POLYETHYLENE HEAT SEAL VALVE BAG 
Chinese manufacturer of polyethylene heat seal valve bag export US . 
It has the best sealing performance, even the ultra-fine and strong fluidity powder will not leak out.
The thickness of the bag can be thinner, saving the cost of raw materials.
No substances harmful to human body, including bisphenol A and laphenic acid
Used in high standard industries such as food additives