Insulated mailers

Cooling envelopes: isothermal shipping envelopes for small chilled shipments

A cooling envelope (also called an isothermal envelope, thermal envelope, insulated envelope or isothermal pouch) is an insulating package in envelope format for shipping small, flat, temperature-sensitive products chilled. Cooling envelopes are used most in pharma, and also for food and cosmetics.

What is a cooling envelope?

A cooling envelope is made of bubble film with a reflective, metallised aluminium layer. That combination insulates against outside temperatures and cushions shocks in transport at the same time. A self-adhesive strip closes the envelope quickly and neatly, without tape, so the cold chain stays intact from sender to recipient.

What are cooling envelopes used for?

In pharma, cooling envelopes are widely used for shipping medicines, vaccines and laboratory samples chilled, for example shipments between 2 and 8 °C or sample transport between sites and laboratories. They are also used for fresh food (cheese, cold cuts, sushi, chocolate) and temperature-sensitive cosmetics that must arrive within 24 hours.

Bubble film envelope or paper insulated bag?

This category has two types. The bubble film cooling envelope with an aluminium reflective layer gives the best insulation and shock absorption and suits pharma and fragile products. The paper insulated bag is made of recyclable paper with an insulating lining and is a sustainable choice for e-commerce and food shipments. Both close with an adhesive strip.

Which size of cooling envelope do I need?

The bubble film cooling envelopes are available from 25x35 cm to 60x60 cm; the paper insulated bags from about 245x381 mm to 341x483 mm. Smaller sizes fit through a letterbox and save a lot on shipping costs compared with a cool box, while larger sizes go as a parcel. Choose a size just a little bigger than your product plus the cooling element.

How long do the contents stay cold?

With 1 to 2 gel packs or ice pack sheets, the contents usually stay at temperature for 12 to 24 hours, depending on the outside temperature and the amount of product. For a strict range of 2 to 8 °C or longer transit times, combine the cooling envelope with extra cooling elements or PCM packs.

Combine cooling envelopes with the right gel packs and cooling elements or flat ice pack sheets. Larger or heavier shipments are better sent in a cool box or thermal box, optionally with insulated bags as an insulating inner lining. All cooling envelopes are ready to ship from stock.