1.1 Flashcards
Understand materials and their applications and classifications
handle
how a fabric feels when touches
drape
the way a fabric hangs under own weight
lustre
ability to reflect light from textiles surface to appeaar glossy
tensile strength
ability to resist breaking under tension
abrasion resistant
ability to resist surface wear caused by rubbing contact with another material
elasticity (crease resistant)
ability to be deformed and return to original shape when force is removed
absorbency
ability to absorb and retain liquid
easy-care
ability to maintain optimum appearance with minimum of effort when laundering
colour fastness
ability to retain dye during manufacturing process and when washed or exposed to sunlight
electrostatic charge
ability for static electricity to develop in fibres under exceptionally dry conditions
thermal insulation
ability to trap air, preventing transfer of heat through material
corrosive solvent resistance
ability to withstand attack and decay from organisms eg bacteria and moths
flammability
ability to burn or ignite, causing fire or combustion
thermo-plasticity
ability to become pliable and mouldable when heated, enabling creases to be set and retained once heated
formability
ability to manipulate and deform fabrics without damaging them
natural plant/cellulosic fibres
cotton, linen, ramie
natural animal/protein fibres
wool, silk
natural animal hair/protein fibres
cashmere, mohair, angora, merino
regenerated fibres
- manufactured from chemically modified natural cellulose
- viscose (wood pulp), acetate (cotton waste)
new generation lyocell fibres
- cellulose harvested from sustainably grown trees
- closed loop system reducing chemicals needed
- modal, lyocell (e.g Tencell)
polyamides
- polyamide (nylon), Tactel (microfibre), Supplex
- developed from polyamides: aramid fibres e.g Kevlar, Nomex, cordura
polyesters
polyester, trevira (microfibre), polartec (polar fleece)
polyacrylic
acrylic
elastomeric fibres
- from synthetic polymers with small amount of elasticity in core of corespun yarn
- elastane (e.g Lycra, spandex)
what are chlorofibres and flurofibres
- manmade synthetic fibres
- used for coatings on textiles making it stain-repellant, water repellant and breathable
chlorofibres and flurofibres examples
chlorofibres: polyvinyl chloride (PVC)
fluorofibres: (PTFE) Teflon
inorganic fibres
- created from natural elements, processed at high temps and become fibres
- glass, carbon, metallic, ceramic
smart materials
- react to external stimuli in environment without human intervention
- once stimuli is removed, material reverts to original form
reactive materials
respond to changes such as loss of heat or levels or air pollution
photochromic dyes
respond to changes in UV light
phase-changing materials
- e.g Outlast used in performance wear
- has the ability to absorb, store and release body heat to regulate person’s microclimate
modern materials/technical textiles
new materials developed through invention of improved processes
microfibres
- extremely fine fibres
- e.g Tactel (polyamide origin) and Trevira (polyester origin)
microencapsulated fibres and fabrics
microcapsules with beneficial or cosmetic chamicals are embedded in fabrics and gradually released by rubbing
nano-fibres
- significantly finer than microfibres
- e.g anti-stick/self-cleaning and UV protective properties
workshop test for flammability
- use precisely cut fabric samples and paper fuses
- light the fuse and use a stopwatch to time how long it takes for the flame to reach the wire marker
- record time and other observations when the flame comes into contact with fabric
workshop test for crease resistance
- fabric folded in half and places between pieces of paper under the weight
- after placing fabric sample on measuring block, leave it to recover for 5 mins then calculate the distance between its two ends on the horizontal scale
- record result and repeat with other fabrics being tested
workshop test for colour fastness
- affected by washing and exposure to sunlight
-samples sewn onto white fabric and washed at an agreed temperature and duration - dried samples are compared to control sample and white fabric is checked for staining
issue with workshop testing for colour fastness
reliable workshop testing for colour fastness in fabrics is impossible as a lot of time is needed and lgiht intesity cannot be controlled in the same way as in a laboratory
wokrkshop test for shrink resistance
- sew coloures cross-stitches or use a permanent pen to mark an exact 10cm square
- retain control samples and wash remaining samples at different temps and levels of washing machine and agitation
- dry and iron samples
- work out percentage shrinkage
percentage shrinkage
distance before- distance after ➗ original length X 100
workshop test for strength
- prepare same sized samples
- make a small cut at the warp, weft and bias edges
- tear the samples along the cut to see which tears easily and which fabric requires more force
issue with workshop test for strength
difficult to replicate as it is impossible to achieve the large forces needed to break a fabric using basic tools and equipment.
