Final Thesis

SEMESTER –VII

THESIS TITLE

“STUDY OF PET WASTE RECYCLING“

PROJECT ADVISOR

ASSOCIATE PROFESSOR ARSHAD FARUQUI

GROUP MEMBERS

QASIR NAZIR 16-PE-12

YASIR ABBAS 16-PE-18

ADIL HANIF KALWAR 16-PE-20

ISRAR AHMAD 16-PE-22

IJAZ HUSSAIN 16-PE-07

FARAZ ALI KHAN 16-0-PE-05

MUHAMMAD FAIZAN KHALID 16-0-PE-12

SALEEM SIDDIQUI 16-0-PE-18

ACKNOWLEDGEMENT

In the name of Allah, the Most Gracious and the Most Merciful Alhamdulillah, all praises to Allah for the strength and blessing in completing this thesis. Special appreciation goes to Professor Dr. Naim Masood Hasan , Associate Professor Zaheer Ahmed Chaugtai , Associate Professor Tariq Jamal . Associate Professor Arshad Faruqui for his supervision and constant support. We also wish to acknowledge Laboratory & Technical staff for helping us. Sincere thanks to all our seniors for their support during the study.

Last but not least, deepest gratitude goes to our beloved parents for their endless love, prayers and encouragement. To those who indirectly contributed in this research, your kindness means a lot to us. Thank you very much.

___________________________________

TABLE OF CONTENT

ACKNOWLEDGEMENT………………………………………………….………………………………….i

INTRODUCTION...................................................................................................1

CHAPTER 1. Literature Survey……………………………………....……………………………...2

Poly(ethylene terephthalate)……………………………………………………….……………………………………….2

History of PET……………………………………………………………………………….………………………………………2

Chemistry of PET………………………………………………………………………….….……………………………………3

Formation of PET………………………………………………………………………….………………………………………3

Morphology of PET……………………………………………………………………….………………………………………5

Properties of PET………………………………………………………………………….…………………………………..….6

Process ability of PET…………………………………………………………………….…………………………………..…6

Application of PET………………………………………………………………………….………………………………….…6

CHAPTER 2. Recycling of PET Plastics……………………...........................................9

Introduction……………………………………………………………………………….……..…………………………………9

PET Recycling…………………………………………………………………………….……………………………………….11

History of PET Recycling…………………………………………………………….……………………………………….11

Effect of Contaminants of PET…………………………………………………....………………………………………11

CHAPTER 3. Physical Recycling Techniques…………………………….…………………….13

Flotation or Hydrocyclone Process…………………………………………….……………………………………….13

Water Bath / Hydrocyclone Process………………………………………….…………………….………………….14

Solvent /Floatation Process……………………………………………………….……………………………………….14

Physical Recycling of PET bottle to Form Fibre………………………….…………………….………………….15

PET bottles recycling in Pakistan…………………………………………………………………….………………....19

CHAPTER 4. Chemical Recycling to form Unsaturated Polyester Resin ………..22

Glycolysis………………………………………………….…………………………………………………………….………….22

Hydrolysis………………………………………………….……………………………………………………….………………24

Methanolysis…………………………………………….……………………………………………………….……………….25

Chemical Recycling Of Pet on Laboratory Scale…………………..………………………………………………25

Formulation of Recycled Unsaturated Polyester ……..…………………………………………………………26

CHAPTER 5. Applications of Recycled PET……………………………..………………………27

Unsaturated Polyester Products…………………………………………………………………………………………29

a. GRP Pipes ……….………………………………………………………………………………………………………29

b. GRP SHEETS…………………………………………………………………………………………………………….29

c. GRP Houses…………………………………………………………………………………………………………….30

d. Cultured Marble……………………………………………………………………………………………………..30

CHAPTER 6. Testing………………………………………………………………..…………….………33

Fibre Testing…………………………………………………………………………………………………….………………..33

Description of Test for Fibre…………………………………………………………………….…………………………33

a. Denier Testing…………………………………………………………….……………….………………………….33

b. Cut Length………………………………………………………………………………….…………………………..34

c. Friction Measurement……………………………………………………………….……………………………34

d. Draw Ratio…………………………………………………………….………………….…………………………….34

e. Thermal Shrinkage…………………………………………………….…………….……………………………..35

f. Tensile Strength And Elongation at Break for Fibre………..…….………………..….….……….37

Comparison Test Report of Virgin Unsaturated Polyester Resin with Recycled

Unsaturated Polyester Resin (8THSemester) .…………………………………………..….……………….…38

Description of Test for Unsaturated Polyester Resin…………….……………………………….……………39

a. Density…………………………………………………………………….……………………………………………..39

b. Acid Value……………………………………………………………….………………………….…………………..39

c. Viscosity………………………………………………………………….………………………...……………………39

d. Gel Time………………………………………………………………….……………………………………………..39

e. Exothermic Temperature……………………………………….……………………………………………….39

f. Peak Time………………………………………………………………..................................................39

CHAPTER 7. Market Survey…………………………………..………………………..…………….40

Local Market Survey………………………………………………………………………………………….……………….42

International & Local Manufacturer, Supplier & World Scenario…………….……………….…………46

CHAPTER 8. Work Plan…………………………………………………………………….……..……………………48

References…………………………………………………………………………………………….……...…………………..49

STUDY OF PET WASTE RECYCLING 2012

P L A S T I C S T E C H N O L O G Y C E N T R E

Page 1

INTRODUCTION

Poly (ethylene terephthalate), PET is an important engineering thermoplastic

which is widely used all around the world. The basic sources of raw materials for

PET resin production are crude oil and natural gas. PET is a condensation polymer

derived from terephthalic acid (TPA) or dimethyl terephthalate (DMT) and

ethylene glycol (EG). The great acceptance of PET as a packaging material is due

to its toughness, clarity, capability of being oriented and reasonable cost.

Compared to glass, PET containers are lightweight and shatter-resistance. They

provide an acceptable barrier and they are considered as the most recyclable

plastics in world. Each year millions of tons of PET remain as scrap after being

used in several areas. Because of the governmental and environmental

regulations, PET is being recycled [1].

In this study, bottle grade and fibre grade Polyester was recycled by two different

methods, such as physical recycling and chemical recycling. In physical recycling

the PET bottle were crushed washed and extruded to get fibre but In Chemical

recycling PET bottle flakes were used, there are different methods in chemical

recycling such as, Glycolysis, Hydrolysis, Methanoylsis etc. However, in industry

glycolysis method is used for chemical recycling.

