S²PC® – Fiber Compounds
This document is intended to provide information relevant to understanding the environmental performance of our products especially PP S²PC 3545 BO.
Sunflower hulls for production of a bio-based fiber
Golden Compound uses the waste hulls from sunflower kernel production as a bio-based fiber additive for plastic compounding.
The hulls are grinded & prepared to specifications for optimized performance in plastic formulations.
While our focus is on sunflower fibers we want to ensure the performance benefits are captured and thus we offer finished compounds which we call Sustainable Sunflower Plastic Compound: S²PC.
S²PC are compounds of polypropylene (PP) or poly lactic acid (PLA) with our sunflower fibers. Post-consumer recycle option are available.
The current compounds are especially developed for injection molding process while other conversion processes are under development.
The fiber content can be as high 50 % while maintaining excellent processability.
Environmental features of the fiber
- 100 % bio-based
- Sequesters carbon
- Does not use a food source
- Does not compete with the food chain
- Does not require additional areal
An eco-profile is a useful tool to assess environmental impact of S²PC. The profile adds up all of the inputs and outputs to arrive at our formulated product. So from the origin of the raw materials to the granule leaving our plant. In our case the eco-profile contains input from the sunflower fibers, the polymer matrix and our manufacturing process. The eco-profile of sunflower fibers takes into account all the inputs & outputs from growing a sunflower including but not limited to water to grow the sunflower, CO2 sequestered by plants, energy of the sun but also energy to produce fertilizers. Industry data for polymers are published by Plastics Europe, manufacturing data are propriety at this point in time.
An eco-profile or full Life Cycle Assessment (LCA) has not been completed yet as we are a young company and in the early stage of our product development. However the following consideration are relevant to share.
Key indicators in a product’s environmental footprint are Green House Gas (GHG) – the “Carbon Footprint” – and non-renewable energy use (NREU).
Sunflowers require CO2 to grow and this makes sunflowers a natural carbon storage. This sequestering of CO2 means that the sunflower fibers have in fact negative GHG emission value on the pellets leaving our plant. Quick indicative calculations show that our 35 wt% containing formulations in a polypropylene matrix have a 25-30 % lower carbon footprint than straight polypropylene.
The energy of the sun is captured in the sunflower seed hulls and thus reduced the requirement for non-renewable energy use on the granules leaving our manufacturing facility. Quick indicative calculations show that our 35 wt% containing formulations in a polypropylene matrix have a 25-30 % lower non-renewable energy requirement than straight polypropylene.
Bio-based Content Certification
Bio-based content is expressed in different ways – not all are intuitively understood by the general public.
Renewable content refers to weight percentage of a renewable content added to the total formulations. For our 35 wt% containing formulations this is 35 %.
Organic carbon content refers to a chemical molecular structure classification used in scientific context. Both natural grown materials as well as petroleum derived polymers have both organic carbon content. Our 35 wt% sunflower fiber containing formulations have 74 % organic carbon content. Claims of organic carbon content to the average consumer are thought to be misleading although technically correct.
Renewable carbon content or biogenic carbon content relies on C14/C12 analyses and actually measures which part of the carbon is renewable and which part is derived from petroleum sources. Testing is done according ASTM D6488 – Standard Test Methods for Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis. The carbon content of our sunflower fibers is about 65 % the remainder being oxygen and hydrogen.
Our PP S²PC 3545 BO is certified by Vinçotte under (B 15-306 -A) awarding the use of the OK Biobased label.
The recyclability of PP S²PC 3545 BO has been assessed by Kunststoffinstitut Lüdenscheid, Germany. The test is as simple as effective. Parts were injection molded with PP S²PC 3545 BO and afterwards grinded. Parts were injection molded with 100 % regrind. This was epeated 5 times with no introduction of virgin material at all. The results are presented in the graph below.
The E-modulus showed 6.4 % reduction after 5 cycles. Charpy Impact showed a 5.8 % reduction and Tensile Strenght a 4 % reduction both after 5 cycles.
Based on these test results it can be concluded that PP S²PC 3545 BO can be recycled up to 5 times without any significant loss of properties.
Plastic Parts Marking code
The part identification code is important for material identification for subsequent decision making on recycling, reuse or disposal The abbreviated terms suggested are consistent with ISO 11469:2000 Plastics – Generic Identification and Marking of Plastic Products and ISO 1043:2011-1 through ISO 1043:2011-4 Plastics – Symbols and abbreviated terms.
The following codes are suggested for different materials:
For our standard 35% sunflower fiber containing formulation PP S2PC 3545 BO the following code is suggested
Our impact modified grade with 35% sunflower fiber PP S2PC 3545 BO 15IM16
Our glass fiber modified grade PP S2PC 3545 BO GF20
Resin Identification Code
The resin identification codes (RIC) were originally developed by the Society of Plastic Industry (SPI) in the United States to accommodate recycling of plastic packaging in communities. Focus was on the dominant polymers used in plastic packaging. Later RIC was transformed into an ASTM standard.
Our RIC recommendation is in line with the ASTM 7611: Standard Practice for Coding Plastic Manufactured Articles for Resin Identification.
Please note that under D7611, this marking symbol is now specified as a solid equilateral triangle around the number instead of chasing arrows. For further information please look at http://www.astm.org/COMMIT/d7611.pdf
Our PP S²PC 3545 BO has been subjected to eco-toxicity tests according to OECD 208 Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test by OWS in Gent, Belgium,. The test results showed that PP S²PC 3545 BO does not exhibit eco- toxicity. A picture of the most sensitive test specimen (cress) is added.
100 % Renewable Energy
Golden Compounds’ manufacturing facility and offices are using 100 % certified renewable energy using the concept of WaterGreen+-Konzept. This means that not only the energy is 100 % from renewable resources but also that at least one third of the power plants is not older than 12 years, offering an additional incentive to build newer and more efficient power plants designed to use renewable resources. WaterGreen+ has been awarded with the ok-power label from the independent EnergyVision association.
Electronic Product Environmental Assessment Tool (EPEAT) is an initiative of the Green Electronics Council.
EPEAT’s three current categories are based on the IEEE 1680 family of Environmental Assessment Standards. This includes the “umbrella standard,” and three related product standards 1680.1, 1680.2, and 1680.3 containing specific criteria for “PCs and PC Displays”, “Imaging Equipment”, and “Televisions”, respectively.
In all of the three product standard our S2PC materials gain 1 additional point in the Material Selection assessment based on the bio-based content. If recycled-containing versions of or materials are used than an additional 2 points can be obtained.