PET Packaging - Milk

8/3/2019 PET Packaging - Milk

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Milk / Yogurt Milk is an emulsion of fat globules and a suspension of casein

micelles ( composed of casein, calcium, and phosphorous), allsuspended in an aqueous phase which contains solubilizedlactose, whey proteins, and some minerals and salts. Leukocytes

in milk are part of the suspended phase. Milk is composed of water, carbohydrate (lactose), fat, protein,

minerals and vitamins; milk is secreted as a complex mixture ofthese components.

Some other physicochemical characteristics of cow milk include:

pH of normal milk is about 6.6 - 6.9 osmotic pressure is about 700 kPa freezing point depression is about 0.54 K ionic strength is about 0.08 molar water activity is about 0.993


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Pasteurization of MilkPasteurization of milk is done to kill bacterial contaminants

while not substantially altering the milk characteristics. Heating at 74 C for 15 seconds (low temperature pasteurization)

results in killing most organisms and inactivates some enzymes, but

does not otherwise alter the milk. Heating at 90 C for 15 seconds (high temperature pasteurization)

results in killing all vegetative microorganisms, inactivating mostenzymes, but also rendering some whey proteins insoluble.

Heating at 118 C for 20 seconds sterilizes the milk, killing allmicroorganisms, including spores, inactivating all enzyme

activities, but also causes changes to the milk such as the browningreaction involving the proteins and sugars. Ultra-high temperature (UHT) pasteurization of milk at 145 C for a

few seconds sterilizes milk while minimizing the chemical changes.UHT milk which is properly stored has a long shelf life, even atroom temperature.


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Factors affecting shelf life Light not only degrades flavor, but also vitamins. Since

vitamins are essential nutrients, their loss by photodegradation decreases the nutritional value of food.

Vitamins A, C, and B2 are of particular concern in dairy

products and numerous studies have been producedshowing how light negatively affects flavors and degradesvitamins.

Time Parameters for Light Damage to Milk

Time of Exposure, Hrs % of panelist detected offflavor

1/2 34.5

1 45.6

2 50

3 70.7


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Factors affecting shelf life (Schematics)


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Then what are the requirements of

a Dairy package? Package integrity and stability in transportation and

storage. Barrier to UV light, to prevent photo oxidation of vitamin A

& Ascorbic acid. Barrier to low wavelength visible light, up to 550nm, toprevent photo oxidation of Riboflavin.

Oxygen barrier, to prevent oxidation of milk. Un breakable.

Printability. Good shelf presentation. Easily recyclable. Environment friendly.


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Properties comparison of polymers

Parameter Units PP PET HDPE HIPS

Specific Gravity .g/cm3 0.90 1.33 0.952 1.04

Water Vapor

transmission

.g/m2 24hrs 0.29 2.3 0.32 1.3

Oxygen Permeation .cm3/m3 24hr at 1 bar

73 2.2 72 120

CO2 Permeation .cm3/m3 24hr at 1 bar

129 14 210 640

Tensile strength @Yield MPa28.4 55~62 26.9 19

Flexural modulus GPa 1.23 2.2~2.55 1.3 1.65

PET is 3.26 times stronger than HIPSPET better oxygen barrier than HIPS by 55 timesPET has better carbon di-oxide barrier than HIPS by 45 times

Hence PET is the most preferred packaging material.


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Weight / Reduction in thickness Container wall thickness can be reduced as PET has

much better mechanical strength compared any otherpolymer under discussion.

Higher density of PET is a major constraint in reducingthe total container weight, as PET is 30% more heavierthan common polymers.

The wall thickness reduction has to be engineered tomeet the product requirements, by means of providingsuitable stiffeners to the package by ribs, contouredsurfaces, etc.


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Imparting light / UV BarrierObjective:

UV blocking (up to 400 nm) Prevents photo oxidation of Vitamin A Prevents photo oxidation of Ascorbic acid.

Low wavelength visible light blockers. (up to 550nm) Prevents photo oxidation of B2(Riboflavin)

Options available: UV blockers (Dosage: As per supplier)

Transparent, only imparts amber tint to the container.

Amber color (Dosage: 0.5 ~ 1.0%) Translucent, dark amber color.

Titanium oxide (Dosage: 2 ~ 4%) Opaque, bright white color.

PET packaging can be imparted with best UV / light barrierproperties to provide adequate protection to dairy productsduring their intended shelf life.


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Effect of colors in light / UV transmittance.


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Shelf presentation PET dairy packaging can be transparent or opaque as per the

requirement of the brand; Transparent package can be made by adding transparent UV

blockers.

Opaque white packages can be made with opaque TiO2. This willalso provide good visibility to the printed matter on the containersurface.

Translucent packages can be made by means of colorants; where thecustomer will have feel of the level of product in the container. (it isknown to develop customer confidence)

PET thermoformed cups is the only choice of packaging forSparkling Yogurt, to provide the required the shelf life.

Thus PET package provides wide choice of package shelf visibilitysuiting to the product and its brand image requirements.


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Printability Container surface can be printed with suitable inks

using silk screen process.


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Green image PET is fully recyclable.

PET being the most preferred polymer in food andbeverages packaging; has lead to the development of

sound waste collection and recycling systems, bywhich the polymer can be recycled again and againinto the food packaging application without anydeterioration of properties.


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PET Bottles in Dairy packaging


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PET thermoforms


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Stock Rachel's and show your true colours (green, of course!)

Leading premium dairy brand launches UK's first recycled yogurt pot

Rachel's, the UK's leading premium organic dairy brand, is to make category history by becoming the first ever yogurt producer to announce the use of

recycled plastic in their yogurt pots.

Like most yogurt pots, Rachel's plastic inner pot were made of polystyrene (PS) and over-caps of polypropylene (PP).From late June 2009 however, Rachel's - recently voted the UK's Greenest dairy brand in an independent YouGov study will be the first dairybrand in the UK to make the switch to PET, which is the same type of plastic as most water bottles are made of and one of the best plastics forrecycling.Even better Rachel's has used 60% recycled PET known as r-PET.Steve Clarke, Rachel's Marketing Director explains: "Using recycled plastic saves energy and so reduces the carbon footprint of our pot. It alsoreduces consumption of finite oil resources, from which new plastic is made. By making the switch to r-PET we will save up to 210 tonnes of

plastic per year. Better still, we are using materials that might otherwise end up in landfill."Every 1 tonne of r-PET used saves approx 1.5 tonnes of Carbon and by using 60% r-PET the carbon footprint of the new pots is reduced byapprox 30%.As well as the benefits of using recycled plastic, the new inner pot and over-cap are also fully recyclable.Not only is this great news for the environment, the Rachel's switch to r-PET is also being warmly welcomed by retailers at a time whenconsumers are increasingly worried about environmental issues.A recent Nielsen survey confirmed that shoppers are beginning to assess retailers' green credentials more than ever, with over 40% ofrespondents indicating that they try to buy products that are ethically produced or kinder to the environment.Packaging waste specifically is a growing area of concern amongst shoppers with 63% of respondents stating that they would change to anew brand specifically if the alternative had recycled or recyclable packaging.Clarke continues: "Here at Rachel's we share our customers' environmental concerns and have always strived to make our operations as

green as possible. We are extremely proud therefore, to be leading the way with our new r-PET pots."Furthermore, in true pioneering style, Rachel's is also hoping to raise awareness of the fact that not all local councils can accept yogurt potsfor recycling. Currently some local councils can only accept plastic bottles for recycling a fact that Rachel's would like to help change.Clarke explains: "Our campaign aims raise awareness of the difficulty with recycling yogurt pots. In theory PET or r PET yogurt pots arerecyclable but closing the recycling loop relies on all parties doing their bit. If more people buy r-PET yogurt pots, more local councils will beable to accept them for recycling. By signing our pledge consumers will be letting their local councils know that they are committed torecycling their yogurt pots. We hope that this in turn will encourage more and more local councils to allow r-PET yogurt pots into the recyclingstream."The petition will be officially launched by Welsh Assembly Government Sustainability Minister Jane Davidson during National Recycle Week(June 22nd 28th).

The new, recycled PET pots will be available from late June 2009

look out for the new On-Pack Recycling Label logo.Visit www.rachelsorganic.co.uk/aboutus/packaging for more details and to sign the Rachel's pledge.
http://www.rachelsorganic.co.uk/aboutus/packaginghttp://www.rachelsorganic.co.uk/aboutus/packaginghttp://www.rachelsorganic.co.uk/aboutus/packaginghttp://www.rachelsorganic.co.uk/aboutus/packaginghttp://www.rachelsorganic.co.uk/aboutus/packaginghttp://www.rachelsorganic.co.uk/aboutus/packaginghttp://www.rachelsorganic.co.uk/aboutus/packaginghttp://www.rachelsorganic.co.uk/aboutus/packaging

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PET Packaging - Milk