US 4,304,750 AGranted

Process for the edge knurling of a thermoplastic web

AssigneeAgfa-Gevaert

InventorsFrancois J. Pira, Jozef C. Van Wijk

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Abstract

A moving length of a thermoplastic web is subjected to edge knurling along the margins of its two opposite edges by passing each of such margins through a knurling zone including a backing wheel in supporting engagement with the reverse surface of the margin and in engagement with the obverse margin surface a freely rotatable knurling wheel carrying a plurality of raised minute surface projections thereon as an exterior knurling pattern, while heaving a portion of the rim periphery to a temperature sufficiently high to soften a surface stratum of the web margin by conduction from the heated rim, and simultaneously adjusting the force exerted by the two wheels on the web margin to cause said knurling projections to enter and depress localized areas of the heat softened surface stratum while the regions of the same surface stratum adjacent such depressed areas become upset and raised above the original surface without causing deformation of the reverse web surface as a consequence of the entry of the knurling projections into the obverse web surface stratum.

Claims1

Dependent claims

A process for edge knurling a moving length of a thermoplastic web having two opposite side edges which comprises the steps of:

passing each of the opposite edge margins of said web through a knurling zone, said zone comprising a backing wheel in supportive engagement with the reverse surface of said margin and a freely rotatable knurling wheel in engagement with the obverse surface of said margin, said knurling wheel having a plurality of raised minute surface projections thereon to form an exterior knurling pattern;
heating the knurling wheel to an elevated temperature sufficient to soften an obverse surface stratum of said web margin by conduction from said wheel;
and adjusting the force exerted by said wheels on the web margin passing through the nip thereof to cause the areas of the heated and softened obverse surface stratum to be entered by said projections and thereby depressed and the regions of the same surface stratum adjacent said depressed areas to become upset and raised relative to the original web surface without deformation of the reverse surface as a consequence of said entry of said surface stratum by said projections.

Dependencies are inferred from the claim text.

Facts

Application: 06/040,427Filed 18 May 1979 · continuation
Priority: GB 26249/731 Jun 1973
Granted: 8 Dec 1981
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

B29C 67/0044
Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00: for shaping edges or extremities
B29C 33/026
With incorporated heating or cooling means: in rolls, calenders or drums
B29C 59/04
By mechanical means, e.g. pressing: using rollers or endless belts
B29C
Shaping or joining of plastics

Family

Serial474,989Parent of this continuation · filed 31 May 1974
Serial669,623Parent of this division · filed 23 Mar 1976
Serial744,238Parent of this continuation · filed 23 Nov 1976
US 4,021,179 AParent of this division · filed 3 May 1977
US 4,304,750 AThis patent

From the US filing history. Foreign family members aren’t listed.