each section of heat pipe for melting down the poly
and at the end of the day I can make whatever I want with poly...then sell it and buy more picaxe chips :) .....I mean
buy more 20X2 picaxe chips.

Now I'm back to learning 101 ways to ruin a turkey

Dow Corning DC-4 silicone grease is good to about 400 degrees F. It will work above that, but gets pretty thin and runny. Available at any auto parts store, and commonly used as a thermal contact grease.

Chemours Krytox greases are good to at least 750 degrees F. Be seated when you check the price.
 

newplumber

Senior Member
#8
Dow Corning DC-4 silicone grease is good to about 400 degrees F. It will work above that, but gets pretty thin and runny. Available at any auto parts store, and commonly used as a thermal contact grease.

Chemours Krytox greases are good to at least 750 degrees F. Be seated when you check the price.
Thats funny ... I always try to be seated even when I need to install a vent pipe thru a roof :)
the older i get....the more I see turtles winning races
 

newplumber

Senior Member
#10
Your thermocouple sensor from Ebay is not a contact probe ! It must be screwed into material.
ok ... I'm going to thread them into my heat plate of course after they show up from china.
it would be cool to maintain perfect heat at all areas of the heat plate tube

FWIW If this press with a heat plate fails to work out as expected I have a back up plan
which seems to cost more but results are guaranteed! and that is to use 50 ton+ press with much stronger
plates and in theory will crush the poly into any shape I want.....but its funner watching the picaxe chip
wiz out the sensors and all heat controls
 
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