Opaque plastics envelope with window

摘要

An envelope formed of an opaque plastics material has an aperture 12 covered by a sheet of clear plastics material 28 cohered to the surface of the opaque plastics material to enable a mailing address contained in a document placed into the envelope to be viewed. The sheet of clear plastics material 28 may extend across the entire width of the envelope and may be cohered to the envelope along its edge near the mouth of the envelope so as not to interfere with the introduction of documents into the envelope. The clear plastics sheet 28 may be cohered to the opaque plastics material by adhesion or welding. The opaque plastics material may be polyethylene and may be in the form of one or more layers. A process for manufacturing the envelope is also disclosed which comprises the steps of cutting out an aperture in a first region of a sheet of plastics material which is to form the front panel 22 of the finished envelope, cohering a clear plastics sheet 28 to the inside of the front of the envelope which covers the aperture, folding a second region of the plastics sheet which is to form the back panel 20 of the finished envelope over the clear plastics material and subsequently cohering the first and second regions together to form side seams of the envelope. The envelopes may be formed individually or two or more at a time (see figs 3-8) from an extruded tube.