Plastic milk container

Packaging of milk is regulated by regional authorities. Use of food contact materials is required: potential food contamination is prohibited. Strict standards of cleanliness and processing must be followed.

The most common material in milk packaging is high density polyethylene (HDPE), recycling code 2. Low density polyethylene (LDPE) and polyester (PET){{Citation

| last =Sidel

| title =Many Good Reasons for Liquid Dairy to Switch to PET Packaging

| journal =Canadian Packaging

| date =18 August 2018

| url =https://www.canadianpackaging.com/features/many-good-reasons-for-liquid-dairy-to-switch-to-pet-packaging/

| access-date =16 September 2020

}} are also in use. Polycarbonate had been considered but had concerns about potential contamination with bisphenol A.{{cite journal

| last = Carwile

| first =J L

| title =Polycarbonate Bottle Use and Urinary Bisphenol A Concentrations

| journal = Environ Health Perspect

| date =2009

| pages =1368–1372

| volume = 117

| issue =9

| pmc =2737011

| pmid =19750099

| doi =10.1289/ehp.0900604

| bibcode =2009EnvHP.117.1368C

}}

Blow molded plastic milk bottles have been in use since the 1960s.{{cite patent

| number =US3225950A

| title =Plastic bottle

| pubdate =1965

| inventor =Josephsen

| url =https://patents.google.com/patent/US3225950A/en

}}{{cite patent

| number =US3152710A

| title =Plastic milk bottle

| pubdate =1964

| inventor =Platte

| url =https://patents.google.com/patent/US3152710A/en

}}{{cite patent

| number =US3397724A

| title =Thin-walled container and method of making the same

| pubdate =1966

| inventor =Bolen

| url =https://patents.google.com/patent/US3397724A/en

}}

HDPE is the primary material, but polyester is also used. A wide variety of milk bottle designs are available. Some have a round cross section while others have a more square or rectangular shape. A special flat-top square milk jug was recently{{when|date=November 2024}} developed to maximize shipping and storing efficiency but had some difficulties in dispensing. Many milk bottles have integral handles.

Milk bags are also in use. The milk is sold in a plastic bag and put into a pitcher for use. Larger bags are the inner bladder of a bag-in-box, sometimes used for institutional dispensing.

Small individual containers of milk and cream are often thermoformed or injection molded and have a peelable lid. These are often used in restaurants.

The shelf life of pasteurized milk in HDPE bottles and LDPE pouches has been determined to be between 10 and 21 days when stored at {{cvt|4–8|C|F}}. Other factors such as light and temperature abuse have effects. Shelf life can be extended by ultrapasteurisation and aseptic processing.{{Citation

| last =Galic

| first =K

| date =August 2018

| title = Packaging materials and methods for dairy applications

| magazine=New Food

| url =https://www.newfoodmagazine.com/article/26394/packaging-materials-dairy/

| access-date =11 September 2019

}}{{cite journal

| last =Petrus

| first =R R

| title =Microbiological Shelf Life of Pasteurized Milk in Bottle and Pouch

| journal =Journal of Food Science

| volume =75

| issue =1

| pages =M36-40

| date =2010

| url=https://www.researchgate.net/publication/44620432

| access-date = 11 September 2019

| doi=10.1111/j.1750-3841.2009.01443.x| pmid =20492183

}}

File:VolumeAdjuster.jpg

Milk containers for retail sale must contain the same amount of milk as indicated on the label. To be acceptable to consumers, the containers must also appear to be completely full. Therefore, the volume of the container must be precisely controlled.

The designer of a die for a blow moulded bottle can never be completely sure of how much the finished bottle will hold. Shrinkage always occurs after the item is released from the mould. The amount of shrinkage depends upon many factors, including cycle time, inflation air pressure, time in storage prior to filling, storage temperature, and more.

A volume adjuster insert is one way to slightly adjust the volume of a bottle, without building a completely new mould. A volume insert attaches to the inside of a mould, creating a circular indentation on the side of the finished bottle. Different size inserts can be used as manufacturing circumstances change, for example mould temperature or cooling rate. The volume of finished bottles is periodically measured, and volume inserts are changed as needed.{{cite web |title=Understanding Dairy Bottle Shrinkage |author=Lauren Joshi |date=June 2017 |publisher=Qenos |url=http://www.qenos.com/internet/home.nsf/(LUImages)/WP%20Understanding%20Dairy%20Bottle%20Shrinkage/$File/WP%20Understanding%20Dairy%20Bottle%20Shrinkage.pdf |access-date=July 28, 2019}}

Many potential factors are involved in environmental comparisons of returnable vs non-returnable systems. Researchers have often used life cycle analysis methodologies to balance the many diverse considerations. Often the comparisons show benefits and problems with all alternatives.{{Citation |last=Van Doorsselaer |first=K | author2 = Fox |year= 2000|title=Estimation of the energy needs in life cycle analysis of one-way and returnable glass packaging

| journal = Packaging Technology and Science |pages=235–239 |doi=10.1002/(SICI)1099-1522(199909/10)12:5<235::AID-PTS474>3.0.CO;2-W |volume=12 |issue=5 }}{{Citation

| last =Spitzly

| first =David

| year =1997

| title =Life Cycle Design of Milk and Juice Packaging

| publisher =U.S. Environmental Protection Agency

| url =http://css.umich.edu/sites/default/files/css_doc/CSS97-08.pdf

| access-date =29 June 2014

}} One recent life cycle study of one-way recyclable HDPE bottles indicated the importance of secondary packaging: returnable plastic crates can allow lower tare weight bottles. {{cite journal

| last =Singh

| first =J

| title =Life Cycle Inventory of HDPE Bottle-Based Liquid Milk Packaging Systems

| journal =Packaging Technology and Science

| volume =24

| pages = 40–60

| date =2011

| doi =10.1002/pts.909

| s2cid =6850034

| url =https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1061&=&context=it_fac&=&sei-redir=1&referer=https%253A%252F%252Fscholar.google.com%252Fscholar%253Fhl%253Den%2526as_sdt%253D0%25252C24%2526q%253Dlife%252Bcycle%252Bplastic%252Bmilk%252Bbottle%2526btnG%253D#search=%22life%20cycle%20plastic%20milk%20bottle%22

| accessdate =7 October 2021| url-access =subscription

}}

Reuse of bottles requires a reverse logistics system, cleaning and sanitizing bottles, and an effective quality management system. A key factor with glass milk bottles is the number of cycles of uses to be expected. Breakage, contamination, or other loss reduces the benefits of returnables. A key factor with one-way recyclables is the recycling rate: In the US, only about 30–35% of HDPE bottles are recycled.{{cite web

|url= https://plastics.americanchemistry.com/2016-US-National-Postconsumer-Plastic-Bottle-Recycling-Report.pdf

|title= 2016 United States National Postconsumer Plastic Bottle Recycling Report

|publisher=Association of Plastic Rcyclers

|year =2017

|access-date=12 October 2018}}

File:Coffee fresh (2012.08.04).jpg|Individual plastic container of coffee creamer, Japan

File:Spring roll with milk.jpg|11.5 US fl oz, 340 ml, PETE bottle

File:Israeli Milk Bag.jpg|Plastic bags of milk

File:Plastic bottle of milk.jpg|1419 ml, 48 US fl oz PETE bottle

File:Square milk jug side.JPG|Flat-top square jug

File:Plastic Milk Bottle.tif|HDPE milk bottle, 40 US fl oz, 1 1/4 US quart (1183 ml)

{{Portal|Food}}

• Bagged milk
• Gallon smashing, internet challenge involving participants deliberately spilling milk in a supermarket by breaking containers
• Tea set, which includes a small jug for milk or cream

{{Reflist}}

• {{Cite book |last=Yam |first=Kit L. |year=2009 |title=The Wiley Encyclopedia of Packaging Technology |edition=3rd |location=Hoboken, N.J. |publisher=John Wiley & Sons |isbn=978-0-470-08704-6 |oclc=361969419}}

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Category:Liquid containers

Category:Milk containers

Category:Retail packaging