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To Pack Better: Round Bales vs. Square

Comparison: Round Bales vs. Square

A number of bale packing systems for waste are offered on the market. Principal difference is the geometry of the bales; and the common opinion is that square bales provide more dense storage. Let us make comparison and find out what is better.

In practice, an often argument about round bales is that they need more place to be stored than square bales. That’s not the truth. So now let us explain why.

Because of the risk to damage the film during transportation by wheel loader, square bales have to be stored with a certain space between each other. Further, at the edges of a square bale the film is stretched extremely, so it is cracking as a result of overstressing.

The edges of square bales are normally less compacted than the rest of the bale because during process of wrapping they get dented. That means, that also square bale storages bring out hollow spaces which are comparable with the volume of a round bale storage. But BPS-2 round bales have a twice as much volume, so in comparison to square bale storages there are less bales and therefore less hollow spaces. In the end, with same floor area around bale storage picks up more wrapped waste than a square bale storage.

The shape of round bales leads to a trigonal shaped hollow space between each other. In comparison to stored square bales, these hollow spaces mean an advantage for stacking and taking bales from the storage by use of a gripping device. They give enough space to absorb the round bales without damaging the film. Further, the round bale shape brings the positive effect that the bales are stored side by side without gaps in between. That provides a stable erection of the bale storage.

Round-bales-2

Example: 4.800 tons/month x 6 months = 28.800 tons

SystemBPS-2Square bales
Bale dimensions in cmØ 150 x L 160170 x 100 x 80 (L x B x H)
Bale volume in m³2,831,36
Bale weight in t *1,98 (0,7t/m³)0,95 (0,7t/m³)
Number of bales (28.800 t)14.53830.252
Hollow spaces in m³0,12approx. 0,12
Storage volume in m³42.88044.770

* domestic waste with 25 % organic components
* industrial waste/mattresses 750 – 900 kg/bale

Square Bales

Square_bales

Disadvantages:

  • Because of the distances between the bales there is no stability given for the erected bale storage.
  • In case that the bale gripping device is not removed exactly after put down the bale, the film is damaged inevitably.
  • The overhanging film at 2 sides of a square bale carries the risk of rain water entering the bales.
  • The bales are fixed with steel wire or plastic ribbons. Special equipment is required to remove wire and ribbons to prepare the bales for further treatment to a later point of time.
  • Normally, ribbons are disturbing for a further treatment. Even the use of special equipment does not guarantee that there is no remaining wire or ribbon entering the utilization resp. incineration plant. Example: 1% of the wire used for a quantity of 28.000 tons comes to the incinerator means that 9.200 m wire impacts on the incinerating grate.

Square-bales-2

  • During wrapping process, the edges of square bales will be overstressed up to 200 %. That involves the risk that bulky material pierces through the film and causes undesirable holes. These holes are perfect for rain water and oxygen to enter the bales
  • Square bales do not have the half weight of BPS-2 produced round That means twice as much ways to go, more transport vehicles and more staff.

BPS-2 Round Bales

Round-bales
The hollow spaces are enough for a gripping device to put down and take out the round bales without damaging the film.

Round-bales-3
No gap between bales = stable storage

Advantages of BPS-2 Round Bales

  • less storage volume
  • stable erection of storage
  • large bale volume – less wrapping material per ton
  • no wire, no net – less wrapping costs and easy opening of bales

Pyramid-shaped Bale Storage with Round Bales

(alongside extendable at will)

Round-bales-4
Round-bales-5

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