quality aspects of rigid pet for beverage packaging

Quality aspects of rigid PET for beverage packaging

Introduction

Beverage packaging: worldwide & India market scenario

The PET bottle stands out as one of the most dynamic pack formats in the retail packaging marketplace, particularly in its stronghold of soft drinks where it accounts for 77% of all packaging unit volume gains over 2004-2009. Health-driven purchasing decisions further provide potential for PET outside its core remit of bottled water. RTD tea, juices and milk offer other sources of growth.

Global Polyethylene Terephthalate (PET) market is estimated at 20.98 million tonnes in 2014. The market is expected to grow at a CAGR of 6.1% during the forecast period, to reach 29.93 million tonnes by 2020. Asia-Pacific, with its thriving economies and rapidly expanding population, will experience highest growth rate during this period.

Replacement of traditional packaging applications and reduced atmospheric emissions are the reasons for increase in the demand of Polyethylene Terephthalate (PET). The Asia-Pacific region contributes to 38% share of the global consumption. China is the largest consumer in the Asia-Pacific region.

About 77 % of the PET resin demand is from packaging bottle industry which includes beverage bottles for mineral water, carbonated soft drinks, ready to drink tea, dairy, and functional & energy drinks. It is expected that light-weight PET bottle trend will continue in future as it is an efficient cost saving measure.

Indian market for PET bottles

The market of PET bottles is around Rs 4,000 crore and is growing at the rate of 20 per cent. Liquor and pharma companies are increasingly switching over to plastics as it is a more convenient form of packaging compared to glass. It is unbreakable, occupies less space, and is liked by consumers.

Rigid PET Bottles

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In glass, the biggest problem is breakage and metal closure and it is also more expensive now. Beverage manufacturing is growing at the rate of 20 per cent and all the global beverage makers are very bullish on India. They are investing in new facilities and will continue to drive our growth.

New techniques like flip open caps and better closures are emerging and there is greater emphasis on packaging with the growth of modern retail and rising competition

In India, dairy to emerge as a major consumer of PET bottles by 2020

Demand for PET bottle packaging of milk and milk products is clocking 25-30 per cent CAGR.

As dairy majors increase packing milk products in PET bottles, packaging firms are upbeat on the growing demand. Besides, dairy majors like Amul are mulling to add two more aseptic lines that will create an additional one million bottle per day capacity at two sites, Gandhinagar and near Godhra.

In dairy, the advent of PET is very recent, about two-three years old since the time Gujarat Cooperative Milk Marketing Federation (GCMMF) set up the aseptic PET bottle line.Amul is planning to add another one million bottles per day (bpd) capacity in two aseptic lines, one each at Gandhinagar and Godhra in the coming months for an investment of about Rs 200 crore, informed GCMMF, Managing Director, R S Sodhi. He added that with the expansion, Amul's total bottling capacity would touch 2.5 million bpd.

"We are the pioneers in bringing in aseptic technology in India, and it involves a rigorous process of heating the liquid to about 170 degrees, then cooling it down, sanitising the bottles as well as the filling chamber," he said adding that as of

Dr. R. Rangaprasad*, Sapan Pandya, Hardik Soni & Swati PatilPET Testing Laboratory, Hemshell Services, 903/1, GIDC Makarpura, Vadodara-390 010.

Mr. Sapan PandyaDr.R.Rangaprasad Mr. Hardik Soni Ms. Swati Patil

POPULAR PLASTICS & PACKAGING m MAY 2016 m 25

now GCMMF had no plans to pack liquid milk inPET bottles as the shelf life would be low. GCMMF is packing its flavoured milk and certain other value-added products in PET bottles as one of the greatest advantages of such packaging is it is not only handy and is multi-serve(one can just close the lid and consume the remaining liquid later), it is also more convenient to transport.

Other dairy majors, like Maharashtra-based private dairy player Parag Milk Foods too is upbeat on PET bottle packaging. It has, in fact, started trials for packing liquid milk in PET bottles apart from flavoured milk. Devendra Shah, chairman and managing director of Parag says that demand for PET bottle packaging is growing fast. "At present, it is still a negligible portion of our milk packaging. We mostly pack our flavoured milk in such packs, however, the demand is growing at a tremendous rate in metros," he said.

