US 4,854,984 A · Dynamic mechanical bonding method and apparatus

Abstract

A method of and apparatus for dynamically mechanically bonding together a plurality of laminae, at least one of which comprises thermoplastic material: for example, polyethylene. In one aspect of the invention the laminae are forwarded in face to face relation through a pressure biased nip between a patterned nip defining member and an opposing nip defining member (e.g., a relief patterned cylinder and an anvil cylinder) which members are independently driven to maintain a predetermined surface velocity differential between them. In another aspect of the invention which is particularly useful at intermediate and higher line velocities--preferably for line velocities of about 300 feet or more per minute and, more preferably, for line speeds of about 450 feet or more per minute--the nip defining members may be operated with equal surface velocities. In each of these aspects of the invention, the members may be biased towards each other to provide a predetermined pattern-element-psi loading; and, additionally, they may be independently heated to provide each with an elevated surface temperature which is, preferably, in a predetermined range below the melt temperature of the thermoplastic lamina disposed closest to or in contact with each respective nip defining member as the laminae are forwarded through the nip.

Claims16

Dependent claims

A method of dynamically bonding plural laminae together, at least one of which laminae comprises thermoplastic material, said method comprising the steps of:

forwarding said laminae, with portions thereof in face to face relation, through a pressure biased nip between a relief patterned nip defining member having pattern element segments, and a nip defining anvil member;
biasing said nip defining members towards each other with a predetermined pattern-element loading of not more than about 90,000 psi;
and
driving said nip defining members to provide a predetermined surface velocity differential therebetween, said surface velocity differential having a magnitude of from about 2 to about 40 percent of the surface velocity of said nip defining member having the lower surface velocity.

1 more element

A method of operating an apparatus for dynamically bonding plural laminae together at least one of which laminae comprises thermoplastic material, said apparatus comprising a patterned nip defining member and a nip defining anvil member, means for mounting said nip defining members to define a nip therebetween through which nip said laminae may be forwarded with portions thereof in face to face relation, means for controllably biasing said nip defining members towards each other, and means for driving said nip defining members to provide predetermined surface velocities, said method comprising the steps of:

driving one of said nip defining members at a predetermined first surface velocity of at least about 450 feet per minute;
and
interactively driving the other of said nip defining members to provide a surface velocity differential relative to said predetermined first surface velocity of from about 2 to about 40 percent of the surface velocity of said nip defining member having the lower surface velocity, in combination with a substantially non-deleterious level of said biasing to effect dynamically thermally bonding said laminae together while obviating deleterious tearing or perforating of said laminae.

Dependencies are inferred from the claim text.

Dynamic mechanical bonding method and apparatus

Life of this patent

Dynamic mechanical bonding method and apparatus

Life of this patent

Abstract

Claims16