My materials science notes

Started 13Dec2019. Updated 26Feb2023. I am a happy materials science amateur. It is a very interesting theme: to tell about my experiences with different materials. However, it remains to be seen how this note ends. Observe Standard disclaimer since I mention companies and products here.

Alphabetical list

A

  • Acrylic boxes (or acrylics or polyacrylates) is a big group of different plastics: https://en.wikipedia.org/wiki/Acrylate_polymer. Also see Poly(methyl methacrylate) (PMMA) (below)
    • Such boxes, either complete with top and bottom, or just open trays are useful for making private boxes. However, they must be cast as single pieces, no gluing at the corners!
    • Åhlens in Sweden (they gave up Norway). Storage boxes («Förvaringsask» in Swedish) as product name «Saltsjön», in several sizes, like here. Examples: My aquarium notes and My USB watchdog (and relay output) box (also shows IKEA chopping boards cut up and used) (chopping board = cutting board?)
    • Søstrene Grene, here. Open trays (material type is not specified, but it looks and feels like acrylics, even if it says «Not suitable for food contact»). Example: My IceCore notes (23.9*11.9*3.0 cm at the bottom, about a mm wider at the top. Same for 15.5*15.5*4.6 cm. Both have feet also meant for stacking. These boxes cannot be bored if one later want to screw in them (metal or plastic screws are just as bad). Breaking lines will appear in the plastic. It will crack. It’s very annoying. I had to give it up, when I ended up with a home made box in My XC softblinking PWM notes (search for «box» there)
    • IKEA box “Björnarp” (obsoleted?) is in Poly (methyl methacrylate) (PMMA): https://en.wikipedia.org/wiki/Poly(methyl_methacrylate). Example: My «Day’s End» by Jane Hart reflection
    • If you need 90° bent transparent acrylic plastic as a material, try buying the IKEA picture ledge called Mellösa (here, link as of Nov2020). It’s IKEA 604.462.39

B

  • Bakelite (No: «bakelitt») is a beautiful, early plastic material. If you find any boxes made from it, or any sheet bakelit, keep it! I did reuse an instrument box, see Et strippet og ombygd voltmeter. It’s in Norwegian, but there is a summary in English there, with a link to Google translate. Then, search for «bakelite». Wikipedia

C

  • Carbon fibre (fiber) composites, see here. I mailed Easy Composites in the UK about this: due to tolerances the 0.5 mm Carbon Fibre Rod 1000 mm long (here) will not fit inside the 1 mm (0.5 mm inner diameter) Microtube Carbon Fibre Tube 1000 mm long (here). Also see My Lisbon tram 28 diorama
  • Chopping boards in polyethylene. The nice thing about them is their surface, which looks nice in many uses. However, they seem to get out of fashion (Jan2020), now chopping boards seem to be mede from wood. Also nice raw material!
  • CURVER.com box of type BETON (here) seems to glue with silicon. Even if some of the other products are made from recycled plastic (but which plastic type?), I am not certain about the BETON range

D

  • Diffusers for direct lamps, like spotlights. See Wikipedia Diffuser (diffusor?)
    • Used LED lamps with E27 sockets will often have a diffuse plastic dome. It is perfect for LED spots! See note 201
    • White foil paper. Also in note 201

H

  • HDPE – High-density polyethylene or polyethylene high-density (PEHD) is high-density polyethylene plastic (here). As used in my My soft pill holder

P

  • PEHD see HDPE
  • PE-LD (LDPE): https://en.wikipedia.org/wiki/Low-density_polyethylene –
    • Sainsbury (UK), 45.5*29 cm, 9 mm thickness, white, product 124143353 (here). Harder chopping board that may break. I do not like to work with it just because I got a bad feeling. I’ll update when I have used it
    • Dalaplast (Sweden), 25*15 cm, 6.5 mm thickness, light blue, rose red, grey black, light green. These feel more like the IKEA boards made from PE-LLD (below). I’ll be back when I have used them
  • PE-LLD (LLPPE): https://en.wikipedia.org/wiki/Linear_low-density_polyethylene
    • IKEA. Polyethylene without bisphenol A (BPA). Max 70°C (dishwasher safe). Made in India (supplier number 21293, 22092). Also called «etenplast» in Norwegian
      • Example: My USB watchdog (and relay output) box. I have found no glue for it, so I have always instead screwed it or fastened parts with brass pins etc. – provided I bored a suitable hole first. If not the sheet will split up as if it were wood! However, it may be nicely cut with my Proxxon 27070 FET table saw. (I think «FET» is a German abbreviation for «Feinschnitt-Tischkreissäge» or fine-cut table saw.)
      • IKEA «Legitim» chopping boards. 34*24 cm white and green, 8 mm thickness. White (transparent look), 34*24 cm is product 902.022.68. The green I have used a lot, but is now (Jan2020) obsoleted, product 301.531.24. The last green was in a set paired with a smaller and thinner (4.5 mm thickness) blue
      • IKEA «365+» set of three chopping boards (green, red and grey/light blue), 22*16 cm, 7 mm thickness
  • Polycarbonathttps://en.wikipedia.org/wiki/Polycarbonate (Lexan) plastic sheets. May be bent into 90° angle without breaking. Mine is transparent
  • Poly(methyl methacrylate) (PMMA)
  • Polystyrene
  • POM (polyoxymethylene) solid plastic – https://en.wikipedia.org/wiki/Polyoxymethylene – may be glued with silicon onto glass. Mine is white. Example: My aquarium holiday automatic fish feeder (for granules)
  • PVC (polyvinyl chloride) plastic sheetshttps://en.wikipedia.org/wiki/Polyvinyl_chloride
    • Beautiful to work with. I have only screwed pieces together, but I think they are fine to glue as well. Some strange smell when I cut it with my table saw. Does not glue very well with silicon, i.e. very bad
    • Example: The top and the base of the aquarium: My aquarium notes
    • Like product 148-21-869 (grey) from Elfa Distrelec. No brand. 98 cm x 49 cm x 8 mm (5490 grams)
    • Like product 148-21-867 (grey) from Elfa Distrelec. No brand. 98 cm x 49 cm x 5 mm (3430 grams)

S

  • Screws (tiny screws)
    • Make sure not to throw away any waste electronic products before you have opened them and picked all the nice screws! There are so many different type of screws! Some times even defective E27 LED lamps will have screws (plus diffusers, see above)
  • Shape-memory alloy (SMA) for actuators
  • Springs
  • Steel wire
    • We had an egg cutter that didn’t work as we wanted to. I saved the wire: 0.5 mm very bendable wire that I did find some use for. Observe that heating wires may do the same for you. Save some of it when you discard a fan oven (plus, the thermostat and the overheating thermostat plus the melting fuse, plus..)
  • Styrene-acrylonitrile resin (SAN)
    • This is styren-akrylnitril (SAN) from Biltema (here). They call it «plastglass» (plastic glass). It has a protective shield against UV light (which I believe is needed for polystyrene, which SAN is similar to). Wikipedia https://en.wikipedia.org/wiki/Styrene-acrylonitrile_resin. Two pieces of SAN are glued very well with silicon
  • Styrofoam
    • Save the pieces that pass by you, of the type that does not disintegrate by a pinch. This material is so nice, but terrible to produce. See 201:[Upside down on the workbench]

T

  • Thermoplastic elastomer (TPE) or thermoplastic rubbers. Some transparent rubber, quite elastic feet for tables appeared on my desk the other day (here). It says on the label that they can also be used to dampen vibrations from speakers. Nice material See https://en.wikipedia.org/wiki/Thermoplastic_elastomer

Y

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