Industry insiders feel that demand for PET bottle packaging of milk and milk products is clocking a 25-30 per cent CAGR. Herein lies the opportunity for packaging players like Manjushree Technopack, which are packer for some of the top beverage companies in the country including Pepsico and Coca Cola. Currently water, juice and carbonated beverages contribute almost 45 per cent to its turnover.

VimalKedia, managing director of Manjushree said that Parag is working with them for PET bottle packaging. The company has invested over $5 million to bring in the high-speed aseptic line to India, with an eye to tap the dairy market. Parag has introduced its 'Farm-to-Home' fresh milk in select cities in PET bottles. Dairies in South India are using PET packaging for products like ghee.

Today, 60 per cent of PET consumption comes from the beverage sector and it is believed that by 2020 liquor and milk alone will account for 20 per cent of the consumption. Kedia said, "Until now PET bottles were used to pack value added dairy products only. Fresh milk has a shelf life of four to seven days and needs to be in the cold chain compulsorily. Since we do not have the requisite infrastructure in place, PET bottle is not yet popular for fresh milk. However things are changing quickly; Parag Milk from Pune has given us a go ahead for packaging milk in PET bottles across Pune and Mumbai." He added that Manjushree is also working with state run co-operatives like KMF (Karnataka Milk Federation), MILMA (Kerala) and AAVIN (Tamil Nadu) in the dairy sector.

For that matter, the company, which is using about 66,000 tonnes per annum capacity out of its 80,000 tonnes per annum installed capacity, is now planning to add another manufacturing unit at Harohalli near Bangalore to increase the capacity to 1 lakh tonnes per annum in the coming years.

News flash

CocaCola may stop glass bottles Times of India

http://timesofindia.indiatimes.com/business/india-business/CocaColamaystopglassbottles/articleshowprint/

Coca-Cola may stop selling soft drinks in glass bottles as

they have become more expensive to produce compared to plastic bottles and cumbersome for most consumers to carry.

The company is sampling Rs 10-12 small plastic bottles in Maharashtra, said people familiar with the development, and it may withdraw reusable glass bottles from most regional markets in the next three to four years. In its biggest market, the US, Coke stopped selling its iconic 6.5 oz (192 ml) glass bottles in 2012 due to similar reasons.

"Each of our packages play a role in our OBPPC (occasion, brand, price, pack and channel) plans. Returnable glass bottles are a big part of this plan and serves as a recruitment pack," said a CocaCola India spokesperson.

"So, doing away with glass bottles is not a possibility. As a part of providing choice, we are launching several single-serve packs this season -Tetra Pak, 250 ml juice PET and the 300 ml sparkling PET."

Recently, Coca-Cola and PepsiCo, the largest beverage makers in the country, have come under threat from small local players, who have managed to wrest away around 10% market share from the Rs 14,000 crore aerated drinks industry.

"At least 20 new players including Delhi-based Xalta, Alwar-based Jayanti Beverages and Bareilly's Boss Beverages have been nibbling away at the biggies' market shares with cheaper products packaged in small plastic bottles," said a soft drink bottler.

Even packaged water maker Bisleri entered the segment this year with four ? zzy beverages priced at Rs 10. "Glass bottles are a nuisance for a beverage maker," said Ramesh Chauhan, founder of Bisleri.

"First, you have to sell them many times to recover cost of the bottle. Secondly, their cleaning process is a big headache. Add tothat their weight that increases logistics cost.”

Introduction to PET

PET, which stands for polyethylene terephthalate, is a form of polyester.It is moulded into rigid bottles and containers for packaging foods and beverages, home care, personal care products, edible oil, pharmaceutical preparations etc.

Manufacturing routes for PET

PET resins are produced commercially from ethylene glycol (EG) and either dimethyl terephthalate (DMT) or terephthalic acid (TPA). DMT and TPA are solids. DMT has a melting point of 140°C (284°F), while TPA sublimes (goes directly from the solid phase to the gaseous phase).Both processes first produce the intermediate bis-(2-hydroxyethyl)-terephthalate (BHET) monomer and either methanol (DMT process) or water (TPA process). The BHET monomer is then polymerized under reduced pressure with heat and catalyst to produce PET resins. The primary reaction for the DMT process is:

26 m POPULAR PLASTICS & PACKAGING m MAY 2016

Rigid PET Bottles

The primary reaction for TPA process is:

In chemical terms, ethylene glycol is a diol, an alcohol with

a molecular structure that contains two hydroxyl (OH) groups, and terephthalic acid is a dicarboxylic aromatic acid, an acid with a molecular structure that contains a large, six-sided carbon (or aromatic) ring and two carboxyl (CO2H) groups. Under the influence of heat and catalysts, the hydroxyl and carboxyl groups react to form ester (CO-O) groups, which serve as the chemical links joining multiple PET units together into long-chain polymers. Water is also produced as a by-product.

