Bioplastics Background

1. Everybody talks about bioplastics. What exactly does that mean?

2. Are there any interactions between the bioplastics and foods or other products?

3. What has to be regarded sensorially or organoleptically?

4. What happens to the bioplastics in contact with water, air and earth?

5. May the bioplastics be composted at home?

6. How is the CO2-balance in comparison with traditional packagings?

7. Which barrier properties do bioplastics have (gas/aroma, H2O)?

8. Bioplastics are great innovative products. But where are their limits?

9. What gauges can be extruded?

10. Are bioplastics as thick as comparable PE-films?


11. What about the strength of the new bioplastics?

12. Which kinds of bioplastics are there?

13. Which fields of application are there for biofilms nowadays?

 

1. Everybody talks about bioplastics. What exactly does that mean?

In industry the term bioplastics is used for various products. These products only have one thing in common: They are eco-friendlier than conventional products because they are compostable or derived from renewable raw materials.

2. Are there any interactions between the bioplastics and foods or other products?

There are no interactions known which are different to the values of traditional films in contact with food.

3. What has to be regarded sensorially or organoleptically?

Here bioplastics are not different to conventional PE-packaging films.

4. What happens to the bioplastics in contact with water, air and earth?

Since the decomposting procedure needs special temperatures, humidity and microorganisms, the bioplastics decay very slowly under normal environmental conditions. So it would be useful to inform the end consumer that a negligent disposal of the film in natural surroundings should be avoided.

5. May the bioplastics be composted at home?

In a functioning composting system the bioplastics can be composted at home. Due to the long duration of the decomposting process and the expected suboptimal conditions in private composters we would only restrictively recommend this version of dispose.

6. How is the CO2-balance in comparison with traditional packagings?

According to the standards ISO 14040 ff. CO2-balances offer a possibility to compare two products of the same kind in a company for example. Therefore, a comparison of two groups of products such as bio and conventional films is not useful. Definite statements would scientifically not be stable. As a rough guide we can say that bioplastics in comparison with conventional PE-films designed for the same application are better and produce a lower CO2 emission during their product lives. This rule of thumb is based on the fact that the production of conventional films based on fossil resources energetically is far more complex than the production of granules derived from renewable raw materials. Furthermore the disposal of conventional films (via Green Dot Germany for example) is more complex than the disposal of bioplastics.

7. Which barrier properties do bioplastics have (gas/aroma, H2O)?

Normally, bioplastics have got better barrier properties against oxygen than comparable PE-films. The barrier against steam is worse. This combination may positively influence the packed fruit and vegetable products: Humidity can escape more easily – that avoids quick moulding. Less oxygen reaches the product which may slow down the oxidation process. The product should be kept longer.

8. Bioplastics are great innovative products. But where are their limits?

Currently, bioplastics can already be used in many areas but sometimes with curtailments. High transparent films and flexible soft films are possible (for example for fruit and vegetable bags) - the research has not yet achieved a combination of these properties. Especially high transparent bioplastics are pretty stiff and inflexible whereas soft and flexible films are quite matt. Furthermore there are no biaxiale films possible.

9. What gauges can be extruded?

Nowadays, bioplastics can be extruded in single or multi-layered qualities from 15 mµ to 120 mµ.

10. Are bioplastics as thick as comparable PE-films?

Generally it can be mentioned that bioplastics can be extruded 25% thinner to gain properties similar to PE-films. A reduction in weight cannot be achieved because bioplastics have got a higher density and therefore are heavier than a comparable traditional PE-film.

11. What about the strength of the new bioplastics?

The strength of the seals is comparable with the values of traditional films. Bioplastics for bags of 5 kg are easily feasible.

12. Which kinds of bioplastics are there?

Basically the term bioplastics includes three different classes of films:

1. compostable films which are not made of renewable raw materials
2. compostable films which are made of renewable raw materials
3. non-compostable films made of renewable raw materials

Mixtures of class 1 and 2 are possible. The part of granulate material made of renewable raw materials  is about 30-50% with an upward tendency. Films made of 100% renewable raw materials are possible but their special features only allow a limited use as packaging films.

13. Which fields of application are there for biofilms nowadays?

Nowadays, biofilms can already substitute the conventional PE-films in many areas, for example:

- compostable bin liners
- shopping bags
- Erdenfolien
- packaging films for fruit and vegetables
- packaging films for fresh meat
- brochure films for the dispatch of newspapers and magazines