How to differentiate degradable, biodegradable and compostable？

01 Definition

Degradable

Degradable means the capability of a significant  change of structure and loss of performance (such as: process changes, relative molecular structure or strength) under the influence of certain mechanics within a certain period of time and including one or more steps.

From the definition of degradation, it can be seen that the result of plastic degradation is not necessarily to change the plastic from macromolecules to small molecules and finally to carbon dioxide and water. As long as the plastic structure changes significantly and the performance is lost, it can be summarized as degradation.

Degradable plastic includes photodegradable plastics, thermo-oxidatively degradable plastics, biodegradable plastics, etc.

Biodegradable

Biodegradable plastics are those that can be fully digested by the microorganisms in the processing system as food for energy (entering the food chain). Significant changes in the chemical structure of materials are caused by degradation through biological activities, especially the action of enzymes .

Biodegradable plastics are degraded by the action of microorganisms existing in nature under natural conditions such as soil and sandy soil, or under specific conditions such as composting conditions or anaerobic digestion conditions or in aqueous culture solutions, and finally completely degraded into carbon dioxide. (CO2) or/and methane (CH4), water (H2O) and mineralized inorganic salts of the elements they contain, and new biomass.

Compostable

Under composting conditions, due to the biological reaction process, it can be degraded and disintegrated, and finally completely decomposed into carbon dioxide (CO 2 ), water (H 2 O) and its mineralized inorganic salts of the elements it contains, as well as new biomass , and the heavy metal content, toxicity test, residual debris, etc. of the final compost must comply with relevant regulations.

Compostable is divided into industrial composting and home composting. 

Industrial composting refers to the process of aerobic mesophilic or high temperature degradation of solid and semi-solid organic matter by microorganisms under controlled conditions to produce stable humus. The general cycle is 180 days, but with changes in aerobic composting technology, the shortest time is 30 days or even shorter.

Home composting refers to the process of aerobic composting mainly using household kitchen waste or garden waste for the production of composting for own use. Home composting takes longer than industrial composting, but generally no longer than a year.

02 Differences among degradable, biodegradable and compostable plastics

First, the difference between degradable and biodegradable plastics. Degradable plastic is a large category, including photodegradation, thermo-oxidative degradable plastic and biodegradable plastic. Biodegradable plastic is just one of them, but it can be biodegraded into carbon dioxide (or methane) and water etc. under natural environment, composting and other conditions. 

Second, the difference between biodegradable and compostable plastics. Biodegradable plastics refer to a class of plastics that can be biodegraded in the natural environment or composting conditions or soil conditions or high solids, while compostable plastics refer to a class of plastics that can be decomposed into carbon dioxide and water under composting conditions, In the latter, in addition to the material requirements to become carbon dioxide and water, it also requires that the plastic can be turned into small pieces less than 2cm in size during the composting cycle, and the heavy metal content of the compost produced by composting must meet the standards of various countries. Compared with traditional compost, it will not adversely affect the growth of plants.

Although the international requirements for biodegradation performance are not the same, the detection methods are similar. The organic content is required to be more than 60%, the biodegradation rate of each material with a composition of more than 1% is required to be more than 60% (within 180d), and the organic content of the material is required to be more than 50%. European requirements requires a relative or absolute biodegradation rate of more than 90%.

The national standard for degradation performance in China is GB/T 20197. The standards required for compostable plastics are mainly ASTM D 6400 and 6868 in the United States, EN13432 and 14995 in the European Union. ISO 17088 is basically formulated on the basis of ASTM D 6400 and EN13432. China has technical requirements for compostable plastics in GB/T 28206-2011, and similar regulations have also been made in GB/T20197.

01 PBAT

Polybutylene terephthalate-adipate, is also known as PBAT. According to the source of biodegradable plastics, they can be divided into bio-based biodegradable petrochemical materials and petrochemical-based biodegradable materials. PBAT belongs to the latter. At present, the research on biodegradable plastics is very active and PBAT is one of the best biodegradable materials in the market.

PBAT is prepared from 1,4-butanediol (BDO), hexanediol (AA), terephthalic acid (PTA) or diol terephthalate (DMT), produced through esterification or exchange method .

02 Properties of PBAT

Different from the fully biodegradable plastic material PLA, PBAT is a material with good flexibility, high elongation but low strength. The Tg of PBAT is -30°C, the crystallization temperature is 110°C, the melting temperature is 130°C, and the decomposition temperature is 375°C.

The aliphatic soft segment of PBAT has good degradation performance and can be decomposed into CO2 and H2O by microorganisms in the soil, and the hard segment has excellent physical properties, heat resistance and impact resistance.

03 Main Manufacturers of PBAT

At present, BASF from Germany obtains the most mature PBAT production process. 

BASF's PBAT brand name is ecoflex; Italy's Novamont is the first company in the world to industrialize biodegradable plastics. Novamont's PBAT brand name is Origo- Bi. 

The top three companies in global PBAT capacity are China's Lanshan Tunhe (PBAT capacity of 128,000 tons/year), Italy's Novamont (PBAT capacity of 100,000 tons/year) and Germany's BASF (PBAT capacity of 74,000 tons/year).

04 Applications of PBAT

PBAT is a fully biodegradable thermoplastic, and it is one of the most active biodegradable plastics for research and one of the best biodegradable materials in the market. It is an important product worldwide to "eliminate white pollution", and it is also the "best partner" for any other fully biodegradable materials for modification. 

