Conair SC-5 - Manuals

1-1 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter ● ● Purpose of the User Guide . . . .1-2 ● ● How the User Guide is organized . . . . . . . . . . . . . . .1-2 ● ● Your Responsibilities as a User . . . . . . . . . . . . . . . .1-2 ● ● ATTENTION: Read this so no one gets hurt . . . . . . . . . . .1-3 ...

WARNING: Improper installation, oper-ation, or servicing may result inequipment damage or personal injury. This equipment should only be installed, adjust-ed, and serviced by qualified technical person-nel who are familiar with the construction, oper-ation, and potential hazards of this type ofmachi...

In order to protect the operator from possible harm from therotating blade wheel, several safety features are built into thiscutter. They include: Two electric switches make a contact between the side and the clear polycarbonate sliding blade observation windows such that the windows MUST BE CLOSED ...

H OW TO U SE THE L OCKOUT D EVICE UGE059/1003 SC-5 SURE CUT Servo Knife Cutter I NTRODUCTION 1-5 WARNING: Electrical hazard Before performing maintenance or repairs onthis product, disconnect and lock out electricalpower sources to prevent injury from unexpect-ed energization or start-up. A lockable...

2-1 ● ● What is the SC-5 Sure Cut Knife Cutter . . . . . . . . . . . . . . . 2-2 ● ● Typical Applications . . . . . . . . . . 2-4 ● ● How the SC-5Works . . . . . . . . . . . 2-5 ● ● SC-5 Features . . . . . . . . . . . . . . . . 2-7 ● ● Specifications . . . . . . . . . . . . . . . . 2-7 ● ● Optional ...

The Conair SC-5 Sure Cut Series rotary knife cutter has beendesigned to be “The most versatile cutter of the industry”. With both capacity to cut small parts at high speeds or largetubes or profiles at low speeds this cutter can eliminate theneed for moving cutters in and out of a line per applicati...

W HAT IS THE SC-5 S URE C UT ? C ONTINUED D ESCRIPTION 2-3 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter The larger diameter flywheel used on the servo cutter offersthe potential of higher surface speeds at dramatically lowerblade rpm’s with high cutting torque. The typical grey areabetween on-demand...

Cutting from Below the Bushing Holder The SC-5 Sure Cut Servo Cutter housing maximizes versatili-ty and operational ease. Due to the size of the flywheel it wasdetermined best to mount it directly below the bushing holderkeeping the center of gravity low and offering the followingbenefits: ● Accessi...

Extruded material that has been sized and cooled enters thecutter from the upstream side (See How the SC-5 Sure CutWorks, Section 2, step 1). Typically, a puller is placed justbefore the cutter; the puller pulls the extrudate through thesizing and/or cooling tanks and feeds it into the cutter. The p...

The SC-5 Sure Cut Servo Cutter features: SC-5 F EATURES D ESCRIPTION 2-7 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter Swivel Casters Parts discharge chute or optional discharge conveyor Optional slide base assembly with position locking mechanism Wide Range of Cutter Bushing Capacities 24-inch diame...

O PTIONAL E QUIPMENT SC-5 SURE CUT Servo Knife Cutter UGE059/1003 2-8 D ESCRIPTION Slide Base This option is highly recommended for cutting flexible extru-dates. While the cutter base is fixed and aligned with thepuller, the cutter itself is mounted on a set of linear slides thatallow as much as 12 ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter D ESCRIPTION 2-9 TIP: Conair strongly recom-mends the use of an isolationtransformer. Ensuring cleanand proper power can helpavoid the need for costly ser-vice calls. Discharge Conveyor A discharge conveyor facilitates the removal of cut parts.Discharge c...

3-1 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter ● ● Unpacking the Boxes . . . . . . . . .3-2 ● ● Preparing for Installation . . . . . .3-3 ● ● Positioning the SC-5 Sure Cut . . . . . . . . . . . . . . . . .3-4 ● ● Connecting the Main Power Source . . . . . . . . . . . . .3-6 ● ● Installing the Enco...

The SC-5 Sure Cut Series Servo Knife Cutter comes fullyassembled in a single crate. U NPACKING THE B OXES SC-5 SURE CUT Servo Knife Cutter UGE059/1003 3-2 I NSTALLATION CAUTION: Lifting To avoid personal injury or damage to the cut-ter, lift the cutter using a forklift or hoist withstraps that have ...

