US 3824143 A
Description (OCR text may contain errors)
July 16, 114 g, COOPER ETAL METHOD OF SPLIGING 0F WEB MATERIAL 2 Shets-Sheet 1 Filed Jan. 21. 1972 FIG-.l,
July 16, 1914 R coopgR EIAL 3,824,143
METHOD OF SPLICING 0F WEB MATERIAL Filed Jan. 21, 1972 2 Sheets-Sheet 2 United States Patent 3,824,143 METHOD OF SPLICING 0F WEB MATERIAL Ronald Charles Cooper and Alan Albert Aldridge, Ilford, England, assignors to Ilford Limited, Essex, England Filed Jan. 21, 1972, Ser. No. 219,668 Claims priority, applicationmG/i fiat Britain, Jan. 27, 1971,
3,3 Int. Cl. B31f 5/00; B65h 19/00, 69/02; G03d /04 US. Cl. 156-157 1 Claim ABSTRACT OF THE DISCLOSURE A method of splicing together the ends of two abutted webs is described. In this method a tape dispensing device which contains a roll of pressure-sensitive adhesive tape wound together with a release-surface backing tape is traversed across the abutted ends of the webs laying down a strip of adhesive tape and at the same time separating the backing tape and rolling it up.
This invention relates to the splicing of web materials and in particular to a method useful in splicing the leading end of a fresh reel of web material to a trailing end of a web which is being fed into a web treating machine.
The splicing together of two webs by overlapping their ends and sticking these ends together by means of an adhesive sometimes gives rise to difficulties because a double thickness of web material, at the splice, is thereby produced. To overcome this difiiculty it has been proposed to abut the end of the webs to be joined and to lay down on one face of the webs, a length of adhesive tape to cover the line of abutment. A similar length of adhesive tape may be applied to the other face of the webs also along the line of abutment. By providing that the applied tapes are thin in themselves the build-up of excessive thickness in the region of the splice can thus be avoided.
A method has been devised for laying down strips of tape wherein a tape dispensing device is traversed across the abutting ends of the two webs. As the device is moved across the ends of the webs a strip of pressure-sensitive adhesive tape is laid down over the joint and pressed down so that the strip of adhesive tape is afiixed to the ends of both the webs; thus forming a splice. In another method one strip of pressure sensitive adhesive tape is laid down adhesive face upwards under the ends of the two webs and another strip is laid down on the ends of the two webs.
Both these methods of splicing the two ends of web material have been used with considerable success but difficnlties have arisen when the web material to be spliced in comparatively thin and thus easily wrinkled.
SUMMARY OF THE INVENTION It is the object of the present invention to provide a method of splicing two abutting web ends which can be used when splicing thin webs and which tends to decrease the occurrence of wrinkles and flute marks in the vicinity of the splice.
According to the present invention there is provided a method of splicing the ends of two lengths of web material which are in abutment which comprises traversing across the abutted ends a tape dispensing device, which carries a roll of pressure sensitive adhesive tape wound together with a release-surface backing tape, whereby the device dispenses a strip of pressure sensitive adhesive tape so that it covers the ends of both the abutted webs along its length and at the same time separates the backing tape from the pressure sensitive adhesive tape and rolls it up, and then bringing the adhesive action of the pressure sensitive adhesive tape into effect thus splicing the two webs together.
3,824,143 Patented July 16, 1974 Preferably in the method of the present invention the dispensing device is traversed across the abutting ends of the film webs twice, in one movement a strip of pressure sensitive adhesive tape is laid down adhesive face upwards and in the other movement a strip of pressure sensitive adhesive tape is laid down on to the abutting ends of the webs adhesive face downwards. In both these movements the backing tape is separated from the pressure sensitive adhesive tape and wound up inside the dispensing device. Therefore according to a preferred embodiment of the method of the present invention the tape dispensing device has a plough-shaped projection and in a first traversing movement of the device across the abutted ends of the webs the plough-shaped nose of the device lifts the abutted ends and lays beneath them a strip of pressure sensitive adhesive side upwards and at the same time separates the backing tape from the adhesive tape and rolls it up internally, then holding the so-laid strip of pressure sensitive adhesive tape at the end of the first traversing movement and then in a second traversing movement, traversing the dispenser back along the line of abutment of the webs thereby laying down a strip of pressure sensitive adhesive tape on the abutted ends of the webs adhesive side downwards and at the same time separating the backing tape from the adhesive tape and rolling it up internally and in the same traversing movement pressing the strips of adhesive tape and the ends of the webs together.
By a release-surface backing tape is meant a thin tape which carries no adhesive and to which the adhesive used on the adhesive tape will not adhere or will not adhere to very firmly, being easily separated therefrom. A release surface is obtained usually by treatment of the surface with a compound such as a silicone to which most adhesives will not adhere firmly.
