Recycling of Plastic Bottles into Yarn & Fabric

Recycling of Plastic Bottles into Yarn & Fabric

Prof Yogita Agrawal(Asst.Prof) ,Prof. Rupali Kapoor(Asst.Prof),

Prof. Tanveer Malik (Asst.Prof) ,Ms Vidhi Raghuwanshi

Shri Vaishnav Institute of Technology and Science, Indore(MP)

[email protected]

Abstract

In this project report I am going to discuss about the recycling of the plastic bottles into the yarn and fabric. In this report it is describe how the plastic bottles that are a non degradable waste which is increasing the waste and one of the reasons for global warming can be converted into a useful product that is fiber and than it can be further used for making yarn and into fabric.

In this report it will be discussed about the making of the fiber from the plastic bottles and then formation of yarn. Further we will study the properties of the yarn and its application in different field.

Introduction

Today, the utilization of recycled materials is matter-of-fact, although in virtually no other sector is it quite as advanced as it is in the case of the manufacture of manmade fibers. Compared to using new plastics, utilizing recycled materials can lead to a significant reduction in energy consumption and CO2 emissions. Furthermore, valuable raw material resources such as oil are preserved and the amount of waste at dumps is reduced

The clothing industry is a heavy user of resources and an equally heavy polluter. It is a consumer industry that by its nature encourages people to buy and discard clothing according to the fashion of the day rather than in terms of durability or environmental impact. Environmental fashion, organic fashion, and recycled fabrics are attempts to alter the status quo. Organically produced cotton avoids the use of chemicals and poisons but is still a minority of what is available. On the other hand, Australian company INSTYLE selects wool over recycled PET for its textiles because wool is locally produced and doesn’t contain the hazardous chemicals which are present in PET.

“The fabric made out of the PET fibre is basically polypropylene and it is ten times stronger than a normal polyester fabric. But to weave or knit the yarn made out of PET bottles needs very heavy machines and till now Europeans have mastered in this technology and the looms/knitting machines are very expensive,” points out Gautam. However, the company is exploring the possibility of manufacturing PET based fabrics in India.

Literature review:

• Fiber and filaments, expert’s magazine, August, 2013
• Scrap-pet-bottles-to-re-generated-polyester-staple.

Objective:

1. To make the yarn and fabric from plastic bottles.
2. To study the various properties of the yarn and fabric formed.

History

“There’s been a fundamental change in our culture when it comes to recycling and sustainability,” remarked William L. Jasper, president and CEO of Greensboro, N.C.-based Unifi Inc., manufacturer of Repreve® recycled fibers and yarns. “The younger generation thinks about it differently than the older generation. It’s really much more important now, and it’s going to continue to be. People are starting to recognize there are only so much landfill space and only so much oil.”

Post-industrial (PI) recycling has been practiced for years, and the first recycled-content textile products contained primarily or exclusively PI materials, which would include trimmings left on the cutting room floor in apparel and other textile product manufacturing facilities.

In recent years, post-consumer (PC) content has increased as more and more consumer recycling programs have been established in communities across the United States and in other countries worldwide.

Terminology:

What is polar fleece?

• polyester fleece or polar fleece is a soft, fluffy, two-sided pile fabric which is really warm, really durable, resists moisture and dries quickly
• popular for outdoor wear since the early 1990s because it’s lighter and warmer than wool
• has also been used for more unusual garments e.g. underwear for astronauts, ear-warmers for winter-born calves
• the polymer used to make polyester fibres is known as polyethylene terephthalate or PET; the same is used for drink bottles
• some or all of the yarn can be made from recycled bottles

What is PET?

• PET is the name of the resin used to make transparent, light, shatterproof bottles for soft drinks, juices, alcohol, water, detergents, soap etc
• PET stands for polyethylene terephthalate
• bottles are the most significant use for PET
• PET is fully recyclable

Methods:

The recycling process – the basis for further processing:

Expert processing of waste is the decisive prerequisite for manufacturing high-end recycled yarns. It enables the utilization of recycled materials in place of new material with merely a small change to the processing method. To this end, there are two different processing approaches, described as chemical or mechanical recycling.

In the case of chemical recycling, the old plastic is broken down into its original monomers by means of glycolysis, hydrolysis or methanolysis. These monomers are then used to manufacture new plastic granulate through polymerization. To this end, the quality of the recycled product is very close to that of new materials and it can be used to spin high-end yarn.