You need these tools for installation: ❒ wire strain relief ❒ 16- or 18-inch adjustable wrench ❒ set of Allen wrenches ❒ set of feeler gauges ❒ ½ inch open or box end wrench ❒ flashlight Plan the location. Make sure the area where the servo cutter is installed has the following: ● A grounded power s...

Move the servo cutter into position. Place the servo cutter in position downstream of the belt puller. Determine the best distance from the belt puller to the SC-5 Sure Cut cutter. ● For flexible products, the cutter should be located as close to the puller as possible to insure a mini-mum amount of...

Align the cutter with the extrusion line. Measure the centerline height of the extrudate as it exits the extrusion die. Adjust all equipment on the extrusion line (sizing tank, cooling tanks, belt puller, and cutter) to thisheight. Adjust the cutter's floorlock/caster assembly to the center height o...

3-6 I NSTALLATION Open the servo cutter’s electrical enclosure. Turn the disconnect dial on the door to the OFF or O position and open the door. Insert the main power wire through the knockout in the side of the enclosure. Secure the wire with a rubbercompression fitting or strain relief. Connect th...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter I NSTALLATION 3-7 Conair uses bi-directional encoders to ensure that only productthat moves forward is counted.Installing the encoder consists of sever-al parts: ● the encoder ● the measuring wheel ● the connecting cable The encoder is fitted with a one f...

SC-5 SURE CUT Servo Knife Cutter UGE059/1003 3-8 I NSTALLATION I NSTALLING THE C UTTER B LADES DANGER: Sharp blades! Most injuries caused by knife blades occurwhen the cutter has been turned off. Handleblades with care at all times. ● Always lock out power to the cutter beforeopening the cutting cha...

I NSTALLATION 3-9 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter TIP: We recommend that you: ● Apply some protective cover on the portion of the blade you are handling, such as masking tape to help prevent getting cut during installation and to leave it on until such time that you will start and check...

DANGER: Sharp blades! Always wear cut-resistant gloves when the cut-ting chamber is open and when handlingblades. Never open cutting chamber withoutlocking out the cutter power and waiting untilthe cutter head stops spinning. 3-10 I NSTALLATION SC-5 SURE CUT Servo Knife Cutter UGE059/1003 M OUNTING ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter I NSTALLATION 3-11 C HECKING THE A LIGNMENT OF THE B USHINGS For more information aboutsetting and adjusting the gapfor the bushings, see AboutCutter Bushings in theAppendix C. Checking the Alignment of bushing to blade Once you are sure that the blade wi...

SC-5 SURE CUT Servo Knife Cutter UGE059/1003 3-12 I NSTALLATION C HECKING R EPEATABILITY Before any Conair SC-5’s are shipped, they are tested for cuttime repeatability to be sure they are within performance spec-ifications. The repeatability test checks the performance of therotary knife cutter to ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter I NSTALLATION 3-13 Make sure all components are installed according to assembly drawings. Make sure that all bolts on the cut-ter have been tightened. Check that cutter is firmly locked into position with the anchoring screws. Check that all wiring confor...

4-1 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter ● ● The Cutter Control . . . . . . . . . . .4-2 ● ● Before Starting . . . . . . . . . . . . . .4-3 ● ● Powering Up . . . . . . . . . . . . . . . .4-3 ● ● Main Screen . . . . . . . . . . . . . . . .4-5 ● ● Total Screen . . . . . . . . . . . . . . . .4-...

SC-5 SURE CUT Servo Knife Cutter UGE059/1003 4-2 O PERATION O PERATOR C ONTROL F EATURES The Operator Control provides an intuitive user-friendlymethod to interface with the Conair Servo Cutter. Informationis viewed and entered at the Operator Control and is commu-nicated to the servo positional amp...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter O PERATION 4-3 Before you start daily operation of the servo cutter, you needto perform preventative maintenance. Necessary maintenanceis described in the Maintenance section of this Users Guide,see preventative maintenance, Section 5. Daily maintenance i...

SC-5 SURE CUT Servo Knife Cutter UGE059/1003 4-4 O PERATION P OWERING U P C ONTINUED Open the knife guard. The machine start push button should go out. If the cutter is not working properly at any time, turn it offimmediately and refer to the Troubleshooting section of thisUser Guide. If you do not ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter O PERATION 4-5 MAIN SCREEN There are two types of main screens, length or time measure-ment and cuts per minute measurement. The type displayedvaries depending on the current cut mode setting.See the mode operator display overviews. The Main Screen has se...

