Barrier materials and containers made therefrom

摘要

A barrier structure comprises: a first membrane substantially reflective of electromagnetic radiation; a second membrane spaced apart from the first membrane and bound to the first membrane about an edge thereof to form a bladder, the second membrane resistant to vapor transmission; and a fibrous insert disposed between the first membrane and the second membrane so as to maintain the spaced apart relationship, the fibrous insert defining a space holding an insulating medium resistant to the transmission of thermal energy and interspersed therethough. The first membrane may further comprise a multilayer composite and may include a polymer resistant to vapor transmission, for example including at least one of H₂O, CO₂ and O₂. The polymer may be a polyester. The multilayer composite may further comprise a structure substantially reflective of thermal energy. The composite may further comprise one or both of an outer metallization layer and an inner metallization layer. The composite may further comprise a sealing member. The sealing member may be a polyethylene layer. The fibrous insert may comprise randomly oriented fibers of plural deniers bonded together in a crush-resistant structure. The plural deniers may be within a range of 3 to 100 denier. The fibrous insert may further comprise an acrylic binder, an EVCL binder, a polyvinyl acetate (PVA) binder or other polymer binder and combinations thereof. The EVCL binder may be included in the fibrous insert as a percentage of material comprising the fibrous insert of about 35-75% w/w. The first membrane, the second membrane and the fibrous insert may all possess substantially similar melt flow indices. Also shown, a shipping container may comprise plural wall structures according to the thermal barrier structure described, disposed on at least two sides of a payload region, such as a box or envelope. The plural wall structures may be bonded together along at least one edge, for example to form a shipping envelope having an interior payload region surrounded by the bladders of the plural wall structures. The plural structures may further comprise a third membrane resistant to vapor transmission; and another fibrous insert disposed between the second membrane and the third membrane.