eBottlespromotes the use of Glass and PET (Polyethylene Terephthalate, Resin Identification Code #1) for cannabis packaging as the most sustainable option for our products due to their common presence in the waste stream and the ease and high value of recycling these materials. PET is the most widely used packaging resin, PET is also the most widely recycled plastic material in the world.
Design for Recyclability®is an initiative by independent recycling companies, consumer product companies, equipment manufacturers, testing laboratories, organizations, and others committed to the success of plastics recycling. The goal of the program is to educate packagers on the impact of package design to achieve maximum recycling opportunities. The primary consideration is to create packages which can be easily recycled through the use of automated equipment thereby ensuring sustainability in the market. Recycling is the best choice for rigid packaging such as bottles and jars. The barrier to more cost effective recycling is the plethora of materials and colors in the waste stream and the mixture of difficult to separate items used in individual packages.
Due to its clarity and natural Oxygen and CO2 barrier properties, PET is the most widely used packaging resin. It is easily blown into a bottle or formed into a sheet, thereby becoming the resin of choice for beverage, food and personal care applications. PET bottles and jars are accepted in virtually all recycling programs in the United States and Canada.
Over 2 billion pounds of PET are collected for recycling annually. The EPA estimates that 1% of municipal solid waste in the U.S. is attributed to PET containers.
RPET IS EMPLOYED FOR NEW PRODUCTS SUCH AS:
New PET containers
Polyester carpet fiber
Fiberfill for sleeping bags & coats
Sheet and film
The use of recycled PET in place of virgin resin typically results in reduced energy consumption, lower cost, and reduced environmental impact.
DESIGN FOR RECYCLABILITY®CONCERNS:
PET does not normally have the desired properties for closures, attachments or labels so other polymers are commonly used for these items and affixed to the PET package. PET properties can be enhanced with colorants, UV blockers and other additives. Each modification and addition to the base, clear PET in a package must be considered for its effect on the recycling stream. Items should either be economically removed from the PET in the typical recycling process or be compatible with Recycled PET (RPET) in future uses.
The density of PET is 1.38 and so it sinks in water. Closures, labels and attachments should be made from materials with a density less than 1.0 that will float in water and therefore be readily separated from the PET.
Additives to plastic materials are available which increase the rate of degradation of plastic both in aerobic and anaerobic environments. While these additives significantly improve the time required for plastic to degrade, there are no official test standards which when met can allow a marketer to make the claim that their packaging is “Biodegradable”. ASTM D5511 is the standardized test method developed to determine the amount of plastic degradation which will occur in a controlled environment in the presence of pretreated household waste. Claims of performance are limited to the numerical result obtained in the test and can not be used for unqualified “biodegradable” claims. The State of California in particular has fined several companies for making this claim:
Important California Notice
California law prohibits the sale of plastic packaging and plastic products that are labeled with the terms ‘biodegradable,’ ‘degradable,’ or ‘decomposable,’ or any form of those terms, or that imply in any way that the item will break down, biodegrade or decompose in a landfill or other environment. These restrictions apply to all sales in or into the State of California, including such sales over the Internet.
PUBLIC RESOURCES CODE - PRC DIVISION 30. WASTE MANAGEMENT [40000 - 49620] PART 3. STATE PROGRAMS [42000 - 42999] CHAPTER 5.7. Plastic Products [42355 - 42358.5]
Recycling is the best choice for rigid packaging such as bottles and jars. The barrier to more cost effective recycling is the plethora of materials and colors in the waste stream and the mixture of difficult to separate items used in individual packages.
COLOR: CLEAR PET IS PREFERRED:
Clear materialhas the highest value as a recycled stream since it has the widest variety of end-use applications. It is the most cost effective to process through the recycling system. Transparent light blue packaging is a suitable product for recycling. Light blue material is often included with the clear material stream to act as a bluing agent and offset some yellowing. This not only adds volume to the high value clear stream, it improves its quality when used in limited amounts. Normally it can also be added to the green stream with little negative effect. Transparent green packaging is preferred.
Green materialhas significant volume in the marketplace. At the Materials Recovery facility (MRF), it is baled along with the clear PET and may comprise up to 30% of the PET bale. The green material is separated from the clear by the original reclaimer, who may process it into a value added product, or send it to a reclaimer dedicated to green material. Its value is second only to clear material. However, green is not without its issues. Because a consistent, clear color is critical to future products using clear RPET, the recycling process includes a great deal of machinery and manpower dedicated to separating colored material. This adds significant cost to the operation. Even so, small but significant amounts of colored material, including transparent green, pass into the clear stream, thereby affecting the quality of clear RPET. Markets such as clothing, carpet, soft drink bottles and thermoformed sheet depend on very precise colors, using clear material as a basis.
Most communities with curbside collection allow for collection of colored PET bottles and these are often included in bales of clear PET bottles. PET reclaimers can use color auto-sorters to remove the colored bottles from the clear stream. However, reclaimers regularly report that there is low market demand and low value for mixed color PET containers. Reclaimers report that transparent colors can be used in applications such as bulk fiber and black sheet and are more likely to find a market application than opaque colors. Today, most reclaimers report that opaque bottles do not often find an economically viable market and so become a waste stream.
