| Abrasion Resistance |
The degree that a fibre or fabric can withstand surface wear |
| Acrylic |
Synthetic fibre, 30% of the break strength of polyester, with high resistance to UV. Firbre used in Sunbrella and in marine covers. |
| Aramid |
Polyamide fibre - Kevlar, Twaron, Technora. High tensile strength, low stretch, and resistant ro heat. |
| Balanced Construction |
Sailcloth having the same size yarns in both warp and fill directions |
| Bias |
45 degrees to the warp of a fabric. Direction of most stretch |
| Breaking Strength |
The tensile strength, the maximum load or force required to break a sample in tension |
| Bright |
In synthetic fibres, the normal lustre not reduced by chemical or physical etching. |
| Burst Strength |
Force required to rupture a sample at 90 degrees to the plane of the sample |
| Calandar |
A machine used to finish fabric - 2 or more heavy heated rollers through which cloth passes under heavy pressure. Shrinks and flattens the yarns to stabilise the material. |
| Cloth Weight |
Confusingly many measures for this - in sails mainly Ounces per Sailmakers Square Yard (28.5 inches x 36 inches), Ounces per square yard and Grams per square metre. |
| Coated Sailcloth |
A coating, usually urethane, is applied to stiffen and stabilise the weave for performance gain. Creates poorer tear strength, an increase in weight and a stiffer feel to the fabric |
| Crimp |
Number of warp yarns (ends) and fill yarns (picks) per inch in a woven fabric |
| Dacron |
DuPont name for polyester fabric |
| Denier |
The weight in grams of 9000 metres of a yarn |
| Decitex |
weight in grams of 10000 metres of a yarn |
| Denier per inch |
DPI.Method of measuring and comparing density of fibres in laminated sailcloth. The Yarn Denier x number of yarns in an inch |
| Durability |
The resistance to loss of physical properties due to use |
| Elasticity |
The property of a material by which it can recover its original size and shape after deformation. |
| Elastic Limit |
The strength and stress testing, the load below which the fabric shows elasticity, and above which it shows permanent elongation. |
| Elongation |
Deformation caused by tensile load. Elongation is measured either by units of length or percentage of the original length. |
| End |
An individual warp yearn |
| Fabric |
A plane textile structure of interlaced yarns or filaments |
| Fibre |
Anything able to be spun into a yarn, or able to be made into a fabric by interlacing by weaving, knitting or twisting |
| Filament |
A fibre with indefinite or extreme length |
| Fill |
For a woven fabric, the yarn running from selvedge edge to selvedge edge - 90 degrees to the warp. Each fill yarn is called the "pick". In weaving it is the fill that is carried by the shuttle (or other yarn carrier) |
| Fill-oriented |
Having the greatest number of yarns and strength in the fill direction (acroos the fabric). This suits Cross-cut sails. High performance woven fabrics over 3oz will be fill-oriented. |
| Film |
A thin sheet of plastic. Commonly Mylar (polyester). Tedlar and nylon are available. Films are normally isotropic (same strength in all directions) |
| Finish |
A substance or process applied to textiles to produce a desired outcome - improved stretch resistance, water repellency etc |
| Finishing |
The process after weaving - scouring, heat setting, calendaring and resinating. |
| Flutter Test |
A test strip of material is spun for a set time and speed on a rotating wheel - creates fatigue stress. Load Tests comparing the original material's results with the fatigued sample give a measure of the extent of the fabric to fatigue. |
| Gore |
Any long panel, usually triangular, in a sail |
| Greige fabric |
A fabric straight from the loom - unfinished |
| Hand |
The feel, the softness of a material - not a test, but a subjective "touch" |
| Heat setting |
Process to create dimensional stability in fabrics - polyester fabrics benefit hugely from this. |
| High-aspect cloth |
A woven polyester optimised to perform well in high aspect sails, by having a high fill content and fill yarn denier. Bias stability is reduced however. |
| Hydrophilic |
An affinity for the absorption of water - at a molecular level. |
| Hydrophobic |
A resistance to the molecular absorption of water |
| Impact Flutter Test |
As in the Flutter Test, with a surface added, which the sample hits on every revolution - to emulate the sail hitting an object. Very severe test, which shows up any finishing or laminating faults |
| Impregnated finish |
A finish appied to a woven fabric in which the weave is completely filled with a liquid, usually melamine, throughout its thickness. Contrasts with a coated finish |
| Kevlar |
Trade name for DuPonts aramid fibre |
| Knitting |
A method of constructuing a fabric by a series of interlocking loops of one or more yarns. In sailcloth it consists of a warp and fill yarn, and a third small yarn to "knit" them together. |
| Laminate |
A fabric containing two or more layers, joined by adhesive to form one consolidated whole |
| Laminator |
A machine able to apply adhesive, heat and pressure to a layer to achieve consolidation. |
| Lot |
A unit of cloth production - having therefore similar properties throughout. |
| Melamine |
A resin used to impregnate woven polyester sailcloth to stabilse it so reducing stretch |
| Mil |
Measure of film thickness. 1 mil = 0.001 of an inch |
| Modulus of Elasticity |
Coefficient of the materials resistance to stretch. The higher the number the better. |
| Monofilament |
Any single filament with a denier larger than 15 |
| Mylar |
A polyester fim made by DuPont. |
| Nylon |
Fibre made of long chain polyamide. Good strength to weight ratio, takes dyes well, good elatic recovery and fatigue resistance. Is stretchy though, and is affected by UV.