The method of the present invention, by employing an apparatus which comprises a platform adapted to hold two abutted web ends, means mounted on the platform for securing the webs, a tape dispenser device which has a projecting plough-shaped nose and which has present therein a rotatable spool which has wound thereon a roll of pressure sensitive adhesive tape wound up together with a release-surface backing tape, tape dispensing rollers, means for separating the adhesive tape from the backing tape, and means for rolling-up the separated backing tape and a pressure-applying roller. The apparatus also comprises means for traversing the dispenser device and means connected to both sides of the platform for holding the strip of pressure sensitive adhesive tape.
Preferably the dispensing device is mounted on a supporting runner fixed above the platform.
Preferably there is present in the tape dispensing device a take-up spool which is rotatably connected with the spool on which the adhesive tape and backing tape are wound together so that when this spool rotates when the dispensing device is traversed across the abutted webs the take-up spool also rotates and rolls up the backing tape which has been separated from the adhesive tape.
When an adhesive tape wound with a release surface backing tape is used the roll of tape is able to be unwound very easily. In the previously used methods certain tensions and uneven strains were produced in the tape as it was peeled from the surface of the next turn of tape against its own adhesive action. This tension and uneven strain tended to cause flute marks and creases in the webs in the region of the splice, especially when very thin webs were spliced, when the tape having tension therein was laid on the webs. Another disadvantage which has been overcome by the method of the present invention is that the surface of the tape in the previously used method was always contaminated with some adhesive derived from the adhesive side of the tape being in contact with the top surface in the rolled up tape. This contamination was undesirable in a number of manufacturing processes, for example layers could not be coated evenly over the splice area and this tended to produce elongated coating faults which extended well beyond the splice area. This contamination of the surface of the tape has been eliminated by the use of a release-surface backing tape which separates the adhesive side of the tapes from the front surface of the next turn in the wound up tape.
Preferably adhesive tape having on one surface an adhesive the reverse surface being a release surface should not be used when the web being spliced is to be coated because this release surface would prevent the splice area being coated and thus cause also serious elongated coating faults.
BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with particular reference to the accompanying drawings wherein FIG. 1 is a side sectional elevation of a tape dispenser device of use in the present invention. FIG. 2 is a side elevation of the tape dispenser device having accomplished half of the first traversing movement. FIG. 3 is a front elevation of the tape dispenser device in the same position as in FIG. 2. FIG. 4 is a side elevation of the tape dispenser device having accomplished half of the second traversing movement. FIG. 5 is a front elevation of the tape dispenser device in the same position as in FIG. 4. In these drawings for the sake of clarity the tape is shown as a thickness comparable with that of the web, but in practice it is likely to be considerably less.
DETAILED DESCRIPTION OF THE INVENTION Referring to these drawings, in FIG. 1, the tape dispenser device 1 comprises a double wound roll of tape 2. A length 3 of this tape has been led off the roll 2. As the length of tape 3 is lead past the sharp edge of the separator bar 4 the backing tape 5 which has a release surface is separated from the pressure sensitive adhesive tape 6. The backing tape 5 is wound onto a spool 7. In this figure the device 1 is being moved in the direction indicated by the arrow. When the movement is in this direction the tape 6 is lead from the separator 4 round the dispenser roller 8 and is laid adhesive face upwards on the platform 9. (If the device were travelling in the opposite direction the tape 6 would be lead over the dispenser roller 10 and would be laid adhesive face downwards over the abutting webs. This is indicated by the dotted line which joins 4 to 10.)
Also shown in FIG. 1 is the projecting plough 11 and the pressure roller 12, and shown diagrammatically is a drive gear 15 which is attached to the back of the spool 16 which holds the roll 2. The gear 15 meshes with an idler gear 17 which meshes with a gear wheel 20 which is attached to the back of the backing tape take up spool 7. The gear wheel 15 is connected to the spool 16 via a felt pad (not shown). This felt-pad constitutes a slip drive.
The device is loaded by packing a complete roll 2 of double wound tape on to the roll spool 16. A length of tape 3 is then led from the roll 2 over the separator bar 4. This causes the backing tape 5 to separate therefrom. The free end of the backing tape is then secured on to the spool 7. Spool 7 is then rotated by hand to take up any slack. The tape 6 is then pulled round the dispensing roller 8 and secured on to the platform by a nipping plate 18.
In operation the dispenser device is moved to the left. As the tape 6 is pulled from the roll 2 the backing tape spool 7 is driven by the rotation of the spool 16, through the gear system which comprises the gear wheels 15, 17 and 20, the gear wheel 15 being connected via the felt pad to the spool 16. This gearing arrangement is so' arranged that the backing tape is always fully wound up on the spool 7. The gear ratios chosen are such that when a new roll of double wound tape 2 is used the surface speeds of the tape roll 2 and the backing tape spool 7 are matched. As the tape roll 2 is used and becomes diminished in size the spool 7 is over-driven and slipping occurs at the felt pad drive. This inhibits the spool 7 from causing tension to occur in the tape 5 via tape 3.
