Plastic milk container

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Plastic bottle of milk. One US gallon Bottle of milk.jpg
Plastic bottle of milk. One US gallon
Plastic bottles with indentations for handles Borie del serre.JPG
Plastic bottles with indentations for handles

Plastic milk containers are plastic containers for storing, shipping and dispensing milk. Plastic bottles, sometimes called jugs, have largely replaced glass bottles for home consumption. Glass milk bottles have traditionally been reusable while light-weight plastic bottles are designed for single trips and plastic recycling.

Contents

Materials

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), [1] are also in use. Polycarbonate had been considered but had concerns about potential contamination with Bisphenol A. [2]

Container forms

Blow molded plastic milk bottles have been in use since the 1960s. [3] [4] [5] 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 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.

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

Shelf life

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 4-8 °C. Other factors such as light and temperature abuse have effects. Shelf life can be extended by ultrapasteurisation and aseptic processing. [6] [7]

Volume control

The indentation on the left side of a milk bottle adjusts the volume of the bottle. VolumeAdjuster.jpg
The indentation on the left side of a milk bottle adjusts the volume of the bottle.

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. [8]

Environmental comparisons

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. [9] [10]

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. [11]

Examples

See also

Related Research Articles

Milk White liquid produced by the mammary glands of mammals

Milk is a nutrient-rich liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals, including breastfed human infants before they are able to digest solid food. Early-lactation milk is called colostrum, which contains antibodies that strengthen the immune system and thus reduces the risk of many diseases. It holds many other nutrients, including protein and lactose. Interspecies consumption of milk is not uncommon, particularly among humans, many of whom consume the milk of other mammals.

Pasteurization Process of preserving foods with heat

Pasteurization or pasteurisation is a process in which packaged and non-packaged foods are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life. The process is intended to destroy or deactivate organisms and enzymes that contribute to spoilage or risk of disease, including vegetative bacteria, but not bacterial spores.

Ultra-high-temperature processing food sterilization process

Ultra-high temperature processing (UHT), ultra-heat treatment, or ultra-pasteurization is a food processing technology that almost sterilizes liquid food by heating it above 135 °C (275 °F) – the temperature required to kill many bacterial endospores – for 2 to 5 seconds. UHT is most commonly used in milk production, but the process is also used for fruit juices, cream, soy milk, yogurt, wine, soups, honey, and stews. UHT milk was first developed in the 1960s and became generally available for consumption in the 1970s.

Reuse of bottles

A reusable bottle is a bottle that can be reused, as in the case as by the original bottler or by end-use consumers. Reusable bottles have grown in popularity by consumers for both environmental and health safety reasons. Reusable bottles are one example of reusable packaging.

Nalgene

Nalgene is a brand of plastic products developed originally for laboratory use, including such items as jars, bottles, test tubes, and Petri dishes, that were shatterproof and lighter than glass. The properties of plastic products make them suitable for work with many substances in various temperature ranges.

Container-deposit legislation

Container-deposit legislation is any law that requires the collection of a monetary deposit on beverage containers at the point of sale and/or the payment of refund value to the consumers. When the container is returned to an authorized redemption center, or retailer in some jurisdictions, the deposit is partly or fully refunded to the redeemer. It is a deposit-refund system.

High-density polyethylene Class of polyethylenes

High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or "polythene" when used for HDPE pipes. With a high strength-to-density ratio, HDPE is used in the production of plastic bottles, corrosion-resistant piping, geomembranes and plastic lumber. HDPE is commonly recycled, and has the number "2" as its resin identification code.

Plastic recycling is the process of recovering scrap or waste plastic and reprocessing the material into useful products. Due to purposefully misleading symbols on plastic packaging and numerous technical hurdles, less than 10% of plastic has ever been recycled. Compared with the lucrative recycling of metal, and similar to the low value of glass recycling, plastic polymers recycling is often more challenging because of low density and low value.

Water bottle Water container

A water bottle is a container that is used to hold water, liquids or other beverages for consumption. The use of a water bottle allows an individual to drink and transport a beverage from one place to another.

Low-density polyethylene

Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethylene. It was the first grade of polyethylene, produced in 1933 by Imperial Chemical Industries (ICI) using a high pressure process via free radical polymerization. Its manufacture employs the same method today. The EPA estimates 5.7% of LDPE is recycled in the United States. Despite competition from more modern polymers, LDPE continues to be an important plastic grade. In 2013 the worldwide LDPE market reached a volume of about US$33 billion.

Glass milk bottle

Glass milk bottles are glass bottles used for milk and are generally reusable and returnable. Milk bottles are used mainly for doorstep delivery of fresh milk by milkmen: retail store sale is available in some regions. After customers have finished the milk they are expected to rinse the empty bottles and leave it on the doorstep for collection, or return it to the retail store. The standard size of a bottle varies with location, common sizes are pint, quart, Litre, etc.

