{
  "$type": "site.standard.document",
  "description": "The first wall (2) is porous. Inside is a film (4). This is sufficiently thin to avoid acoustic effects; its superficial weight is less than 100 g/m2. The film is fixed to the porous wall, leaving at least 50% of the area which faces the wall unattached.",
  "path": "/patents/1090542",
  "publishedAt": "2004-01-07T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F02M35/024",
    "WECOSTA [FR]"
  ],
  "textContent": "The first wall (2) is porous. Inside is a film (4). This is sufficiently thin to avoid acoustic effects; its superficial weight is less than 100 g/m2. The film is fixed to the porous wall, leaving at least 50% of the area which faces the wall unattached.",
  "title": "Porous pipe with a thin film layer"
}