The main objective of this study is to obtain fibre and unsaturated polyester resin

from recycling of PET. In addition to this main objective is to reduce the

manufacturing cost of fibre and to manufacture unsaturated polyester resin from

bottle grade PET to reduce the manufacturing cost of UP resin and improve the

physical and chemical properties of UP resin[2].



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CHAPTER 1

LITERATURE SURVEY

1.1. Poly(ethylene terephthalate)

Poly (ethylene terephthalate), PET, is one of the most commercially used

thermoplastic. PET is a linear condensation polymer that has been used in

applications that have seen rapid growth especially as packaging material for

carbonated beverages since it was introduced as a container resin. Prior to this

surge in use, PET was used as food packaging film, including boil-in-bags for

frozen vegetables, and most commonly for the production of fiber for clothing

and other applications. The structure of PET is as follows [3].

Figure. Chemical structure of PET

1.1.1. HISTORY OF PET

PET has been well known under the name of polyester for more than 60 years.

The following milestones mark the development from polyester fibres in the

early 1940ies to modern PET bottles. Calico Printers Association [4], a small

English company, developed the first laboratory samples of poly (ethylene

terephthalate) in fiber form in 1941. Polyester research began in the United

States after World War II. Nathaniel C. Wyeth is a inventor of PET bottle. In the

1950s, this research was based on textiles such as DuPont's Dacron™ and ICI's

Terylene™. In 1962, the first polyester tire cord was manufactured by Goodyear

[4]. In 1977, PET was produced commercially for packaging applications such as

film, sheet, coatings, and bottles - although oriented PET film was available in the

1950s. Since then due to the new improvements in mechanical and barrier

properties, the consumption of the resin has grown rapidly, primarily for

carbonated beverage bottles.

1941: production of first polyester Fibres.

1950s: production of textile fibres (brand names: “Trevira”,

“Dralon”)



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1950-60s: extended use in textile industry

1970s: first production of packaging containers

End of 1980s: first refillable beverage containers

1.1.2. CHEMISTRY OF PET

PET is made industrially by two methods, the first step in each of which involves

conversion of the TPA and DMT feed stock with ethylene glycol (EG) into bis

(hydroxyethyl) terephthalate (BHET). In the early stages, polymer technology was

not developed to produce TPA with sufficient purity. In the early 1960s, pure TPA

was produced directly from p-xylene with bromide-controlled oxidation. DMT

was made by esterification of terephthalic acid. However, a different process

involving two oxidation and esterification stages is now used to produce most

DMT. The intermediate product, ethylene oxide is produced by oxidation of

ethylene. Then ethylene glycol is obtained by reaction of ethylene oxide with

water.

1.1.3. FORMATION OF PET

PET is a step-growth (condensation) polymer derived from terephthalic acid

(TPA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) according to the

following chemical reactions

Figure 2.2 PET formation via acid route

Figure 2.3 PET formations via ester interchange



Page 4

In condensation polymerization, if the system is heated with antimony catalyst, a

reversible reaction takes place between two polyfunctional molecules to produce

one larger polyfunctional molecule, with the possible elimination of a small

molecule such as water or methanol. The polycondensation rate is heavily

dependent on the type and concentration of the catalyst. The reaction continues

until almost all of one of the reagents is used up; an equilibrium is established

which can be shifted at high temperatures by controlling the amounts of the

reactants and products. “Copolyesters, which are produced commercially to

reduce the crystallinity of PET, are made by replacing the TPA or EG portion with

another dibasic acid or glycol or both. The step growth polymerization occurs in

two steps: First, a low molecular weight precursor is formed (BHET), which is

then transesterified to form a high molecular weight reactor grade resin. To

achieve very high molecular weights

(I.V.: 0.72-0.84) and thus avoid thermal degradation in the melt, condensation is

also performed in solid phase in a vacuum or under nitrogen. The molecular

weights of the PET are adjusted to the intended application area”[5], which were

given in

Table 2.1 Application areas and molecular weights of PET

PET Application IVDCA

(dl/g) MW Range

Fibers 0.57 – 0.65 38500 - 46000

Fibers, low pilling 0.39 – 0.51 23000 – 32000

Filaments, textile 0.65 – 0.68 46000 – 49000

Filaments, technical

0.65 – 1.00 46000 – 84000

Bottles 0.70 – 1.00 51000 – 84000

Films 0.59 – 0.69 41000 – 51000

Solid State Polymerization:

Dry monomers can be submitted to solid state polymerization as well as

solid prepolymers (i.e., low-molecular-weight polymers derived from

conventional polymerization techniques). The former process is usually referred

as direct SSP; meanwhile, in the latter case, post-SSP (SSP finishing) is used to

further increase the molecular weight and to improve processability and end-

product properties, respectively [26–28]. To the same perspective, SSP is proved

to be an efficient recycling technique [29,30], through which the molar mass of

the post consumer material is increased, thus permitting processing without

severe recycled material deterioration.



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1.1.4. MORPHOLOGY OF PET

PET is a linear molecule that exists either in an amorphous or in a crystalline

state. In the crystalline state, the molecules are highly organized and form

crystallites, which are crystalline regions that extend no more than a few

hundred angstrom units. The maximum crystallinity level that can be achieved is

probably no more than 55 %. The crystallinity in the PET soft drink bottle is

normally about 25 % [4]. PET produced by solid stating comes from the reactor in

crystalline form. It is shipped to the fabricator in this form. Polymers in either

amorphous or crystalline form can be uniaxially or biaxiallly oriented. In either

case, orientation greatly increases the strength of PET; because strain induced

orientation usually imparts some crystallinity. As the crystalline state is the

normal state for PET, the amorphous PET is produced deliberately. Amorphous

PET is prepared by rapidly cooling the molten resin from a melt temperature of

260 °C to temperature below the glass transition of 73 °C. On the other hand,

slow cooling of the molten resin will produce a crystalline polymer. A recycler of

PET who produces pellets by extrusion will normally produce crystalline polymer.