Compared to mechanical recycling, the chemical procedure requires greater energy consumption. Add to this the fact that due to the high capital investment requirements, this option is only available to large-scale manufacturers, as cost efficiency can only be achieved from annual capacities of 50,000 tons and more.

For this reason, mechanical recycling has been the clearly predominant recycling method to date. Here, plastic waste is melted directly without any chemical decomposition. The melt can then be either processed directly into the end product or first granulated into chips. There is a current trend towards systems for in-house recycling of production waste in the form of chips. Recycling systems available on the market can process various forms of waste, including solid start-up lumps, for instance. To this end, the waste is shredded, melted and re-granulated. Processed in this way, it can then be simply reintroduced to the production cycle.

How do you turn a few plastic bottles into polyester and performance apparel?

It all starts when you toss a PET bottle (labeled #1) into a recycling bin. These bottles are sorted at a recycling facility and bundled together in large bales.  The bales of PET bottles are then taken to a PET reclaiming facility. The bottles are thoroughly cleaned, the labels and caps are removed, and the bottles are separated by color (the clear bottles will produce a white-ish polyester yarn and the green bottles produce a green-ish yarn).

Once they’re sorted, the bottles go into a grinder where they are ground into small flakes. The flakes are tossed in hot air to give them a hard candy coating and then dried to remove any remaining moisture. Next, the dry, crispy flakes are shoved through hot pipes to melt them into a thick liquid. That liquid gets filtered through a dye plate with 68 tiny holes. As the liquid polyester flows through the holes, it forms filaments that are more than five times finer than human hair. The filaments pool and harden and are then sent over rollers where air entangles the filaments to create a dental floss-like yarn. The machine spools the yarn and then pulls it over hot metal rollers to stretch it and realign the polyester molecules. The resulting yarn is ready to be woven into polyester clothing.

PET recycling process

• PET bottles are sorted from other recyclable plastics such as PVC and HDPE, as the reclaimed material (PET flakes) is most valuable when it is most pure
• bales of recycled bottles are sorted manually or automatically on the basis of colour, and to remove any foreign material or non-PET lids and bases
• the plastic is washed in a sterilising bath, after which the clean containers are dried and crushed into tiny flakes
• the flakes are washed again to ensure the purest possible final product
• these flakes become the raw material for new products
• for yarn, the light-coloured flakes are bleached, while flakes from darker bottles are used for yarn that will be dyed a dark colour; the flakes are melted in a vat and forced through spinnerets to produce fibres

Production process flow

Properties:

Recycling Facts

• 10 plastic bottles = 1 pound of polyester fiber
• 1 ton (2000) lbs of plastic bottles recycled saves 3.8 barrels of oil
• 1 million plastic bottles recycled saves 250 barrels of oil
• 1 million plastic bottles recycled eliminates 180 metric tons of CO2 emissions from being released into the atmosphere
• 10% of all US oil consumed (2 million barrels per day) is used to make plastics
• Recycling plastic bottles takes 8 times less energy than to produce an equivalent amount of new ones
• 150 fleece garments made from recycled plastic bottles save 1 barrel of oil
• 500 Custom t-shirts made from recycled plastic bottles saves 1 barrel of oil
• 50 back packs made from recycled plastic bottles saves 1 barrel of oil
• Supplying the plastic bottles that Americans consume each year requires 47 million barrels of oil and releases 1.0 billion pounds of CO2 into the atmosphere

Fiber and Yarn Construction Capabilities

• FIBERS: All natural and manmade fibers and blends
• OPEN-END: .4Ne. to 14Ne. or .67Nm to 23.6Nm. in singles and plies
• DREF SPUN: Customized solutions and proprietary capabilities
• TWISTING: Up to 16 components

Plan of work

Sorting

When the PET bottle is returned to an authorized redemption center, or to the original seller in some jurisdictions, the deposit is partly or fully refunded to the redeemer. In both cases the collected post-consumer PET is taken to recycling centers known as materials recovery facilities (MRF) where it is sorted and separated from other materials such as metal, objects made out of other rigid plastics such as PVC, HDPE, polypropylene, flexible plastics such as those used for bags (generally low density polyethylene), drink cartons, glass, and anything else which is not made out of PET.

Post-consumer PET is often sorted into different color fractions: transparent or uncolored PET, blue and green colored PET, and the remainder into a mixed colors fraction. The emergence of new colors

(such as amber for plastic beer bottles) further complicates the sorting process for the recycling industry.