The presence of a large aromatic ring in the PET repeating units gives the polymer notable stiffness and strength, especially when the polymer chains are aligned with one another in an orderly arrangement by drawing (stretching).After polymerization in the melt phase, the molecular weight of polyester can be further increased by polycondensation of PET chips in the solid state and this process is called solid state polymerization (SSP).

Polycondensation reaction is exothermic, therefore, it can also be driven forward to give polymer with higher molecular weight if the reaction is carried out at a lower temperature. At lower temperatures of polycondensation, equilibrium shifts forward to higher completion enabling formation of higher molecular weight of the product. Since temperatures cannot be lowered in melt polymerization, the best solution is to carry out the reaction in solid state, wherein temperatures lower than melting point of the polymer can be used. At these temperatures, the kinetics of the reaction is slow and it takes a long time to complete the reaction.

The SSP is performed at temperatures between 220 and 235°C for PET, which lie above the glass transition temperature and below the crystalline melting point of PET. Under these conditions, polymer chain end groups are mobilized sufficiently to undergo polycondensation. The annealed chips are heated in a stream of hot inert gas or by agitating in a vacuum drier to remove small traces of EG and other volatile by-products. As the reaction is carried out in the solid phase, volatile by-products can diffuse easily to the surface of each polymer chip and are instantly carried away by the gas flow or high vacuum.

The molecular weight can be increased up to IV 0.90 for bottle grade and as high as IV 1.20 for technical applications such as tyre cord, seal belts and air bags.

Key attributes of PET

lPET is a virtually unbreakable, colourless, lightweight, transparent polymer.

lAs PET is transparent, it allows the content of the container to remain visible. The robustness of PET is vitally important for beverage packaging since it makes the bottles completely safe for on-the-go or sports use.

lCrystal clear products look good, pure and healthy.

Sparkling PET bottles attract attention. Brilliant glass-clear presentation of your products

lPure products taste good. PET complies with international food contact regulations.

lSafe PET bottles are tough and virtually unbreakable during production, storage and transportation. If they do fail, they split, not shatter. Their high impact and tensile Strength makes them ideal for carbonated products.

lGood barrier the low permeability of PET to oxygen, carbon dioxide and water means that it protects and maintains the integrity of products giving a good shelf life. PET also has good chemical resistance.

lLightweight 10% weight of an equivalent glass pack, PET bottles reduce shipping costs by about 30%, and because the material in the wall is thinner, shelf utilization is improved by 25% on volume compared to glass. High strength, low weight PET bottles can be stacked as high as glass.

lNo Leakage Absolute closure integrity is possible because of the injection molded neck finish. The absence of a weld line in the base means that PET bottles don't leak.

lGood Resistance PET offers the best chemical resistance performance of any mainstream polymer used in packaging today.

lLong Shelf-life very good shelf-life performance, especially with the new higher barrier formulations.

lRecyclable excellent environmental profile due to single material. Used PET bottles can be washed, granulated into flakes and reshaped as PET bottles or employed as material for strapping, carpeting, fibre filling, etc. Specially designed thick-wall bottles can be washed, refilled and reused. PET is made from the same three elements (carbon, oxygen, and hydrogen) as paper, and contains no toxic substances. When burned, it produces carbon dioxide gas and water, leaving no toxic residues.

lDesign flexibility suitable for containers of all shapes, sizes, neck finishes, designs and colours.

Manufacturing process of PET preform and bottles

lPET bottles are produced by a two-stage process known as Injection Stretch Blow Moulding (ISBM). The process depicted in figure involves the production of an injection moulded PET bottle blank or preform followed by subsequent reheating, stretching and blow-moulding to produce a full-sized bottle. PET naturally absorbs water from its surroundings. Before processing it is usually heated to reduce its moisture content to less than 50 parts per million to avoid hydrolytic reactions which reduces its quality by generation of acetaldehyde. After about 4 hours of drying at a temperature of not more than 160°C (to avoid thermal degradation), the PET is melted and injected into the preform mould, resulting in the production of the PET bottle preform.

