Proud2BeGreen Products and Technology
Proud2BeGreen only uses cutting-edge green technology to produce the strongest, most durable garbage bags on the market: TDPA™ - An Additive for Oxo-biodegradable Plastics.
Traditional plastics represent a significant environmental problem, both as litter and as solid waste in landfills. As litter, disposable plastic products (in particular, plastic bags) are a visible and widespread pollutant, and a threat to animal and marine species and to human health. In landfills, they add to landfill volume, hinder landfill compaction and delay the biodegradation of discarded organic materials, thereby fostering the formation of methane, a harmful greenhouse gas. Plastics that would degrade and biodegrade relatively quickly to non-toxic end products in these disposal environments would be a welcome step in managing these issues.
Over the last two to three decades, companies in the plastics industry have developed various approaches to make degradable and biodegradable plastic products that process and perform equivalently to inexpensive and widely-used commodity plastics. The intent has been to develop a degradable and biodegradable plastic that is as functional as commodity plastics, but that would degrade and biodegrade relatively quickly in a disposal environment (litter, landfill, compost, water soil).
Many companies claim that their products are degradable and biodegradable but their claims remain un-proven. EPI's Totally Degradable Plastic Additive (TDPA™) technology is scientifically proven.
TDPA™, when added in small quantities to the most common and widely used commodity resins during the manufacture of finished plastic products, causes the modified plastic to degrade at a controlled rate. The degradation, which involves the reaction of the plastic with oxygen in the air, is initiated by exposure to ultraviolet light (sunlight), elevated temperatures and/or mechanical stress. It is "programmed" to start degradation on disposal after the product has fulfilled the required shelf and service lives as defined by end users. Products made with polyethylene (such as grocery, shopping and garbage bags), have been shown to subsequently be biodegradable into non-toxic end products.
Biodegradable plastics incorporating TDPA™ is processed, performs and is visually indistinguishable from conventional non-degradable plastic materials. They are cost-competitive. They are also compatible with existing recycling operations and can be safely co-mingled with conventional plastic inputs prior to the onset of degradation.
How Does TDPA™ Work?
The chemical degradation process involves the reaction of very large polymer molecules of plastics, which contain only carbon and hydrogen, with oxygen in the air. This reaction occurs even without prodegradant additives but at a very slow rate (conventional plastic bags are estimated to remain for over 1,000 years in landfills). The addition of TDPA™ formulations catalyze or accelerate this reaction and increase the rate of the degradation by several orders of magnitude – i.e. 100’s to 1000’s of times faster, making TDPA™ incorporated products degrade and physically disintegrate within a few weeks to 1-2 years, depending on the formulation and the disposal environment.
To illustrate, a TDPA™ incorporated plastic bag and a conventional plastic bag were hung on the fence and the difference in degradation rates was observed in the following degradation test:
These lower molecular weight fragments are known to, and have been shown, in laboratory simulated composts, to biodegrade into carbon dioxide, water and biomass (cell structure of micro-organisms), which are materials found in nature and part of the biocycle. Commercially available LDPE films incorporating TDPA™ have been shown to convert 60% of their carbon backbone into carbon dioxide in 1.5-2 years with most of the balance of the carbon remaining as micro-organism cells. Unmodified films would take much longer to achieve this.
The chemistry described above has been well known to polymer scientists for years. Indeed manufacturers of polymer resins routinely add antioxidant chemicals to their products to prevent any oxidation during thermal processing into products. EPI's contribution lies in its ability to manage these processes in a predictable way – to balance the effect of its catalytic additives with the effect of contained antioxidants in order to make products that satisfy needs for adequate shelf and service lives while providing degradation/biodegradation rates suitable for the final disposal environment.
A useful feature of catalyzed oxo-degradation chemistry is that, as long as there is any residual antioxidant in the plastic, the catalytic additive has absolutely no effect. These antioxidants are slowly consumed as they do their job. This fact is important in designing shelf and service life of TDPA™ incorporated products and allow these products to be safely recycled in existing recycle streams prior to them exhibiting visual signs of degradation – brittleness or disintegration. Other practical features of the technology are that it is applied to the most common commercially available and used polymers and does not affect the processability or the other properties of these polymers.
EPI is the pioneer and world’s leading practitioner of oxo-biodegradable technology and has the experience and technical knowledge to design additive systems for polyethylene, polypropylene and polystyrene to meet widely varying needs for shelf and service life and degradation performance in a range of disposal medium and situations.
