Targeting Inaccurate Length and Speed in Converting Applications with a Non- Contact, Laser-Based Measurement System Presented by Marcel Kloubert, Beta LaserMike
Transcript
Slide 1
Presented by Marcel Kloubert, Beta LaserMike
Slide 2
Traditional Length and Speed Measurements Accomplished by using
a roller that contacts the material being measured The material
turns the roller as the material moves An encoder or tachometer is
attached to the roller - Generates pulses as the wheel or roller
rotates - Relies on friction between the material and roller
Slide 3
Disadvantages of Contact Encoders/Tachometers Error caused by
slippage Dependent on friction Wheel pressure Product surface
Grease/ lubricant on surface Mechanical inertia Recalibration
Diameter changes because of wear Diameter changes because of debris
build-up Maintenance Bearings and other mechanical parts wear
out
Slide 4
Problem because of Slippage Slippage due to texture, slick
coatings, lubricants, etc. Contact method relies on wheel
circumference and # of rotations Contact measurement wheel: Rides
on product Builds-up debris or wears down, requires
recalibration
Slide 5
d d = 100mm 1 circ = 314,16mm 0,5 mm build up: d = 101 mm
Problem because of Build-up = 0,989 % Loss off material 1 circ =
317,3mm
Slide 6
Non-Contact Measurement Technology Highly accurate, repeatable
product length and speed measurements Measures product directly
Uses Laser Doppler Velocimetry (LDV) technology True Zero Speed and
direction measurement Better than +/-0,05% accuracy, +/-0,02%
repeatability Permanent calibrated Independent of density and color
of material
Slide 7
Standoff Distance Laser Beams Non-Contact Encoder Pass Line
Depth of Field +Vel -Vel Non-contact encoder projects an
interference pattern on the surface to be measured How Non-Contact
Laser Measurement Works As product moves, light is scattered back
to the unit at a frequency proportional to the speed of the
material
Slide 8
Fringe direction LaserSpeed LDV Theory
Slide 9
Non-Contact Encoder Applications
Slide 10
Application Example > Labeling 1,5 % length and speed
inaccuracy 6000 meter roll 90 meter of uncertainty Each roll costs
a significant amount in unnecessary expense Give away = roll length
x material cost/sqm x contact encoder accuracy (1,5%) Problem
Slide 11
Application Example > Labeling Install non-contact encoder
at specific measurement points on the line Control length and speed
of lamination line and coating application +/- 0,02% repeatability
Instead of 90 meter per every 6000 meter of uncertainty Lowers
error to a max of 1,2m on a 6000 meter roll Coating Control
Lamination Control Solution
Slide 12
Solving tail out boards problem Z Application Example >
Cross Cutter Control
Slide 13
Application Example > Flying Saw Control
Slide 14
Application Example > Cutting Control Problem with slippage,
mechanical inertia Control length direct to the PLC Instead of +/-
1mm at line speed of 140m/min Lowers error to +/- 0,2mm by
eliminate slippage and mechanic issues Solution
Slide 15
Application Example > Nonwoven, Soft Surfaces 2% length
variation due to the density and surface Each variation costs a
significant amount Give away + inaccurate length cut Control the
guillotine or flying saw to improve to +/- 1mm length
Problem/Solution
Slide 16
Application Example > rough surface Problem/Solution 2%- 3%
length variation due to the roughness of surface Give away +
inaccurate length cut Machine Control to improve to +/- 0,05%
Slide 17
Conclusion: Laser Non-Contact Encoder Advantages Laser
non-contact encoder is proven on many different types of
manufacturing processes No slippage error - optical system and does
not contact the product Permanent calibrated High +/-0.02%
repeatability minimizes product waste, increases savings No moving
parts to wear out: reduces maintenance and downtime, and lowers
cost of ownership
Slide 18
Slide 19
Fringe Pattern Expanded Constructive Interference occurs when
two laser beams are in phase and add together to equal the original
laser density - light stripe Destructive Interference occurs when
two laser beams are out of phase and the two laser beams cancel
each other out - dark stripe