It is important to do so because the processor, who normally dries the recycled

PET before using it, prefers pellets of crystalline PET. Amorphous resin tends to

soften and stick at elevated temperatures of drying, forming clumps and

adhering to the walls of the drying unit. The crystallization rate of PET is very

important in processing. Crystallinity has a great effect on the product clarity and

process ability. However, if the size of the crystallite is small enough to minimize

light scattering, clarity can be achieved in spite of the crystallinity of the polymer.



Page 6

1.1.5. PROPERTIES OF PET The rapid growth of PET is due to the following properties:

can be used as an amorphous or crystalline material,

has good impact strength,

can be made transparent or opaque as required,

permits continuous service temperatures of around 180 °C (partially

crystalline) and 60 °C (amorphous),

is environment-friendly; it can be recycled or incinerated to form carbon

dioxide and water, leaving virtually no residue,

Offers an excellent price/performance ratio.

very good chemical resistance

Some properties are given in the Table [6].

Property Value Units

Specific Gravity 1.37 – 1.38 ---

Crystalline Melting Point 250 – 255 °C

Vicat Softening Point 261 °C

Moisture absorption (in water)

24 h at 23°C 0.02 %

2 h at 100°C 0.1 %

Tensile Strength (at yield) 71.5 MPa

(at break) 52.9 MPa

Flexural Strength 110.3 MPa

Flexural Modulus 2758 MPa

Izod Impact Strength 29 – 38 J/m

Elongation 70 %

1.1.6. PROCESSABILITY OF PET

PET can be processed by different methods such as melt spinning, injection

molding, stretch blow molding, flat-film extrusion, thermoforming, etc. The

resulting products (e.g. fibers, films, injection-molded articles, bottles, and

sheets) can be colored, adhesive bonded, welded, painted and laser marked.

1.1.7. APPLICATTION OF PET

The fact that the mechanical properties of PET, especially its impact resistance,

improved by biaxial drawing have contributed to the success that PET has



Page 7

experienced throughout the packaging sector. This trend is continuing and PET is

also expected to expand its future market share. Polyester bottles have gained

wide acceptance as soft drink containers for the following reasons:

93 % weight saving compared to glass,

High barrier properties, especially for oxygen (O2) and carbon dioxide

(CO2)

Excellent transparency and gloss,

Very good mechanical properties,

Shatter-resistance up to drop height of 2.5 m,

Shock-resistant and tough,

Very good chemical resistance,

Approved for food contact (FDA/ BGA),

Readily recyclable.

PET has also gained favor in other food packaging applications other than

carbonated beverage containers. Syrups, oils, and mustard can now be found in

PET bottles. Nonfood packaging items include those for cosmetics, toiletries, and

household products. PET film is used for photographic film and magnetic tapes

[7]. New developments have led to use of PET in manufacturing of beer and

other hot fill applications [8]. Disposable PET containers are now being used in

hospitals for wound drainage systems [9]. The bottles are extrusion blow

molded, radiation sterilized, and they exert and maintain a constant starting

vacuum of 600 mmHg to provide optimum suction for wound drainage. Sekisui

Kaseihin Kogyo Company, Japan [10], has developed foam of crystalline PET,

known as Cell-PET. This foam has high thermal resistance and has good potential

to be used in packaging of foodstuffs. Glass fiber reinforced PET can also be used

in electrical and electronic goods [11]. It can be used in appliances such as



Page 8

sandwich toasters, tabletop ovens, cooker components and electric irons. PET

can also be used in electrical components such as power switches, light bulb

bases, and sensor housings, as well as in specialized applications such as housings

for measuring instruments.



Page 9

CHAPTER 2

RECYCLING OF PET PLASTICS

2. INTRODUCTION

Although the percentage of refillable PET beverage containers increases in

Europe and North America, the majority of PET bottles worldwide are one-way

bottles which are discarded after use. PET-bottles contribute increasingly to the

generation of waste and litter especially in developing countries [12]. One-way

discarded PET-bottles have a negative impact on the environments because they:

waste resources

pollute soil, rivers, coastal areas

pollute the air when burned

consume a lot of landfill site space

get scattered and make the environment look untidy.

Recycling of PET-bottles

saves 65% of the energy for primary PET-production

Offers jobs and income for low-income groups.

Depending on the type of raw material, three types of recycling are

possible:

Recycling of PET material by re-melting

Recycling of feedstock material

Energy recycling



Page 10

FIGURE: - 1



Page 11

2.1. PET RECYCLING

Plastics are a small but significant component of the waste stream. Plastics have

become an integral part of our lives. The amount of plastics consumed annually

has been grown steadily. Its low density, strength, user-friendly design and

fabrication capabilities and low cost, are the drivers to such growth [13]. Besides

its wide use in packaging, automotive and industrial applications, they are

extensively used in medical delivery systems, artificial implants and other

healthcare applications, etc.

The main problem during material recycling is the segregation of polymers. A

polymer after segregation is typically not completely pure. The presence of

contaminants generates some problems such as cleavage of chains, an increase

in carboxylic end groups, a reduction in molecular weight, a decrease in intrinsic

viscosity (I.V.) leading to a decrease in mechanical properties of the material. The

main problem in recycling of PET is the elimination of all impurities that may

catalyze hydrolysis [14].

2.2. HISTORY OF PET RECYCLING

The recycling of poly (ethylene terephthalate) soft drink bottles began after their

introduction in 1977 because some states had laws requiring a deposit on all

beverage containers. By 1989, the recycling rate had increased to 23 % up from

only 10 % in 1982. In U.S., more than 90 % of the bottles were collected from

deposit sites in 1989. Over the past decade, the technology for recycling PET soft

drink bottles has been advancing rapidly. However, most commercial recycling

systems depend on some flotation system to separate PET from the high-density

polyethylene (HDPE) base-cup resin, alternative systems have been developed.

One of the serious contaminants in PET recycling is the adhesive used to attach

the base cup and the label to the PET bottle. Today, new technology has

minimized this problem and has allowed the recycling industry to produce a very

pure recycled PET [4]. According to a survey carried by NAPCOR the PET bottle,

industry continued its strong growth in 1997. ASG (Analytical Sciences Group)

determined that 2.551 billion pounds of PET bottles and jars were available for

recycling in 1997 in the U.S., which represents an almost 16 % increase from

1996. The additional new applications, particularly in the area of hot filled bottles

and jars, are expected to lead this continued strong growth in 1998.

