Styrofoam packing peanut inner structure

Foam peanuts, also known as foam popcorn, packing peanuts, or packing noodles, are a common loose-fill

packaging Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of designing, evaluating, and producing packages. Packaging can be described as a c ...

and

cushioning Package cushioning is used to protect items during shipment. Vibration and impact shock during shipment and loading/unloading are controlled by cushioning to reduce the chance of product damage. Cushioning is usually inside a shipping container s ...

material used to prevent damage to fragile objects during shipping. They are shaped to interlock when compressed and free flow when not compressed. They are roughly the size and shape of an unshelled

peanut The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible seeds. It is widely grown in the tropics and subtropics, important to both small an ...

and commonly made of

expanded polystyrene Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is ...

foam. 50–75 millimetres (2-3 in) of peanuts are typically used for cushioning and void filling packaging applications. The original patent was filed for by Robert E. Holden in 1962 and was granted in 1965.

Polystyrene foam

Polystyrene-based packing peanuts were developed and patented by

Tektronix Tektronix, Inc., historically widely known as Tek, is an American company best known for manufacturing test and measurement devices such as oscilloscopes, logic analyzers, and video and mobile test protocol equipment. Originally an independent ...

Inc. They were made commercially available circa 1965 by

Dow Chemical The Dow Chemical Company, officially Dow Inc., is an American multinational chemical corporation headquartered in Midland, Michigan, United States. The company is among the three largest chemical producers in the world. Dow manufactures plastics ...

. Originally made from 100% virgin polystyrene resin, peanuts made from 100% recycled polystyrene have been commercially available since the mid-90s. The color and shape sometimes indicate what it is made of and who made it. Often green is 70% or possibly more recycled polystyrene, white is 70% or more virgin resin and pink means an

antistatic agent An antistatic agent is a compound used for treatment of materials or their surfaces in order to reduce or eliminate buildup of static electricity. Static charge may be generated by the triboelectric effect or by a non-contact process using a high ...

has been applied; although there are some variations. The most common shapes are similar to a "S", "figure 8" or "W". Foam peanuts are very light (usually around 3 grams per litre/0.17 to 0.2 lb per cu ft) and easy to use. Polystyrene peanuts may be used and reused many times with little or no loss in protection for the product shipped. They may be reused and recycled at many packing and shipping stores. Because of their build-up, polystyrene peanuts may also be used for various methods of home insulation, although it is not recommended because they are not flame retardant.

Starch-based

In the early 1990s, starch-based packing peanuts were developed as a more environment-friendly alternative. The

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human die ...

in the peanuts comes from crop-based sources rather than petroleum-based polystyrene, and is non-toxic. One of the first brands of

biodegradable Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegrada ...

peanuts, Biofoam, is made from the grain

sorghum ''Sorghum'' () is a genus of about 25 species of flowering plants in the grass family (Poaceae). Some of these species are grown as cereals for human consumption and some in pastures for animals. One species is grown for grain, while many other ...

; other brands are made from

corn starch Corn starch, maize starch, or cornflour (British English) is the starch derived from corn (maize) grain. The starch is obtained from the endosperm of the kernel. Corn starch is a common food ingredient, often used to thicken sauces or sou ...

. Biodegradable foam peanuts have no

electrostatic Electrostatics is a branch of physics that studies electric charges at rest ( static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for ...

charge, another benefit over polystyrene. Being biodegradable and nontoxic, they are also safe for humans and pets if ingested accidentally. However, they are not produced in food-safe conditions, and are not recommended for eating. Also, during the manufacturing process, the nutritional value is removed from starch-based packing peanuts. This removes edible components, such as sugars, that would otherwise attract rodents and bugs. Their main drawbacks compared with polystyrene are lower resilience, higher weight (6.5 to 13 g per litre/0.4 to 0.8 lb per cubic foot), dust creation, potential attraction of rodents, and higher price. While polystyrene peanuts are soluble in

acetone Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscibl ...

, starch-based peanuts are soluble in water, so starch based products can be disposed with down the sink, dissolving on contact with water.

References

General references

* Yam, K. L., ''Encyclopedia of Packaging Technology'', John Wiley & Sons, 2009, {{packaging Packaging materials

Polystyrene foam

Starch-based

See also

References

General references