| 摘要 |
<p>A coated membrane for use in controlling the oxygen and carbon dioxide ratio inside of a package that holds respiring produce such as fruits, vegetables or flowers. The coated membrane comprises a porous substrate, such as a polypropylene film, and has an oxygen permeance in the range of 5,000 to 30,000,000 cc/100 in<2>-atmosphere-day. The substrate is coated with a material that is substantially impermeable to oxygen, such as an acrylic emulsion, so that the amount of substrate surface area covered with the coating causes a decrease in the oxygen permeance of the substrate. The coating is applied to the substrate using a flexographic or rotogravure or rotary silkscreen process. An aperture of approximately 0.15 mm is placed in the coated membrane to allow the internal pressure to approximate the external pressure without a significant loss of relative humidity.</p> |
