1. QUALITY CONTROL FOR TECHNICAL TEXTILES
FILIZ AVSAR LAWSON-HEMPHILL, USA
MEDICAL TEXTILES
PROTECTIVE TEXTILES
TRANSPORTATION TEXTILES
GEOTEXTILES
Medical textiles are a broad group of technical textiles such as:
non-implantable materials (wound dressings, bandages, plasters)
extra corporeal devices (artificial kidney, liver, lung, skin)
implantable materials (sutures, vascular grafts, artificial joints)
health/hygiene products (surgical gowns, beddings, etc.)
Test Methods for Medical textile include:
friction & diameter uniformity measurements for Sutures (CTT)
crimp measurements for Vascular Grafts (TYT-E)
comfort factor measurements for Bandages (CTT-E)
Protective textiles, especially the ones that are used in ballistic prevention need to stop the projectile flight in the shortest distance possible.
Best protection at the lowest weight is a combination of high specific modulus as well as tenacity and elongation to break.
Since the basis of the ballistic prevention is to extract maximum energy from the incoming projectile, absorption of the kinetic energy of the projectile needs to be studied. This absorption is related to the wave propagation and frictional energy dissipation.
Velocity of the wave propagation, c is calculated as follows:
Transportation industry is the largest user of the technical textiles. These textiles can be anything from the car seats, tires, seatbelts, bicycle parts, helicopter rotor blades to parts of a spacecraft.
Many different fibers are used in this field. For example, carbon-glass yarn is used for making light weight gears, whereas textured PES yarn will be preferred for car interiors.
Geotextiles represent a subgroup of Geosysnthetics, which includes geotextiles, geogrids and geomembranes. Geotextiles need to have high tensile strength. The mechanical response of a geotextile depends on the orientation and regularity of the fibers.
Vegetable Fibers such as Flax and Sisal have this property naturally.
Synthetic yarns need to be drawn and heatset.
Higher draw tension values > higher number of crystalline regions
Lower draw tension values > higher number of amorphous regions
Shrinkage Force and Shrinkage % Measurements with LH FST
High modulus and low shrinkage PES yarns are used in the tirecords. Aramids offer high strength and high temperature resistance and they are used in airplane tires and performance cars.
Draw Force Measurements with LH HDK-DFT
Friction & Diameter Measurements for Sutures with LH CTT
Sonic Velocity Measurement with LH DMT
Lawson Hemphill Dynamic Modulus Tester, DMT is designed to measure the Sonic Velocity through materials. DMT can be used to test yarns as well as strips of almost any material with these options:
Fiber Scanner Option > for yarn testing
Planar Mount Option > for material testing
Steel Wire (c = 5.07km/sec) Paraaramid (c = 7.23km/sec)
Nylon Tirecord (c = 3.63km/sec) UHMPE (c = 7.59km/sec)
CTT COF
Suture 1
0.18
Suture 2
0.19
Suture 3
0.20
Suture 4
0.15
Suture 6
Suture 7
0.17
Suture 8
0.22
Tear and Burst Testing
Yarn Evenness and Entanglement Measurement with LH ACE
Entangled and Air textured yarns are very common in car interiors.
LH ACE program measures the Entanglements and YAS program measures the yarn diameter evenness to find defective sections.
Vascular Graft Yarn Crimp Measurements with LH TYT-E
TMI Tear Tester
TMI Burst Tester
Dye Shade Variation Checks with LH FAK-S
Car seats are the biggest user of the technical textiles and the yarns that are used for them need to be knitted for dyeshade variation.
LH FAK-S knitting machine is the only lab knitting machine with fully automatic stitch control, which eliminates the tension variation during knitting.
Comfort Factor and Draw Measurements with LH CTT-E
Contact information
LAWSON-HEMPHILL
a TMI Group Company
1658 GAR Highway, Unit 6
Swansea, MA, USA
Tel:
Fax: