Glossary

 

Below we present a glossary of some of the most commonly used terms in the industrial fabric industry. It is by no means comprehensive, but it provides definitions for many of the terms which are widely used in the industry. It is our hope that it will be of assistance to current and potential customers in understanding the terminology used on this web site, and in the industrial fabric industry in general. If a word or phrase for which you are seeking a definition does not appear here, please do not hesitate to use our contact form to request a clarification or explanation of any term used on Fabrico’s site or, for that matter, on the site of one of our competitors.

Abrasion Resistance is a measure of the ability of a material (either a film or a coated or laminated fabric) to resist wearing away when under abrasive conditions. Several standards for measuring abrasion resistance have been established by organizations such as the American Society for Testing and Materials (ASTM) and their European counterparts. Increased abrasion resistance in a polymeric material is achieved by the addition of certain chemical compounds to the mix of components of the polymer.

Anti-Static materials are those which resist the build-up of static electric charge on their surfaces. They are useful in applications such as clean room curtains or computer server storage rooms in which alternating aisles are cooled (to protect the electronics from the heat which they generate); the curtains which separate the hot and cold aisles are typically made with an anti-static material to avoid the build-up of static electricity, which could discharge into the servers and damage their circuits. Some industrial fabrics are inherently anti-static, while others can be rendered static resistant by additives or by surface treatments.

Bar Tack is a type of seam in which short, parallel stitches are located immediately next to each other for a given length, combined with longer stitches which run perpendicular to the short stitches, forming an extremely strong connection with the appearance of a “bar,” the source of the name. Bar tacks are extremely strong, and are often used to form loops in webbing in which the bar tack is as strong as, or stronger than the webbing itself.

Box Stitch is another means of securely attaching webbing to itself or to fabric. Its appearance is that of a rectangle of stitching, with additional stitching running between the corners of the rectangle which are opposite of each other. While generally not as strong as a bar tack, a box stitch is often sufficient to attach webbing straps to industrial fabric assemblies.

Chain Stitching and Lock Stitching are the two main types of commercial stitches. Their structures are difficult to describe without illustrations, but a chain stitch has the bottom length of thread (from the bobbin) looping through alternating top stitches, whereas a lockstitch loops the upper and lower threads together at every stitch. Chain stitching is considered by many to have a more attractive finished appearance than lock stitching, and is used extensively in apparel manufacturing; on the other hand, lock stitches are far less likely to unravel over time, and are generally considered stronger than chain stitches. Fabrico uses lock stitching almost exclusively.

Coated Fabric is one of the mainstays of the industrial fabric industry. It consists of a base fabric, or cloth (also called a scrim or a substrate) which is usually either woven or knitted, and a coating (or multiple coatings) of a thermoplastic polymer. Common materials used for the base fabric include nylon and polyester, but the range of materials used for the base fabric is quite wide, and includes, in addition to nylon and polyester, cotton, fiberglass, KevlarR, NomexR and a number of other materials. Most of the materials used to manufacture base fabrics are themselves polymeric materials (see Polymer below). The polymer coating is typically a plastic (such as polyvinyl chloride (PVC), polypropylene or TeflonR), a synthetic rubber (such as polyurethane, silicone or neoprene) or, in rare instances, natural rubber (latex). The characteristic which distinguishes a coated fabric from a laminated fabric is the method of applying the polymeric exterior to the scrim. Coated fabrics have the polymer applied to the scrim in a liquid or semi-liquid form, with the thickness of the end product determined by the amount of coating applied to a given area of the scrim; laminates are manufactured by applying a film of the polymer, usually in conjunction with an adhesive, to the surface of the scrim under pressure and heat. Laminated fabrics are typically less expensive than coated fabrics, but it is usually more difficult to make an air tight, liquid tight seam using laminated fabrics.

Cold Seam is a term used to describe a flawed thermal weld between two pieces of material. Cold seams can be detected by the use of apparatus such as a vacuum box or an air lance. Cold seams are more likely to be found in welds which have been made using hot air or a heated wedge, as opposed to RF welding.

Corrosion (commonly known as rust) is a phenomenon which takes place at the surface of metals. It is the result of a chemical reaction between oxygen in the air surrounding the metal and the molecules at the metallic surface, and is accelerated by the presence of moisture (water vapor) in the air; thus, the less water vapor in the air surrounding a metallic component, the more slowly the component will corrode. Certain materials, such as stainless steels, are inherently more resistant to corrosion than others (such as carbon steel). Fabrico’s 4034 low moisture transmission material, when used to create a flexible storage and/or shipping container, reduces the tendency of the stored metallic components to corrode, by creating a corrosion-resistant container.

