In a previous blog we noted the number of shipping delays caused by cold weather: This year’s weather may have a bigger impact on shipments than normal. It looks like January’s cold temps across the country are extending into February. Temperatures were in the minus 20’s F at in the beginning of January and they came very close to minus 20 F again in Minneapolis at the end of January. The lowest Minnesota temperature ever recorded was minus 60 F in Embarrass Minnesota in 1996.
So how would your typical packaging materials stand up to minus 60 F? Do shipments have a greater risk of damage during extreme cold because of packaging material properties?
Here is a list of common materials used in packaging and how well they would stand up to minus 60 degrees F:
- Cardboard: Corrugated Cardboard is the most commonly used packaging material and also the cheapest. One should be more concerned about flammability than cold, but exposure to minus 60F would definitely degrade the mechanical strength, probably not enough to risk falling apart. You might want to rethink about re-using a cardboard shipping box if it has been exposed to that kind of temperature. Higher temperature and exposure to moisture would have far more damaging effects.
- Wood: Wood can certainly withstand minus 60 F for an indefinite period of time, but some of wood packaging is plywood. Plywood is made of layers of wood bonded together with an adhesive. In cold weather, the adhesive and the adhesive bond are the weakest link. Plywood may become more brittle at extreme cold and possibly lose some structural integrity. There are many grades and types of plywood. The lower grade plywood could start to delaminate at minus 60F while higher grade plywood (better adhesive and wood) may withstand prolonged exposure. Most wood materials used in commercial crating would not degrade significantly when exposed to minus 60 F. Plywood and other types of manufactured wood can be susceptible to moisture and potentially delaminate over prolonged exposures to moisture and high humidity. Fortunately high humidity and cold don’t coexist.
- Styrofoam: Styrofoam (expanded polystyrene) is one of the lowest cost ways of providing cushioning for your product. Styrofoam is commonly found as end caps for printers or other electronic devices. Styrofoam peanuts are also commonly used. Extreme cold should not affect Styrofoam’s protective properties.
- Cushioning Foam: Typical foam products for shipping are either made of low density polyurethane or polyethylene. Polyethylene may lose some flexibility at extreme cold conditions and may not have optimal cushioning characteristics at minus 60 F although it is rated to minus 80F. Polyurethane will maintain its high level of flexibility even at minus 60F.
- Corrugated Plastic: Polypropylene and polyethylene are the two most common materials in corrugated plastic. Polypropylene will become slightly brittle as temperatures drop below zero Fahrenheit. At minus 60F, Polypropylene could crack if dropped or kicked. Polyethylene has superior resistance to cold than Polypropylene and will withstand repeated exposure to extreme temperatures. Polyethylene should do fine at -60F.
Conclusion: Most packaging materials should maintain their properties when exposed to extreme cold, at least well enough to protect that product before it reaches its destination. It is very unlikely that a product would suffer damage during shipment because the packaging materials lost their properties. It is far more likely that the contents of the package would degrade due to cold than the packaging materials. Other affects of extreme cold such as icy roads and auto or truck failures will have a much larger impact on shipping packages than the packaging materials.