2.3. EFFECT OF CONTAMINANTS OF PET

“A major concern during reprocessing of PET is to remove all contaminants that

can catalyze the hydrolysis of PET. Also, the reprocess or must avoid adding such

cleaning agents as caustic soda in the wash step. These compounds are



Page 12

sometimes used to help removal of labels. Often, adhesive residues are trapped

in the PET granules and remain there after washing. Since these adhesives

darken when treated at PET extrusion temperatures, the recycled PET becomes

discolored and hazy. During removal of labels, ionic or non-ionic surfactants are

used to prevent the re-sticking of the PVA adhesive on to the flakes. If not

cleaned properly, residual contaminants in recycled PET could be a risk to the

public health, especially when intended to use for direct food contact

applications”. In addition, PVC content exceeding 50 ppm in the scrap PET makes

it worthless for advanced applications such as film forming.



Page 13

CHAPTER 3

PET RECYCLIGN TECHNIQUES

3.1. FLOTATION OR HYDROCYCLONE PROCESS

Hydrocyclone is a centrifuge device with a greater gravity force that simply

accentuates the action of a sink-float tank. In this process, PET and high-density

polyethylene (HDPE) are separated by differences in their density. In this process,

the system is fed with crushed, baled bottles with and without caps. If the bales

consist of both green and colorless bottles, the bottles are color sorted by hand

or by photocell (sensors). The dirty, sorted bottles are first reduced to 32-9.5 mm

(0.125-0.375 in.) flake by being processed through a granulator. Labels and loose

dirt are removed by blowing air at low pressure. The contaminated flake is then

metered into an agitated washing tank along with a hot non-foaming detergent

solution. All recyclers have their own detergent recipes, a preferred solids

concentration in the slurry, and a preferred temperature and wash cycle. The use

of caustic soda in the wash solution is not recommended because it facilitates

the hydrolysis of PET chains that results in drop in intrinsic viscosity. The washing

step removes the last traces of label material, disperses, and sometimes

dissolves the adhesives. The polymer flakes are thoroughly rinsed with fresh

water to remove residual wash solution, label and other materials. Now cleaned,

the crude flake or chip moves into hydro-cyclone that separates the heavy PET

from light HDPE in water medium. HDPE floats in water while PET sinks. Ethylene

vinyl acetate (EVA), if present from the cap liner, stays with the HDPE. The

effectiveness of the hydrocyclone depends on the concentration of the solids and

the speed of the centrifuge. The "heavy" and "light" product streams from the

tank or the hydrocyclone are typically flushed once more with fresh water and

processed first through spin dryers and then through hot air dryers. Then the

metal impurities (if any) are removed by feeding the PET flakes into the

multistage electrostatic separator. An interesting variation on the flotation or

hydrocyclone process is the addition of a step that granulates or grinds the PET

bottles cryogenically. Because adhesive contaminants are embrittled at cryogenic

temperatures, whereas PET is not, adhesive contaminants in a cryogenic process

become a fine powder. The fines are easily removed from the coarser PET flake

by screening.



Page 14

DIAGRAM OF HYDROCYCLONE

3.2. WATER BATH/ HYDROCYCLONE PROCESS

This process developed by Reko, a division of DSM in Holland, operates either

with PET bottles that have plastics caps or with cap-free bottles. In this process,

bottle components are substantially separated before granulation. Color-sorted

crushed bottles from the bale move continuously through a hot water bath (1 -

1.5 min.) that is at least 70 °C and close to 100 °C. At these temperatures, the PET

bottles, which are blow-molded by a process that orients the PET, shrink. As a

result, the labels and caps, which do not shrink, separate from the PET bottles.

From the immersion tank, the separated components are deposited on a

vibrating screen that removes the detached labels. After washing and rinsing, the

PET flake in water medium moves through a hydrocyclone that removes any

residual polyethylene and adhesives. Finally, the clean and dried recycled PET

passes through a metal detector to ensure the absence of any traces of metal

3.3. SOLVENT / FLOTATION

This system was developed by Dow Chemical. The process begins like the

conventional flotation process, discussed before, but it is followed by a series of



Page 15

float/sink steps using chlorinated solvents. After the water-flotation step that

separates the polyethylene and some labels from the PET flakes, the ''heavies"

move first through a float/sink step with 1,1,1-trichloroethane as the solvent and

then through another float/sink step using a mixture of perchlomethylene and

trichlomethane. The trichloroethane dissolves the adhesives and floats any

remaining label materials. Finally, the solvents are removed and recovered in a

closed distillation system and the adhesive free

PET is dried.

3.4. PHYSICAL RECYCLING OF PET BOTTLE TO FORM FIBRE

Recycling is processing used materials (waste) into new products to prevent

waste of potentially useful materials, reduce the consumption of fresh raw

materials, reduce energy usage, reduce air pollution (from incineration) and

water pollution (from land filling) by reducing the need for "conventional" waste

disposal, and lower greenhouse gas emissions as compared to virgin production.

65%

30%

4%

1%

GLOBAL RECYCLED APPLICATION OF PET

Polyester Fibers

PET Bottle Resins

Polyester Film

Others

http://en.wikipedia.org/wiki/Material

http://en.wikipedia.org/wiki/Waste

http://en.wikipedia.org/wiki/Energy

http://en.wikipedia.org/wiki/Incineration

http://en.wikipedia.org/wiki/Landfilling

http://en.wikipedia.org/wiki/Greenhouse_gas



Page 16

FOLLOWING STEPS INVOLVE IN PHYSICAL RECYCLING OF PET BOTTLE TO FORM FIBR Step 1 Bale Breaking Stage

Used plastic bottles are collected from municipal curbside systems and deposit centers and are compressed into half-ton bales for delivery to the Carbon LITE process facility in Riverside CA. A bale-breaking machine de-compresses the

bales back into single bottles. Step 2 Bottle Cleaning Stage

The single bottles are separated from any trash and debris and washed in hot

caustic water.



Page 17

Step 3 Bottle Sorting Stage

Automatic sorting equipment segregates the bottles into three streams: clear

PET, green PET and non-PET. The non-PET stream is re-baled and sold to others for subsequent processing into various plastic products.

Step 4

Washing Stage

The clear and green streams of bottles are ground into cornflake-like flakes. These flakes are intensively washed, rinsed and dried.