It can be widely used in packaging materials, catering utensils, sanitary products, plastic films and other disposable plastic products, and can also be used in medical materials, optoelectronic chemistry, fine chemicals and other fields through modification.

01 PLA

PLA, known as Polylactic Acid, is a polyester polymer obtained by the polymerization of lactic acid. It is a new type of biodegradable material. 

Polylactic acid possesses good thermal stability, the processing temperature is 170-230 °C, and it has good solvent resistance. It can be processed in various ways, such as extrusion, spinning, biaxial stretching, and injection blow molding. In addition to being biodegradable, products made of polylactic acid have good biocompatibility, gloss, transparency etc.

02 Pros of PLA

1) Good degradability

Polylactic acid is a new type of biodegradable material. It has good biodegradability. After use, it can be completely degraded by microorganisms in nature, and finally generates carbon dioxide and water, which does not pollute the environment. It is very beneficial to protect the environment and is recognized as an environmentally friendly material.

2) Good mechanical and physical properties

Polylactic acid is suitable for various processing methods such as blow molding and thermoplastic. It is easy to process and widely used.

3) Good compatibility and degradability

Polylactic acid is also widely used in the field of medicine, such as the production of disposable infusion equipment, non-disassembly surgical sutures, etc., . Low molecular polylactic acid can be used for drug sustained-release packaging.

4) Unique performance

In addition to the basic characteristics of biodegradable plastics, polylactic acid also has its own unique characteristics. Traditional biodegradable plastics are not as strong, transparent and resistant to climate change as ordinary plastics.

5) Wide application

The basic physical properties of polylactic acid and petrochemical synthetic plastics are similar, that is to say, it can be widely used for various applications. Polylactic acid also has good gloss and transparency, which is comparable to the film made of polystyrene, which cannot be provided by other biodegradable products.

6) Good tensile strength and ductility

Polylactic acid can also be produced in various common processing methods.

7) Polylactic acid film has good air permeability, oxygen permeability and carbon dioxide permeability, and it can also isolate smell.

8) When incinerating polylactic acid, its combustion calorific value is the same as that of incinerating paper, which is half of incinerating traditional plastics (such as polyethylene), and incinerating polylactic acid will never release toxic gases such as nitrides and sulfides. The human body also contains lactic acid in a monomeric form, which indicates the safety of this degradable material.

03 Application of PLA

Packaging

Mainly used in packaging bags, packaging films, medical films, foam plastics, tableware, etc.

PLA packaging film

PLA material has a smooth surface and high transparency, so it can compete with polystyrene and PET in certain applications.

PLA used in food packaging

PLA has been used in rigid packaging for fruits and vegetables, eggs, cooked and baked goods.

Textiles

PLA applied in textiles

Medical 

Drug controlled release system, orthopaedic fixation, tissue adsorption materials, surgical sutures, oral fixation materials, ophthalmic materials etc. 

3D Printing

Other durable goods (electronics, auto parts, etc.)

The impact resistance, heat resistance, rigidity and flame retardancy of PLA could be enhanced after modification. It has been widely used in the manufacture of computer parts, notebook casings, mobile phone parts, DVD player casings, optical discs and home appliance parts, auto parts, etc. 

PLA could blend with other resins, inorganic materials and other materials into a new compound with excellent physical properties. These materials have excellent properties in antistatic, dimensional stability, tear strength, compressive strength, tensile strength, impact strength, etc., and are ideal new eco-friendly synthetic materials.

JMSW products are not only 100% biodegradable, but also compostable. 

Our products are certified compostable with DIN CERTCO EN13432 ASTMD6400, BPI, TUV OK COMPOST HOME and ABA AS4736 etc.

While biodegradable items refer to just any material which breaks down and decomposes in the environment, compostable goods are specifically organic matter which breaks down, the end product having many beneficial uses which include fertilizing and improving soil health. Most importantly compostable items don't leave toxic residue behind because it's already organic. Unlike compostable, certain biodegradable products can take several years to break down and in some cases even leave toxic waste behind.

Moreover, we need to understand that there are commercial compost/industrial compost and home compost. 

For industrial/commercial compost, the products will decompose into water, carbon dioxide, biomass within 180 days under temperature around 60 Celsius and humidity around 85%. 

For home compost, the time is longer, generally within 12 months under temperature 25 Celsius and normal humidity around 50%-60%. 

PLA products require certain amounts of heat, moisture and air to compost. Regrettably typical landfills do not contain these necessary circumstances and the items dumped in the trash usually end up at these landfills. Also, landfills are typically sealed which means that decomposition happens below the surface and what is thrown in the trash can is preserved for decades after.

PLA's property is non heat-resistant. The more PLA the products contains, the less heat-resistant the product is. 

Keep PLA products in cool, dry spaces with the temperature never exceeding 110 degrees (F). Although not required, refrigerated truck/heat insulation measure is highly recommended in transporting PLA products.

Yes, if the beverage temperature does not exceed 110 degrees (F). PLA products perform better when used with cold beverages although the typical heat tolerance of PLA products is 110 degrees (F). We have heat-resistant CPLA coffee cup lid to match paper cup which can be used in hot beverages.

The average cost depends on the brand, type, and size of the order. Yet the cost compared to regular plastic products is becoming more competitive as the interest in biodegradable product rises. The disparity in prices is about 15+%.

PLA products are not edible yet are generally non-toxic. Small pieces of PLA will most likely pass harmlessly through the gastrointestinal tract. Once passed through the gastrointestinal tract it will be eliminated in the stool. Please consult a doctor if pain or discomfort arises.