Have You Chosen the Right Cable Jackets?

Have you noticed that patch cables are all wrapped in various jackets? These cable jackets are important to serve as the protection for inner cable parts. Different kinds of jackets can influence the applications as well. Knowing the differences of cable jackets will help you make better decisions when choosing cables. Lots of materials can be made as cable jackets to cope with different situations. This article will mainly introduce some common types and analyze their distinctions.

cable-jacket

PVC

PVC (polyvinyl chloride) is a common jacket type widely used for general patch cables. The low cost and easy manufacture contribute to its popularity around the world. You can find PVC jackets almost everywhere when patch cables are used. PVC material is highly moisture-resistant so that can be perfectly applied to humid environment. But it also has some defects that will limit the service lifespan. For example, PVC material often becomes fragile under direct sunlight and its flexibility is restricted when greater bending is required.

LSZH

LSZH (low smoke zero halogen) is the material that gives off low toxic and corrosive gas under fire. It greatly ensures the high visibility and low respiratory damage when cables come across open fire or short circuit fault. LSZH cable jacket is typically applied to areas where smoke factor is considered to be the most important, such as aircraft, rail cars, ships, buildings and so on.

OFNP

OFNP (optical fiber nonconductive plenum) is specified by NFPA (National Fire Protection Association), which has no electrically conductive component inside optical cables. This type of cable jacket can effectively prevent fire and emit low smoke. OFNP cable is the highest fire rating fiber cable and has no replacement. Places including ducts, plenums, and other building airflow areas are suitable for installation.

PUR

PUR (polyurethane) cable jacket is the thermoplastic material that is usually used in harsh environment. It provides both mechanical resistance and chemical resistance. Thus, PUR cable can be installed for industrial applications where strong protective coating is demanded. Also, its flexibility makes itself a good material for retractile patch cables in continuously flexing applications. But it is more expensive than the common cable jackets.

PTFE

PTFE (polytetrafluoroethylene) sheath is a synthetic fluoropolymer material suitable for extreme environment. It is very durable under both high and low temperatures and can not be affected by most oils, fuels and fluids. This kind of cable jacket is widely used in military, aerospace, coaxial, and appliance wiring applications.

Rubber

Rubber jacket is a good option for portable power applications in outdoor or wet environment. It has better performance than plastic materials in flexibility, high temperature resistance and durability. Other applications like mining submersible pumps, control circuits, motor and associated machinery, construction equipment, etc. are also available.

Silicone

Silicone is the synthetic rubber with greater flexibility and stronger resistance against extreme temperatures and chemicals. Of course, it does not operate as high temperatures as PTFE. But with the extremely supple characteristic, silicone cable sheath is perfect for applications where lots of wire bending are required. And when it encounters fire, only a small amount of smoke will be produced which is also environmental-friendly.

Conclusion

After reading this article, you may get a general idea about the current cable jacket types and where they should be used. And certainly, if you want to find the most suitable jacket for your project, knowing these information is not far enough. But I hope this article can let you understand the importance of choosing a right cable jacket in your future applications.

Construction Design And Jacket Materials Of A Cable

Fiber optics has high bandwidth and can transmit data over longer distances. Turn to buy fiber optic cable, you may confused as  there are so many types of cables and it’s difficult to  figure them out. An optical fiber cable consists of a center glass core surrounded by several layers of protective material. The outer insulating jacket is to prevent interference. The construction design and choices of materials are vital in determining characteristics of a cable. The design factors for some types of fiber optic cables are listed below.

Indoor cables- Fire safety is the number one factor in selecting indoor cables, particularly those that run through plenum spaces. Indoor cables must pass the flame-retardant and smoke-inhibitor ratings specified by NEC.

Outdoor cables- Moisture resistance and temperature tolerance are the major factors when choosing materials for outdoor environment cables, like waterproof cables and outdoor cables do. They also need to be ultraviolet (UV) resistant.

Aerial/Figure 8 Self-Supporting Cables- Aerial cables must endure extreme temperature ranges from sunlight heat to freezing snow. They also must survive high wind loading.

Cable Jacket Materials

Polyethylene (PE). PE (black color) is the standard jacket material for outdoor fiber optic cables. PE has excellent moisture – and weather-resistance properties. It has very stable dielectric properties over a wide temperature range. It is also abrasion-resistant.