Rigid PET Bottles


recommended. The IV of PET is determined from the flow times of polymer solution and pure solvent in a viscometer at a designated temperature. The IV value will vary depending on the type of solvent used and temperature conditions. IV is measured in an Ubbelohde Viscometer using Phenol + 1, 1, 2, 2-Tetrachloroethane (60:40 w/w) solvent at 30°C as per ASTM D 4603.

l

A microprocessor controlled, capillary Melt Viscometer, is specifically designed to test the flow properties of PET. The system can be used to test other polymers and because it does not require solvents, it can also be used to test insoluble polymers. It consists of a heated vertical barrel, a calibrated die, a small piston called a "follower", a displacement transducer called a "probe" and control systems for the nitrogen gas flow and extruder temperature. The equipment is based on a system developed by ICI. It is designed for both research and quality control of polyethylene terephthalate (PET), which is hygroscopic and liable to degrade due to oxidation in the melt phase. The apparatus is recommended for use in the quality control of polyester polymers to measure the intrinsic viscosity and degradation rates. The Viscometer extrudes molten PET similar to an MFI but is specially developed to prevent the polymer from degrading due to contact with the atmosphere. The polymer is isolated from moisture and oxygen because the barrel is sealed and the polymer is extruded through the die using pure nitrogen at high pressure. Therefore, an external supply of Nitrogen gas of 30 Bar pressure is required. This nitrogen gas not only provides an oxygen and moisture free environment for the sample but also applies the extrusion force. The quantity of polymer extruded is calculated similar to the MFI method B using an LVDT "probe" to measure the movement of the "follower". The rate of extrusion is accurately measured by the "probe", which is designed to operate under the highpressure conditions within the barrel during extrusion.The system calculates the total thermal and hydrolytic degradation. Therefore, a "Melt" test can show the degradation due to the presence of moisture in the polymer so can be used to check the performance of the production drying system. A "Melt" test can also be used to measure the thermal degradation factor caused by the production extruder. PET has historically been measured using the solution method and this indicates the potential Intrinsic Viscosity (IV) of the polymer but does not show how the polymer will behave or degrade during extrusion. The solution technique is being phased out due to the insoluble nature of highly crystalline polymer plus high environmental and disposal costs of solutions. It is also

MIV (Melt intrinsic viscosity):

The PET bottle preform is heated to the correct profile for blowing, after which it is introduced into the blow mould. The hot preform is simultaneously stretchedand blown inthe blow mould to form the bottle.

Role of machine builders in producing quality PET bottles

The role of machine builder in the success of PET as an alternative to glass as a packaging material of choice cannot be underplayed.

The type of dryers, preform injection moulding units & blowing stations all combine to deliver top quality bottles at very high production speeds.

Machine builders like SIDEL, Husky, Ferromatik Milacron, Windsor, etc. are a part & parcel of the PET success story.

Technical Characteristics of PET Resin Preforms& Bottles and their significance

The key to produce a good preform & have it converted in to a usable bottle, meeting the specifications of the end user industry,is a technology, comprising intimate knowledge of material attributes, machine & the ability to control the journey of the PET material from raw material to a dimensionally accurate rigid packaging format.

These attributes are discussed in detail below

lIntrinsic Viscosity (IV):PET resins are classified on the basis of IV which is a measure of average length of polymer molecular chains or molecular weight. It influences the melt viscosity and processing behaviour of PET and properties of the end products. It is used by most PET producers to control the polymerization process, to assist customers in the selection of polymers for specific Application and to control the preform moulding process. Generally, if an application requires higher strength, a high IV is

FIG: Manufacturing process of Preforms and Bottles


Rigid PET Bottles

not so suitable for testing reground or recycled material because the quantity tested is very small and may not show the "Average IV" of the mixed granules. The instrument is designed to replace the solution method so directly reports the Intrinsic Viscosity (IV) of the polymer and not the Melt Flow Rate. PET is hygroscopic and any water molecules present at melt temperatures > 250C will give an irreversible break in the chain at the ester linkage, which gives a drop in the IV. Therefore, the PET Plus can ONLY give the same IV as the solution method if ALL the moisture is removed from the polymer before it is tested (less than 20ppm moisture). The instrument is a semi-automatic system so can be left unattended after the sample has been loaded and preconditioned. The test takes a total of 17 minutes after loading the sample.

