the following factors should be considered when selecting. a packaging speed. for the sake of improving production efficiency, double-chamber or multi-chamber vacuum packaging machines can be used. to improve the whole. the progress of the production. b whether the packaged items need to be filled with other protective gases. optional multifunctional vacuum packaging machine with inflatable setting. c requirements for the vacuum degree of the packaged goods. if the packaged items need to be kept in good condition under the condition of high vacuum degree; you need to choose a cavity vacuum packaging machine. d the requirements of the component status of the packaged items on the vacuum packaging machine. when purchasing, aluminum alloy can be used for packaging solid √ particles and other relatively dry and non-corrosive materials. the packaging comes with soup, materials with high salt and acid content. you can choose stainless steel or ~magnesium alloy material. the sealing ring is generally made of silicone rubber armpit and black rubber. a small number of low-end products use foamed rubber armpits. silicone rubber is resistant to high temperatures and candles, has good sealing performance and long service life. foam rubber has poor sealing performance and is easy to fall off and has a short service life. there are many varieties of food vacuum packaging machines.