FIGS. 2-5 shows diagrammatically how the adhesive tape is laid down in the first and second traversing movements.
In all the figures a tape dispensing device 1 lays down adhesive tape 6. The device 1 is mounted on a traverse bar 25 over a joining platform 9. The two ends of the film webs 27 and 28 are laid over a support platform 9 and are clamped in position on the platform by pneumatic clamping bars 30 and 31 (or full length suction pads). The two ends of the film webs are then trimmed by slitting cutters. The webs are separated horizontally by a small gap by horizontal movement of the clamps 30 and 31. This prevents overlapping of the said two abuting webs and allows the top and bottom adhesive faces of the tape to adhere in the centre of the joint thus increasing the strength and flexibility of the joint. The end of the tape 6 is then secured by a nipping plate 18. The device 1 is pushed by hand over the platform 9 to the left. This is shown in FIGS. 2 and 3. When the device has reached the left hand side of the platform the plough shaped nose 11 of the device 1 actuates a trigger (not shown) and causes an arm 35 to clamp the adhesive tape 6 to the platform such that no tension is induced into the tape 6. During this traversing movement the adhesive tape 6 is laid adhesive face upwards under the abutting ends of the webs 27 and 28 and the backing tape is rolled up on spool 7 of the device 1.
The device 1 is then pushed by hand over the platform 9 to the right. This is shown in FIGS. 4 and 5. During this traversing movement the adhesive tape is laid down adhesive face down on to the abutting ends of the film webs 27 and 28 and the backing tape is rolled up on spool 7 in the device 1. The pressure roller 12 presses the film webs and two lengths of tape into close contact. When the device 1 reaches the right hand side of the platform 9 (in FIG. 4) the tape 6 coming from the dispenser is then cut. Thus the two ends of the film webs have been spliced.
Neither top surface of the two strips of adhesive tape has been contaminated with adhesive. Very little if any tension is caused to occur in the tape 6 asit is laid down and thus 'a very even joint with substantailly no flutes or creases is obtained. Joint strength is increased by the adhesion of the top and bottom layers of tape 6 in the middle of the joint.
In the embodiment of the invention described above the splicing head is caused to traverse the webs by hand but it will be appreciated that the forward and reverse motion may readily be carried out automatically and automatic means may also be provided to cut ed the ends of the tape which overlap the spliced webs.
In a further modification of the invention air jets are provided 40 and 41 (shown in FIG. 2 to 5). At the commencement of the first traversing movement air is forced through these jets which lifts one side of the ends of the two webs. This enables the tape dispenser more easily to move between the ends of the webs. Also the ends of the web are prevented from falling down on to the tape as soon as the tape dispenser has passed between them. The air cushion provided by the jets is sufiicient to prevent approximately the first third of the length across the two abutted webs from falling down onto the tape. When the dispenser device has traversed across the abutted webs the air to the jets is stopped and the ends of both the webs are then able to fall down onto the tape.
Alternatively lifting fingers may be provided instead of air jets. These fingers would be located in the same place as the air jets 40 and 41 would have occupied. These fingers would equally well prevent the ends of the webs 5 6 from falling on the tape as soon as the tape dispener traversing in a second direction, opposite to said first had passed between them. These fingers would be lowered direction, along said line of abutment of said ends when the dispenser device had traversed across the said roll of adhesive tape, while simultaneously sepabutted webs. arating a second length of said adhesive tape from We claim as our invention: 5 said backing strip, laying said second length of ad- 1. A method of splicing the ends of two lengths of hesive tape down on top of said abutted ends with web material which are in abutment, said method comthe adhesive of said tape facing downwardly in conprising the steps of: tact with said abutted ends, and pressing together fixed positioning said two lengths of material with said first and second lengths of adhesive tape and said ends thereof in abutment; 10 said abutted ends. traversing in a first direction along the line of abutment of said ends a roll of pressure-sensitive adhesive References Cited tape wourii1 together with a backing strip which car; UNITED STATES PATENTS ries no a esive and to which the adhesive of sai adhesive tape will substantially not adhere, While si- 15 3694293 9/1972 Prader et 156 506 multaneously lifting said abutted ends, separating a 2,947,346 8/1960 Thompson 156-159 X first length of said adhesive tape from said backing 3578534 5/1971 Johnson 156545 strip, laying said first length of adhesive tape down 3582436 6/1971 Bucher 156*545 X beneath said lifted ends with the adhesive of said tape facing upwardly, and returning said ends to said 20 WILLIAM POWELL Primary Exammer abutted position on top of said first length of ad- U S C] XR hesive tape; holding the end of said first length of adhesive tape 545 at the end of such first traversing step; and