Step 5

Solid State De-contamination Stage

The dried clean flakes are heated under vacuum to remove any contaminates that may exist. This system of de-contamination is recognized by the FDA as



Page 18

acceptable for subsequent use in direct food packaging. The purified flakes are melted and extruded into pellets. This is our finished product and it is similar in consistency to rice. Step 6 Final Packaging Stage

The food-grade pellets are transported to bottle manufacturers and other customers in bulk hopper road trucks or railcars. Some customers prefer the pellets to be packaged in one-ton plastic bags on pallets. And then these bags of flakes goes to different industries to achieve final production just like these flakes can be use in the production of Synthetic fiber, films, Gel Coats, Coating applications and different other applications. The example of Polyester Synthetic fiber with processing is given bellow:

Synthetic Fibers

Synthetic fibers are "man-made textile fibers produced entirely from chemical substances, unlike those man-made fibers derived from such natural substances as cellulose or protein." The polymers of synthetic fibers do not occur in nature, instead, they are produced from scratch in chemical plants or laboratories, "usually from by-products of petroleum and natural gas." Of these polymers is polyethylene terephthalate/polyester. Synthetic fibers are "spun and woven into huge consumer and industrial products", from garments such as shirts and scarves, home furnishings such as carpets ad drapes, to industrial parts such as flameproof linings and drive belts.

Stages in the Melt Spinning of polyester fibers



Page 19

3.5. PET BOTTLES RECYCLING IN PAKISTAN

Bales of used bottles (Post Consumer Bottles for Recycling)

Crusher used for cutting the used bottles into flakes



Page 20

Crusher front view

Washing line used for cleaning up the pet flakes



Page 21

PET flakes are drying in SUN

Final Recycled PET flakes (Final Product)



Page 22

CHAPTER 4

CHEMICAL RECYCLING OF PET TO FORM UNSATURATED POLYESTER

RESIN

Chemical recycling is also an established method for the recovery of process

waste. However, equipment costs are high and require large turnovers to be

economically viable.

4.1. GLYCOLYSIS

Glycolysis is a chemical process of PET waste recycling which required heat for

processing so it is an endothermic reaction. If recycled PET is treated with excess

glycol, a transesterification reaction takes place. The reduction of high molecular

weight PET to short-chain fragments is achieved by heating the PET with a glycol

such as propylene glycol (PG) in the presence of a catalyst. Typical catalysts are

zinc, manganese, or cobalt acetic acid. Typically this glycolysis reaction takes

place over an 8 hour period at 200 °C with a PG/PET and major products are bis-

hydroxyethyl terephthalate, bis-bydroxypropyl terephthalate, and mixed EG/PG

terephthalate diesters, plus some free EG and PG. The reaction is carried out

under continuous nitrogen purge to inhibit degradation of the resulting polyols.

Under these reaction conditions, the resulting polyol has a number average

molecular weight of 480 and a hydroxyl number of 480. If a higher molecular



Page 23

weight polyol were desired, the PG/PET ratio is lowered; i.e. less PG is used per

mole of PET. Glycolysis reaction can also be done using glycerol, which produces

a polyol with higher hydroxyl number, or with diethylene or dipropylene glycol

(DEG). [17]



Page 24

PIOLET PLANT

4.2. HYDROLYSIS

Treating PET with water in excess at an elevated temperature of 150-250 °C in

the presence of sodium acetate as catalyst produces terephthalic acid (TPA) and

ethylene glycol (EG) in four hours. Catalysts for hydrolysis are either acids (such

as sulfuric) or bases (such as ammonium hydroxide) [16]. An acid catalyst will

promote the hydrolysis in 10-30 minutes at 60-95 °C. Alternatively, PET can be

treated with an excess of methanol, to produce dimethyl terephthalate (DMT)

and EG. A typical PET/methanol ratio is 1:4. [17]



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4.3. METHANOLYSIS

Weighed amounts of PET (w1), methanol and ionic liquids were added in an

autoclave with a stirrer and a thermometer. The mixture was heated up to the

given temperature for certain time. The reaction mixture was filtered to remove

the unreacted PET (w2). The obtained filtrate was diluted with an equal volume

of water and a precipitate was obtained and filtered. The obtained filtrate was

distilled under vacuum to remove water and ethanediol, the residue that is

mainly composed of ionic liquid and catalyst was reused directly as solvent and

catalyst. The filter cake which is mainly composed of dimethyl

terephthalate(DMT) was dried to obtain DMT product . [17]

4.4. CHEMICAL RECYCLING OF PET ON LABORATORY SCALE

It is a process in which polymer chain breakdown into oligomer. Such as PET flakes are converted to BHET (Bis Hydroxyethyl Terephthalate). So this process consists of following Steps. i- First PET bottle Cut into Flakes of size 10mm ii- We take three neck Flask in which we put PET flakes and Diethylene Glycol

(DEG) as we know that glycolysis consist of transesterifaction of PET. As transesterifaction decrease the molecular weight of the polymeric chain.

iii- And then Zinc Acetate is added which is used as a catalyst and temperature is 210oC for 5 hour. And this reaction takes place in three neck round bottle flask.

iv- Nitrogen gas is supplied throughout the reaction. v- After this it is cooled down to 100oC at room temperature.



Page 26

vi- Now After this the solution is filtered and again pour it in to the flask vii- Then nitrogen supply is started to the flask to avoid oxygen to react with the

solution. viii- After this heating is started and phthalic anhydride, hydroquinone and maleic

anhydride is added to the flash. Due to which unsaturated polyester resin is formed

ix- After this styrene, monomer is added to the flask because it can start cross linking and stop the pre maturing.

x- And our unsaturated polyester resin is ready to use.

FORMULATION OF RECYCLED UNSATURATED POLYESTER

The Below formulation is approximate by weight.

S.No MATERIALS PERCENTAGE % 1 PET Flakes 24

2 DEG 27

3 MA 18

4 Styrene 28

5 THQ 0.01

6 HQ 0.001

7 WAX 0.05

8 Zn. Act 0.007

9 St. Acid 0.05



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CHAPTER 5

APPLICATION OF RECYCLED PET

Regrind PET can be used for reprocessing into cheap fiberfill for pillows and

sleeping bags or used directly in filled and reinforced PET molding compounds.

