• Portorb Exim

What is Compostable Bags?

Updated: Jun 4, 2020

the bags made from corn starch material
Compostable Carry bags


The world is confused between compostable bags and biodegradable bags. So we will try to give basic understanding of Compostable bags.

As everyone knows, many countries are placing plastic ban, so there will be huge demand for the compostable bags in coming years.

Compostable bags are eco friendly and 100 % made from non plastic material.

Grocery stores and shopping malls can replace their plastic bags with compostable bags.

So with this article,

Let's solve all your common quarries about

Compostable Bags, Compostable garbage bags and Compostable shopping bags.

We will to cover the following information in this article

  • What is Compostable bags?

  • What material used in Compostble bags?

  • How Compostable bags made?

  • Are Compostable bags Biodegradable?

  • What are the uses of Compostable Bags?

Let's Start

What is Compostable bags?

Definition - Bags which will compost in 180 days are call Compostable bags.

Different plant based starch used to make polymer of compostable bags. Some of them are Corn starch, potato starch, sugarcane starch and cassava starch.

The most important point here is

Petrolium based plastic is never used in compostable bags.

Hence they are popular as " I AM NOT PLASTIC " bags.

From Which Polymer Compostable bags made?

As stated above Compostable bags made from plant based polymers.

PLA ( Poly lactic Acid) is the main polymer which is used in compostable bags.

as per wikipedia

Polylactic acid, or polygalactic acid, or polylactide (PLA) is a thermoplasticpolyester with backbone formula (C3H4O2)n or [–C(CH3)HC(=O)O–]n,obtained by condensation of lactic acidC(CH3)(OH)HCOOH with loss of water (hence its name).

It can also be prepared by ring-opening polymerization of lactide[–C(CH3)HC(=O)O–]2, the cyclic dimer of the basic repeating unit.

The monomer is made from fermented plant starch such as corn, cassava, sugarcane, or sugar beet pulp.

How Compostable bags are made?

The manufacturing process of compostable bags is same as the plastic bag manufacturing.

The Blow film extruder is the main machine. Blown film extruder melts the master batch of PLA and extrude it into the big double layer film.

I have found very good video about how blown film extruder works. Thanks POLYSTAR for making such good video.

After extrusion of PLA , the blown film is rolled on roller.

These rollers are then sent for second operation of printing and cutting. Please go through the video below for clear understanding.

So form the above two videos we can easy know that how compostable bags are made.

Are Compostable bags Biodegradable?

This is the one of the biggest confusion going around the world right now.

Many people confused between Biodegradable bags and Compostable bags.

Lets Check what wikipedia says

Biodegradable bags are bags that will decomposed by bacteria or other living organisms.

so from above it is clear that compostbale bags are biodegradable.

Let's further explore the Difference between Biodegradable bags and compostble bags

The word biodegradable means an object is capable of being decomposed by bacteria or other living organisms,


"Compostable" is defined as able to decompose in aerobic environments that are maintained under specific controlled temperature and humidity conditions.

Compostable means capable of undergoing biological decomposition in a compost site such that the material is not visually distinguishable and breaks down into carbon dioxide, water, inorganic compounds and biomass at a rate consistent with known compostable materials.

So from above it is clear that Biodegradable or oxo-biodegradable bags which made from petroleum based plastic polymers with added additives are not compostable bags.

What are the uses of Compostable Bags?

Hope you enjoyed the article.

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