CLOSURES AND DISPENSERS
Polypropylene and polyethylene closures and components that float in water are preferred. Since these polymers float in water, they are most easily separated from PET flake in conventional separation systems. Additionally, the PET recycling process captures floatable polyethylene and polypropylene to create an ancillary stream of marketable material.
Care must be taken when modifying the polyethylene or polypropylene, with mineral fillers for example, to ensure the modifier does not increase the overall density to the point it sinks. Silicone, polystyrene, thermoset plastics, nylon and acetal are examples of plastics that are expected to sink in the float-sink tank with PET and be detrimental to PET recycling. Sinking plastics are difficult to remove from PET, thereby causing contamination in the final product. Reclaimers may remove packages known to employ these sinking plastics manually to reduce contamination levels if they are commonly found in the recycle stream.
PE, EVA and TPE liners in plastic closures are preferred. PE, EVA and TPE float in water and will be separated in the recycling process with the floatable polyethylene and polypropylene closures. Since PET reclaimers can recover PE, EVA and TPE in the float stream, they are preferred liner materials. Dispensers, closures or lidding with metal components require testing to determine the appropriate recyclability category Metal contamination is highly undesirable in recycled PET so the use of metal components with PET packaging is discouraged; metals create wear in process machinery, increase operation costs and yield loss, and are a primary source of defects in products made with recycled PET. MRFs and PET reclaimers use magnets, eddy current separators and metal detectors to keep packages with metal components out of the process stream. Any metal components that trigger these devices will cause the entire plastic product to be removed from the stream and render the package non-recyclable. When metal components are not detected and removed by process equipment, the package generally passes into the granulator and the metal components are considered detrimental to PET recycling. In cases where a package with a metal component passes through metal detection, some PET reclaimers remove these manually from the stream to reduce the impact of metal contamination; packages removed manually become waste. Aluminum components are particularly difficult to remove effectively due to the limitations of eddy current separators and flake sorters in detecting smaller nonferrous components or granulated pieces.
The use of PVC closures or closure liners renders the package non-recyclable per the Association of Plastic Recyclers (APR).
PVC sinks and is extremely hard for the recycler to remove, particularly in small pieces. The recycled PET stream is very intolerable to even minute amounts of PVC.
LABELS, INKS AND ADHESIVES
Label selection should be considered carefully to find the solution most compatible with the recycling process that also provides the necessary performance characteristics. There are many label designs available and each of these designs performs differently in the various recycling processes. As a minimum, labels should use adhesives that release from the bottle and be designed so Near Infrared (NIR) sorting machinery can identify the bottle polymer with the label attached. Label systems, adhesives and inks designed to perform in specific portions of the recycling process are all beneficial. Removing adhesives is a significant component to the cost of recycling so the packages using the lowest quantity of appropriate adhesive are the most compatible. An overview of labels and their compatibility with specific portions of the recycling process can be found at:
Polypropylene or polyethylene labels with a specific gravity less than 1.0 are preferred.
These materials float in water so they are separated from the PET in the float-sink tank with the closures. Since they are the same general polymer as most of the closures they do not contaminate or devalue this stream.
Care should be taken to ensure that any modifiers to the label material do not increase its density above 1.0.
Laminated labels require testing to determine the appropriate APR recyclability category.Labels that break into small, very thin pieces of material are more difficult to manage in the recycling process because they behave erratically in a float-sink tank. Therefore, labels that stay intact are preferred. Carry-over of delaminated labels into the RPET can result in contamination.
Full bottle sleeve labels require testing to determine the appropriate APR recyclability category. Full bottle sleeve labels cover a large amount of the bottle surface with a polymer that is not the same as the bottle body. Because of this, a sleeve label designed without considering recycling may cause a false reading on an automatic sorter and direct a PET bottle to another material stream where it is lost to the process. Furthermore, some sleeve label materials cannot be removed in the recycling process and contaminate the RPET produced. Sleeve labels that have been found compliant with the APR test protocols should be selected.
Pressure sensitive labels require testing to determine the appropriate APR recyclability category. Pressure sensitive labels generally require complete adhesive coverage which is greater than other typical label methods. This raises the importance of the compatibility of the type of adhesive with the recycling process.
Adhesives resistant to washing in the recycling process allow labels to remain on the PET and become contaminants in the final product. Adhesives that have been found compliant with the APR test protocols should be selected.
It is important to make a distinction between bio-based and bio-degradable packaging.
Bio-based plastics are made of renewable raw materials such as sugar cane, starch, glucose, vegetable oils and cellulose. The raw materials are derived from different agricultural products or plant residues and subsequently transformed into basic substances to be processed into different types of bioplastics. Bio-based plastics are not necessarily biodegradable. In general, they have the same properties as their fossil predecessors.
The big advantage of these raw materials is that they are made from renewable resources and can be processed in an existing recycling process and that they can be re-used for plastic products. BioPET is a plastic based on 30% renewable raw material and 70% oil-based raw material. Coca-Cola Company has been using BioPET since 2009 in the form of the “Plant Bottle”. The mechanical and thermic properties of BioPET are similar to other oil-based PET products.
PET (62%) and HDPE bottles (37%) together represent 99% of all plastic bottles recycled
PP (1%) is often co-mingled with HDPE when recycled due to its failure to have enough material in the waste stream to reach “critical mass”.