Mylar Bags
Posted: Thu Oct 21, 2010 2:08 am
Mylar Bags
LDS Preparedness Manual-Mylar Bags
https://thesurvivalmom.com/wp-content/uploads/2010/08/LDS-Preparedness-Manual.pdf
Page 87
HOW DO I USE MYLAR BAGS?
Sealing food in Mylar bags is a straight-forward affair, but it may take a bit of practice to get it right, so purchase one or
two more bags than you think you’ll need in case you don’t immediately get the hang of it
#1 - The bags typically sold by storage food dealers look rather large when you compare them to the five or six gallons buckets they are commonly used in. That extra material is necessary though if you are to have enough bag material left over after filling to be able to work with. don’t trim off any material until after the sealing operation is completed
#2 - Place the bag inside the outer container and fill with the food product. Resist filling it all the way to the top. You need at least an inch or so below the bucket rim left open to get the lid to seat completely. If you'll be using desiccants and oxygen absorbers place the desiccant on the bottom of the bag before filling.
#3 - When the pail seems to be full, gently thump it on the floor a few times to pack the product and reduce air pockets. Add any makeup food necessary to bring level back to where it should be.
#4 - Take the bag by the corners and pull out any slack in the material so that all sides can be pulled together evenly. Place your oxygen absorbers inside if you are going to use them. Now place a board over the top of the bucket and fold the bag end down over it keeping it straight and even. Place a piece of thin cotton fabric such as sheet or t-shirt material over the edge of the bag mouth. Using a clothes iron set on the cotton, wool or high setting run it over the cloth-covered Mylar about a half-inch from the edge for about twenty seconds or so until it seals. You'll probably have to do the bag in sections. Temperature settings on irons vary so experimenting on a leftover strip to find the right setting is a good idea.
#5 - When you've done the entire bag allow it to cool then try to pull the mouth of the bag open. If moderate pressure doesn’t open it, fold the bag down into the pail until you feel the trapped air pillowing up against the material and wait to see if it deflates. If it stays buoyant, your seal is good. You can seal on the bucket lid at this point or take the further step to vacuum or gas flush the bag. Once a seal has been obtained the bags can be left as-is, vacuum sealed or gas flushed. To obtain the most efficient oxygen removal the bags can be first drawn down with a vacuum pump and then purged using an inert gas.
Vacuum Sealing Mylar Bags
Once you have obtained a good seal on the bag, pulling a vacuum on the contents is straight forward.
First you'll need something to make a vacuum with. This can be either a regular vacuum pump, a vacuum sealer such as the Tilia Food Saver or even the suction end of your household vacuum cleaner. The end to be inserted into the bag will need to be of fairly small diameter in order to keep the hole in the Mylar from being any larger than necessary. This means that if you use a vacuum cleaner you'll need to fashion some form of reduction fitting. One such that I've seen is a plastic film canister with a hole drilled in the bottom and a piece of plastic tubing epoxied in place.
Cut a hole into the Mylar bag on a corner, making the opening only just large enough to admit the vacuum probe. Insert the nozzle and using a sponge, or something similar, push down on the material over the probe to make a seal. Now draw down a vacuum on the bag. When it's drawn down as much as possible, run a hot iron diagonally across the cut corner resealing the bag.
Gas Flushing Mylar Bags
Flushing with inert gas works essentially like vacuum sealing except that you're putting more gas into the bag rather than taking it out. You'll want to keep the entry hole small, but don't make a seal around it as above. Beyond that, follow the directions as given in Section III.B.2 - CO2 and Nitrogen. When you feel that the bag has been sufficiently flushed, run the iron across the corner as above to seal.
Flushing with dry ice can also be done, but it is important to wait until the frozen carbon dioxide has completely sublimated into gas before making the final seal otherwise the bag will burst like an overfilled balloon.
LDS Preparedness Manual-Mylar Bags
https://thesurvivalmom.com/wp-content/uploads/2010/08/LDS-Preparedness-Manual.pdf
Page 87
HOW DO I USE MYLAR BAGS?
Sealing food in Mylar bags is a straight-forward affair, but it may take a bit of practice to get it right, so purchase one or
two more bags than you think you’ll need in case you don’t immediately get the hang of it
#1 - The bags typically sold by storage food dealers look rather large when you compare them to the five or six gallons buckets they are commonly used in. That extra material is necessary though if you are to have enough bag material left over after filling to be able to work with. don’t trim off any material until after the sealing operation is completed
#2 - Place the bag inside the outer container and fill with the food product. Resist filling it all the way to the top. You need at least an inch or so below the bucket rim left open to get the lid to seat completely. If you'll be using desiccants and oxygen absorbers place the desiccant on the bottom of the bag before filling.
#3 - When the pail seems to be full, gently thump it on the floor a few times to pack the product and reduce air pockets. Add any makeup food necessary to bring level back to where it should be.
#4 - Take the bag by the corners and pull out any slack in the material so that all sides can be pulled together evenly. Place your oxygen absorbers inside if you are going to use them. Now place a board over the top of the bucket and fold the bag end down over it keeping it straight and even. Place a piece of thin cotton fabric such as sheet or t-shirt material over the edge of the bag mouth. Using a clothes iron set on the cotton, wool or high setting run it over the cloth-covered Mylar about a half-inch from the edge for about twenty seconds or so until it seals. You'll probably have to do the bag in sections. Temperature settings on irons vary so experimenting on a leftover strip to find the right setting is a good idea.
#5 - When you've done the entire bag allow it to cool then try to pull the mouth of the bag open. If moderate pressure doesn’t open it, fold the bag down into the pail until you feel the trapped air pillowing up against the material and wait to see if it deflates. If it stays buoyant, your seal is good. You can seal on the bucket lid at this point or take the further step to vacuum or gas flush the bag. Once a seal has been obtained the bags can be left as-is, vacuum sealed or gas flushed. To obtain the most efficient oxygen removal the bags can be first drawn down with a vacuum pump and then purged using an inert gas.
Vacuum Sealing Mylar Bags
Once you have obtained a good seal on the bag, pulling a vacuum on the contents is straight forward.
First you'll need something to make a vacuum with. This can be either a regular vacuum pump, a vacuum sealer such as the Tilia Food Saver or even the suction end of your household vacuum cleaner. The end to be inserted into the bag will need to be of fairly small diameter in order to keep the hole in the Mylar from being any larger than necessary. This means that if you use a vacuum cleaner you'll need to fashion some form of reduction fitting. One such that I've seen is a plastic film canister with a hole drilled in the bottom and a piece of plastic tubing epoxied in place.
Cut a hole into the Mylar bag on a corner, making the opening only just large enough to admit the vacuum probe. Insert the nozzle and using a sponge, or something similar, push down on the material over the probe to make a seal. Now draw down a vacuum on the bag. When it's drawn down as much as possible, run a hot iron diagonally across the cut corner resealing the bag.
Gas Flushing Mylar Bags
Flushing with inert gas works essentially like vacuum sealing except that you're putting more gas into the bag rather than taking it out. You'll want to keep the entry hole small, but don't make a seal around it as above. Beyond that, follow the directions as given in Section III.B.2 - CO2 and Nitrogen. When you feel that the bag has been sufficiently flushed, run the iron across the corner as above to seal.
Flushing with dry ice can also be done, but it is important to wait until the frozen carbon dioxide has completely sublimated into gas before making the final seal otherwise the bag will burst like an overfilled balloon.