Polymer & Plastic waste and Recycling

Dr. Manohar Singh Saini

Director,

Guru Nanak Dev Engg. College, Ludhiana

January 3, 2012

 

Plastic products improve our daily lives and have made vast improvements in areas such as:

Transportation - Automotive, Aerospace, Space

Exploration

Medicines - helping us all live longer, healthier lives

Electronics - information, communication, and

entertainment

Building and Construction - durability, aesthetics, and

high performance

Personal protection - children, athletes, police and

firefighters

Innovative packaging - freshness, storage stability,

and protection from bacteria Recyclability and reuse (SPI created the international

recycling symbols/numbers to facilitate recycling)

A Global Look at Plastics: Quantities, Uses

and Benefits

Benefits of Plastics Case Study: Transportation During the oil crisis in the 70’s, automakers

found that plastics made cars more energy efficient by reducing weight.

Plastics began finding their way into automobile components (bumpers, fenders, doors, etc.)

Plastics were also used for theirDurabilityCorrosion ResistanceToughnessResiliencyLightweight

Benefits of Plastics Transportation cont… Plastics reduced the weight of the

average passenger car built in 1988 by 66 Kgs.

That saves millions of gallons of fuel each year and will save the energy equivalent of 21 million barrels (2428 million litres) of oil over the average lifetime of those cars.

U.S. Plastic Resins Growth – 2004

Production grew in 2004 to 52 billion Kgs.

An increase of 8.1 percent over 2003.

Sales and captive use rose 6.9 percent, the highest growth rate since 1996, reaching 52 billion Kgs.

(Source: American Plastics Council)

Plastics is a complex industry Processors – (four main processing

methods)

Injection MoldingExtrusionBlow MoldingThermoforming

Equipment Suppliers Raw Material Suppliers

Range of Products

Plastics Bags Plastic Packaging Film

and Sheet Non-packaging Film

and Sheet Plastics Profile Shapes Plastics Pipe & Pipe

Fittings Laminated Plate,

Sheet and Shape

Polystyrene Foam Products

Urethane and Other Foam Products

Plastic Bottles Plastic Plumbing

Fixtures Resilient Floor

Covering Plastics Products, Not

Classified Elsewhere

Uses of Plastics - Statistics

Plastic products have become an integral part of all our lives, and play an

irreplaceable role in our day-to-day activities.

Today’s Reality

Comparison with Other IndustriesUnited States Plastics industry is the nation’s 4th

largestmanufacturing industry (shipments):1. Motor Vehicles and Equipment2. Petroleum Refining 3. Electronic Components and

Accessories4. Plastics

Scope of the Plastics Industry United States The U.S. plastics industry

employed more than 1.4 million people.

Another 772,000 persons were employed by upstream industries that supplied the plastics industry.

Total of 2.2 million workers – about 2 percent of the U.S. workforce.

Scope of the Plastics Industry United States Nearly 25,000 plastics industry

establishments generated approximately $310 billion in shipments.

Another $83 billion was generated by upstream, supplying industries.

Total annual shipments from plastics activity to $393 billion

Plastics – Global ImportanceImport and Export

Plastic resins and plastic finished products are imported and exported at a significant level across the world, via the oceans and by other means.

Canada, Mexico, other Latin America and China account for dominant percentages of U.S. plastics industry exports and imports.

Growth of Plastics(per capita consumption 2001-2010)

2001 2010 North America 101 Kgs 148 Kgs Latin America 20 Kgs 30 Kgs Western Europe 94 Kgs 136 Kgs Eastern Europe 12 Kgs 24 Kgs Africa/Middle East 8 Kgs 10 Kgs Japan 88 Kgs 116 Kgs Southeast Asia 13 Kgs 24 Kgs**Less than 2% of a barrel of crude oil is

used in the production of plastics.(Source: BASF AG)

Energy Resources & Plastics

Basic Questions(A)Why are rubbish dumps thought to be a bad thing?(B)What does recycling mean?

EFFECT OF PLASTICSON

ENVIRONMENT!!!

INTRODUCTION

Plastic is the general common term for a wide range of synthetic or semi synthetic organic solid materials suitable for the manufacture of industrial products. Plastics are typically polymers of high molecular weight, and may contain other substances to improve performance and/or reduce costs. Plastic is one of the few new chemical materials which pose environmental problem. Polyethylene, polyvinyl chloride, polystyrene, PET are largely used in the manufacture of plastics.

