Post on 18-Apr-2018
transcript
Sungmin Kim
SEOUL NATIONAL UNIVERSITY
Fashion Technology7. Manufacturing Technology
Printing Process
Conventional Silk-Screen Printing
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Printing Process
Conventional Rotary-Screen Printing
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Digital Textile Printing
Digital Textile Printing (DTP) Features
Unlimited range of expression
Small lot printing for sampling and production
Needs pre and post treatment
Slower than rotary-screen printing
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Digital Textile Printing
Digital Textile Printing Ten Reasons for using DTP
Short run printing advantage
– Run lengths as low as one yard of fabric without the need for screen changes
Lower water and power consumption
– Elimination of the substantial amount of water and electrical energy for rotary screen printing
Less chemical waste
– Results in significantly less ink usage and waste relative to rotary screen printing
Large repeat sizes
– Without the usual screen printing limitation in pattern repeat size
Reduced production space requirements
– The production footprint for digital printing is a fraction of the size of screen print facility
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Digital Textile Printing
Digital Textile Printing Ten Reasons for using DTP
Less printed inventory needed
– Reduction of the need for pre-printed inventory of fabric that may or may not be used
Sampling and production done on same printer
– Samples of designs will exactly match the final printed material
Print flexibility
– Small quantity printing for market test before high volume rotary screen printing
Variety of creative design choices for printing
– Capable of photographic/continuous tone images
Low capital investment
– Lower capital investment compared to rotary printing production
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Digital Textile Printing
Digital Textile Printing Application Fields
Apparel
Upholstery
Transportation
Footwear
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Digital Textile Printing
Digital Textile Printing Application Fields
Rapid Prototyping
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3D Printing
3D Printing Technology Stereolighography (SLA)
Patented by Charles Hull, co-founder of 3D Systems, Inc in 1986.
3D model is converted into an STL file (up to ten layers per each millimeter)
SLA machine exposes the liquid plastic and laser starts to form each layer of the item
After plastic hardens the platform drops down in the tank a fraction of a millimeter
Printed object is rinsed and placed in an ultraviolet oven for finish processing
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3D Printing
3D Printing Technology Digital Light Processing (DLP)
Created in 1987 by Larry Hornbeck of Texas Instruments
Uses digital micro mirrors laid out on a semiconductor chip
– The same technology applied for movie projectors
One section of object is built simultaneously
– The printing speed is pretty impressive
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Other method DLP method
3D Printing
3D Printing Technology Selective Laser Sintering (SLS)
Developed by Carl Deckard and Joe Beaman (Texas University) in 1980s
Doesn’t need any support structure
More spread among manufactures rather than 3D amateurs at home
– Use of high-powered lasers, which makes the printer to be very expensive
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3D Printing
3D Printing Technology Selective Laser Melting (SLM)
Developed in Fraunhofer Institute ILT in 1995
The fine metal powder is intensively fused by applying high laser energy
– Metal powder melts fully and forms a solid object (stainless steel, titanium, chrome, aluminum)
Applied to parts with complex geometries and structures
– Thin walls, hidden voids or channels
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3D Printing
3D Printing Technology Fused Deposition Modeling (FDM)
Developed by Scott Crump, Stratasys Ltd. founder, in 1980s
Slower than SLA or DLP
Simple-to-use and environment-friendly
Different kind of thermoplastic can be used to print parts
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3D Printing
3D Printed Garment Advanced 3D Printing (4D Printing)
Life-size Garment
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Sewing Robot
Sewbo Prototype Sewing Robot (Jonathan Zornow, 2016)
Using water soluble thermoplastic to stiffen fabric to be as sturdy as cardboard
Fabric manipulation using universal robot
Sewn garment is put into hot water for the plastic to melt off
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Objective Evaluation
Application Fields Quality Evaluation
Visual appearance
– Seam pucker, wrinkle, smoothness appearance, pilling, color fastness, etc.
Physical property
– Drape coefficient, etc.
Structure Analysis
Extraction of fabric design parameters
Technology Non-contact 3D Measurement
Image Analysis
Numerical Analysis
Artificial Intelligence
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Objective Evaluation
Fabric Surface Quality Evaluation Conventional Method
Comparison of specimen with standard replica by human experts
Newly Developed Method
Objective evaluation of specimen with 2D/3D measurement
Wrinkle Replicas Smoothness Replicas Seam Smoothness Replicas
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Objective Evaluation
Fabric Surface Quality Evaluation Non-Contact 3D Measurement
Laser Scanning
Stereovision
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Object
Shift
Objective Evaluation
Fabric Surface Quality Evaluation Fractal Dimension
Index of Shape Complexity
: 2.5
N( ) : 21
: 5
N( ) : 14
: 10
N( ) : 7
CD
LDDNL
N D
ln
lnlnln
)(
y = -2.012x + 11.379
R2 = 0.999
0
2
4
6
8
10
12
0 1 2 3
ln
ln N
()
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Objective Evaluation
Fabric Surface Quality Evaluation Suggestion of New Evaluation Criteria
Linear relationship between grade and actual visual appearance
y = -0.0396x + 2.3112r2 = 0.7618
2.05
2.1
2.15
2.2
2.25
2.3
2.35
0 1 2 3 4 5
2.08
2.12
2.16
2.2
2.24
2.28
2.32
0 1 2 3 4 5
Fra
cta
l D
imensio
n
New linear evaluation criteria
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Objective Evaluation
Image Analysis Image acquisition
Digital camera
Image processing
Grayscale conversion
Binary conversion
Topology modification
– Opening, closing, thinning, skeletonization, etc.
