JAVELIN MACHINERY (AUSTRALIA)
J800 /J900 OPERATION MANUAL
(incl. Troubleshooting Machine Problems)
JULY 2016
Page 4
KNIFE SELECTION
~ always use cut resistant gloves when handling knives ~
KNIFE BEVELS When slitting narrow widths only a primary bevel is required
but with wider widths a back bevel is needed to balance the forces on either
side of the knife so that it will cut straight through the roll without deflecting
(See note re bevels below)
CAUTION: Knife may be damaged or shatter if insufficient back bevel on knife
when slitting wide widths. Trying to slit a roll to a wide width from a tightly wound
log roll, using a knife with insufficient back bevel, risks chipping or shattering the knife.
Diagram No.
Slitting range
Knife requirements
1
Up to 22 mm (7/8”)
No Back Bevel
2
25.4 mm (1”) - 38 mm (1½”)
0.5 mm (1/64”) Back Bevel
3
40 mm (1 5/8”) - 96mm (4”)
1.5 mm (1/16”) Back Bevel
4
Over 100mm (4”)
Equal Bevel both sides of knife
5
Any width (very hard materials)
Tightly wound denser rolls will require test slitting to determine
the best knife bevel & edge for product Additional angle on
primary bevel
Dense materials that will not displace
Must be rewound to a lesser tension
THE ABOVE DIMENSIONS ARE A GUIDE ONLY AND WILL VARY ACCORDING TO THE DENSITY OF THE MATERIAL TO BE
SLIT.
Diagram 1:
Knife with no
back bevel
Diagram 2:
Knife
with
0.5mm
(1/64”)back bevel
Diagram 3:
Knife
with
1.5mm
(1/16”)back bevel
Diagram 4:
Knife with equal
bevel both sides
Diagram 5:
Knife with reinforced
edge (No. 2 angle)
(refer to manual for
details)
NOTE: A rounded edge is preferred for most adhesive tapes.
Some exceptions
would be, for example, foam sealant & paper tapes which require a sharp
edge.
Too sharp an edge can result in edge breaking down (chipping).
Edge should be slightly rounded with Shielded oil stone to prevent this
occurring.
KNIFE DIAMETER The rule is to use the smallest diameter knife possible to minimise any run out. Using a dial indicator, check
the knife for excessive run out.
KNIFE BEVELS
.The primary bevel on each knife has a long bevel at 8º with a smaller bevel at the outer edge of the knife at
11º to strengthen knife edge. All Javelin grinders are factory set to 11º and care must be taken for this not to change. We
recommend knives be either ground on your machine or returned to Javelin in order to maintain 11º bevel. Knives sent to
contractors may result in bevel angle being changed with resultant slitting problems. To ensure knives are sharpened to the edge
we suggest running a thin mark around the outer edge with a black pental pen. This mark will disappear once the knife has been
sharpened to the edge.
NOTE
:
It is imperative records be kept for specific materials so the operator knows which knife to choose each time a particular
product is to be slit. Ref: Operator Reference Sheets in the Manual.
No. 1 angle
No. 2 angle
1 - 2mm (1/16” - 3/32”)
**With interlined materials it may be necessary to glue end of log roll to prevent centre of roll moving out,
also if tightly wound a Diagram 3 bevel may be required. (Ensure log roll is pushed up against chuck face
or spacer roll)