Another outlet for used PET is as a fuel source. According to Eastman, PET burns

cleanly to produce carbon, oxygen, and water, and one pound of PET has the

same heating value as one pound of soft coal. There are different uses of waste

PET it will be converted in to UP resin which is thermosetting material and it can

be uses for variety of purposes and PET waste can also be converted to polyols

for use in rigid or flexible urethane foams. Urethane foams made from recycled

PET are relatively cheaper than those made from normal virgin polyols. A variety

of clothing, including uniforms, working wear, T-shirts, polo shirts, sweatshirts

and using filament yarn, sweatshirts (jersey), windbreakers (woven), bags

(woven), tents (woven) and umbrellas (woven), are being manufactured from

recycled PET bottles. Recycled PET is also used as the plastics clamshells for

bakery and deli products.

This clamshell is produced by thermoforming a 3-layer sheet in which the middle

layer contains the recycled PET. Previously recycled PET cannot be used for food

packaging due to the restriction of Food and Drug Association (FDA). Now after

the development of new, advanced and sophisticated recycling processes, the

FDA has started giving approval to recycled PET up to a certain level. This has

opened new doors for the use of recycled PET. As one of the major users of

plastic containers for food use, and as a leader in the beverage industry, The

Coca-Cola Company has been involved in PET recycling from the start and was

one of the first companies to receive a "no-objection" letter from U.S. FDA,



Page 28

allowing the use of recycled PET for food-contact application. Since then many

different companies have taken an interest in developing some process for

recycling PET so that it can be used in direct food contact packaging and have

gained success [18]. The market of recycled PET for beer bottles is also igniting

interest of various manufacturers [19].Development in the field of reinforced

recycled PET is also catching up. Glass/mineral filled PET is now being used as

automotive grille opening retainers by Ford Motor Company, Mitsubishi Motors

and Toyoda Gosei Co. Ltd. jointly are now molding car engine covers entirely

from recycled PET soft drink bottles. [20]

RECYCLED PET T SHIRT & Lamp made with recycled PET straps

Extensive research investigated the use of resin based on recycled poly (ethylene

terephthalate) plastics waste for the production of a high performance

composite material, namely polyester concrete, for the construction industry.

Resins using recycled PET offered the lower source cost of materials for forming

good quality polyester concrete. Other applications include polyester resin for

sail boats, shower units, and floor tiles, lumber, floor coverings, corrugated

roofing, home insulation, industrial strapping, rope, non-food containers, light

weight auto body parts, and machine housings.

Athletic shoes made from recycled PET Recycled bottles & Recycled PET Grocery Bag



Page 29

UNSATURATED POLYESTER PRODUCTS

GRP PIPE

GRP Pipes are manufactured using filament winding process on computer

controlled machines. By adjusting the relative speed of mandrel rotation and

glass distribution head movement, helical reinforced layers with different angles

can be wound. In order to increase the pipe stiffness, especially on large

diameter pipes, silica sand can be added to parallel layers of wall. Pipes

manufactured using this process are used for aboveground and underground

installations, with gravity flow, medium and high internal pressure.

GRP SHEET



Page 30

GRP HOUSE

CULTURED MARBLE



Page 31

Building (panels, corrugated/flat sheets, profiles, infrastructure, bridges,

sanitary ware, swimming pools, subsea construction etc.)

Tanks, Containers, Pipes (incl. relining of pipes)

Electrical (wind turbines, appliance)

Marine (pleasure boats, utility vessels)

Automotive (cars, trucks, trains, container panels)

Castings (artificial stone, marble etc.)

Shirt Buttons

Synthetic marble castings Formulated products (gel coats, adhesives, putties)

Air conditional Panels

Air craft Components

Archery Bows

Arrow Shafts

Hoods

Trunk Lids

Floor Pans

Airscoopes

Bathroom Products

Building Panels

Cable Trays

Dish Washer Parts

Furniture

Helmets

Solar Energy Panels



Page 32

Unsaturated Polyester Button

Front Panel of Train Cultured marble

CAR Putty



Page 33

CHAPTER 6

TESTING

6.1. FIBRE TESTING

6.1.1. DESCRIPTION OF TEST FOR FIBRE

a. DENIER TESTING

TESTING STANDARD: - ASTM D 1059

Scope: To determine the Denier and filament count of all types of yarns.

Measure length of sample Weigh in grams Calculate count Count filaments

DENIER TESING MACHINE



Page 34

b. CUT LENGTH


c. FRICTION MEASUREMENT


METHOD:-

The test yarn is pulled over a friction body at a certain speed and a certain

angle. The tensile force is measured before and behind this friction body. The

friction coefficient is calculated

µ - METER

d. DRAW RATIO

TESTING STANDARD: - ASTM D1708

METHOD:-

During the course of a cycle, machine continuously measures the tension

produced in a sample yarn, which is heated to a certain temperature and

drawn to a certain percentage.



Page 35

DRAW TENSION TESTING INSTRUMENT

e. THERMAL SHRINKAGE


METHOD:-

Up to 10 samples are heated to a certain temperature for a specified period

of time or they are exposed to a temperature ramp. Either the

samples‘changes in length and/or the forces built up in the samples are

monitored via the connected computer. Since the instrument is computer

controlled, all test parameters are easily set and stored corresponding to

different tested materials. Therefore, once the test configuration is set, the

operator just needs to prepare the samples onto the measuring sensors and

the whole test takes place automatically.



Page 36

THERMAL SHRINAGE TESTING INSTRUMENT

f. TESNILE STRENGTH AND ELONGATION AT BREAK FOR FIBRE




Page 37

UNIVERSAL TESTING MACHINE



Page 38

6.2. COMPARISON TEST REPORT OF VIRGIN UNSATURATED POLYESTER

RESIN WITH RECYCLED UNSATURATED POLYESTER RESIN.

(8TH SEMESTER)

S.NO PROPERTIES VIRGIN UP RESIN

VALUE

UP RESIN FROM PET

VALUE

1 Appearance clear -

2 Viscosity 25oC

(DIN CUP) 90-110sec -

3 Density (25oC) 1.15 -

4 Acid Value (mgkoh/g)

35-40 -

5 Gel time 30oC (7-10)min -

6 Exothermic

Temperature (155-170)0C -

7 Peak Time (14-25)min -



Page 39

6.2.1. DESCRIPTION OF TEST FOR UNSATURATED POLYESTER RESIN

A. DENSITY TEST ASTM D4052

B. ACID VALUE TEST ASTM D3643

C. VISCOSITY TEST DIN 53211 D. GEL TIME TEST ASTM D3532

E. EXOTHERMIC TEMPERATURE TEST ASTM D2471

F. PEAK TIME TEST ASTM D2499

The above mentioned tests will be performed in semester 8th.



