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US 4,497,679 AGranted
Method of forming plastic envelopes
OwnerCharles T. Hathawayinventor
Life of this patent
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Abstract
The invention includes apparatus for and process of forming a plurality of plastic mounting envelopes from continuous plastic sheet material through cutting the plastic and bead sealing the margins by providing a high energy source to sever the plastic and bond the marginal edge of said plastic without physical contact. The invention also includes said plastic envelopes to serve as mounts and protectors for receiving flat paper objects such as stamps, letters, etc.
Claims4
The process of forming plastic protective envelopes from sheet polyester which is untreated with material to aid in marginal bead sealing including:
- superimposing at least one sheet of relatively thin untreated polyester upon another sheet of relatively thin untreated polyester;
- drawing said superimposed sheets over a mandrel;
- interposing a plurality of fixed first cutting and sealing means independent of said mandrel in the path of said sheets capable of simultaneously cutting said sheets into endless strips and bead sealing endless marginal edges of said strips;
- feeding said sealed strips through stop clamp means to regulate the speed and metering of said strips;
- positioning a vacuum means in the path of said metered strips adapted to releasable retain said strips in a fixed position;
- and
- activating a second cutting sealing means adjacent said vacuum means in the path of said vacuum retained strips capable of simultaneously cutting said metered strips and bead sealing marginal edges normal to said endless marginal edges to form said individual untreated polyester envelopes.
4 more elements
Dependencies are inferred from the claim text.