Filtering
– Average, median, Gaussian, edge detection, etc.
Frequency domain analysis
– Fast Fourier transformation (FFT)
Quantitative analysis
– Counting, measurement
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Objective Evaluation
Image Analysis Fabric Pilling Evaluation
ASTM 3512 photographic pilling standards
Grade 1 Grade 2 Grade 3 Grade 4 Grade 5
FFT, Gray Scaling, Binarization, Counting
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Objective Evaluation
Image Analysis Fabric Structure Analysis
Extraction of Design Parameters
Warp/weft density Fabric cover factor Fabric thickness
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Objective Evaluation
Image Analysis Fabric Structure Analysis
Extraction of Design Parameters
Evaluation of crimp Orthogonality Defect detection
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Objective Evaluation
Image Analysis Yarn Crimp
Evaluation of yarn crimp under zero-tension condition
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Objective Evaluation
Image Analysis Fabric Drape Coefficient
Quantitative analysis of drape phenomenon
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Objective Evaluation
Physical Measurement Garment Fit
Strain/pressure simulation and measurement
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Objective Evaluation
Physical Measurement Evaluation of Human Factors
Interaction between…
– Human body and garment
– Garment and environment
Physiological analysis
– Garment function
– Garment comfort
– Safety factors
Elimination of questionnaire
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Artificial Intelligence
Negative View ? Evil Self-Conscious A. I. in Movies
HAL 9000 (2001 Space Odyssey, 1968)
Sky Net (Terminator, 1984)
Ava (Ex Machina, 2015)
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Artificial Intelligence
Current Status
Problems Easy for Computer
Hard for human
– Simple-repetitive-precise calculation
– Huge data analysis
Problems Hard for Computer
Easy for human
– Voice, image, text recognition
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Artificial Intelligence
Killer Robots ? DARPA Robotics Challenge
Most robots could not cross a few hurdles made of brick pieces
Just climbing a ladder or opening a door were difficult
The key to success is the seamless interaction with the real world
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Artificial Intelligence
Solution of NP-Hard Problems Nondeterministic Polynomial Time Problem
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3!=64!=24...35!=1040
Artificial Intelligence
Optimization
Definition
Determination of optimum set of independent variables
Examples
Determination of the area, height, and cost of building construction
Consideration of the price, function, and after-service of goods
Determination of the optimal route for overseas travel planning
Determination of an index from a number of variables without any visible relationship
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Artificial Intelligence
Traditional Solution Numerical Analysis
Simulated Annealing
Conjugated Gradient
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NFL (No free lunch) Theorem !
Artificial Intelligence
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A. I. Solution Artificial Neural Network
Imitation of neuron-synapse system
Error back propagation network
Artificial Intelligence
A. I. Solution Genetic Algorithm
Calculation based on Natural Evolution Process
– Simulated evolution
– Similar terms are used : Population, Generation, Fitness, Selection, Cross-Over, Mutation
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24%
24%
20%
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InitialPopulation
FitnessEvaluation
Selection Cross-Over Mutation
Artificial Intelligence
A. I. Solution Fuzzy Inference
Logic for the Description of Vague Concepts
– Meaningless and ambiguous properties such as person’s appearance etc.
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Level of Middle Agedness
Age35 55
1
1
Application Fields
• Control
Subway
Robot arm
Furnace temperature
• Social Science
Fuzzy questionnaire
• Information Science
Fuzzy database
-15 -10 -5 0 5 10 15
-45 -30 -15 0 15 30 45
Artificial Intelligence
Applications in Fashion Technology Material Selection
Fusible Interlining– Input
» Physical properties of fabric and adhesive» Fusing condition (temperature, pressure)
– Output » Optimum interlining
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Neural Network
Artificial Intelligence
Applications in Fashion Technology Categorization
Multivariate nonlinear regression
– Body type
– Insole type
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Artificial Intelligence
Applications in Fashion Technology Pattern Nesting
Classic NP-Hard problem
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