Page 40

CHAPTER 7

MARKET SURVEY

7.1. LOCAL MARKET SURVEY

PET FLAKES DEALERS

NHN PETRO INDUSTRIES

Contact Person:- Mr. Shareef Siddiqui (PLANT INCHARGE)

Phone No:- 0213-512-1136

Cell No:- 0300-272-7911 / 0313-209-2092

Address:- Plot No:-44, Sector No:-24, Korangi Industrial Area Karachi Pakistan.

PRICE

White Flakes Rs. 96/Kg

Blue Flakes Rs. 94/Kg

Green Flakes Rs. 90/kg

QUALITY TRADER

Contact Person:- Yunus Lodhi

Phone No:- 0213-825-0533

Cell No:- 0334-303-0140

Address:- Plot No:- 120-A, Sector No:- 27, Korangi Industrial Area Karachi Pakistan.

PRICE

White Flakes Rs. 98/Kg

Blue Flakes Rs. 97/Kg

Green Flakes Rs. 89/kg



Page 41

SHER SHAH KARACHI

Contact Person:- Mr. Bilal

Cell No:- 0345-256-9235

Address:- Phanka hotel Street near Caltex Petrol Pump Karachi Pakistan.

PRICE

White Flakes Rs. 73-75/Kg

Blue Flakes Rs. 73-74/Kg

Green Flakes Rs. 73-74/kg

IMPORTANT INFORMATION

A. PRICE FLUCATION:-

In summer price per kg 50-55

In winter price per kg 72-75

B. CRUSH SELLING COST:-

In summer Crush = Rs 60/kg

In Winter Crush = Rs (80-85)/kg

C. WASH PRICES:-

Hot wash (SODA CASTIC)= Rs. 10/kg

Cold Wash =Rs. 5/kg

D. OTHER COST:-

Crush (LABOUR COST)= 3/kg

Separation Labor Cost = 2-3/kg



Page 42

LOCAL CHEMICAL MARKET SURVEY

AHMED CHEMICAL CO. importer distributor & supplier of chemicals

Phone No:- 0213-243-0561 / 0213-243-7345

E-mail:- [email protected]

Address:- Daryalall Street, Jodia Bazar, Karachi Pakistan

S.No CHEMICALS PRICES

1 Monoethylene Glycol 140/Kg

2 Diethylene Glycol 135/Kg

3 Propylene Glycol 250/Kg

4 Malic Anhydride 220/kg

5 Phthalic Anhydride N/A

6 Zinc Acetate N/A

7 Hydroquinone 7800/Kg



Page 43

COC [CENTER OF CHEMICALS] dealer & importer of chemical Phone No:- 0213-400-6934 / 0213-243-3522


Address:- Shop # 6, Maryam Manzil, Katchi Gali # 1, Jodia Bazar Karachi-Pakistan.



2 Diethylene Glycol N/A

3 Propylene Glycol N/A

4 Malice Anhydride 220/kg

5 Phthalic Anhydride 340/Kg

6 Zinc Acetate N/A

7 Hydroquinone 7380/Kg



Page 44

ILYAS SONS CORPORATIN HOUSE OF SPECIALTY CHEMICALS (IMPORTER & MANUFACTURES REPRESENTATIVE) Phone No:- 0213-400-6934 / 0213-243-3522


Address:- 156/3-A, Kutchi Gali No. 1, Jodia Bazar, Karachi-74000



2 Diethylene Glycol 300/Kg




6 Zinc Acetate N/A

7 Hydroquinone N/A



Page 45

Karachi Scientific Traders (Stockiest & suppliers) of Laboratory Chemicals, Glassware, Scientific Instruments, P.H. & TDS Meters.

Phone No:- 02132513527 / 02132526057


Address:- Shop #. G-13 Union Chamber, North Napier Road, Karachi.



2 Diethylene Glycol N/A




6 Zinc Acetate N/A

7 Hydroquinone 8500/kg



Page 46

International Chemical Market Survey

CHEMICALS COMPANY PRICE

DEG

Nangong Xihua Felt Co., Ltd. China

US $1200-2000 /

Metric Ton

Adinath Chemicals India

US $1200-1600 /

Ton

YOUNG'S CORPORATION South Korea

US $1.2-1.5 /

Kilogram

MEG

Shanghai Homore Industrial Co., Ltd

China

US $700-1000 /

Ton

Adinath Chemicals India

US $1000-1500 /

Ton

Hana International Trade Co. Iran(Islamic Republic of)

US $1020 / Metric

Ton

PG

Qingdao Baijie International Trade Co., Ltd.

China

US $1500-1800 /

Ton

BeoChems Industrial US

US $3-9 / kg

Fancying Industrial LTD South korea

US $1500-1540 / Metric Ton

MALEIC ANHYDRIDE Zhengzhou Qiangjin Science And

Technology Trading Co., Ltd. China

US $1610-1750 /

Metric Ton

PHTHALIC ANHYDRIDE Shijiazhuang Baicheng Chemical

Co., Ltd. China

US $1535-1800 /

Ton

ZINC ACETATE Tianjin Flourish Chemical Co., US $1846-2153 /

http://chinafelts.en.alibaba.com/

http://www.alibaba.com/company/107209266.html

http://y555j.trustpass.alibaba.com/

http://homore.en.alibaba.com/

http://homore.en.alibaba.com/



http://baijiegroup.en.alibaba.com/

http://baijiegroup.en.alibaba.com/



http://yustronger.en.alibaba.com/

http://yustronger.en.alibaba.com/

http://sjzbcchem.en.alibaba.com/

http://sjzbcchem.en.alibaba.com/

http://tjhfe.en.alibaba.com/



Page 47

Ltd. China

Ton

Shijiazhuang Haosheng Chemical Co., Ltd

China

US $1650-1950 /

Metric Ton

Beijing Sanyoujinbiao Chemical Co., Ltd.

China

US $1035-1527 /

Metric Ton

HYDROQUINONE

Xi'an Aladdin Biological

Technology Co., Ltd China

US $30-200 /

Kilogram

N.A.K.P. Foto Inc Canada

CA $11.50-12.00 /

Kilogram

Protech Science Corp. US

US $9850.00-

10835.00 / Ton

STYRENE MONOMER

AK-TAS DIS TICARET A. S. Turkey

US $1200-1600 /

Metric Ton

Shandong Hao Na Import & Export Co., Ltd.

