澳大利亚实验检测报告(一)

ASSESSMENT OF THE DISINTEGRATION AND COMPOSTABILITY OF PLASTIC FILMS

Material ID: Biograde BOR-Q-805F

        Report Number: BFD 024332-JS

John Scheirs (ExcelPlas)

P.O. Box 2080, Edithvale, VIC 3196

scheirs.john@pacific.net.au

Issue date: 9th November, 2004

COMMERCIAL-IN-CONFIDENCE

 1.  Objective: To determine the degree of disintegration of biodegradable plastic film under composting conditions in a pilot scale test according to ISO 16929:2002(E).  According to the European certification scheme for biodegradable materials, Performance Standard BS EN 13432, the pass threshold for this test is 90% of the material passing through a 2 mm sieve after the 12 week test period.

2.  Materials and Method:

2.1  Material Identification Starch based polymer films (BOR-Q-805F) of two different thicknesses (75 µm and 120 µm) were obtained from 999 Guangdong San Jiu Biodegradable Plastic Co., Ltd., (Guangdong, PRC).  The plastic films were assessed for compostability and biodegradability at a commercial composting facility in Melbourne.

2.2  Composting Facility: The composting trial was conducted at Pinegro Products Pty Ltd., Riding Boundary Road at Deer Park under the supervision of the Manager, Ken Hirst. Pinegro Products Pty Ltd was established in 1979 and is a joint venture between Amcor Ltd and Arthur Yates & Co Ltd.  Pinegro has Australian Standards Accreditation for Compost, Soil Conditioners and Mulches (AS-4454).  Their full details are available at www.pinegro.com.au The films were evaluated for compostability in accordance with INTERNATIONAL STANDARD ISO 16929 (2002-11-01) "Plastics — Determination of the Degree of Disintegration of Plastic Materials under Defined Composting Conditions in a Pilot Scale Test".

2.3  Compost Composition: The compost composition used was based on 66% Green Waste and 34% Sewage sludge with a carbon:nitrogen (C:N) ratio of 25 and a moisture content of between 55-85%.  This formulation is used as it gives reliable temperature, pH and aeration profiles.

2.4  Composting Set-up: The plastic film material was enclosed in stitched bags made from shade cloth netting.  The test material was in the form of film having thicknesses of 75 µm and 120 µm.  Multiple samples of 10cm x 10cm were included along with some larger sizes for the purpose of tensile strength measurement.  The samples were mixed with compost and sealed in the net bags.

2.5  Test Procedure:
The following procedure was followed:
1.  Plastic specimen for testing were cut from the film (see Figure 1)
2.  The test hole was dug in a fresh Winrow compost heap (see Figure 2)
3.  The bags were filled with a mixture of plastic and immature compost (ratio of less than 1: 10 plastic: compost) (see Figure 3)
4.  The plastic films were placed inside stitched shadecloth bags (see Figure 4)
5.  The test bags were placed in the hole (see Figure 5)
6.  The rows of compost are turned over as required using the Window machine shown (see Figure 6).

2.6         Test Method  Test method and analysis was based on the International Standard ISO 16929:2002(E), 'Determination of the degree of disintegration of plastic materials under defined composting conditions in a pilot scale test'.

3.  Results: The net bags containing test films were retrieved at intervals of 1 month (i.e. after composting for 1, 2 and 3 months respectively) for inspection.  The photographs corresponding to these time intervals are shown in the attachments.  It can be seen that there was a significant decline in test film fragment size. After 1 month the 75 µm film was almost totally disintegrated whereas the 120 µm film was still largely intact although it was quite brittle (see Figure 7). Microbial attack and staining of the films is clearly visible and biodegradation of the films is apparent (see Figure 8).  After 2 months the films have continued to fragment (see Figure 9).  The results at this point suggest the films are inherently biodegradable. After 3 months the film had totally disintegrated and no discernible film samples remained. The most dramatic change in film size was observed between 2 to 3 months duration (see Figure 10). At the end of the testing period the compost is normally sieved through standard 10mm, 5mm and 2mm sieves and the total dry solid content of tested film collected and weighed.  In this test there was no material identifiable at the end of the 3 month period except for a few small singular fragments.

4.  Conclusions: The testing shows that the plastic film samples used in this test are completely compostable as demonstrated by their 100% disintegration after 3 months.  This suggests the plastic films are inherently biodegradable.



 John Scheirs, B.Appl.Sci., Ph.D., MSPE, C.Chem