The bag in the box is generally made of aluminum plated, pure aluminum, PDPE or nylon composite materials. The bag, faucet and carton are used together, so it is also called faucet valve bag. The valve is mainly butterfly valve, so it is also called butterfly valve liquid bag. The capacity varies from 1L to 220l. It is made of multi-layer materials, which can meet the needs of different liquid packaging. For example, the bag in the double bottom box generally needs to be customized.