China

US $1250-1550 /

Ton

http://haosheng-chem.en.alibaba.com/

http://haosheng-chem.en.alibaba.com/

http://sanyoujinbiao.en.alibaba.com/

http://sanyoujinbiao.en.alibaba.com/

http://www.alibaba.com/product-free/125034336/Hydroquinone.html

http://alading.en.alibaba.com/

http://alading.en.alibaba.com/



http://fatihsuekinci.trustpass.alibaba.com/

http://beitechem.en.alibaba.com/

http://beitechem.en.alibaba.com/



Page 48

WORK PLAN

The Strategy for this Project,

PET WASTE RECYCLING

Consist of two sections on which our work is based. The content to be covered in two

sections is summarized below according to the semester.

SEMESTER-7

In this semester our strategy consist of theoretical detail about,

Bottle Grade & Fiber Grade Recycling

Physical Recycling Process

Chemical Recycling Process

Market Survey

Testing Techniques

Application of Unsaturated Polyester Resin

SEMESTER-8

Semester 8th will include brief detail about,

the structural analysis of material on which the PET recycling is based.

Practical work will include physical and chemical recycling to form fiber and

unsaturated polyester (UP) resin respectively.

Testing results and data from recycling process will be obtained and discussed in

detail.



Page 49

REFERENCES

*1+ Lubin G., “Handbook of Fiberglass and Advanced Plastics Composites”, Van Nostrand Reinhold Company, New York, (1969) *2+ Chaudhari K. P., Kale D. D., “Impact Modification of Waste PET by Polyolefinic Elastomer”, Polymer International, Vol. 52, p. 291-298 (2003) *3+ Deanin R. D., “The Relationship Between Structures, Properties, and Applications in Polymer Structure, Properties and Application”, Cahners Publishing Company Inc., York, Pennsylvania, (1972) *4+ Ehrig R. J., “Plastics Recycling, Products & Processes”, Hanser Publishers, New York, (1992) [5] Brandrup J., Bittner M., Michaeli W., Menges G., "Recycling and Recovery of Plastics", Carl Hanser Verlag, New York, (1996) *6+ Brydson I. A., “Plastics Materials”, 4th Ed., Buterworth Scientific Press, London, (1982) *7+ Nitschke C., “Modern Plastics Encyclopedia”, McGraw Hill, New York, (1985) [8] KOSA, "Innovative PET Resin for Beer and Hot-Fill Markets", Plastics News International, (2000) *9+ Eastman Chemical Products Inc., “PET Bottles Move Into Medical Care Application”, Modern Plastics International, Vol. 15, p.46 (1985) [10] Sekisui Kaseihin Kogyo Co., Japan, "New Polymer Applications'', Plastics Industry News (Japan), Vol. 39, p. 20-21 (1993) [11] Ticona GmbH, Hoechst GmbH, "Inform Issue 5. Electrical/ Electronics Industry - Celanex - Impet - Vmdar", Frankfurt am Main, p. 28-30 (1997) *12+ Mantia F., “Handbook of Plastics Recycling”, Rapra Technology Limited, Shawbury, (2002) [13] Paci M., La Mantia F., "Influence of Small Amounts of Poly Vinyl Chloride on the Recycling of Polyethylene Terephthalate", Polymer Degradation and Stability, Vol. 63, p. 11-14 (1999) [14] Torres N., Robin J. J., Boutevin B., "Chemical Modification of Virgin and Recycled Poly(ethylene terephthalate) by Adding of Chain Extenders During Processing", Journal of Applied Polymer Science, Vol. 79, p. 1816-1824 (2001) *15+ Pawlak A., Pluta M., Morawiec j., Galeski A., Pracella M., “Characterization of Scrap Poly(ethylene terephtahlate)”, European Polymer Journal, Vol. 36, p. 1875-1884 (2000)



Page 50

*16+ Lamparter R. A., Barna B. A., and Jonsrud D. R., “Process for Recovering Terephthalic Acid from Waste Polyethylene Terephthalate”, U.S. Patent 4,542,239, (1985) *17+ Gruschke H., et al. “Process of Depolymerization of Polyethylene Terephthalate to Terephthalic Acid and Dimethyl Ester”, U.S. Patent 3,403,115, (1968) [18] Doba J., "FDA Gives Go-Ahead for Recycled PET Use", Plastics News,Vol. 11, p. 4 (2000) [19] Defosse M., "Promising Beer Bottle Market is Igniting Interest in Recycled PET", Modern Plastics International, Vol. 29, p. 38 (1999) [20] Moore S., "Auto Engine Cover is Made from PET Bottles", Modern Plastics International, Vol. 30, p. 32-36 (2000) *21+ Jang B. Z., “Advanced Polymer Composites: Principles and Applications”, ASM International, Materials Park (1994) [22] http:// www.accessscience.com McGraw-Hill Encyclopedia of Science & Technology Online *23+ Simon G. P., “Polymer Characterization Techniques and Their Applications to Blends”, Oxford University Press, (2003) *24+ Strong A. B., “Plastics, Materials & Processing”, Prentice Hall, New York, (2000) *25+ Yılmazer U., Cansever M., “Effects of Processing Conditions on the Fiber Length Distribution and Mechanical Properties of Glass Fiber Reinforced Nylon-6”, Polymer Composites, Vol. 23, p. 61-71 (2001)

[26]. Dujari R, Cramer G, Marks D. Method for solid phase polymerization (E.I. du Pont de Nemours & Company). WIPO Patent WO 98/23666, 1998.

[27]. Flory P. Polymerization process (E.I. du Pont de Nemours & Company). U.S. Patent 2,172,374, 1939.

[28]. Monroe G. Solid phase polymerization of polyamides (E.I. du Pont de Nemours & Company). U.S. Patent 3,031,433, 1962.

[29]. Cruz S, Zanin M. PET recycling: evaluation of the solid state polymerization process. J. Appl. Polymer. Sci. 2006; 99:2117–2123. [30]. Karayannidis G, Kokkalas D, Bikiaris D. Solid-state polycondensation of poly(ethylene terephthalate) recycled from postconsumer soft-drink bottles: I. J. Appl. Polym. Sci. 1993;50(12):2135–2142.

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