Frequently Asked Questions

  1. What is GreenGran technology?  

  2. What is special in GG technology?

  3. Is GG technology (AFC) competing with NMT or WPC?

  4. Is GG technology a proprietary innovation?

  5. Will the product vary with different fibre or different quality of fibres?

  6. Will the product vary with different fibre types?

  7. Any pre-treatment required on the bast fibre?

  8. Besides bast fibres, is it possible to use others such as bamboo and cotton?

  9. Is there any problem with moisture content in fibre?

  10. It is a general believing that natural fibre cannot be processed with a temperature exceeding 200°C.  Is it applicable to GG technology as well?

  11. Can the smell and the dark colour of the material (in case of high temperature compounding/processing) be avoided?

  12. Is there any requirements on the specification of PP matrix?

  13. Is GG using virgin material or recycled material?

  14. Is it possible to use bio-plastics like PLA or PHA as matrix?

  15. Is it possible for GG to produce tailor made granules?

  16. What will be the price compared to glass fibres?

  17. Are pre-treatments required on GG granules before production?

  18. The impact strength of GG-NF is lower than that of GFPP

  19. What is the mechanism of increasing HDT?

  20. For the increased UV resistance, is it the effect of GG technology or effect of the fibre itself?

  21. What is the water absorbance of the composite?

  22. What is the machine residence time for GG-NF?

  23. If use GG product to make a car roof, will there be a problem with the continuous rising temperatures?

  24. What is the shrinkage?

  25. Is the shrinkage different with different fibres?

  26. Did GG test the material at low temperature conditions?

  27. Is there any problem on colouring?

  28. Are there any difficulties in surface processing such as coating or laminating?

  29. When has GG started its industrial scale production?

  30. What specification of products can GG provide?

  31. Is any pre-treatment process required for burning at the end of life-cycle?

  32. What are the applications of GreenGran material grades?

 

1.    What is GreenGran technology?

An innovative way to produce low cost, high performance nature fibre reinforced polymeric composite granules for injection moulding applications.

Top

2.    What is special in GG technology?

The existing natural fibre composite technologies utilize natural fibres in a different way.  NMT (Non-woven Mat Thermoplastics / Natural fibre Mat Thermoplastics) is designed for compression moulding of thick wall articles; WPC (Wood Plastic Composite) is designed for extrusion of profile or thick wall articles as well.

GG technology, the third generation of natural fibre composite technologies can effectively optimize the aspect ratio of the fibres up to the magnitude of several hundreds, and thus improves substantially the stiffness & strength properties of the granules.  As such it competes with traditional engineering plastics, like GF/PP, HH ABS, PC/ABS, PA and PBT.

Top

3.    Is GG technology (AFC) competing with NMT or WPC?

No, in fact, the GG technology is designed for injection molding and reinforcement to the polymer; therefore, it is a unique technology - and supplementary to the others.

Top

4.    Is GG technology a proprietary innovation?

The technology is patented in EU, US, Canada, Japan, India, Bangladesh & China.  Since the extrusion- and injection moulding technology has been well developed for years, it is not easy to obtain a patent like this.

Top

5.    Will the product's quality vary with different fibre or different quality of fibres?

No. The composite is fibre quality independent.  GG technology utilizes elementary fibres which are the same for various quality of fibre.  In fact, the seasonal changes affect the number of bast fibre bundles but not the structure of the elementary fibre.

Top

6.    Will the product vary with different fibre types?

No.  The properties of the composite prepared from different bast fibres do not differ significantly.

Top

7.    Any pre-treatment required on the bast fibre?

No pre-treatment to the bast fibre is required.  Therefore, there is no risk on contamination by chemicals or extra cost on chemical treatments such as bleaching or purifying.

Top

8.    Besides bast fibres, is it possible to use others such as bamboo and cotton?

GG technology can be applied to almost all kinds of natural fibres including bamboo and cotton.  However, the properties of the composites will vary substantially according to the intrinsic nature of the fibre.  For instance, the bamboo fibre composite is not as good as cotton fibre composite if we consider the reinforcement performance.  However, if we consider the cost factor, cotton is more expensive than bamboo fibre. 

A good natural fibre composite should be designed with consideration on the balance between performance and cost and one must consider the usage of the composite.

Top

9.    Is there any problem with moisture content in fibre?

Most moisture is removed by degassing during the compounding process.  In fact, it’s necessary to keep a little moisture content in the fibres. Maximum moisture content of the granules is 5%. Predrying – contact us for details – brings moisture content down to below 0.3%.

Top

10.    It is a general believing that natural fibre cannot be processed with a temperature exceeding 200°C.  Is it applicable to GG technology as well?

GG NF was tested in matrices like PBT & ABS at a high compounding temperatures ranging from ~230°C up to ~265°C and smoking happened.  Interestingly, the strength and the stiffness increase were not affected.  It is surmised that the smoke was caused by the evaporation of low molecular weight moiety of the composite like lignin & hemicelluloses while the fibre structure by itself was kept intact under the high temperatures.  The only aftermath would be a darker colour and an odor like roast coffee bean.

Top

11.    Can the smell and the dark colour of the material (in case of high temperature compounding/processing) be avoided?

