FEP 1.3:1 Heat Shrink

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Zeus provides the ideal method for the application of a tight and protective jacketing to items that ultimately will be subjected to extremes of heat, corrosion, shock, moisture, and other harsh environmental conditions. Heat shrink tubing extends the life of the protected components nearly indefinitely and helps to sustain their performance. Zeus heat shrink tubing has a high presence in the aerospace, electrical, chemical, optical, medical, and automotive fields.

Fluorinated ethylene propylene, or FEP, heat shrink tubing is chosen particularly for its lower shrink temperature than other heat shrinks such as PTFE. FEP also has greater flexibility, optical clarity, and high lubricity in comparison to PFA. In addition to those traits, FEP heat shrink is commonly chosen for its lower cost and for applications where large heat shrink ratios are not needed.

Zeus heat shrink tubing products are provided in their expanded state. With the brief application of heat, they mold themselves snugly around the most intricate and irregular shapes to form a completely sealed covering. Sources of heat and methods of heating are optional. Please contact your Zeus Technical Account Manager for guidance on selecting the best heat option for you.

Shrink Ratios and Recovery

Heat shrink ratio refers to the final diameter of the heat shrinkable material after being allowed to shrink fully unrestrained compared to the original diameter of the pre-shrunk material. After heat shrinking is complete, the material is considered to be in its “recovered” or “recovery” state. Thus, final dimensions for heat shrink usually refer to recovered or fully shrunk dimensions.

As an example, for a heat shrinkable material with a 3:1 heat shrink ratio, the final diameter of the fully shrunk material will be reduced to 1/3 of the pre-shrunk diameter. Or, put another way, the original diameter of the pre-shrunk material will be 3× the diameter of the fully shrunk (recovered) material; the ratio of their diameters, pre-shrunk:recovered, will be 3:1.

Note that heat shrink is typically applied over a material or component to encapsulate it; thus, in practical application, it is restrained from being shrunk completely.

Heat shrink ratio is a fundamental consideration for every application based on the degree of non-uniformity of the items or components to be covered. The more irregular the shape, the greater the heat shrink ratio needed to cover the shape. Conversely, for more uniform parts such as cylinders or wires, smaller heat shrink ratios will generally suffice to achieve proper coverage. Consideration should also be given to tapered parts: While appearing generally uniform in shape, the degree of taper should be taken into account when selecting heat shrink and its shrink ratio.

Zeus FEP heat shrink tubing is available with 1.3:1 and 1.6:1 or greater shrink ratios and can be selected based on American Wire Gauge (AWG) or fractional sizes. This heat shrinkable material incorporates all of the same high standards and characteristics of FEP. We can also provide custom micro-miniature dimensions and other tailored specifications and tolerances upon request.

Heat Shrinking Guidelines for FEP Heat Shrink Tubing

Always assure good ventilation in the immediate work area before beginning the heat shrink process. (Caution: Fumes can cause nausea and dizziness).

  1. FEP heat shrink tubing requires approximately 420 °F ± 50 °F (215 °C ± 10 °C) to initiate shrinkage. While this is a liberally safe range, these temperatures are approximate. Actual shrink temperatures may vary based on dimensions and wall thickness of the tubing, methods of application, and other factors. Zeus is happy to provide samples to test in your application and help you determine the best material to use.
  2. The mandrel (part) to be covered by FEP heat shrink must be able to tolerate the range of the heat shrink temperature.
  3. Parts or mandrels may act as a heat sink. Therefore, Zeus recommends preheating larger diameter mandrels and other parts.
  4. FEP heat shrink needs only a small degree of recovery. You may experience some slight longitudinal change depending on the amount of recovery. Contact Zeus if longitudinal change is a concern.
  5. Heating and cooling should be even on all sides for best results. Uneven heating or cooling tends to split the side still in the “gel” state while the other side is in the hard or crystalline state, particularly upon recovery.
    Note: Shrinking starts when the FEP is brought up to the “gel” state but completes its recovery during the cooling cycle. In its gel state the tubing becomes crystal clear and glassy in appearance.
  6. Ovens are the most reliable way to recover heat shrink products due to their ability to ensure even heating and reduce the risk of overheating the material (which can lead to brittleness and cracking). If a heat gun is to be used, please contact our team our team or call toll-free in the US 1-800-526-3842 or +1-803-268-9500 internationally for tips on proper heat application to achieve the most uniform recovery.