PET bottles are separated from other plastics in a materials recovery facility.

 

 

Bales of crushed PET bottles sorted according to color: blue, transparent, and green.

 

Bales of crushed PET bottles.

 

 

Processing for sale                                            

The sorted post-consumer PET waste is crushed, pressed into bales and offered for sale to recycling companies. Colourless/light blue post-consumer PET attracts higher sales prices than the darker blue and green fractions. The mixed color fraction is the least valuable.

Further treatment

The further treatment process includes crushing, washing, separating and drying. Recycling companies further treat the post-consumer PET by shredding the material into small fragments. These fragments still contain residues of the original content, shredded paper labels and plastic caps. These are removed by different processes, resulting in pure PET fragments, or “PET flakes”. PET flakes are used as the raw material for a range of products that would otherwise be made of polyester. Examples include polyester fibers (a base material for the production of clothing, pillows, carpets, etc.), polyester sheets, strapping, or back into PET bottles.

Melt filtration

Melt filtration is typically used to remove contaminants from polymer melts during the extrusion process. There is a mechanical separation of the contaminants within a machine called a ‘screen changer’ a typical system will consist of a steel housing with the filtration media contained in moveable pistons or slide plates that enable the processor to remove the screens from the extruder flow without stopping production. The contaminants are usually collected on woven wire screens which are supported on a stainless steel plate called a ‘breaker plate’ a strong circular piece of steel drilled with large holes to allow the flow of the polymer melt. For the recycling of polyester it is typical to integrate a screen changer into the extrusion line. This can be in a pelletizing, sheet extrusion or strapping tape extrusion line.

Once the flakes are dried up, they pass through a process called electrostatic separator, which produces magnetic field to separate PET flakes from metal, besides different kinds of plastic particles and other contaminations. The cleaned flakes of reclaimed PET are then forwarded to production section for the final product to produce fibre. According to Gopal Agarwal, CFO, GPL, the sorting and processing of raw material is a key factor for maintaining uniform quality of finished product on constant basis as raw material is not having uniform characteristics, and quality of finished goods may have significant degree of variations.

How plastic is converted into yarn to weave or knit fabric?

Converting it into garment or home furnishing products is an interesting transition. It actually happens by re-melting the PET bottles and then thick material is pressed through spinnerets, leaving them as filaments – just like in case of the production of virgin synthetic fibres. Filaments can be used as endless yarns or curled and cut into length-defined fibres for spinning. After weaving, the fabric is converted into garment, preferably fleece pullovers, jackets or sweatshirts.

The recycled PET thread or yarn can be used either alone or together with other fibres to create a very wide variety of fabrics. Traditionally these fabrics were used to create strong, durable and rough products, such as jackets, coat, shoes, bags, hats and accessories. However, these fabrics are too rough on the skin and could cause irritation. Therefore, they are not used on any clothing that may irritate the skin, or where comfort is required. But in today’s new eco-friendly world, there has been more of a demand for “Green” products. As a result, many clothing companies have started looking for ways to take advantage of this new market and new innovations in different ways to process the fabric, to use the fabric, or blend the fabric with other materials for better finish so as to be more wearer-friendly.

Technology

The processing of the melt from recycled material can in principle be carried out in the same way as in the case of utilizing new granulate. The filaments are cooled, drawn, textured and wound following melting and spinning. Fundamentally, recycling applications in yarn manufacturing include: staple fibers, carpet and textile filaments as well as nonwovens. As examples, the number of 2-liter PET bottles required for specific applications is roughly as follows: 5 for a T-shirt, 20 for the filling of a winter jacket, 20 for a sweater, 35 for a sleeping bag and 40 for 1 m2 of carpeting.

The overall trend is moving away from simple fillers to more differentiated products with higher value added. These include, for example, spun-dyed FDY filaments.

BCF applications – for which the deployment of recycled PET is already widespread – are extremely interesting. Recycled PET is frequently used in regranulated form and incorporated in different ratios. However, applications with 100 percent inputs of flakes are currently possible using Oerlikon Neumag technology. It is particularly in this sector that there is currently strong growth, with an increase of 13,000 tons per annum in 2013 and a further 27,000 tons per annum by 2015.