4-6 O PERATION Menu function key is used to access the Menu Area. This area can only be accessed from the main display screen for each mode. See the Menu Area section for moreinformation.Parts Select Area ScreenUnder the current mode on the left side of the bottom line ofthe display is a soft key la...

O PERATION 4-7 Reset Softkey3Under the counter, on the right is a soft key labeled Reset.Pressing this key will zero the counter. EXIT or PREV, fixed function keys return the display to theParts Select screen. BATCH SCREEN By pressing softkey3 located under the word Batch on theParts Select Screen, ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter O PERATION 4-9 Numeric keysKey in the batch required and press enter. If you require abatch of 50 parts you must key in 50 and then press enter. Enter or Delete?If the keyed in number is correct press the enter key for it tobe accepted and return to the M...

SC-5 SURE CUT Servo Knife Cutter UGE059/1003 4-10 O PERATION Exit or Prev, if no change is required press Exit or Prev to return to the Main screen. Raise will increase the preset by 0.010 inch. The key can bepressed once for each 0.010 inches increment required or helddown to scroll up. Releasing t...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter O PERATION 4-11 Exit or Prev, If no change is required press Exit or Prev toreturn to the previous Length Screen. Raise will increase the number by 1. The key can be pressedonce for each increment of 1 required or held down to scrollup. Releasing the key ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter O PERATION 4-13 Raise will increase the preset by 0.010 second. The key canbe pressed once for each 0.010 second increment required orheld down to scroll up. Releasing the key will freeze the pre-set at the last value then press enter. Lower will decrease...

Raise will increase the preset by 1.0. The key can be pressedonce for each 1.0 increment required or held down to scrollup. Releasing the key will freeze the preset at the last valuethen press enter. Lower will decrease the preset by 1.0. The key can be pressedonce for each 1.0 decrement required or...

Raise will increase the preset by 1. The key can be pressedonce for each 1 increment required or held down to scroll up.Releasing the key will freeze the preset at the last value thenpress enter. Lower will decrease the preset by 1. The key can be pressedonce for each 1 decrement required or held do...

Next or Prev, Pressing Next selects the second Function Area.Pressing Prev returns the display to the first Function Areascreen. Pressing Prev from the first Function Area screenreturns the display to the active main mode screen. Menus are a convenient way to access and monitor parametersthat do not...

O PERATION 4-17 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter Next, Pressing Next selects the DevCC test if available. If thearrow on the top right hand side of the screen is visible thecurrent mode also supports the DevCC test. The DevCC repeatability tester also displays total deviationtime in mill...

4-18 O PERATION Mode SoftkeyBy pressing the soft key located under the word Mode, the dif-ferent Cut Modes are available. There are two Cut Modescreens. The first screen provides choices for the standard-modes available on all cutters. The second screen displays choices for optional cut modes.The us...

4-20 O PERATION Menus are a convenient way to access and monitor parametersthat do not need to be altered often, i.e. home position,encoder direction, scale or unit of measure. In addition, pre-ventive maintenance parameters can be monitored for trouble-shooting and scheduling purposes. Factory Soft...

O PERATION 4-21 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter Encdr Softkey By pressing the soft key located under the word Encdr on theMaint. Area Screen, there are three sub-menus, Drctn, U/M,and Scale accessible. Additional information on how to access this screen can be found in the Maintenance A...

4-22 O PERATION If a negative symbol is shown to the left of the count value onthe main mode screen the encoder signal is reversed, i.e. rotat-ing in the wrong direction. The Cutter will not function whilethe encoder is going negative. The Direction function correctsthis by changing what the servo d...

O PERATION 4-23 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter C ONTROL I NSTRUCTIONS S CALE D ISTANCE DISTANCE SOFTKEY By pressing the soft key located under the word Dist. on theScale Value Screen, the scaled distance is available. This valuemust be set after a U/M change. Additional information onh...

4-24 O PERATION C ONTROL I NSTRUCTIONS S CALE C OUNTS COUNTS SOFTKEY By pressing the soft key located under the word Counts on theScale Value Screen, the scaled counts are available. Additionalinformation on how to access this screen can be found in theMaintenance Area of the operator display overvi...