Glass bottle

A glass bottle is a bottle made from glass. Glass bottles can vary in size considerably, but are most commonly found in sizes ranging between about 200 millilitres and 1.5 litres. Common uses for glass bottles include food condiments, soda, liquor, cosmetics, pickling and preservatives. These types of bottles are utilitarian and serve a purpose in commercial industries.

Plastic bottle Bottle constructed of plastic

A plastic bottle is a bottle constructed from high-density or low density plastic. Plastic bottles are typically used to store liquids such as water, soft drinks, motor oil, cooking oil, medicine, shampoo, milk, and ink. The size ranges from very small bottles to large carboys. Consumer blow molded containers often have integral handles or are shaped to facilitate grasping.

Milk bag Plastic bags that contain milk

A milk bag is a plastic bag that contains milk. Milk bags are usually stored in a pitcher or jug with one of the corners cut off to allow for pouring. A typical milk bag contains approximately 1 L (1.8 imp pt) of milk in South America, Iran, Israel, Eastern Europe and the Baltics, while in the UK they contain 2 imperial pints (1.1 L), in Canada 1+13 litres (2.3 imp pt), and in India, 0.5 L (0.9 imp pt).

Square milk jug

The square milk jug is a variant of the plastic gallon container of milk commonly sold in the United States. The design was introduced in the summer of 2008 and is marketed as environmentally friendly because of the shape's advantages for shipping and storage.

Ecologic Brands, Inc. is an Oakland, California-based company that designs and manufactures bottles from recycled cardboard and newspaper.

Bottles are able to be recycled and this is generally a positive option. Bottles are collected via kerbside collection or returned using a bottle deposit system. Bottlerecycle.org reveals that just 14% of all plastic packaging is recycled globally PET bottles production is predicted to grow by about 5% a year. Currently just over half of plastic bottles are recycled globally About 1 million plastic bottles are bought around the world every minute and only about 50% are recycled.

Reusable packaging is manufactured of durable materials and is specifically designed for multiple trips and extended life. A reusable package or container is “designed for reuse without impairment of its protective function.” The term returnable is sometimes used interchangeably but it can also include returning packages or components for other than reuse: recycling, disposal, incineration, etc. Typically, the materials used to make returnable packaging include steel, wood, polypropylene sheets or other plastic materials.

Plastic-coated paper is a coated or laminated composite material made of paper or paperboard with a plastic layer or treatment on a surface. This type of coated paper is most used in the food and drink packaging industry.

Packaging waste

Packaging waste, the part of the waste that consists of packaging and packaging material, is a major part of the total global waste ,and the major part of the packaging waste consists of single-use plastic food packaging, a hallmark of throwaway culture. Notable examples for which the need for regulation was recognized early, are "containers of liquids for human consumption", i.e. plastic bottles, tetrapaks and the like. In Europe, the Germans top the list of packaging waste producers with more than 220 kilos of packaging per capita.

References

  1. Sidel (18 August 2018), "Many Good Reasons for Liquid Dairy to Switch to PET Packaging", Canadian Packaging, retrieved 16 September 2020
  2. Carwile, J L (2009). "Polycarbonate Bottle Use and Urinary Bisphenol A Concentrations". Environ Health Perspect. 117 (9): 1368–1372. doi:10.1289/ehp.0900604. PMC   2737011 . PMID   19750099.
  3. US3225950A,Josephsen,"Plastic bottle",published 1965
  4. US3152710A,Platte,"Plastic milk bottle",published 1964
  5. US3397724A,Bolen,"Thin-walled container and method of making the same",published 1966
  6. Galic, K (August 2018), "Packaging materials and methods for dairy applications", New Food, retrieved 11 September 2019
  7. Petrus, R R (2010). "Microbiological Shelf Life of Pasteurized Milk in Bottle and Pouch". Journal of Food Science. 75 (1): M36-40. doi:10.1111/j.1750-3841.2009.01443.x. PMID   20492183 . Retrieved 11 September 2019.
  8. Lauren Joshi (June 2017). "Understanding Dairy Bottle Shrinkage" (PDF). Qenos. Retrieved July 28, 2019.
  9. Van Doorsselaer, K; Fox (2000), "Estimation of the energy needs in life cycle analysis of one-way and returnable glass packaging", Packaging Technology and Science, 12 (5): 235–239, doi:10.1002/(SICI)1099-1522(199909/10)12:5<235::AID-PTS474>3.0.CO;2-W
  10. Spitzly, David (1997), Life Cycle Design of Milk and Juice Packaging (PDF), U.S. Environmental Protection Agency, retrieved 29 June 2014
  11. "2016 United States National Postconsumer Plastic Bottle Recycling Report" (PDF). Association of Plastic Rcyclers. 2017. Retrieved 12 October 2018.

Books, general references