Batch method and apparatus for heating envelope edges to separate the envelope panels

A method of processing envelopes wherein each envelope has two generally rectangular planar panels that (1) define opposite faces of the envelope and (2) are connected together along a top edge, a bottom edge, and two oppositely facing end edges;

• said method being effective to separate said panels of each envelope along at least said end edges and said top edge;
• said method comprising the steps of:
• (a) arranging a plurality of envelopes in face-to-face relationship to form at least one batch of envelopes with an outer envelope at each end of the batch, with one end edge of each envelope in the batch disposed substantially in a first common plane that is generally normal to the envelope faces, with the second end edge of each envelope in the batch disposed substantially in a second common plane that is generally normal to the envelope faces, and with said top edge of each envelope in the batch disposed substantially in a third common plane that is generally normal to the envelope faces;
• (b) maintaining said batch of envelopes under compression by exerting a force against a portion of the surface of each of the two outer envelopes in the batch;
• (c) applying to said two end edges and to said top edge of each of the envelopes in said batch an envelope material degrading agent that functions as a degrading agent more effectively when heated;
• (d) moving a pair of end edge heating surfaces toward each other on either side of said batch in directions generally normal to said first and second end edge common planes to contact the end edges of the envelopes and to exert sufficient force on said envelopes with said end edge heating surfaces to bend the envelopes in the batch inwardly at each end edge more than 1/32 inch beyond the point of initial contact and to bend the contacted edge of each envelope out of the plane in which it was located prior to said contact;
• (e) with contact established by (d), reciprocating the end edge heating surfaces in directions substantially parallel to said first and second common planes to intermittently reverse the orientation of the envelope end edge bends and effect transient increases of the spacing between the contacted end edges of the adjacent envelopes for promoting more effective transfer of heat to the contacted envelope end edges and for facilitating escape of vapor from the contacted envelope end edges;
• (f) terminating steps (d) and (e);
• (g) moving a top edge heating surface in a direction normal to said third common plane of the envelope top edges to contact the top edges of the envelopes and to exert sufficient force on said envelopes with said top edge heating surface to bend the envelopes inwardly at the top edge more than 1/32 inch beyond the point of initial contact and to bend the contacted top edge of each envelope out of the plane in which it was located prior to said contact;
• and
• (h) with contact established by step (g), reciprocating said top edge heating surface in opposite directions substantially parallel to said third common plane to intermittently reverse the orientation of the envelope top edge bends and effect transient increases of the spacing between the contacted top edges of adjacent envelopes for promoting more effective transfer of heat to the contacted envelope top edges and for facilitating escape of vapor from the contacted envelope top edges.

A method of processing envelopes wherein each envelope has two planar panels that (1) define opposite faces of the envelope and (2) are connected together along a plurality of edges;

• said method being effective to separate said panels of each envelope along at least one of said edges;
• said method comprising the steps of:
• (a) arranging a plurality of envelopes in face-to-face relationship to form at least one batch of envelopes with an outer envelope at each end of the batch and with at least one edge of each envelope in the batch being disposed substantially in a common plane that is generally normal to the envelope faces;
• (b) maintaining said batch of envelopes under compression by exerting a force against a portion of the surface of each of said two outer envelopes in the batch;
• (c) before or after step (a), applying to at least said one edge of each of the envelopes an envelope material degrading agent that functions as a degrading agent more effectively when heated;
• (d) effecting relative movement between said batch of envelopes and a heating surface towards each other to contact the edges of the envelopes in said batch to which said agent has been applied and to exert sufficient force on said envelopes with said heating surface to bend the batch of envelopes inwardly beyond the point of initial contact and to bend the contacted edge of each envelope out of the plane in which it was located prior to said contact for promoting more effective transfer of heat to the contacted envelope edges;
• and
• (e) reciprocating said heating surface parallel to said common plane with a stroke length of about 3 inches at a frequency of about 1/4 Hertz for a total of 3 cycles.

An apparatus for processing envelopes wherein each envelope has two planar panels that (1) define opposite faces of the envelope and (2) are connected together along a plurality of edges;

• said apparatus being effective to separate said panels of each envelope along at least one of said edges to which a degrading agent has been applied that functions more effectively upon application of heat;
• said apparatus comprising:
• (a) means for holding a plurality of envelopes in face-to-face relationship to form at least one batch of envelopes with an outer envelope at each end of the batch and with at least one edge of each envelope in the batch being disposed substantially in a common plane that is generally normal to the envelope faces;
• (b) clamping means associated with said envelope batch holding means for exerting a force against a portion of the surface of each of the two outer envelopes in the batch to maintain the batch of envelopes under compression;
• (c) heating means for contacting and heating the envelope edges to which said agent has been applied;
• (d) means for effecting relative movement between said envelope batch holding means and said heating means towards each other to contact the envelope edges to which said agent has been applied;
• and
• (e) means for effecting relative reciprocating movement between said batch of envelopes and said heating means in directions substantially parallel with said common plane of the contacted envelope edges for promoting more effective transfer of heat to the contacted envelope edges and for facilitating escape of vapor from the contacted envelope edges.

A method of processing envelopes wherein each envelope has two planar panels that (1) define opposite faces of the envelope and (2) are connected together along a plurality of edges;

• said method being effective to separate said panels of each envelope along at least one of said edges;
• said method comprising the steps of:
• (a) arranging a plurality of said envelopes in face-to-face relationship;
• (b) aligning the envelopes with at least one edge of each envelope being disposed substantially in a common plane but is generally normal to the envelope faces;
• (c) maintaining the envelopes under compression along a line of action generally normal to the envelope faces;
• (d) before or after step (a), applying to at least said one edge of each of the envelopes an envelope material degrading agent that functions as a degrading agent more effectively when heated;
• (e) effecting relative movement between the envelopes and a heating surface toward each other to contact the edges of said envelopes to which said agent has been applied;
• and
• (f) with contact established by step (e), reciprocating the heating surface in opposite directions substantially parallel with said common plane of the contacted edges for promoting more effective transfer of heat to the contacted envelope edges and for facilitating escape of vapor from the contacted envelope edges.