O PERATION 4-25 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter C ONTROL I NSTRUCTIONS H OMING HOMING A defined Home location is required for all servo-positioningapplications. After initial power up, emergency stop or guardopened, home position must be found. All motion is relative tothis home positio...

4-26 O PERATION Raise will increase the value by 1.0. The key can be pressedonce for each 1.0 increment required or held down to scrollup. Releasing the key will freeze the value at the last value. Lower will decrease the value by 1.0. The key can be pressedonce for each 1.0 decrement required or he...

O PERATION 4-27 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter PREVENTIVE MAINTENANCE SOFTKEY Pressing the soft key located under the word P/M on theMaint. area screen. Selects the P/M area screen. Three pre-ventive maintenance sub-menus for monitoring Inputs, Timeand Cycles are displayed. Additional ...

4-28 O PERATION C ONTROL I NSTRUCTIONS P OWER O N T IME TIME SOFTKEY Pressing the soft key located under the word Time on theP/M area screen, selects the Power-On time screen. The Power-On time screen displays the total time in hoursthat the machine has had the power switched on. This infor-mation c...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter Press the manual cut button and observe the movement of the cutter blade. The cutter head makes asingle rotation and the blade moves through the cutter bushings without interference. Insert a piece of extrudate through the cut-ter bushings. Press the manu...

M AKING A DJUSTMENTS D URING O PERATION 4-30 O PERATION There are several adjustments you can make during normalcutting. These adjustments include: ● In Timer mode, adjust the time between cuts ● In Encoder and Follower modes, adjust the length ● In Product mode, adjust the hold-off time ● In Flywhe...

Use this procedure to safely stop the servo cutter: Press Cut On/Off soft key to stop cutting (soft key text changes to off). Press Stop Cutter button to disable the servo motor (start light is off). Turn the rotary disconnect to the off posi-tion. Disconnect the power cord if it is equipped with a ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter M AINTENANCE 5-3 WARNING: Voltage Hazard This equipment is powered by alternating cur-rent, as specified on the machine serial tag anddata plate. Do not operate the equipment atpower levels other than what is specified on themachine serial tag and data pl...

This section describes the daily, weekly, monthly and semi-annual maintenance schedules that should be performed whenchanging materials or lines, or when changing equipment, aswell as the maintenance procedures to follow. Cutting either flexible or rigid materials generates tremendousshock and vibra...

● Weekly ❒ ❒ Cleaning the blade lubrication tray (if the cutter has this option). See Cleaning the Blade Tray, Section 5. ❒ ❒ Lubricating shafts on optional slide rail system See Cleaning the Blade Tray, Section 5. ● Monthly ❒ ❒ Checking hardware on the knife guard Inspect the hardware on the knife ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter M AINTENANCE 5-7 Check the set screws that secure the cutter bushings. If bush-ings move during cutting, cutting blades and possibly thedrive chain could be damaged. I NSPECTING C UTTER B USHING S CREWS C HECKING THE K NIFE G UARD Check the hand knob and ...

Follow all warnings and cautions listed at the beginning of theMaintenance section of this User Guide. Be sure the main power is disconnected and the cutter is locked out. Loosen the set screws that hold the cutter bushings. Remove the cutter bushings. Check the depth of the proximity switchface for...

Open the electrical enclosure. Inspect all wires and connections . Look for loose wires, burned contacts, and signs of over-heated wires.Have a qualified electrician make any necessary repairs orreplacements. Close the electrical enclosure door. Inspect the exterior power cords. Cords should not be ...

B-LOC Corporation 26 Gilbert Street Monroe, NY 10950 For technical assistance, please call 1-800-865-7756 INSTALLATION AND REMOVAL INSTRUCTIONS FOR B-LOC™ LOCKING ASSEMBLY SERIES B112 Thank you for purchasing a B-LOC™ Keyless Frictional Locking Device.B-LOC™ keyless connectors provide a high capacit...

6-1 UGE059/1003 SC-5 SURE CUT Servo Knife Cutter ● ● Before Beginning . . . . . . . . . . . .6-2 ● ● A Few Words of Caution . . . . . .6-2 ● ● Identifying the Cause of a Problem . . . . . . . . .6-3 ● ● Electrical Problems . . . . . . . . . .6-4 ● ● Product Quality Problems . . . . .6-8 Repair ● ● R...

