label   9545

« earlier    

Identifying Unknown Plastics
"This is a piece of free-burning ABS tubing showing characteristic flame color and smoke. The burn test, as it’s known, correlates a plastic sample’s composition with a set of observable properties including…

whether or not the material will freely burn in air when a gas ignition flame is removed,
the color of the flame,
the smell,
the presence or absence of molten drips, and
the color and properties of any smoke, esp. the reactivity of smoke with wet litmus paper.
Though useful, the burn test should be used with caution of the toxicity of many plastic combustion products, and need not be a first resort when confronted with a sample of unknown polymer.

To risk stating the obvious, the first step in identifying a piece of plastic should be to look for a label. Since 1988, the SPI resin identification coding system (Wikipedia) has been widely adopted by plastics manufacturers to label their products for post-consumer recycling. Though the variety of possible plastic materials is essentially infinite, the familiar SPI recycling codes are a useful basic taxonomy of the polymers one is likely to encounter “in the wild.”

SPI # Abbreviation Name Example Use Density (g/mL)
1 PETE/PET Polyethylene terephthalate Water bottles 1.37-1.45
2 HDPE High-density polyethylene Milk jugs 0.93-0.97
3 PVC Polyvinyl Chloride Pipe 1.3-1.45
4 LDPE Low-density polyethylene Saran wrap 0.91-0.94
5 PP Polypropylene Food containers 0.85-0.94
6 PS Polystyrene Model kits 1.05
9 ABS Acrylonitrile butadiene styrene Lego bricks 1.04
Assuming your sample has no label that would indicate its composition, then, the test which offers the best combination of safety, utility, and convenience is probably density. If your sample is made of a single material, solid through and through, its density can be checked against a set of reference liquids of known densities by simply dropping the sample in a small vial of each liquid: If it floats, it is less dense than the reference, and if it sinks, it is more dense than the reference. Polyethylenes and polypropylenes float in water (density = 1 g/mL), for instance, while most other plastics sink. Among heavier-than-water plastics, ABS and PS will float in glycerin (density = 1.26 g/mL), but PETE and PVC do not.

Other useful tests for discriminating plastics are the Beilstein copper wire test (which indicates the presence of chlorine, e.g. in PVC), susceptibility to acetone (most plastics besides polyethylene and polypropylene will become “tacky” on exposure), and whether the plastic turns white under stress, e.g. when bent (PVC whitens; PET does not)."
plastic  identify  unknown  flame  toxic  test  burn  polymer  label  SPI  PETE  PET  HDPE  PVC  LDPE  PP  PS  ABS 
4 weeks ago by cosmic
Flexbox: Inputs with icons
Flexbox solves the age old problem of displaying inputs alongside icons, without odd CSS hacks. Was used as a demo in a Smashing Magazine article, Marc...
flexbox  input  style  label 
7 weeks ago by accacin

« earlier    

related tags

!!!  $1.5  #muterkelly  &  '  'rap  'unfair'  'ye  1"  10  2"  2-5/8"  2  30  4"  5160  5163  6ix9ine’s  8tb  abs  accuracy  acg  acquisition  activists  activities  activity  address  adds  adventure  adventures  agent  agrachina  ai  album  algorithm  aluminum  amazon  americal  amid  analytics  and  android  anticounterfeiting  anything  artificial  artist  atl  ats  authentication  avery.com  avery  award  bad  bag  bands  basicchannel  beer  berlin  best  bestpracticies  bias  board  bomber  book  booking  bquote  brand  brianza  build  burn  business_advisory_relevant  business_model  calls  calor-mutuo  calssification  career  careers  carhartt  cashierless  chainreaction  chainz  chainz’s  checkout  chicken  claims  classification  climatechange  cologne  colours  commencement  composers  convenience  covered  craft  css  cubaustrade  culture  custom  data  dataset  dawg  de  deal  deals  decision  deep  delivery  demand  denounces  densityplot  designer  dimensions  dispute  diss  dnb  do  doctor  dolph  donald  down  drake's  drake  drop  dropped  dubtechno  dymo  early  easystore  ecological  ecology  econo  economics  economy  econotogo  electronic  embargo  energy-saving  energy  engrave  entertainment  environment  environmentalism  envy  ernestusmark  evaluation  everyday  excel  experiences  expression  face  facet  fascism  fashion  fight  fighting  first  flame  flexbox  food  for  form  former  forum  foundation  framework  function  furniture  galeno  galenopr  game  gav4  gear?  germany  ggplot  ggplot2  ghost  giving  glover  go  google  graphic  graphicdesign  groceries  hacker  hamburg  hardwax  harvard  has  hawaii  hdpe  he's  head  headquarters  health  henkerobert  herb  him  his  historicism  hook  how  hp  hugo  idea  identify  in  includes  indie  industrial  industry  ink  innova  innovation  input  inspiration  intelligence  interior  ir  is  it  italy  jail  jazz  jenkins  job  josh  judge  kanye  kelly  kelly–including  kelly’s  kubernetes  köln  la  labeling  labels  labor  lands  laser  lawsuit:  ldpe  leads  league'  league  leak  lean  learning  leave  let  light  lil  live  logic  logos  machine-learning  machine  machinelearning  magnet  mail  mailing  mainstreet  major  make  management  manufacturing  marchesiscamorza  marking  materiacollective  materials  mature  mcsa  medical  medicine  merch  merge  metal  metrics  milano  million  mix  mixing  modernpsych  movement  multi  munich  music  music_industry  name  nas  nba-style  near  new  nike  nobody  node  noise  north  nothing’  ny  ocr  office  officially  offset  opensource  optical  or  out  outside  over  p18  pac  paper  pattern  per  permaculture  pet  pete  physically  physician  pipe  pipeline  plastic  platform  plot  plotmath  politics  pollo  polymer  pp  pr  practice  print  printer  printing  private  profit  programmable  protest  providers  ps  puerto  pump's  punk  purple  pvc  qr  qrcode  quit  r.  r  re-gram:  react  recalls  record  recording  records  releases  reportedly  research  resources  reverses  rewritable  rhythmandsound  rico  royalty  ruin  sample  scan  science  screen  self  settles  sharecropper  sheet  shipping  shop  shopping  shotti  sklean  snorkel  snyggsida  socialentrepreneur  software  solar  solarpunk  sony  soul  speech  spi  spray  stamping  status  sticker  stickermule  streaming  struggle  studio  style  sue  supervised  sustainability  switzerland  system  tag  talent  tank  tape  techno  technology  tele  telemedicine  template  test  the  this  threatens  thresholds  tikiman  tincture  tinctures  to  tool  top  tour  tours  toxic  tr3yway  track  tracking  training  troubles  turning  typography  uk  umg  unclonable  understanding  unknown  unquote  uv  video  virtual  vonoswaldmoritz  wanted  wants  was  watermark  webdesign  week:  west's  west  white  whitelabel  why  wine  wip  with  work  x  xtendimax  york  you  young  your  zacari  |  ‘like 

Copy this bookmark:



description:


tags: