• Latest
  • Trending
  • All
  • Capacitors
  • Resistors
  • Inductors
  • Filters
  • Fuses
  • Non-linear Passives
  • Applications
  • Integrated Passives
  • Oscillators
  • Passive Sensors
  • New Technologies
  • Aerospace & Defence
  • Automotive
  • Industrial
  • Market & Supply Chain
  • Medical
  • RF & Microwave
  • Telecommunication

Flammability UL94 and What It Means

22.11.2019

Toray to Boost Polypropylene Film Production to Meet Rising Automotive Capacitor Demand

8.6.2023

Yageo Expects Passive Components Inventory Correction for at Least Two Next Quarters

8.6.2023

May 2023 ECIA NA Electronic Components Sales Sentiment below April Expectation

7.6.2023

Paumanok Issues Passive Components in Oil and Gas Electronics Market Outlook 2023-2028

5.6.2023

Researchers Study Aluminum Dissolution to Increase Supercapacitor Voltages, Suggest New Way of Al Thin Film Deposition

5.6.2023

Frenetic Offers Frenetic Zero One Month Free Magnetic Design Tool

5.6.2023
  • Home
  • Privacy Policy
  • EPCI Membership & Advertisement
  • About
No Result
View All Result
NEWSLETTER
Passive Components Blog
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • Market & Supply Chain
    • Medical
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors
    • Resistors
    • RF & Microwave
    • Telecommunication

    Toray to Boost Polypropylene Film Production to Meet Rising Automotive Capacitor Demand

    Yageo Expects Passive Components Inventory Correction for at Least Two Next Quarters

    May 2023 ECIA NA Electronic Components Sales Sentiment below April Expectation

    Paumanok Issues Passive Components in Oil and Gas Electronics Market Outlook 2023-2028

    Researchers Study Aluminum Dissolution to Increase Supercapacitor Voltages, Suggest New Way of Al Thin Film Deposition

    Frenetic Offers Frenetic Zero One Month Free Magnetic Design Tool

    Murata Releases 150C Automotive Crystals

    KAMIC Group Acquires Wound Components Specialist AGW Electronics

    4th PCNS Registration Opens !

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos
    • Sensors

    Exploring Frenetic and Maxwell Options for an Optimal Transformer Performance in LLC Circuit

    Fast 25kW SiC EV Charger Design; OnSemi and Würth Elektronik Webinar

    PFC Inductor Magnetic Design Considerations; Frenetic Webinar

    Introduction to Capacitor Technologies; WE Webinar

    Self-Adjusting and Economical Switched Capacitor Balancer for Serially Connected Storage-Cells

    How to Design EMC Efficient Power Converter; WE Webinar

    Selecting Capacitors for High Power Buck-Booster Converters

    How to use Off-the-Shelf Transformers in Switching Power Supplies

    Simple Capacitors Pre-Charger Based on Unique ‘Floating Integrator’

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Preferred Suppliers
    • Who is Who
  • Events
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • Market & Supply Chain
    • Medical
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors
    • Resistors
    • RF & Microwave
    • Telecommunication

    Toray to Boost Polypropylene Film Production to Meet Rising Automotive Capacitor Demand

    Yageo Expects Passive Components Inventory Correction for at Least Two Next Quarters

    May 2023 ECIA NA Electronic Components Sales Sentiment below April Expectation

    Paumanok Issues Passive Components in Oil and Gas Electronics Market Outlook 2023-2028

    Researchers Study Aluminum Dissolution to Increase Supercapacitor Voltages, Suggest New Way of Al Thin Film Deposition

    Frenetic Offers Frenetic Zero One Month Free Magnetic Design Tool

    Murata Releases 150C Automotive Crystals

    KAMIC Group Acquires Wound Components Specialist AGW Electronics

    4th PCNS Registration Opens !

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos
    • Sensors

    Exploring Frenetic and Maxwell Options for an Optimal Transformer Performance in LLC Circuit

    Fast 25kW SiC EV Charger Design; OnSemi and Würth Elektronik Webinar

    PFC Inductor Magnetic Design Considerations; Frenetic Webinar

    Introduction to Capacitor Technologies; WE Webinar

    Self-Adjusting and Economical Switched Capacitor Balancer for Serially Connected Storage-Cells

    How to Design EMC Efficient Power Converter; WE Webinar

    Selecting Capacitors for High Power Buck-Booster Converters

    How to use Off-the-Shelf Transformers in Switching Power Supplies

    Simple Capacitors Pre-Charger Based on Unique ‘Floating Integrator’

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Preferred Suppliers
    • Who is Who
  • Events
No Result
View All Result
Passive Components Blog
No Result
View All Result

Flammability UL94 and What It Means

22.11.2019
Reading Time: 7 mins read
A A
651
VIEWS

What is the UL94 flammability test that are referred by number of manufacturers using plastic materials such as moulding packages? Omnexus, the material selection platform for plastic material by SpecialChem provides an overview of the test in details.

Preliminary Screening of Plastics for Fire Performance

UL 94 (Underwriters Laboratories test standard UL 94) is one of the most widely used flammability tests for determining relative flammability for plastic materials. It measures the ability of plastic part to extinguish the flame after ignition and its dripping behavior in response to a small open flame or radiant heat source under controlled laboratory conditions.

The tests results are intended to serve as a preliminary indication of the material’s suitability with respect to flammability for a particular application, such as plastic materials used for parts in electronic devices and appliances.

The flammability is influenced by several factors such as:

RelatedPosts

Toray to Boost Polypropylene Film Production to Meet Rising Automotive Capacitor Demand

Yageo Expects Passive Components Inventory Correction for at Least Two Next Quarters

May 2023 ECIA NA Electronic Components Sales Sentiment below April Expectation

  • Ease of ignition – how rapidly a material ignites
  • Flame spread – how rapidly fire spreads across a polymer surface
  • Fire endurance – how rapidly fire penetrates a wall or barrier
  • Rate of heat release – how much heat is released and how quickly
  • Ease of extinction – how rapidly the flame chemistry leads to extinction
  • Smoke evolution
  • Toxic gas generation

Hence, the study of how plastics burn has been, and continues to be, a major area of research to examine:

  • The nature of the burning phenomenon in plastics
  • Various methods to reduce plastics flammability, and
  • Methods to test flammability

Main Types of Testing & Flammability Ratings to Classify Plastics

The UL standard classifies plastics according to the minimum thickness at which it stops burning when tested in a horizontal or vertical orientation.

Types of testing/flammability ratings covered in the UL 94 standard for flammability of plastic materials include:

  • Vertical burning tests (V-0, V-1, V-2, 5V, 5VA, 5VB, VTM-0, VTM-1, VTM-2)
  • Horizontal burning tests (HB, HBF, HF-1, HF-2)
UL Classifications Majorly Used for Plastics
(Source: W. L. Gore & Associates, Inc.)

The UL test methods are aligned with IEC 60707, IEC 60695-11-10, IEC 60695-11-20, ISO 9772 and ISO 9773 standards used to determine fire properties.

Vertical Burning Test for Classifying Materials

UL 94 V Rating: V-0, V-1, V-2

This test measures the self-extinguishing time of the vertically oriented polymer specimen. The top of the test specimen is clamped to a stand and the burner is placed directly below the specimen. The test evaluates both the burning and afterglow times and dripping of the burning test specimen.