Applicable Specifications

FEP Heat Shrink complies with AMS 23053/11 Class 1.

For all cases of military or commercial specifications, latest revisions apply. Our FEP heat shrink is supplied in natural color unless otherwise specified. Mil-STD-104 colors are available upon request.

Please Note: Some of the items above meet UL-224 certification. See our UL chart for the latest information.

  • APPLICATIONS

    Encapsulation – For general purpose protection and covering of components, FEP heat shrink may be the best choice for your application for cost, heat shrink temperatures, and other features making it competitive with products that are more expensive. FEP 1.3:1 heat shrink is best suited for applications that do not require large heat shrink ratios. Such covered parts include medical instruments, temperature probes, roll covers, lighting, hoses, wires and cables, to list but a few. FEP heat shrink’s transparency allows your covered components to remain observable while they are protected from heat, chemicals, moisture, and temperatures.

    Insulation – FEP’s dielectric properties make is a good choice for encapsulating and insulating electrical components such batteries (lithium and alkaline) or solenoids. FEP heat shrink’s heat tolerance likewise allows it to continue to perform at temperatures commonly encountered in electrical environments.

    Wire Harness – This heat shrink material’s excellent dielectric properties make is a good choice for covering wires and cables and can even support splicing. Once covered, FEP heat shrink also serves as insulation.

  • KEY PROPERTIES

    Biocompatible – Our FEP heat shrink is non-toxic and USP Class VI approved, so you can trust that this Zeus product meets your biocompatibility needs.

    Chemically Resistant – FEP heat shrink is impervious to nearly all common solvents whether they are acids, bases, or hydrocarbons.

    Excellent Dielectric Strength – FEP heat shrink possesses exceptional dielectric strength and thus doubles as additional insulating material when used with electrical components.

    Excellent UV Transmission Ratings – FEP’s UV ratings mean that it can stand up to prolonged UV exposure and not degrade or breakdown. The ability of our FEP heat shrink to withstand this type of UV exposure means that it can be used under sterilizing UV light as well as outdoors.

    Flame Resistant – The non-flammable nature of this product makes it a good choice for environments where there is high heat or the possibility of flame exposure. FEP heat shrink is UL 94 V-0 rated.

    Low Absorption of Solvents – Consistent with FEP’s negligible chemical activity, our FEP heat shrink has extremely low absorption of solvents.

    Many Preferred Traits Over PTFE – FEP heat shrink has a lower gas and vapor permeability than PTFE and is less expensive; it is also more flexible than PTFE and possesses greater optical clarity.

    More Lubricious Than PFA – FEP has a lower coefficient of friction than PFA which means it has a highly lubricious surface.

    Optical Clarity – The transparency of our FEP heat shrink assures that your covered parts remain visible yet protected allowing you to monitor the integrity of covered parts or wire splices.

    Sterilizable – FEP heat shrink’s temperature tolerance and physical properties allow it to easily tolerate Gamma, ETO, e-beam, and autoclave sterilization protocols.

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  • CAPABILTIES / SIZING

    FEP 1.3 to 1 Heat Shrink Tubing

    Color: Supplied in “natural” unpigmented state unless otherwise specified. Custom Pantone colors or Zeus standard colors available upon request. See our coloring polymers information for more about Zeus’ coloring capabilities.

    Complies with: AS23053™/11

    FEP Heat Shrink 1.3 to 1 – Shrink Ratio – AWG Tubing
    Recovered Dimension After Shrinking
    Ordered as AWG Size As Supplied Inside Diameter Minimum Inside Diameter (ID) Will Shrink to at Least Wall Thickness
    Min. Nom. Max.
    24 0.031 0.027 0.006 0.008 0.010
    22 0.036 0.032 0.006 0.008 0.010
    20 0.045 0.039 0.006 0.008 0.010
    18 0.060 0.049 0.006 0.008 0.010
    16 0.075 0.061 0.007 0.009 0.011
    14 0.092 0.072 0.007 0.009 0.011
    12 0.115 0.089 0.007 0.009 0.011
    10 0.141 0.114 0.007 0.010 0.013
    9 0.158 0.124 0.007 0.010 0.013
    8 0.180 0.143 0.007 0.010 0.013
    7 0.197 0.158 0.007 0.011 0.015
    6 0.225 0.180 0.007 0.011 0.015
    5 0.248 0.198 0.007 0.011 0.015
    4 0.290 0.226 0.007 0.011 0.015
    3 0.310 0.249 0.007 0.011 0.015
    2 0.365 0.280 0.008 0.012 0.016
    1 0.400 0.311 0.008 0.012 0.016
    0 0.400 0.349 0.008 0.012 0.016
    FEP Heat Shrink 1.3 to 1 – Shrink Ratio – AWG Tubing (Metric Dimensions)
    Recovered Dimension After Shrinking
    Ordered as AWG Size As Supplied Inside Diameter Minimum Inside Diameter (ID) Will Shrink to at Least Wall Thickness
    Min. Nom. Max.
    24 0.79 0.69 0.15 0.20 0.25
    22 0.91 0.81 0.15 0.20 0.25
    20 1.14 0.99 0.15 0.20 0.25
    18 1.52 1.25 0.15 0.20 0.25
    16 1.91 1.55 0.18 0.23 0.28
    14 2.34 1.83 0.18 0.23 0.28
    12 2.92 2.26 0.18 0.23 0.28
    10 3.58 2.90 0.18 0.25 0.33
    9 4.01 3.15 0.18 0.25 0.33
    8 4.57 3.63 0.18 0.25 0.33
    7 5.00 4.01 0.18 0.28 0.38
    6 5.72 4.57 0.18 0.28 0.38
    5 6.30 5.03 0.18 0.28 0.38
    4 7.37 5.74 0.18 0.28 0.38
    3 7.87 6.32 0.18 0.28 0.38
    2 9.27 7.11 0.20 0.30 0.41
    1 10.16 7.90 0.20 0.30 0.41
    0 11.18 8.86 0.20 0.30 0.41
    FEP Heat Shrink 1.3 to 1 – Shrink Ratio – Fractional Inch (Decimal) Tubing
    Recovered Dimension After Shrinking
    Fraction Decimal As Supplied Inside Diameter Minimum Inside Diameter (ID) Will Shrink to at Least Wall Thickness
    Min. Nom. Max.
    3/8 0.375 0.500 0.383 0.011 0.015 0.019
    7/16 0.438 0.580 0.448 0.016 0.020 0.024
    1/2 0.500 0.666 0.510 0.016 0.020 0.024
    5/8 0.625 0.830 0.637 0.021 0.025 0.029
    3/4 0.750 1.000 0.764 0.026 0.030 0.034
    7/8 0.875 1.170 0.891 0.031 0.035 0.039
    1 1.000 1.330 1.020 0.031 0.035 0.039
    1-1/8 1.125 1.500 1.145 0.031 0.035 0.039
    1-1/4 1.250 1.666 1.270 0.031 0.035 0.039
    1-3/8 1.375 1.833 1.390 0.031 0.035 0.039
    1-1/2 1.500 2.000 1.520 0.031 0.035 0.039
    FEP Heat Shrink 1.3 to 1 – Shrink Ratio – Fractional Inch Tubing (Metric Dimensions)
    Recovered Dimension After Shrinking
    Fraction Size (mm) As Supplied Inside Diameter Minimum Inside Diameter (ID) Will Shrink to at Least Wall Thickness
    Min. Nom. Max.
    3/8 9.53 12.70 9.73 0.28 0.38 0.48
    7/16 11.13 14.73 11.38 0.41 0.51 0.61
    1/2 12.70 16.92 12.95 0.41 0.51 0.61
    5/8 15.88 21.08 16.18 0.53 0.64 0.74
    3/4 19.05 25.40 19.41 0.66 0.76 0.86
    7/8 22.23 29.72 22.63 0.79 0.89 0.99
    1 25.40 33.78 25.91 0.79 0.89 0.99
    1-1/8 28.58 38.10 29.08 0.79 0.89 0.99
    1-1/4 31.75 42.32 32.26 0.79 0.89 0.99
    1-3/8 34.93 46.56 35.31 0.79 0.89 0.99
    1-1/2 38.10 50.80 38.61 0.79 0.89