Although the mechanical properties maintain in high temperature situation, it is recommended to process at a lower temperature contact us for details –  such as below 200°C for GG PP-NF to avoid excessive darkening & odor. 

In order to avoid overheating, gating changes may be required.

Top

12.    Any requirements on the specification of PP matrix?

Currently, GG-NF PP granules are produced from standard PP for injection.  Specific properties can be catered by using different PP grades.

Top

13.    Is GG using virgin material or recycled material?

Both can be used.  Depends on the applications and the desired properties, one may choose to order either in virgin material or in recycled material.

Top

14.    Is it possible to use bio-plastics like PLA or PHA as matrix?

Yes.  The combination of a bio-plastic and NF will enable 100% biodegradability of the composite.  In fact such a combination makes it become independent from the oil-based economy.

In 2011 we have devolped several new granules grades, 100% bio-based, made from PLA, PHB and natural fibres. The are used both for ordinary consumer products as well as for special eco-protection applications (biodegradable artificial reef).

Top

15.    Is it possible for GG to produce tailor made granules?

Yes.  GG can design and produce tailor-made fibre/matrix/additives compositions with specific properties according to the product requirements of end-users.

Top

16.    What will be the price compared to glass fibres?

Different sort of bast fibre cost differently but most of them are somewhat cheaper than GF.  However, one must take into consideration the reduced weight due to lower density which will cut down the overall price effectively.  Not to mention the tools wear and the protection procedures for the worker taken during GF production.  Moreover, the broken parts do not bear sharp edges like GFRP does.

Top

17.    Are pre-treatments required on GG granules before production?

Not necessarily in general. However it’s recommended to dry the granules at 105°C for PP-based compounds and to dry the granules at 80°C for PLA-based compounds, for at least 4 hours prior to injection molding.
Please consider the advise given as a first step. Next step would be to contact our experts. They can give more detailed info on the granules' portfolio and assist you during the first processing trials.

Top

18.    The impact strength of GG-NF is lower than that of GFPP

Yes, up to now, this is still the case.  Two remarks, though, first of all, GG NFRPP has an impact strength good for most applications and not all applications require high impact strength. 

Secondly, it is possible to introduce a specific additives into the compound to change the impact strength.  However, other mechanical properties will change as well.

Top

19.    What is the mechanism of increasing HDT?

Probably due to the high volume of natural fibers in the polymeric matrix.

Top

20.    For the increased UV resistance, is it the effect of GG technology or effect of the fibre itself?

It is believed that the UV resistance probably arising from the lignin content released during compounding when the bast fibres are opened up.

However, the colour of the article will become lighter when expose to sun light for a lengthy period.

This feature enables elimination of UV stabilizer from the composite.

Top

21.    What is the water absorbance of the composite?

Test revealed that the water absorption was stable after immersing in 40°C water for 35 days.  Although a certain degree of mechanical downgrade was noticed, the data at the end of 120 days period were still much better than the virgin PP.

Top

22.    What is the machine residence time for GG-NF?

GG-NF passes test on 30 minutes.  Test on 60 minutes are ongoing.

Top

23.    By using GG product to make a car roof, will there be a problem with the continuous rising temperatures?

The HDT is up to 150°C at 0.45 MPa for some of our grades and ongoing research is carried out on this topic.

Top

24.    What is the shrinkage?

The shrinkage rate is about 0.3 - 0.5%, depending on the fibre content.

Top

25.    Is the shrinkage different with different fibres?

No exact data is available at the present moment.  As fibres takes up a considerable amount of space in the composite, the compounds’ shrinkage behavior is much lower than that of PP by itself.

Top

26.    Did GG test the material at low temperature conditions?

Yes.  Tests at -30ºC showed no significant impact to the properties.

Top

27.    Is there any problem on colouring?

Normal masterbatch coloration method can be used on GG granules.

Top

28.    Are there any difficulties in surface processing such as coating or laminating?

There is no problem with lamination.  Test on coating is ongoing.  Due to a similar surface tension character the same procedure as those for PP is expected.

Top

29.    When has GG started its industrial scale production?

Our Hong Kong production site has commenced in Q1, 2010.

Top

30.    What specification of products can GG provide?

GG provides standard granule grades in PP with 25/35/50% of fibre per weight content.  We also provide granules with flame retardancy compatible to UL94 V0. Our latest development is the launch of fully bio-based grades, made from PLA and natural fibers. Click here for more detailed info on our granules' portfolio.

Top

31.    Is any pre-treatment process required for burning at the end of life-cycle?

It’s not necessary.  In Europe, chipping is necessary before burning.  However, this should be subject to local requirements.

Top

32.    What are the applications of GreenGran material grades?

Besides the automotive industry where a lot of parts are made of GFRP, GG-NF is also good for pallets for transportation, furniture, casing for home appliance etc. In fact any plastic article which requires mechanical upgrading, improved HDT, improved dimension stability, better UV resistance, re-use and insulation can be replaced by our GG granules. We have grades for both sustainable solutions, or for biodegradable solution. What is needed depends on your product requirements. If needed we can tailor the composition to the required product specs. Our experts are most willing to further advise you.

Top

If you have further questions, please  us.  Thank you!