In the case of staple fibres, the trend is currently very much on the deployment of bi-component technology. Here, separate extruders with individually temperature-controllable melt pipes and special spinning units are utilized, with either different polymers or the same polymers with various iscosities being used. The spinning beam is connected to the temperature regulating system of the higher-melting polymer. Short dwell times in the spinning beam prevent the lower-melting polymer experiencing thermal damage. The spin pack for bi-component fibres physically separates both melts right up to the capillary that actually creates the filament. Pre-spinneret and spinneret subsequently allow the two components to be arranged in different ways.

Both round and trilobal cross-sections are possible in the case of fibres with mantle and core. One possible combination for the components is recycled PET for the core, with a mantle made from the respective virgin material or a copolymer. To this end, the ratio of core and mantle can be variably adjusted, so that – despite the deployment of predominantly recycled plastic – the thin mantle layer ensures a perfect surface.

And recycled material is also used for manufacturing filament yarn. Here, melt-dyed FDY yarns, which can be produced directly from flakes without preparation, are a growing area. To this end, some companies are – thanks to Oerlikon Barmag machines – already successfully marketing recycled FDY, for example. As minor contaminants can result in more frequent yarn breaks, utilizing the very latest spinning technology is particularly important. POY and DTY from recycled raw materials usually have coarser titers to compensate for weaknesses caused by contaminants (70- 150 den).

China recently introduced three official standards for filaments made from recycled materials: R-POY, R-DTY and R-FDY. These categories, with fixed logos, technical requirements and testing methods have created uniform standards.

In the future, greater deployment of recycling is quite conceivable within the industrial yarns sector. In the Ford Focus, a large proportion of the seat covers today are made from recycled polyester fibres. Here, around 22 plastic bottles are recycled for use in each vehicle. The manufacture of tire cord however is even more problematic and is only possible using chemical recycling. Residual contamination is still too high in the case of mechanical processes.

Advantages

The only difference between the production of recycled polyester yarn and virgin polyester yarn is in the initial material. The production of virgin PET begins with the production of nurdles–teeny tiny plastic resin pellets-made from petroleum and other products. Unfortunately, nurdles are little troublemakers that often find their way into waterways. Additionally, making nurdles requires a lot of energy, much more then grinding up plastic bottles. By some estimates, the production of recycled PET uses 2/3 less energy and almost 90% less water than the production of virgin PET. And of course, no new petroleum is required to produce recycled PET

What is saved?

• landfill: an estimated eight plastic drink bottles are kept out of landfill for each metre of polar fleece made from 80% recycled PET bottles
• fossil fuels: virgin polyester is derived from petroleum, so it saves on fossil fuels
• Patagonia, the leading manufacturer of recycled polar fleece clothing, estimates that 25 drink bottles go into each jacket. They claim that for about 150 garments made, they save a barrel of oil and avoid half a tonne of toxic air emissions compared to making it out of virgin polyester.

Newlife™ is a complete and certified system of recycled polyester filament yarns coming 100 percent from recycled plastic bottles, processed into a polymer through a mechanical (not chemical) process and spun into yarn. The flexible Newlife platform allows for a vast number of applications and performances with levels of quality at least equal to virgin polyester equivalents, but with considerable resource and cost savings for the environment. Applications for Newlife include fashion, sportswear, underwear, technical clothing, work wear, medical garments, outdoor clothes, furnishings and accident prevention textiles. Thirty 1.5 liter bottles make one kilo of Newlife yarn.

Global statistics

Worldwide, approximately 7.5 million tons of PET were collected in 2011. This gave 5.9 million tons of flakes. In 2009 3.4 million tons were used to produce fiber, 500,000 tons to produce bottles, 500,000 tons to produce APET sheet for thermoforming, 200,000 tons to produce strapping tape and 100,000 tons for miscellaneous applications. (Source: PCI, www.pcipetpackaging.co.uk )

Petcore, the European trade association that fosters the collection and recycling of PET, reported that in Europe alone, 1.6 miln tones of PET bottles were collected in 2011 – more than 51% of all bottles. After exported bales were taken into account, 1.12 million tons of PET flake were produced. 440,000 tons were used to produce fibers, 283,000 tons to produce more bottles, 278,000 tons to produce APET sheets, 102,000 tons for strapping tape and 18,000 tons for miscellaneous applications. (Source: PCI for Petcore and EuPR)

In 2012, 81% of the PET bottles sold in Switzerland were recycled.