l

Acetaldehyde is a colourless, volatile substance with a fruity smell. Although it forms naturally in some fruits, it can cause an off-taste in bottled water. Acetaldehyde forms by degradation of PET through the mishandling of the material. High temperatures (PET decomposes above 300 °C or 570 °F), high pressures, extruder speeds (excessive shear flow raises temperature), and long barrel residence times all contribute to the production of acetaldehyde. When acetaldehyde is produced, some of it remains dissolved in the walls of a container and then diffuses into the product stored inside, altering the taste and aroma. This is not such a problem for non-consumables (such as shampoo), for fruit juices (which already contain acetaldehyde), or for strong-testing drinks like soft drinks. But for bottled water, low acetaldehyde content is quite important, because, if nothing masks the aroma, even extremely low concentrations (10–20 parts per billion in the water) of acetaldehyde can produce an off-taste.ASTM F 2013 used for measuring the content of acetaldehyde in PET.The important points to note about AA formation are:lIt is generated under heat, when PET is in molten

condition.lIt is product of Thermo-chemical degradation and,

to a lesser extent of oxidative degradation. lThe rate of formation at a particular temperature is

dependent on resin formulation.lThree different types of AA are analysed in PET

resin and containers are Residual AA measured in – Resin, Preform AA- Preforms, Headspace AA – Bottles, Lower the AA content of the preform, the better it is for the contents.

lColour: The most widely used technique in PET industry is the colorimetric spectrophotometer, which measures the wavelength distribution of light reflected or transmitted

Residual Acetaldehyde (AA) Content:

by a sample and uses this to calculate comparative colour values. PET bottle producers are constantly striving to manufacture high quality products where appearance is an equally critical factor like any other property. Reflected/ transmitted colour, yellowness and haze affect the appearance of a bottle. The colour should be as close to neutral as possible. The colour values are generally measured on an L, a, b scale, by three components, i.e. L*, a* & b*.l'L' denotes - Black to White. When L value is '0', it

indicates Black & '100' indicates White. Black to White goes through 'Grey'.

l'a' denotes – Red to Green. When 'a' value is '+ ve', it indicates Red & '-ve' indicates Green.

l'b' denotes – Yellow to Blue. When 'b' value is '+ ve', it indicates Yellow & -ve' indicates Blue.

lThe L, a, b values are controlled in such a way that the preforms/bottles will have asclose to neutral colour as possible.

lOTR (Oxygen transmission rate) test:This test is used to determine the oxygen transmission rate (OTR) for total formed bottles or containers. Oxygen transmission rate is a critical property in understanding the shelf life of packaged foodproducts. Transmission rates are dependent on surrounding environmental conditions such as relative humidityand temperature. Different packaging materials have different transmission rates. Low barrier materials suchas HDPE have high transmission rates compared to high barrier materials such as PET or EVOH.

lCrystallinity: It is a measure of the degree of crystalline order in PET molecule. The crystallinity is directlyrelated to the density of polyester and is normally derived from the density value. Crystallinity should be above 50%, so that the chips do not soften and form agglomerates during drying prior to moulding.

lMoisture content in resin:PET is a hygroscopic material; it absorbs moisture from the atmosphere. The amount of moisture within a PET sample is measure using the coulometeric Karl Fischer technique.

lFinish dimension or Neck dimension for bottle and preform:The test is designed to ensure that all thread finishes on bottles or preforms comply with the dimensions and allowable tolerances specified on the respective bottle finish design drawings.

lWeight and Capacity:Plastic bottles must meet the capacity requirements of the country in in which the bottles will be used. Bottle weight can impact a number of performance attributes. The purpose of this test is to determine the weight of a

Rigid PET Bottles


bottle along with fill point and overflow capacity.

l

The purpose of this test is to measure wall thickness in distinct regions of plastic bottles or containers in order to monitor and compare with physical performance. Successful bottle or container performance is related to several critical properties that are dependent on the wall thickness profile consistency such as CO permeation 2

rate, O ingress, water vapor transmission rate, volume 2

change, and top-load strength.

lConcentricity of the preform:Various factors of package quality, wall thickness uniformity throughout the preform periphery are dependents on the quality of the Preform. The purpose of this test is to verify that preform wall thickness according to specifications.

