Patent Application
20060102773
This invention relates to refurbishing used hollow cylindrical core members of paperboard material for rolls of paper or other sheet material.
Paper such as newsprint is conventionally wound by the manufacturer on hollow cylindrical core members of paperboard material. When a roll of paper so wound has been used, for example in a newspaper print room, it is economically and also ecologically desirable for the core member to be returned to the paper manufacturer for use or for recycling. However, for one reason or another, the outer surface of a used core member is frequently somewhat damaged and/or marked to such an extent that paper cannot be satisfactorily wound thereon.
U.S. Pat. Nos. 5,845,871 and 6,051,092 (Lynch et al) describe the refurbishing of core members by reducing the diameter of a used core member by about 0.025 inches so that a web of fiber board with a thickness of about 0.0125 inches can be wrapped around the core member of reduced diameter. Unfortunately, if the edges of such a fiber board were overlapped, the diameter where the overlap occurs will be increased by 0.0125 inches which will normally exceed the tolerance of diameter variation and also cause an axial ridge which is transmitted through multiple layers of newsprint wound under tension to cause print and register problems. Consequently, as taught by Lynch et al, it becomes necessary to skive the web edges which will overlap, thus requiring a further manufacturing step for this purpose, or precisely butt them circumferentially which requires precise application.
It is therefore an object of this invention to provide a method of refurbishing such core members which at least substantially overcomes these problems.
According to the present invention, the outer diameter of a used core member is reduced only by an amount in the range of from about 0.002 to about 0.01 inches, and a layer of paper with a thickness of from about 0.002 to about 0.01 inches is secured around the core member of reduced diameter with axially extending edges of the paper layer overlapping. Because of the thinness of the paper, the increase in diameter caused by the overlapping edges can be arranged to be within the required manufacturing tolerance. Also, the extra diametric thickness caused by the overlapping edges will be absorbed by the first few turns of the paper wound on the refurbished core member. These first few turns are usually not used in a subsequent printing process.
The paper used for the layer may be the same paper, such as newsprint paper, as is to be subsequently wound on the refurbished core member, and thus this invention represents unique recognition of the advantage of using a thin overlapping wrap or wraps of this material to meet both diameter specifications and tolerances in core refurbishing.
The present invention therefore provides a method of refurbishing a used hollow cylindrical core member of paperboard material for a roll of paper or other sheet material, including removing a predetermined thickness of paperboard material from the outer surface of the core member to reduce the outside diameter thereof by an amount in the range of from about 0.002 to about 0.01 inches, and securing a layer of paper with a thickness in the range of from about 0.002 to about 0.01 inches around the core member of reduced diameter and causing axially extending edges of the paper layer to overlap.
The paper layer preferably has a thickness in the range of from about 0.002 to about 0.005 inches, for example about 0.003 inches. The paper layer may be adhesively secured to the core member of reduced diameter. The amount of overlap should of course be sufficient to produce a good glue bond.
The present invention also provides a refurbished hallow core member for a roll of paper or other sheet material having a core member of paperboard material having a diameter reduced from a required diameter by an amount in the range of from about 0.002 to about 0.01 inches, and a layer of paper with a thickness in the range of from about 0.002 to about 0.01 inches secured around the core member of reduced diameter with its axially extending edges overlapping.
One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, of which:
Referring to the drawings,
The core member 12 is then buffed or likely ground to reduce its diameter by 0.006 inches to 4.004 inches so as to remove the dirt, blemishes, and/or paper scraps and produce a core member 14 of reduced diameter as shown in
As shown in
The nominal outside diameter of the refurbished core member 18 will be 4.010 inches, i.e. the same as the original used core member 12, except that there will be an increased diametric thickness of 0.003 inches where overlap of the paper layer 16 occurs. However, as this is well within the required manufacturing tolerance of ±0.005 inches in the diameter of core members of this kind, and in any event, this extra diametric thickness will be absorbed by the first few turns of newsprint subsequently wound on the refurbished core member 18.
The advantages of the invention will now be readily apparent to a person skilled in the art from the foregoing description of a preferred embodiment. Other embodiments of the invention will also now be readily apparent, the scope of the invention being defined in the appended claims.