TYPES OF PLASTIC PRODUCTS

PLASTIC BAGSPLASTIC COATINGSPLASTIC FURNITUREPLASTIC SHEETSPLASTIC FITTINGSPLASTIC TANKSPLASTIC TOYSPLASTIC BUCKETSPLASTIC SANITARYWARE PLASTIC STATIONERY

PLASTIC’S ADVERSE EFFECTS ON OURENVIRONMENT

Plastics pollute beaches & oceans

Garbage has been discarded into the oceans for as long as humans have sailed the seven seas or lived on seashores or near waterways flowing into the sea. Since the 1940s, plastic use has increased dramatically, resulting in a huge quantity of nearly indestructible, lightweight material floating in the oceans and

eventually deposited on beaches worldwide.

Plastic bags litter the landscape

Once they are used, most plastic bags go into landfill, or rubbish tips. Each year more and more plastic bags are ending up littering the environment. Once they become litter, plastic bags find their way into our waterways, parks, beaches, and streets. And, if they are burnt, they infuse the air with toxic fumes.

Plastic bags kill animalsAbout 100,000 animals such as dolphins, turtles whales, penguins are killed every year due to plastic bags. Many animals ingest plastic bags, mistaking them for food, and therefore die. And worse, the ingested plastic bag remains intact even after the death and decomposition of the animal. Thus, it lies around in the landscape where another victim may ingest it.

Plastic bags are non-biodegradable

And one of the worst environmental effects of plastic bags is that they are non-biodegradable. The decomposition of plastic bags takes about 1000 years.

PLASTIC’S EFFECT ON HUMAN LIFE

Plastic plays the villain right from the stage of its production. The major chemicals that go into the making of plastic are highly toxic and pose serious threat to living beings of all species on earth. Some of the constituents of plastic such as benzene are known to cause cancer. Plastic resins themselves are flammable and have contributed considerably to several accidents worldwide.

Once plastic is produced, the harm is done once and for all. Plastic defies any kind of attempt at disposal – be it through recycling, burning, or landfilling. When you recycle a hazard, you create a hazard.Recycling of plastic is associated with skin and respiratory problems, resulting from exposure to and inhalation of toxic fumes, especially hydrocarbons and residues released during the process.

MEASURES

1.Single-use plastic bags have become such a ubiquitous way of life that it seems as if we simply cannot do without them. However, if we have the will, we can start reducing their use in small ways.

2.A tote bag can make a good substitute for holding the shopping. You can keep the bag with the cashier, and then put your purchases into it instead of the usual plastic bag.

MEASURES

3.Recycling the plastic bags you already have is another good idea. These can come into use for various purposes, like holding your garbage, instead of purchasing new ones.

4. While governments may be working out ways to lessen the impact of plastic bags on the environment, however, each of us should shoulder some of the responsibility for this problem, which ultimately harms us.

Percentage that can be recycled

About 7% of all household waste is plastic. Annually, 3 million tonnes of plastic rubbish are produced. 57% of litter found on beaches is plastic. In 2001 only 7% of all plastic was recycled.

Why recycle plastic?

Conservation of non-renewable fossil fuels - Plastic production uses 8% of the world's oil production.Reduced consumption of energy. Reduced amounts of solid waste going to landfill. Reduced emissions of carbon-dioxide (CO2), nitrogen-oxide (NO) and sulphur-dioxide (SO2).

How are polymers recycled?

Mechanical recycling of plastics refers to processes which involve the melting, shredding or granulation of waste plastics.Plastics must be sorted prior to mechanical recycling.At the moment most sorting for mechanical recycling is done by trained staff who manually sort the plastics into polymer type and/or colour.

More

Following sorting, the plastic is either

melted down directly and moulded into a

new shape, or melted down after being

shredded into flakes and than processed

into granules called regranulate.

