You are talking about the kind of packaging food, vacuum bags (also known as nylon bags), the material is generally NY/CPE or PET/NY/CPE. this product has a good vacuum effect, high transparency, low permeability (oxygen), moisture-proof performance, tensile strength and puncture resistance to a high degree of ease of heat sealing, sealing, not easy to aging and other characteristics. This product is made of nylon composite polyethylene plastic bags, transparent, non-toxic, tasteless, food-grade packaging vacuum bags. This material to do the bag, can keep the vacuum time long, no leakage, extend the shelf life of food
Go to find the Dashun Packaging Products Company bar in Suzhou, Baidu search on their contact information is very good to look for
This is the first time that I've seen a bag in the world, but I'm not sure if I can find a bag in the world.