Indian companies and foreign companies

FABRIC FROM PLASTIC

• Arora Fibres recycles discarded plastic bottles into polyester used as packaging material Don’t chuck out those plastic bottles that have been piling up in your kitchen for days. They can be re-used to make polyester fabric. Rupinder Singh Arora, Chairman of Arora Fibres Ltd, has been recycling discarded plastic bottles into polyester staple fibre since 1994 after he saw the colossal damage to the environment from mountains of bio-degradable plastic being burned in the country. “We were the pioneers in this field.
• Patrick Yarns is leading the revolution in spinning high quality yarns from recycled fibers. Our proprietary engineered process of certified textile recycling reclaims unwanted cloth or garment fabrics without seriously damaging the fibers.
• The major customers for our PET recycled fibre are spinning mills like Birla Cotsyn, Chenab Textiles, Orient Syntex to mention a few. The end use of this recycled fibre is – spun yarn, hosiery yarn, blended woollen yarn and technical textiles,” shares Gopal.
• The yarn produced out of the recycled fibre is being exported as well as being sold in the domestic market. Delhi-based Orient Syntex is exporting its yarn to Malaysia and in the domestic market it is selling its yarn through agents in Erode,Tirupur, Salem, etc. who are selling these yarns to companies like Export Tex, Javan Knits Garments, etc.
• According to Gautam Sureka of Eastern Silk Industries, Kolkata which has gone for a joint venture with an Italian company SATI to manufacture technical textiles in India for industrial wear, the recycled PET fibre has not picked up so much in India for textile purpose as it is a very expensive process and there is yet no real demand for the same.
• Polar fleece has become the fabric of choice for outdoor enthusiasts because it is so light and warm. Increasing amounts of polar fleece are made from recycled PET bottles in preference to virgin polyester. The process saves on raw materials and energy use, and diverts rubbish from landfill.
• Patagonia, a US based company, pioneered the concept of recycled polarfleece garments for outdoor wear. It employs environmental design strategies at all stages of the garment life cycle. Recycled polar fleece clothing is available in Australia, but the fabric is currently manufactured overseas.
• There are arguments for and against the use of PET over natural fibres. Although recycled PET is a synthetic material, its use is environmentally preferable to cotton. Cotton production uses more land, more water, and more chemicals. Australia is making strides into environmental fashion that extend beyond polar fleece. Tencel and hemp are being used for clothing by Australian companies. Target is using recycled fabrics in its clothing and doonas.

LIBOLON strives for developing recycled polyesters and innovatives RePET®-solution rpet recycled polyesters yarns are more environmentally-friendly than traditional RePET® products due to the elimination of the dyeing process. Using Recycled Polyester and eco textiles, LIBOLON’s RePET®-solution rpet recycled yarns reduce emissions of GHG and COD, lower water consumption, and decrease the amount of chemicals involved in the production process. RePET®-solution rpet recycled yarns also offer higher performance, including light-protection, water-protection, washing-protection, anti-UV, anti-aging, anti-weathering, and color reproducibility properties. LIBOLON’s RePET®-solutions will be your best choice for Recycled Polyesters and eco textile products.

Application

Finished product finds application in spinning of yarn, stuffing of toys and other life style products like pillows, quilts, mattresses and furniture, non-woven carpets and fabrics, automotive non-woven roofing insulation, medical & packaging textile, geo textile, fur fabrics and other technical textiles

Recycled PET bottles used for a range of items

• can be recycled back into bottles, but at present the fibre market is the major outlet for recycled PET
• fibres from recycled PET bottles are used to make a range of items: finer fibres are used for clothing; coarser yarns are used for carpeting

Successful Yarn Applications

• Colored recycled fiber blends producing economical colorfast yarns
• Integrating recycled fibers in the yarn center to create a core filler
• Matching a recycled fiber percentage within a high value, yet economical performance blend
• Optimizing a higher valued recycled fiber percentage in a commodity-driven yarn to enhance product value without significant price disruptions.

BUSINESS STRENGTHS

Point 1: Proliferation in the use of PET bottle on the back of 7 – 8 % CAGR growth coupled with low scale of recycling (about 30 – 40 %) to yield abundant feed stocks to be recycled.

Point 2: Indian Man Made Fiber (MMF): Natural fiber ratio of 41:59 to align to global ratio of 63:37 consumption. Huge scope of growth in consumption of polyester fiber.

Point 3: Raw material price for recycled PSF insulated unlike in virgin PSF which is linked to crude prices (PTA and MEG) thereby ensuring stable margins with scale up of business.

