Answered on 1/31/2011 12:00:00 AM by Customer Care from Sierra Trading Post
Grabber actually sells a new version with a little ziploc bag for this purpose. Works only so-so.||The heat is produced through oxidation of the contents so when you seal them up and exclude oxygen you can slow down and stop the process. When you reopen the bag, the process continues. Unfortunately ziploc bags are not necessarily air tight so sometimes a second use will not work well, especially if they have been sitting for a while because oxygen slowly leaked in.
Answered on 2/29/2012 12:00:00 AM by batmick from San Diego, CA
The warmers operate on a chemical reaction with air similar to rusting. The warmer ingredients are iron, water, cellulose, vermiculite, activated carbon and salt. The heating process takes place in this fashion:|The iron in the pouch, when exposed to oxygen, oxidizes and therefore produces heat (aka, "Air Activated"). When iron oxidizes it produces iron oxide, more commonly referred to as rust.|The salt acts as a catalyst. The carbon helps disperse the heat. The vermiculite is used as an insulator for the purpose of retaining the heat and the cellulose is added as a filler. All of these ingredients are surrounded by a polypropylene bag. Polypropylene allows air to permeate the ingredients while holding in moisture.|The item is a one time use product.
Answered on 11/1/2010 12:00:00 AM by Customer Care from Sierra Trading Post