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FAQ2019-03-18T14:19:15+00:00
Does optical sorting work with all kinds of environmental bags?2019-03-12T08:25:36+00:00

Yes, we have successfully tested optical sorting with different types of environmental bags.

Today we work with the following materials:

  • PE bags made of biologically produced plastic
  • PE recycled plastic bags
  • Biodegradable polymer and paper bags.
Can you add another fraction to an already existing optical sorting plant?2019-03-11T15:17:56+00:00

Yes you can. The Optibag system can handle up to nine different fractions and all plants we are now building are prepared for extension with more fractions.

Do you need to have two bags, i.e. one in the other?2019-03-11T15:08:39+00:00

No, one bag is fully enough. The bags for optical sorting are designed not to leak.

Does wet food waste need to be drained before putting it into the green bag?2019-03-11T15:03:53+00:00

No, put it directly into the bag. Remember to use a double-knot to keep the bag sealed.

Do you need to wrap shrimps or fish in newspaper before putting them into a green food waste bag?2019-03-12T08:14:34+00:00

No, you can put any rubbish directly in the bag. Remember to use a double-knot in order to keep the bag tightly sealed.

What is a fraction?2019-03-11T15:00:43+00:00

A fraction is another word for a waste type. For example, food waste is one fraction and paper is another.

Can biomass from food waste be used as certified agricultural fertilizer?2019-03-12T08:15:21+00:00

Yes, according to the certification standard SPCR 120. The cities of Eskilstuna, Linköping, Oslo, Kalmar and Halmstad are examples that apply optical sorting and have modern facilities that guarantee that food waste can be used for biogas production as well as biologically fertilizer.

Inspections from different pretreatment facilities for food waste show that the biogas and bio fertilizer quality does not depend on whether the food waste is collected in a plastic or paper bags.

Can optical sorting be combined with other collection systems, like waste suction systems or underground containers?2019-03-12T08:16:42+00:00

Yes, in several municipalities that apply optical sorting, different waste collection systems are in place. See the list of examples below.

Vacuum systems: Several municipalities that have chosen optical sorting already had a stationary vacuum system in place. Some examples are Linköping, Södertälje, Tromsø and Oslo.

Underground containers: Several municipalities that have chosen optical sorting also have underground containers. These can be found in Oslo, Linköping, Tromsö, and Södertälje.

Garbage bins: Bins come in different sizes, from 120 to 1100 liters, and all can be used for optical sorting. For bins larger than 400 liters in volume, we recommend a special lid to avoid bulky waste or construction waste.

Will municipalities using optical sorting reach the environmental targets for 2020?2019-03-12T08:19:31+00:00

Yes, waste analysis and statistics from Optibag’s sorting plants show that municipalities with optical sorting already reach the environmental goals.

Eskilstuna Strängnäs Energi & Miljö (ESEM) performed a waste analysis in 2017 for their optical sorting plant. The results showed that 70 % of all total waste was separated for recycling using optical sorting with coloured bags. The remaining 30 % of the total waste was energy recovered.

The analysis also showed that 80 % of the total food waste was collected and sorted in green bags, which is far above the national target. Purity of the sorted food waste was measured to 97 % which is also a very good result.

In total 28 % of the residual waste was packaging materials, which shows that optical sorting is one of the best systems on the market for source separation.

How is the national recycling target calculated?2019-03-12T08:21:43+00:00

This is how we at Optibag calculate collected food waste amounts:

Total amount of sorted food waste of the municipality (in kg), divided by the number of inhabitants in the municipality.

The national collection goal for Sweden and EU for food waste counts for all households in a municipality – not only ”connected” households. If only “connected” households are counted, these indicators give a different value and cannot be used to qualify all households. The national targets are independent of the collection system applied in the municipality.

We believe it is important that all actors in the waste management business use the same standards and definitions when speaking about collected amounts of food waste. Otherwise, no comparison between different collection systems can be made.

The national target for food waste collection is set to 50 % for the year 2020. Municipalities that apply optical sorting have reached this target already today, Oslo being the only exception with a 46,4 % collection rate in the year 2017. However, for a capital city with 653.000 inhabitants, we still believe this is an exceptional achievement which is, to our knowledge, world-leading.

Do waste collection vehicles have to use a lower compression level?2019-03-12T08:22:12+00:00

No, rubbish trucks can compress the waste according to general recommendations.

Does optical sorting also mean replacing the rubbage trucks?2019-03-11T10:41:12+00:00

No, optical sorting works with any type of waste collection vehicle.

Do municipalities with optical sorting need more recycling stations for glass waste?2019-03-11T10:39:09+00:00

No, on the contrary municipalities with 6-7 optical sorting fractions have been able to reduce the number of public recycling stations.

Can optical sorting be introduced in any municipality?2019-03-12T08:23:09+00:00

Yes, optical sorting works for all types of housings, from single-family housing areas to high-rise or multi-family housing.

Optical sorting works well both in inner-cities and in rural areas.

Will the bags or pieces of the bags end up in the environment?2019-03-11T10:32:11+00:00

No, our optical sorting plants are closed systems. This means all bags that come in to the sorting plant will be sorted out. The bags are recycled and become new bags.

Even wrongly-sorted materials will be sorted out, and all plastic bags are taken care of.

Can collection costs really be reduced with optical sorting?2019-03-12T08:25:09+00:00

Yes, comparisons between different collection systems show a large difference in the total number of collection trucks and required time to serve households. With optical sorting, waste management logistics can be optimized to one single waste bin and only 26 collections per year.

As a comparison, a so-called multi fraction waste collection system, where waste is sorted in several different compartments in the waste bin, requires 39 collections per year and household. In addition, multi fraction trucks have to empty their load more often because one compartment fills up faster than the others. It also takes 2-3 times longer to empty one bin. Therefore the system requires more trucks to serve the same amount of households, compared to optical sorting.

For example: In the city of Eskilstuna, about 80 km west of Stockholm, 23.000 single-family houses use source-separation with optical sorting. All houses are served by 4 garbage trucks to collect their waste. If these households were to use multi fraction waste collection system, 7-8 garbage trucks is needed to serve the same city.

Does optical sorting work with all kinds of environmental bags?2019-03-11T15:16:38+00:00

Yes, we have successfully tested optical sorting of different types of environmental bags.

Today we work with the following materials:

  • PE bags made of biologically produced plastic
  • PE recycled plastic bags
  • Biodegradable polymer and paper bags.