Process for making an oxygen permeable multilayer film
AssigneeW. R. Grace & Co.-Conn.
InventorBetsy P. Kuo
Life of this patent
Estimating the term…
Abstract
A multilayer film comprises: a first layer comprising a first homogeneous ethylene/.alpha.-olefin copolymer; a second layer comprising a polyolefin; and a third layer comprising a second homogeneous ethylene/.alpha.-olefin copolymer. The second layer is between the first layer and the third layer, the second layer is chemically different from the first layer and the third layer, and the multilayer film has an oxygen transmission rate of from about 500 to 50,000 cc/m.sup.2 /24 hr STP. Also disclosed are a process for making the film, a packaging process using the film, and a product packaged in the film. The film is especially suitable for the packaging of oxygen sensitive products, such as lettuce, and exhibits exceptional hot tack seal strength.
Claims20
A process for making a film comprising at least three layers, said process comprising the steps of:
- a) providing
- 1) a first composition comprising a first homogeneous ethylene/.alpha.-olefin copolymer,
- 2) a second composition comprising a polyolefin, and
- 3) a third composition comprising an ethylene/.alpha.-olefin copolymer;
- and
- b) extruding said first, second, and third compositions to form, respectively, first, second, and third layers of said film, said second layer being between said first and said third layers,
- said film having an oxygen transmission rate of from about 500 to 50,000 cc/m.sup.2 /24 hr when measured at standard temperature and pressure.
Dependencies are inferred from the claim text.