Polyvinyl Chloride (PVC). PVC is the most common material for indoor cables, however it can also be used for outdoor cables. It is flexible and fire-retardant. PVC is more expensive than PE.

Polyvinyl difluoride (PVDF). PVDF is used for plenum cables because it has better fire-retardant properties than PE and produces little smoke.

Low Smoke Zero Halogen (LSZH) plastics. LSZH plastics are used for a special kind of cable called LSZH cables. They produce little smoke and no toxic halogen compounds. But they are the most expensive jacket material.

Typical fiber cables are made from silica glass, which causes refractions that delay the signal. The standard line is that fiber optic networks transfer data at the speed of light. But in reality, light travels about 31 percent slower through fiber optical cables than it does through a vacuum. But that’s changing, researchers at University of Southampton in England have found a way to build cables that work at 99.7 percent of the speed of light in a vacuum. The researchers’ solution — is a hollow cable with special walls to prevent refraction. They call it an “ultra-thin photonic-bandgap rim”.

Several recent breakthroughs in fiber optics research. For example, scientists at AT&T Labs-Research announced a new record in speed/distance through standard bulk fiber optic cable. And a DARPA-backed team at IBM has found a way to cut the energy use of short-distance fiber optics for supercomputing while doubling the speed.

FiberStore LSZH Cable Solutions

The increasing demand of LSZH cables has been driven by published concerns for safety of humans and electronic circuits during fire, the protection of the ozone layer, non-toxic elements to water table and landfills when discarded, and an increase in requirements/specifications by the European and the International communities.

LSZH cables mean the insulation and jacket compound are free of halogenated materials like Fluorine(F), Chlorine (Cl), Bromine (Br), Iodine (I) and Astatine (At), which are reported to be capable of being transformed into toxic and corrosive matter during combustion or decompositions in landfills.

During combustion, Low Smoke Halogen Free Cable produce low levels of halogen gases, which have a minimal effect on the human respiratory system when inhaled, as well as a low level of Hydrogen Chloride (HCl), which is non-damaging to electronic circuits or machinery. Also, a low level of white smoke is generated, improving visibility by increasing the chances of people to visually find their way out to safety during fire.

LSZH cables emit no more than 0.5% of Hydrogen Chloride (HCl)
10-25% considers irritant(HCl) >25% considers corrosive

Low Smoke Fume, or LSF, is another term used by certain manufacturers for LSZH cables, but there are no standards for LSF. This means manufacturers can label their products LSF as long as they give off reduced (HCl) emissions. LSF cable is, in fact, just reduced HCl emissions, giving off <15% (HCl).

FiberStore product line has been developed to address the industry’s need for LSZH cable products that are UL listed, flexible, flame retardant and resistant to oil and sunlight. Our LSZH cables may be used and installed in places where safety, performance and concern for the environment are important.

LSZH Flame and Smoke Compliances
Vertical Tray Cable Flame Test, IEEE-383 (70,000 BTU) and CSA FT- 4 / IEEE 1202 flame test
Per UL-1685
IEC 60332-1 & -3 Cat. A: Flammability
IEC 61034-1 & 2 and MIL-DTL-24643B and NES 711 Smoke Index Emission
IEC 60754-1 & 2; MIL-DTL-24643B: Halogen Content and Acid Gas Generation

LSZH Versus PVC
PVC and LSZJ are very different. PVC patchcords are very soft. LSZH patchcords are more rigid because they contain the flame retardant compound, and they are aesthetically more pleasing.
A PVC (polyviny chloride) cable has a jacket that gives off heavy black smoke, hydrochloric acid, and other toxic gases when it burns.
Cost: LSZH components are slightly higher in cost than some PVC compounds, but it is the safety factors as they related to humans and electronic equipment as well as friendliness to the environment that should be considered when it comes to cost.

Flexibility: There is a limited range of compound flexibility available for LSZH compounds versus PVC so it not recommended for robotic or continuous flex applications.

Flame Retardant: There is a higher grade of flame-retardant PVC compounds available on the market like Plenum PVC because of the halogen additive in PVC like Chlorine and Bromine that are not allowed in LSZH compounds.

When selecting or designing a cable for any application, the operating environments where the cable will be used, whether extreme or not, must be considered along with availability, performance, and price, among other things. When the safety of humans and the environment is a consideration, along with high-performance and capability, then FiberStore LSZH cables are what you must specify!