|
| Orientation |
The direction of greatest strength ina woven cloth. |
| Peel adhesion |
The froce required to seperate the layers of a laminate |
| Permanent deformation |
The change in length of a sample after the removal of load, after being loaded. Expressed as a percentage of the original length |
| Permeability |
Being able to be permeated by fluids or gases. The ease with which air passes through a fabric. |
| Pick |
The single yarn carried by one trip of a shuttle across a loom |
| Pick Count |
The number of picks per centimetre (or inch) |
| Plain weave |
Most common of the base weaves. Each pick passes over and under each end, successively. |
| Plied Yarn |
A yarn formed by twisting together two or more single yarns. |
| Polyester |
Polyethylene Terephthalate (PET) |
| Sailmakers Square Yard |
A measure of the weight of a yard of sailcloth that is 28.5 inches wide. Originally this was the optimum width of the cotton looms available for the production of high quality cotton in the USA, so was the weight of a linear yard of American cotton sailcloth. |
| Scouring |
An operation to remove the sizing used on the warp yarn in weaving, and to clean the fabric prior to dyeing and finishing. |
| Scrim |
A light weight open weave fabric. Has distinct gaps between yarns. Very unstable on its own, is a useful addition to laminates, giving directional strength and tear resistance with little additional weight. |
| Selvage |
or Selvedge. The narrow woven edge of a woven fabric, often with extra warp yarns to increase strength. In synthetic fabrics, this is commonly cut off, and is a heat-cut edge - the name persists however. |
| Sizing |
Compounds applied to yarns or fabrics to surround the individual fibres. Added to give smoothness, stiffness, abrasion resistance, lustre or weight. Starch, gelatin, linseed oil, and wax are common sizings. |
| Strength |
The ability to resist force without breaking or permanently deforming |
| Strength/Weight ratio |
The working load divided by the weight. Laminates offer high strength to wieght ratios. |
| Stress |
The load applied to the material |
| Strain |
The deformation in the direction of the load of a material |
| Taffeta |
A finly woven plain weave. Sailcloth is a taffeta. Commonly used as the fine woven fabric used on the outside of laminates to offer protection to the films. |
| Tear Resistance |
The resistance to tearing. Measured by pulling a flap of fabric in the sample, it is the force required to propogate the tear. |
| Tedlar |
ETFE film with extremely high UV resistance. Stabilty and strength are poorer than PET films |
| Tenacity |
The tensile stress expressed as the force per density unit, (grams per denier). PET yarns are grouped into High, Normal, and Low Tenacity yarns. High tenacity yarns are lower stretch, more expensive, and difficult to dye. |
| Tensile Strength |
The load at which a sample breaks under tension |
| Thread |
A combination of strands of fibres. A yarn for specific use in sewing. Can be loosely, and wrongly, used as a term in weaving or knitting. |
| Twist |
The rotation of filaments to form a yarn. Number of full rotations per metre. Can be clockwise or anticlockwise. |
| Ultra-violet degradation |
Also called Actinic Degradation. The weakening or fading of febrics caused by the exposure to the ultr-violet radiation of sunlight or artificial light. |
| Unbalanced weave |
A fabric having larger yarns in one direction than the other. Unbalancing the fabric in the fill leads to greater strength and stretch resistance, but higher warp denier in the warp causes crimp, which leads to a loss of stretch resistance. |
| Warp |
The set of yarns which run lengthwise on the loom, and along the roll of fabric. Interwoven with the fill yarns, which pass through the warps as they are alternately lifted and lowered in successive yarn sets. |
| Warp Oriented |
Having the greatest strength and resistance to stretch in the warp direction. Used in radial cut sails. Laminated fabric are commonly warp oriented, but woven fabrics are commonly poor in this construction. |
| Weave |
Three basic weaves are plain, twill and satin. All other weaves are derived from these. |
| Webbing |
Strong closely woven narrow fabric in a variety of weaves. Used for straps which have to withstand high strain. Can be woven in a tubular format, which has no selvedge, is two ply, and is very strong |
| Wet Strength |
The strength of a material when fully aturated with water, expressed as a ratio with its dry strength. Nylon has a big difference between wet and dry strength. |
| Yarn |
Generic term for a continuous strand of fibres or filaments |
| Yield |
The point at which a material has exceeded its elastic limit and is permanently deformed |