You can avoid most problems by following the recommendedinstallation, operation and maintenance procedures outlined inthis User Guide. If you have a problem, this section will helpyou determine the cause and tell you how to fix it. Find any wiring, parts, and assembly diagrams that wereshipped with ...

The Troubleshooting section covers problems directly relatedto the operation and maintenance of the servo cutter. This sec-tion does not provide solutions to problems that originate withother equipment. Additional troubleshooting help can befound in manuals supplied with the other equipment. The mai...

SC-5 SURE CUT Servo Knife Cutter UGE059/1003 6-4 T ROUBLESHOOTING E LECTRICAL P ROBLEMS Look in this section when you have problems such as lights onthe control that are working improperly, buttons that do notexecute the function properly, and when information input isnot executed properly. Symptom ...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter T ROUBLESHOOTING 6-5 Symptom ◆ After pressing Start Cutter, thecutter head rotatesslowly but does notstop. ◆ Master safety relay does not ener-gize ◆ While in Encoder mode, nocount is displayed Possible cause The Blade home proximi-ty switch failed or the...

E LECTRICAL P ROBLEMS C ONTINUED SC-5 SURE CUT Servo Knife Cutter UGE059/1003 6-6 T ROUBLESHOOTING Symptom ◆ In encoder or timer modes, thedisplay shows thecount which resets,but a cut does notoccur at the pointof reset. ◆ Cutter stops and nothing is displayed Possible cause There is a problem witht...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter T ROUBLESHOOTING 6-7 Symptom ◆ Blade speed does not change when newspeed is entered intothe control. ◆ Cutter mode selec- tion does not changecut mode. ◆ The park (home) position is drifting,i.e. the blade parksfurther away fromthe original park site. Pos...

SC-5 SURE CUT Servo Knife Cutter UGE059/1003 6-8 T ROUBLESHOOTING Look in this section when the final product does not meetstandards: has strings, burrs, cracks, or is misshaped. Symptom ◆ Hairs or strings. Possible cause Blade speed is too low. The blade is too thick. The blade is wrong forthe appl...

SC-5 SURE CUT Servo Knife Cutter UGE059/1003 6-10 T ROUBLESHOOTING Symptom ◆ Cracks at cut site. Possible cause The extrudate is too cold. The blade speed is toohigh. The bushings are not pro-viding enough supportduring cutting. The cutting blade is toosharp. If using Nylon, it may becooling too qui...

UGE059/1003 SC-5 SURE CUT Servo Knife Cutter T ROUBLESHOOTING 6-11 Symptom ◆ Cut is not square. Possible cause The blade speed is toolow. The blade is misaligned. The cutter bushings arenot properly gapped. The knife bevel is notsymmetric. For rigid products thepuller is too close to thecutter. Solu...

R EPLACING S AFETY AND P ROXIMITY S WITCHES SC-5 SURE CUT Servo Knife Cutter UGE059/1003 6-12 T ROUBLESHOOTING Three safety switches are included in SC-5 Sure Cut cutters: akeyed safety switch on the knife guard, and a proximity switchon each cutter bushing. A failure in any of these switches willpr...

The home position proximity switch should be 0.010 inchfrom the 5/16 inch thread rod on the cutter head for properoperation. Open the flywheel clear guard window. Locate the 5/16 inch thread rod on the cutterhead. It should be 0.010 inch from the proximity switch sensor when it passes that location....

6-14 T ROUBLESHOOTING SC-5 SURE CUT Servo Knife Cutter UGE059/1003 C HECKING THE E NCODER When the encoder is working properly, the encoder LEDs onthe control panel light or flicker as the encoder wheel movesand generates signals. If the LEDs do not light when theencoder wheel moves: Check all conne...

C HECKING THE E NCODER C ONTINUED Encoder Mounting and General Information The provided encoder is a precision instrument which outputs3000 bi-directional quadrature pulses per revolution of theshaft. Do not apply excessive axial or radial thrust on encoder shaft(rated for 30lbs. axial thrust). Do n...

Open the flywheel clear guard window. Remove the cutter head by loosening the Trantorque assembly. Refer to the manufacturer's guide included withthis User Guide for information about the Trantorqueassembly. Locate the four bolts holding the motor/reducer assembly to the cutter. Remove them and care...

Before any Conair puller/cutters are shipped, they are testedfor cut time repeatability to be sure they are within perfor-mance specifications. The repeatability test checks the perfor-mance of the rotary knife cutter to return the home park posi-tion after a complete cut. Acceptable repeatability t...

S ERVICE I NFORMATION A PPENDIX A-1 Conair has made the largest investment in customer support inthe plastics industry. Our service experts are available to helpwith any problem you might have installing and operatingyour equipment. Your Conair sales representative also can helpanalyze the nature of...

W ARRANTY I NFORMATION UGE059/1003 A PPENDIX A-2 E QUIPMENT G UARANTEE P ERFORMANCE W ARRANTY W ARRANTY L IMITATIONS Conair guarantees the machinery and equipment on thisorder, for a period as defined in the quotation from date ofshipment, against defects in material and workmanshipunder the normal ...

Cutter blade characteristics such as material, design, andthickness can have a large effect on cut quality. Blade materials Blue tempered spring steel is most commonly used becauseof its cost and availability over a wide range of thicknesses(0.010-0.062 inch). It is a very tough material with an HRC...

Blade Design Straight-edge knives have a straight cutting surface. A chop-ping action (which has cutting forces parallel to the cut) istypically obtained with straight-edge blades. Because the blade is mounted on a rotary arm, some slicingaction (which has additional force vectors at various angles ...

Blade thickness Because material is displaced rather than removed in rotaryknife cutting, think of the blade as a wedge. The thicker theblade, the greater the displacement. This displacement cancause fracture in rigid profiles and tubing, which is oftenobserved as a whitening on all or a portion of ...

Calculating Blade Interruption Blade interruption is the length of time which the blade interrupts the extrudate during the cutting process. Knowingblade interruption allows you to optimize blade speed anddesign for specific applications. You can calculate blade interruption for your application ify...

C ONAIR C UTTER B LADES UGE059/1003 B-6 A PPENDIX Part Blade Bushing Blade Blade No. Type Size Thickness Material {inches} x Length {inches} 0235-30496 Straight 4 1/ 4, 5 1/ 4 , 4x10 0.025x9.5 Spring Steel 3515-30496-1 Straight 2 1/ 4 , 2x4, 2x6 0.025x6.48 Spring Steel 3515-30496-2 Straight 3 1/ 4 ,...

UGE059/1003 A LL A BOUT C UTTER B USHINGS A PPENDIX C-1 Rotary knife cutter bushings are probably the most ignoredaspect of cutting. Yet, they are probably the most importantingredient to obtaining clean, square, accurate cuts with mini-mal jamming and broken blades. This appendix contains informati...

Supportive bushings become more important if heat isused to minimize whitening (fracturing). ● If you are cutting a square or rectangular profile, whetherrigid or flexible, a round bushing bore will not offerproper support and will often lead to an "S" shaped cut. Aflat bottomed bushing will...

A PPENDIX C-3 Cutter bushing shear surface quality Similar to a dull pair of scissors, if the cutter bushing shearsurface is not sharp the tube or profile is not supported to theside of the blade and the cut will not be clean. In some cases,the entrance of the downstream cutter bushing is slightlyra...

Cutter bushing length On flexible extrudates, it is important to minimize the lengthof the cutter bushings. It is very difficult to push flexibleextrudates through since it tends to compress as it is pushed,causing a marginal increase in the tube diameter. For this rea-son, bushing lubrication may b...

Adjusting the cutter bushing gap If the bushing gap is too big, material is dragged downbetween the bushings creating a burr, especially with flexibles.This may lead to jamming within the bushings where theupstream side of the cut extrudate actually hits against thedownstream bushing surface. This i...

Common cutting lubricants Commonly used general purpose lubricants include: ● Tap water ● Dish washing liquid (Joy, etc) ● Glycol (anti-freeze, coolant) ● Water-soluble silicone cutting oils ● Diesel fuel ● Mold release ● Mineral oil Medical grade lubricants: ● Distilled water ● Isopropanol (isoprop...

If the blade has a rough surface where the extrudate rubsagainst it, material will accumulate on the blade in a cheesegrater fashion. This scratched material will also be passedfrom the blade to the next cut and be seen as hairs or flakes. Some of the more flexible materials, such as silicones, soft...