Source Reduction

Refers to a reduction in the amount of material used in any application

The simplest methods to employ source reduction are To use fewer products that cause waste To choose size and types of products

where- by waste is minimized To reduce the material requirements of

the product (for manufacturer)

For example: The amount of packaging material in 1

litre drink bottle is 40% less than material in 0.5 litre drink bottle (larger size are more efficient in using materials)

Decrease the thickness of materials in application

PE Trash bag (when it was first introduced)- thickness 0.08 mm

LDPE introduced – thickness of trash bag is 0.05 mm

LLDPE (stronger and tougher material) – thickness is 0.025 mm

HDPE – thickness of 0.017 mm is available now.

Source Reduction

Recycling of Plastics

Refers to the reprocessing and refabrication of a material by a consumer or disposal of solid waste.

This type of recycle is called postconsumer recycle (PCR)- different with recycle (generally called regrind) of the scrap from manufacturing process.

Recycling of Plastics

Reprocessing and refabrication of PCR involves several steps;

Collection Handling/sorting Reclamation/sorting End-use fabrication

Recycling of Plastics

Collection

Voluntary recycling by the consumer is the most single factor in improving recycling of all materials

However, consumers do not sort their solid waste but rather mix all materials together

For many plastics, the cost of virgin plastics is about the same as the cost involve in recycling- create problem in recycling process (different case with recycling of aluminium cans)

Handling & Sorting

Involves conveying materials from the pickup point (from consumer house) to the reclamation facility.

Sorting of materials is necessary (PET bottle, HDPE waste, aluminium alloy, etc) or in broader material groupings (all metals, all plastics, etc).

For the highest economy benefit, the HDPE and PET and other recyclable plastics must be separated from the plastics that are not to be recycled- thus considerable labour is required to pick up the recyclables by hand.

Handling & Sorting

Some sorting can be done by machine, i.e. based on certain characteristics (light absorption), various plastic resins can be distinguished from the others.

Under certain condition, the mixture of several plastic type can be recycled, called as mixed recycled or comingled recycle.

To assist consumers and sorters, Society for plastic Industry (SPI) introduced recycling symbols.

Numbering system for plastic recycling

Recycling No. Abbreviation Polymer Name

PETE or PET Polyethylene Terephthalate

HDPE High-Density Polyethylene

PVC or V Polyvinyl Chloride

LDPE Low-Density Polyethylene

PP Polypropylene

PS Polystyrene

OTHER

Other plastics, including acrylic, polycarbonate, polylactic acid , nylon and fiberglass.

Polymer Name Uses

Polyethylene Terephthalate

Recycled to produce polyester fibres, thermoformed sheet, strapping, soft drink bottles, reinforcement for concrete.

High-Density Polyethylene

Recycled to become various bottles, grocery bags, recycling bins, agricultural pipe, base cups, car stops, playground equipment, and plastic lumber, flower pot, toys

Polyvinyl Chloride

Recycled to become pipe, fencing, and non-food bottles.

Low-Density Polyethylene

Recycled to become plastic bags, various containers, dispensing bottles, wash bottles, tubing, and various molded laboratory equipment.

Polypropylene Recycled into auto parts and industrial fibers.

PolystyreneRecycled into a wide range of products including office accessories, cafeteria trays, toys, video cassettes and cases, insulation board and styrofoam.

Uses of Different Polymers

Reclamation/Cleaning

After sorting, the plastics must be chopped into small flakes or shredded for further processing.

Then the flakes are treated with solvents and washed to remove residual contaminants (original content & paper label).

The flakes are then sent to the fabricators to extrude into pellets.

End Uses- Sorted PCR

The recycled material can be used in the same applications or other applications.

However, PCR plastic cannot be used in medical and food-contacting applications due to danger of contamination and disease.

Thermoplastic- can be reheated and reprocessed many times (with minor changes in resin properties).

Degradation

Means that the plastic can break down into smaller molecules by natural means, biological agent or by sunlight.

In reality, some materials degrade very slowly.

Some applications require that the material do not degrade, i.e. packaging material.

Some applications need degradable properties, i.e. sutures in medical applications.

Waste Tyres

The number of motorcar waste tyres generated annually was estimated to be 8.2 million or approximately 57,391 tonnes. Landfill- as the easiest way of disposing the waste.Other industry users collect waste tyres for retreading, rubber reclaim and shredding.

Tyre Waste

Examples of use are: Tiles and tile adhesives, mixing with asphalt, sports surfaces, carpet underlay, noise and vibration insulation, playgrounds and matting.

Incineration

Incineration or controlled burning is another option for disposing of large percent of solid waste.

