there are many online, and there are many categories (according to quality, material, size and model). There are often some group buying activities, which are not very expensive and easy to find.
there are many supermarkets, and there are many on Taobao, large and small, and the price is more cost-effective
you mean the kind of vacuum bag (also known as nylon bag) that can package food. Its material is generally NY /CPE or PET /NY /CPE. This product has the characteristics of good vacuum pumping effect, high transparency, low air permeability (oxygen), good moisture resistance, high tensile strength and puncture resistance, easy heat sealing, good sealing and not easy to aging. This product is a plastic bag made of nylon composite polyethylene. It is transparent, non-toxic, tasteless and food grade packaging vacuum bag. The bag made of this material can maintain vacuum for a long time without air leakage and prolong the shelf life of food
go to xiashun packaging products Co., Ltd. It’s easy to find their contact information under Baidu search in Suzhou