# Can garbage trucks crush empty but closed plastic bottles?

Empty plastic bottles are often dumped carelessly without being flattened but the cap on. I assume no human can flatten such a 1.5l bottle (see example image), but can a garbage truck? I want to convince my local community to at least loosen the top (so that others can compact the bottles) because otherwise

1. garbage containers fill up more quickly so latecomers will dump theirs around;
2. we pay more as we practically pay the company that collects our garbage to transport air;

Therefore I want to know whether a garbage truck (such as the one depicted below) can exert pressure or has some other means that can crush an empty but closed plastic bottle.

Secondarily, I want to know how much pressure force is required to crush an empty but closed 1.5l plastic bottle.

• Are these garbage trucks picking up recycling or are they taking their load to landfills, incinerators, or some other garbage management endpoint? Oct 23, 2018 at 14:07
• @Jean-PaulCalderone I have no idea, but let's assume they go to recycling or to some other management. My question is really about whether closed bottles pose any problem for a garbage truck (besides taking up space) and whether any mechanism is needed/exist inside to crush closed bottles. Oct 23, 2018 at 14:41

Quoting from an answer on Quora:

[the force of a garbage truck compactor] is ~16.2 MPa [...], which works out to almost 160 atmospheres of pressure. To give you some context, every 33 feet (10 meter) you travel underwater increases the pressure acting on you by 1 atmosphere. [...] You would need to go almost 1 mile below see level (5247 ft) to reach 160 atmospheres. According to wikipedia Submarine depth ratings, modern nuclear submarines will be crushed at less than half of this depth (~2400 ft, ~73 atm).*

If you Google for garbage truck compactor specifications you find similar numbers: 170 bar, Main system pressure: 2500 psi = 17 MPa.

So, there really is no need to screw the caps from the bottles.