Point 4: Changing life styles and cost effectiveness led to innovative applications of the MMF. This has clearly helped to expand its market share. Such trend is likely to continue. Some of the notable ones are winter clothes, Disposables, Non-woven, technical textiles etc. Expanding market lends growth visibility

Point 5: Govt. support in terms of Excise Duty exemption for recycled PSF.

Point 6: Industry associations like CII, have launched programs to reward companies for green endeavour like recycling. In future, government shall extend benefits to such companies.

India Cued into the Trend

In India as well there are companies, which have put up PET phase capacities. As per the estimates, India produces 500,000 tonnes of pet waste every year and due to increasing use of pet bottles in daily consumption, the amount of waste is going to grow by leaps and bounds. At present, the total recycling capacity in India is around 145,000 TPA, out of which Reliance Industries Ltd. has a capacity of 42,000 TPA and Kanpur-based Ganesh Polytex Ltd (GPL) has a capacity of around 39,600 TPA and rest is with other small local players.

Presently GPL is recycling about 1.4 billion PET bottles annually at its Rudrapur plant where the bottles are first cleaned and then sent to shredders and grinders to reduce them to flakes. The flakes are forwarded to the cleaning section for a series of sorting and washing process performed with chemicals to remove any residual.

“Though it is still early, buyers have started showing interest. While interacting with various buying offices like Ahlens, JCPenney, to mention some, they are looking at recycled PET as an alternate to man-made fibre. Says Richard James, Head Ahlens India, “On my recent visit to Thailand, I met a company which is making yarn out of PET, I found the product very interesting and I am now looking at developing fabric with this yarn to do some product development in home furnishing items like for rugs and carpets.”

Whatever developments in PET yarn Richard found in Thailand was in thicker count and not finer counts which can be used for making garment. JCPenney too is looking for PET yarn and fabric makers in Taiwan.

As things are moving it would not take too long for fabrics made out of PET bottles to get popular with consumers especially for industrial garment and sportswear. The demand of course has to percolate from the buyers’ end and when there is demand, the developments will take place. How soon the concept spreads, that is still to be speculated as the technology is expensive but then it’s environment-friendly preposition which is buyer’s first concern; however, it also contradicts their belief that it is not organic and cannot be organic.

Summary

The savings made by utilizing low-cost raw materials for recycled products are usually completely eaten up by complex collection and preparation processes.

Nevertheless, recycling can still generate attractive profits, as customers are increasingly willing to pay higher prices for sustainable and environmentally-friendly products. The growing interest in ecological yarns has been driving the creation of new and highly-respected certificates. To be issued these coveted labels, manufacturers must provide evidence of sustainable production for 100 percent of their recycled material. For this reason, ever more companies are demanding energy-saving machines for manufacturing high-end recycled yarns. Oerlikon Barmag and Oerlikon Neumag have the innovative technologies to cater to this expanding market segment with the right machine concepts.

RESULT AND CONCLUSION

The practical will be further continued in the major project and in that the yarn and fabric will be formed and further study will be done in that.

References:

• Fibers and filament, issue aug,2013
• Scrap-pet-bottles-to-re-generated-polyester-staple.
• https://merridypugh.com/portfolio/recycling-project
• https://www.patrickyarns.com/green_recycled/earthspun/
• https://specialtyfabricsreview.com/articles/1012_np2_postconsumer_polyester.html
• https://www.indiantextilejournal.com/articles/FAdetails.asp?id=2904
• https://www.vrijesh.com/recycled_polyester.htm
• https://www.textileworld.com/Issues/2010/November-December/Features/From_Waste_To_Worth
• Clark Howard, Brian. “Recycling Symbols on Plastics – What Do Recycling Codes on Plastics Mean”. The Daily Green (Good Housekeeping). Retrieved May 7, 2012.
• Teijin Group. “Teijin Develops Eco-friendly Wet-strong Printing Paper Made 100% with Recycled Polyester Derived from Used PET Bottles”. Teijin Group. Retrieved March 12, 2013.
• “Plastic Packaging Resins”. American Chemistry Council.
• Melt Filtration Options and Alternatives
• https://www.bafu.admin.ch/dokumentation/medieninformation/00962/index.html?lang=fr&msg-id=50084
• https://omnexus.specialchem.com/selection-guide/polypropylene-pp-plastic
• https://happydiyhome.com/types-of-pillows/