lPerpendicularity of PET bottle:This test method is used to measure plastic bottle, container, and preform finish Perpendicularity. Bottles and containers must stand upright, perpendicular to their bearing surface for filling. PET preform finishes must be perpendicular for the blow molding operation.

lDrop test on PET bottlesThis test is used to determine the ability of a filled bottle or container to withstand a free-fall drop. The bottles or containers must survive the drop heights specified in this test method. The minimum drop height survival ensures customer satisfaction and acceptable production and distribution environmental performance.

lTop load test of PET bottle:This test is used to measure the top load compression force of empty bottle, filled bottle, Hotfill plastic bottles or containers. The samples must withstand top load forces during use. The top load force survival ensures the empty bottles or containers withstand a compression from lift cylinders in filling and capping operations. Top load results may be used to calculate the finishedproduct pallet stack heights during storage.

lHot fill finish stability:Hot fill is used to evaluate the bottle finish distortion resistance from liquid hot filling. The manufacturing process, container material, crystallinity level, and preform design affect the hot fillprocess distortion resistance of the finish.

lBottle burst testing:This test is used to determine the bottle failure-point from rapid pressurization. Plastic bottles are rapidly pressurized during the filling operation and a low failure point could cause major production issues.

Wall thickness of bottle/preform:

l

Maintaining CO content within specified limits is 2

essential to ensuring product shelf life quality. This testing used to determine the ability of filled and capped bottles to retain carbonation. Plastic bottle carbonation levels vary with time due to volume expansion (creep), sorption, and permeation. Carbonation loss may also result from improperly applied closures.

lSection weight for bottle testing:Weight distribution consistency is an important factor in bottle performance. Each bottle type has a unique material distribution profile depending on the gram weight and processing technique.

lEnvironmental Stress cracking test for CSD bottles:This procedure evaluates the performance of bottle bases when they are exposed to a 0.2% solution of NaOH (Sodium Hydroxide) to simulate the failure associated with Stress Cracking.

The hydroxide ion is the main catalyst of stress cracking in PET bottles. A bottle that has more resistance to Sodium Hydroxide attack should be more resistant to stress crack initiators that a bottle may be exposed to during its lifetime. This procedure evaluates the performance of bottle bases when they are exposed to a 0.2% solution of NaOH (Sodium Hydroxide) to simulate the failure associated with Stress Cracking.

BIS standards for PET

lIS 14764: PET containers for packaging of VANASPATI-specification. This standard covers the requirements, methods of sampling and tests for stretch blow moulded polyethylene terephthalate (PET) containers for packaging of Vanaspatiin quantities of I kg, 2 kg and 5 kg or 1 litre, 2 litres and 5 litres.

lIS 14537: PET bottles for packaging of alcoholic liquors-specification.Thisstandard prescribes the requirements and the methods of sampling and test for polyethylene terephthalate (PET) bottles for packaging of alcoholic liquors.

lIS 12252: This standard covers Specification for PET and PBT for their safe use in contact with food stuffs, pharmaceuticals and drinking water.

lIS 12887: PET bottles for packaging of edible oils-specification. This standard prescribes the requirement and the methods of sampling and testing for polyethylene terephthalate (PET) bottles for packing of 1 kg and 2 kg edible oils.

lIS 13123: Packing of liquid pesticides PET bottles up to 5 litter capacity. This standard prescribes the requirement and the methods of sampling and testing for polyethylene terephthalate (PET) bottles for packing of 5 litter liquid pesticides.

lIS 11298: Plastic films for electrical purposes. This

Carbonation retention testing:


Rigid PET Bottles

the complexities involved in the manufacture of Quality PET bottle for beverage packaging.

References:

1. Business standard online edition2. Times of India online Edition3. Various internet resources4. Published data from various PET raw material suppliers,

Machinery & PET Testing instrument suppliers from various company websites n

Rigid PET Bottles

Standard gives the requirements for balanced biaxially oriented poly-ethylene terephthalate (PET) film for use as electrical insulation.

In conclusion

It is evident that PET is fast emerging as an effective option to glass in the packaging sector. It is therefore, imperative to understand every aspect of this wonder polymer, including raw material, processing & testing to produce a Quality Bottle for the end use application. The review paper is intended to provide the reader an overview of

Rigid PET Bottles


quality aspects of rigid pet for beverage packaging

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