Denier is a unit of measure used to describe the linear density of yarns or threads, and is defined as the mass, in grams, of 9,000 meters of the thread. It is used to describe the density of the yarn or thread used to manufacture the substrate of a coated or laminated fabric; it can also be used to describe sewing thread, although other terms, particularly tex, are typically used in describing sewing thread. Thus a 1,000 Denier fabric substrate is made from yarns which have a mass of 1,000 grams (1 kilogram, or kg) per 9,000 meters of length. Generally speaking, the higher the Denier of the yarns used to manufacture a base fabric of a given material, the stronger the base fabric. However, the density of the weave of the fabric, among other factors, also contributes to the relative strength of a fabric, so that a 1,000 Denier, 10 x 10 weave (10 threads per inch in either direction – see warp and fill below) fabric would be expected to be stronger than a fabric, made from the same material, that is 1,000 Denier with a 9 x 9 weave.

Die Cutting is a method of cutting fabrics in which a precision-built steel rule die is used to cut multiple pieces of fabric at the same time by applying pressure to multiple sheets of fabric lying on top of the die. Die-cutting ensures that the parts are all essentially identical, and are cut to tolerances as small as ±0.020”. It can be used with almost all industrial fabrics.

Fabric Weight is a means of describing the typical weight of an industrial fabric for a standard area. The most common standard of measurement of this characteristic is ounces (weight) per square yard, or, in metric terms, grams per square meter. To convert oz./sq. yd. to g/sq. m, multiply by 33. 9057.

Fabric Thickness is used to describe the average thickness of an industrial fabric, either a film or a reinforced material. It is typically expressed in mils, or thousandths of an inch (.001” = 1 mil). Industrial fabrics, both films and reinforced materials, are available in a wide range of thicknesses, from as thin as 5 mils (.005”) or less to 3/16” (.1875”) or more.

Fiberglass is most commonly associated with thermal insulation; in the industrial fabric industry it is used to make high-temperature woven scrim in specialized applications such as welding curtains, and as insulation in thermal and acoustical insulation curtains.

Fill is the term used to describe the direction across the roll width in industrial fabrics (see warp below).

Film is, in the industrial fabric industry, a term used to describe a sheet of polymeric material which contains no reinforcing fabric or scrim. It is typically used in products (such as bladders or flexible medical devices) which require greater elasticity than reinforced materials. It is also used to manufacture products which, when filled with a gas or liquid, must conform to the interior surface of a rigid container. Films are available in most of the same polymers as the coating or lamination on the surfaces of reinforced fabrics.

Flame Resistance (sometimes called Flame or Fire Retardancy) is a characteristic of many industrial fabrics. The degree of flame resistance is defined by any of a large number of standards established by testing agencies in the U.S. and abroad, including National Fire Prevention Association (NFPA) Standard 701, Federal Motor Vehicle Safety Standard (FMVSS) Standard 302, California Fire Marshal Flame Resistance Standard, American Society for Testing and Materials (ASTM) Standard E-84, among many others. Most of these standards require that an industrial fabric, when exposed to an open flame under laboratory conditions, be self-extinguishing within a maximum period of time – typically a matter of seconds – once the source of the flame has been removed. This characteristic can be inherent in the formulation of the material, or can be added by treating the surface of the material. The former method of making a material flame resistant is considered superior, because it can never wear off, being an inherent property of the material.

Heat Sealing is another term for welding when used in the industrial fabric industry. In this industry, the two terms are interchangeable.

Hydrostatic Resistance is the characteristic of an industrial fabric which measures the material’s ability to withstand liquid pressure without failing. It is often called “Mullen Burst Strength,” and is expressed in terms of the pressure at failure, either in pounds per square inch (psi) or Pascals (Pa – one Pascal is equal to one Newton per square meter in the metric system of measurement).

KevlarR is the trade name for of a polyaramid fiber developed by DuPont in the 1960s, related to other aramid fibers such as NomexR. It is remarkable for its high strength-to-weight ratio, which is approximately five times that of steel. It is available as a base fabric for coated or laminated industrial fabrics for highly specialized applications, and is also available in the form of sewing thread. We recommend its use in only the most demanding applications, due to its high price and the difficulty of working with it in the factory.

Mildew Resistance is a property which, similarly to Fire Resistance, can be incorporated into an industrial fabric, either as an inherent property of the polymer or as a surface treatment. It is  and is especially important when the fabric is likely to come in contact with food products, in medical products, etc. It is also sometimes referred to as “anti-fungal.”

Neoprene is a synthetic rubber material (its generic name is chloroprene) which is particularly flexible, and remains flexible at relatively low temperatures. It has limited uses as an industrial fabric coating or film, as it cannot be welded with RF technology.

Non-wicking Thread describes certain types of fibrous sewing threads which resist the passage of fluids along their length. It is often specified in military applications. Its main advantage over general purpose thread is that a seam sewn with it has less tendency to allow leakage of fluids through sewn seams.

Nylon is a thermoplastic polymer which is used in a wide variety of industries, and is made in a number of different formulations. In the industrial fabric industry it is mainly used in the manufacture of the woven scrim material found in reinforced coated or laminated fabrics, and in the manufacture of webbing (see below). It is slightly stronger than polyester and stretches more easily, but it also somewhat water absorbent.

Polyester is, along with nylon, among the most commonly used materials in the manufacture of the scrim (or base fabric) for coated or laminated fabrics, and in the manufacture of webbing. It is, like nylon, also made in different formulations, depending on the application. It is more resistant than nylon to the absorption of water, and is less elastic than nylon, so it is often used in the manufacture of webbing in which relatively high resistance to stretching is a desired property. Depending on the formulation, polyester can be either a thermoplastic or a thermoset material. Polyester, when produced in non-woven batts (similar in construction to fiberglass insulation), is often used as a thermal or acoustical insulation material in industrial curtains. It’s thermal and acoustical insulation properties are nearly as effective as fiberglass, but do not pose the health hazards to production workers or end users which are a characteristic of fiberglass insulation.

Polymers are, in the general language of chemistry, materials which consist of long molecular chains which are made up of smaller molecules (monomers) with the same physical and chemical properties as the polymer. In the field of industrial fabrics, most of the materials which make up industrial fabrics are polymers, including the base fabric materials (such as nylon and polyester) and the coatings (or the films which have no base fabric).

Polypropylene is one of the most commonly used thermoplastic polymers in the industrial fabric industry. It is used as a fabric coating, as well as in the manufacture of auxiliary items such as rope and webbing. It is chemically relatively inert (it does not emit gases over time and releases almost no particulates from its surface over time), inherently resistant to static charge build-up, and inexpensive when compared to other thermoplastic materials. Its main drawback when used as a coating for an industrial fabric is that it cannot be heat sealed using RF welding technology.

Polyurethane is another thermoplastic polymer which is widely used as a coating for industrial fabrics. It can be welded using RF technology, and it is highly resistant to attack by many industrial chemicals, including, depending on the formulation of the coating, gasoline, benzene, toluene and other aromatic hydrocarbons, making it more effective than PVC or polypropylene in resisting degradation from exposure to chemicals. It is one of the synthetic rubber materials, and is thus relatively flexible. It can be used as a coating, made into a film, and can be combined with other polymers to meet particular needs.

Puncture Resistance is a characteristic of industrial fabrics which varies widely. In certain applications, a high degree of puncture resistance is an important characteristic. Reinforced materials, as opposed to films, generally have much higher puncture resistance as a result of the strength of the base fabric (or scrim).

PVC is an acronym for polyvinyl chloride, commonly known by the simpler term, “vinyl.” It is used in innumerable industrial and commercial applications and products. For example, many automobiles have rigid PVC dashboard panels and flexible PVC seat covers and roof coverings. It is extremely versatile in that its hardness (or rigidity) is relatively easy to control (by the manufacturer) by adding more or less of a variety of plasticizers (the chemicals which make PVC softer or harder). It is also one of the most widely used coatings (or laminations) used in industrial fabrics, because it is relatively inexpensive, yet resistant to a wide range of chemicals, and can have additives to it which increase its flame resistance, UV resistance, mildew resistance, and a variety of more “exotic” features such as low infrared reflectivity (for use in military vehicle covers, for example).

Radio Frequency (RF) Welding is the most effective means of forming a water and air tight seam between polymeric industrial fabrics. For more details on RF welding, please refer to our seaming methods page.

Silicone is a synthetic rubber material which is often used as a coating on industrial fabrics for its very high resistance to attack by industrial chemicals, its high degree of flexibility and its ability to withstand continuous exposure to temperatures up to 500°F (PVC, or vinyl, typically is rated for continuous exposure to temperatures no higher than 200°F).

Tear Strength is a property of industrial fabrics which measures the ability of the fabric to resist the propagation of a tear, once the tear has been made (by puncturing, for example).

Tensile Strength in industrial fabrics is a measure of the amount of tensile force (stretching) which can be applied to a given width of the fabric before it breaks. In reinforced fabrics, it is usually reported, in technical data sheets, as the strength in the warp direction (see below for a definition of warp) and in the fill direction; in most cases the material has less tensile strength in the fill direction than in the warp direction, whereas in films it is typically the same regardless of direction.

Thermoplastic polymers are those which become soft or even fluid when heated above a certain temperature, but which become solid again, with no change in their physical or chemical properties, when cooled. Thermoset materials, polymeric or otherwise, undergo changes in their properties when heated such that they do not return to their original state upon cooling. Thermoplastic polymers are a relatively new development (within the last 70 years or so) which have made possible the existence of the modern industrial fabric industry, in which welding (or heat sealing) plays a prominent role.

UV Resistance is the ability of a material to resist degradation (such as loss of strength, delamination of the coating, etc.) after long-term exposure to sunlight or other sources of ultraviolet radiation. This property is typically achieved by the addition of certain chemicals to the polymer, and it is generally not absolute; even UV-resistant fabrics will be degraded to some degree by long-term exposure to sunlight.

Warp is the term used, in the description of woven fabrics, to indicate the direction along the length of the roll (industrial fabrics are always produced in rolls in which the length greatly exceeds the width). It is the opposite of the fill direction. As noted above, many of the physical properties of reinforced industrial fabrics, whether coated or laminated, are reported on data sheets in both the warp and fill directions.