The most common purpose of burning is to generate electricity.Energy content of various solid waste materials and conventional fuels burned to generate electricity.

Incineration Method

Incineration can destroy some types of chemicals that other methods can't. It is also quicker than many other methods.

Obstacles of Recycling

Usage of various copolymer blends (i.e. PET) from different manufacturers do not dissolve into one another when heated. Instead, they tend to phase-separate, like oil and water.

Another barrier to recycling is the widespread use of dyes, fillers, and other additives in plastics. The polymer is generally too viscous to economically remove fillers, and would be damaged by many of the processes that could cheaply remove the added dyes. Additives are less widely used in beverage containers and plastic bags, allowing them to be recycled more frequently.

Rubber and tyres

Good maintenance reduces waste: To reduce waste and save money, good advice is to treat your tyres properly for maximum tyre life.  Simple maintenance and correct inflation pressures mean you don't need to replace them prematurely.  A worn tyre is not only dangerous, but uses more fuel.  When the time comes to change your tyres, considering the environmental aspects of their replacements may save money.  Why not consider a retreaded tyre?

Re-treads : Re-treading doubles the life of a tyre, reducing the numbers of new tyres needed and minimising waste.  The UK has a well-established re-tread industry (there can be shortages of those used tyres suitable for re-treading) and many old tyres are exported. 

New uses

As tyres cannot go to landfill, and incineration is undesirable, what else can be done?  Alternative ideas for re-using scrap tyres are increasing, but the number of outlets remains less than that which would meet potential demand.  Small numbers are used as boat fenders, playground equipment and by farmers.

Material recovery from tyres and other rubber products is increasing.  The main technique is to shred and reduce the rubber to crumb, and use this as a moulding material or filler.  Applications include brake linings, carpet underlay, equestrian, sports and safety surfaces, including playgrounds, as well as surfacing for, paths, and low grade use as landscape mulch or waste oil absorbent.  Finer grades of crumb are used in rubbers for vehicles.  Small amounts are also being used for stationery and office items

Recycling plastic uses less water and energy resources than in producing new plastics, and produces fewer greenhouse gases.

This is because the polymer chains become damaged or contaminated with food or other types of plastic.

What is the effect of recycling plastics?

One problem with recycling, however, is that is reduces the strength and versatility of the plastic over time.

Biodegradable plastics are increasingly being used in carrier bags, bin bags and food packaging.

One of the problems with traditional plastics is that they do not break down when thrown away.Biodegradable plastics are plastics that can be broken down. They are converted into carbon dioxide, water and minerals by micro-organisms.

Biodegradable plastics, such as polylactide, are plant-based polymers. They are often made from starch that has been modified to become more stable.

What are biodegradable plastics?

Strategies to Develop Biodegradable Polymers

•Green Technol. in Extracting Natural Polymers

•Natural Polymers Like ExtrudableStarch

•Natural Polymers With Chemical Modifications eg. Cellulose acetate

•Semi-Synthetic CopolymersFillers (first generation, 1960’s), Composites & Grafts (second generation, 1970’s)

•Improving Currently Used PlasticsBetter Additives; Chemically-linked Additives(third generation, 1980’s, 1990’s)

• New Generation of Synthetic Polymerseg. Poly(lactic acids), PHA’s, various newcopolymers, new Natural Polymer Based,(fourth generation, 1990’s, 2000+)

Commodity Plastic: Current Scenario in India

Share of commodity plastics (> 80 % of over 5 million tons) mainly used in the making of low-value household articles, pipes, extruded sheets, packaging film, etc.

Polymer consumption is growing faster than any other material. Growth is 14% p.a. (double of GDP).

Development of plastic production technologies based on renewable, sustainable, agricultural wastes (sugarcane bagasse, wheat/rice straw, etc.

Government of India sponsored research projects on environment – friendly plastics from renewable resources (PLA, cellulose acetate from sugarcane bagasse, sugarcane juice, etc.) on-going briskly.

Current Scenario of Plastic Waste

India has a high rate of plastics recycling: +60% (World average is 15-20%).

Recycling is a thriving business in India. India has per capita consumption of ~5 kg

(2005)(greater for urban areas; set to grow rapidly;world average 18 kg).

Plastic in solid waste stream is lowest at 0.5-4% because of recycling (World average is 7-8%).

Synthetic Plastics: Environmental Issues

The area of greatest concern is plastics used in packaging :

In total production of plastics packaging accounts for ~52% in India (total consumption 4.3 mt in 2002, +5.0 mt in 2005, 8.0 mt in 2007).

Growth of plastics consumption is 14% per annum. Urban folks spend about 88% more than their country

cousins on food, education, entertainment, fuel and lighting, clothing and durables, according to latest estimates of the National Sample Survey Organisation (NSSO) (Economic Times, Nov.24, 2005).

Therefore in larger cities, the consumption of plastics is larger; expected to continue to grow at 14%; should reach world average in a few years. Therefore in larger cities, the consumption of pl larger; nm to gmroat 14%. Should reach world

Applications of Waste Plastics

From To Milk pouches Carry bags Packaging film, carry bags Waterproof sheets for

housing Footwear, plastic bottles Footwear Buckets, crates, luggage Buckets, luggage PP film, thermoware, tooth brush, pens

Combs, pens, toys, houseware,

Cement bags Thin ropes Battery boxes, industrial products, thermoware

Luggage, industrial products

Cups, TV cabinets, cassettes

Cassettes, cassette covers, novelty items

CURRENT STATUS IN INDIA: Value and Employment (upto 2010-11)

Major Raw Material Producers

Processing Units Turnover (Processing

Industry) Capital Asset (Polymer

Industry) Raw Material Produced

approx Raw Material Consumed

approx Employed Direct/Indirect Export Value approx Revenue to Government

approx.

15 Nos.

25,000 Nos.Rs.85,000 Crores

Rs.55,000 Crores

5.3 MMT

5.1 MMT3.3 MillionUS $ 1.9 BillionRupees 7300 Crores

Contd…

By 2011 - 12

Demand Potential

Additional Employment

Investment Potential

12.5 MMT

4.0 Million

Rs.84,000 Crores

VISION 2015 – Indian Plastics Industry

Consumption of Polymers @ 15% CARG

Turnover of plastics Industries

Additional Employment Generation

Requirement of AdditionalPlastics Processing Machines

Additional Capital InvestmentIn Machines (2004-2015)

18.9 Million tonnes

Rs.1,33,245 crores

7 Million

68113 Nos

Rs.45,000 crores

Salient features of ISRO Launch VehiclesVehicle SLV-3 ASLV PSLV GSLVGross Lift-off Weight(tonnes)

17 39 275 400

Max. Ddia(m)

1.0 1.0 2.8 2.8

Height (m) 22.0 23.5 44.0 51.0Number ofstages

4 5 4 3

Payload wt.(kg)

40 100 to 200 1000 2000 to 2500

Orbit Low Earth Orbit(LEO)

Sun-Synchr-onousOrbit(SSO)

Geo-TransferOrbit (GTO)

Mission Space Science RemoteSensing

Communi-cations andMeteo-rology

PSLV STAGES AT A GLANCESTAGE – 1 STAGE – 2 STAGE – 3 STAGE – 4 Total

Nomenclature Core PSI +Strapon PSOM 6Nos

PS2 PS3 PS4 ---

Propellant Solid PropellantHTPB Based

UDMH + N2O4 Solid PropellantHTPB

Bi-propellantMMH + N2O4

Based

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Propellant Mass(tonne)

128.0 + 6 X 9.0= 182

37.5 7.2 2.0 228.7

Stage Mass(tonne)

220 43 8.4 2.89 274.29

Max. Thrust (kN) 4500662X6

720 340 7.4X2 ---

Burn Time (sec) 9745

149 76 415 ---

Stage Dia (m) 2.81.0

2.8 2.0 1.3 ---

Stage Length (m) 2010

12.5 3.6 2.1 ---

Control SITVC for Pitch& Yaw, ReactionControl Thrustersfor Roll. SITVCin 2 PSOMs forRollControlAugmentation

Engine Gimbalfor Pitch &Yaw, Hot GasReactionControl Motorfor Roll Control

Flex Nozzle forPitch & Yaw,PS4 RCS forRoll Control

Engine Gimbalfor Pitch, Yawand roll On-offRCS for coastphase control

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Note: Propellant Mass = 83.4 % of total Mass.