- some observations can still be recorded though
workshop test for pilling
- simple abrasion test
- fabrics are stapled onto a wooden block
- glass paper is stapled onto a smaller wooden block
- glass paper block rubbed over the surface of the fabric to stimulate wear
- number of passes required for pills to start forming on surface of fabric is recorded
pilling
formation of little balls of fibres on the surface of the fabric as a result of wear and friction when weak fibres from blended staple yarns are pushes out and held on surface by stronger fibres.
quality control
checking product during production run to test it against specification
quality assurance
planning of procedures and policies that ensure good-quality products.
perfomance codes
technical requirements for a material or process to be fit for its intended purpose
colour fastness
ability for fabric to retain dye fastness during manufacturing processes and when washed or exposed to sunlight
multi-fibre swatch
narrow bond of woven fabric containing separate segments of acetate, cotton, nylon, polyesters, acrylic and wool fibres. Used to demonstrate uptake of dye staining when washing different types of fabrics
industrial test for flammability 1
minimum flame application to cause ignition
- prepared fabric sample is held vertically in a metal frame
- a small flame from a Bunsen burner is applied for two seconds, then three, four, six, eight and ten seconds unit it catches fire
- test is complete if fabric burns for more than one second
- time and observations recorded
industrial test for flammability 2
flame spread and flame behaviour
- this test is used on fabrics with low flammability
- small flame applied to a prepared fabric sample and removed after ten seconds
- duration of the and afterglow are timed and any debris recorded
- size of hole burned into fabric is measured and recorded
industrial test for flammability 3
rate of flame spread
- large sample of fabric placed in metal frame
- test is complete if fabric burns for more than one second
- a small flame is applied and then removed after ten seconds
- as each cotton trip thread is burnt through, its timer will stop, showing the burn distance and allowing burning rate to be calculated
industrial test for crease resistance
- standard test pieces cut from wrinke-free fabric
- samples kept in standard room conditions to ensure fabric temp and humidity is identical
- a sakple is folded in half and compressed under a load for a specific time
- load is removed and one end of the creased sample is clamped onto the instrument. Other end is allowed to fall free.
= dial of the instrument is rotated to keep the free edge of the sample in line with the knife edge - at the end of the time allowed for recovery, the recovery angle is recorded from the engraved scale
- the larger the angle of recovery, the better the crease resistance
industrual test for shrink resistance
- fabric sample is overlocked to prevent fraying
- permanent ink used to mark precise reference on the fabrics
- prepared fabric samples are washed with pieces of polyester fabric to replicate a normal wash load
- the samples are dried using all available options
- if results of re-measuring between refernece points show that a change has occured, the formula used in the workshop test is applied to calculate percentage change.
- fabric shrinkage is shown as a negative percentage. Fabric stretch shown as a positive percentage
industrual test for pilling
- Martindale machine tests for abrasion and pilling
- circular samples of the test fabrics are clamped onto one of the machine’s four discs and a weigh is put onto each disc
- the test samples are rubbed against an abrasive fabric
- the machine controls and records the number of rubbing cycles
- the test samples are examined at regular intervals for the presence of wear leading to pilling
on completion, the samples are compares, in a light box, with the control sample
grey scale cards
used to show differences in colour intensity when comparing control samples with samples exposed to washing and UV light
Xenon arc lamp
produces a bright white light closely mimicing matural sunlight
reveled fabric
fabric eith yarn teased or drawn out from its edges giving it a frayed appearance