The material will be rated:

  • V-0: if flame extinguishes within 10 seconds with no dripping
  • V1: if flame extinguishes within 30 seconds with no dripping
  • V2: if flame extinguishes within 10 seconds with dripping
Flammability rating UL 94 V
Test CriteriaV-0V-1V-2
Burning time of each individual test specimen (s)
(after first and second flame applications)
≤10≤30≤30
Total burning time (s)
(10 flame applications)
≤50≤250≤250
Burning and afterglow times after second flame application (s)≤30≤60≤60
Dripping of burning specimens
(ignition of cotton batting)
nonoyes
Combustion up to holding clamp
(specimens completely burned)
nonono

(Source : UL LLC)

UL 94 VTM Rating: VTM-0, VTM-1 and VTM-2 – Thin Material Vertical Burning Testing

This test method is used for thin specimen or materials that are too flexible or may distort, shrink or flex during the traditional vertical testing (failure to pass the UL 94 V test is a precondition of all VTM ratings). This test is similar to the vertical burning test except that the material is wrapped around a mandrel before clamping to the stand and the flame application is reduced. In this test, the flame is applied only for 3 seconds.

Flammability rating UL 94 VTM
Test CriteriaVTM-0VTM-1VTM-2
Burning time of each individual test specimen (s)
(after first and second flame applications)
≤10≤30≤30
Total burning time (s)
(10 flame applications)
≤50≤250≤250
Burning and afterglow times after second flame application (s)≤30≤60≤60
Dripping of burning specimens
(ignition of cotton batting)
nonoyes
Combustion up to holding clamp
(specimens completely burned)
nonono

(Source : UL LLC)

UL 94 5V Rating: 5V, 5VA, 5VB – Vertical Testing is done on both bar and plaque specimens

For any material to achieve 5V classification, the test specimens must not burn with flaming and/or glowing combustion for more than 60 sec after the fifth flame. Also, the test specimens must not drip.

Flammability rating UL 94
Test Criteria5VA5VB
Burning and afterglow times of specimens after fifth flame application (s)≤60≤60
Dripping of burning specimens nono
Hole formation noyes

(Source : UL LLC)

Horizontal Burning Test for Classifying Material

Specimens molded from the plastic material are oriented in either a horizontal depending on the specifications of the relevant test method, and they are subjected to a defined flame ignition source for a specified period of time.

UL 94 HB Rating

A material having a thickness between 3 and 13mm will be classified as a HB material if it does not have a burning rate exceeding 40mm per minute. For material with thickness less than 3mm the burning rate should not exceed 75mm per minute. The material will also be rated as HB if it ceases to burn before the 100mm mark independent of thickness.

Test criteriaBurning rate in VFlammability rating
Test specimen thickness 3-13mm≤40 mm/minHB
Test specimen thickness < 3≤75 mm/minHB
Flame is extinguished before first mark≡ 0 mm/minHB

(Source: UL LLC)

UL 94 HBF: HBF, HF-1 and HF-2 – Horizontal Burning Foamed Material

This test grants three different types of ratings depending on burning rates and or after flame times. A material will be classified as a HBF material if it does not have a burning rate exceeding 40mm per minute over a 100 mm span or if ceases to burn before flaming or glowing reach the 125mm mark.

Flammability rating UL 94 HBF
Test criteria (test specimens)HF-1HF-2
Burning time (s) 4/5 ≤ 2 1/5 ≤ 10 4/5 ≤ 2 1/5 ≤ 10
Burning and afterglow time of each individual specimen (s)≤ 30≤ 30
Dripping of burning specimen
(ignition of cotton batting)
noyes
Damaged length of individual specimen (mm)< 60< 60

(Source: UL LLC)

Source: Omnexus Specialchem

Related Posts

Capacitors

Borealis Launches Stelora™ High-Heat-Resistant Capacitor Polymer Film Dielectric

3.5.2023
114
Inductors

Magnetics Announced New XFlux Ultra Magnetic Powder Cores

3.5.2023
57
Capacitors

Researchers to Translate Nitrogen-Doped Graphene into High Energy Supercapacitor Prototypes  

31.10.2022
6

Upcoming Events

Jun 13
June 13 @ 12:00 - June 16 @ 14:00 EDT

Pre Cap Visual Inspection per Mil-Std-883 (TM 2017)

Jun 14
11:00 - 12:00 CEST

STRETCH.flex 2.0 Stretchable PCB Technology to the Limits

Jun 20
June 20 @ 12:00 - June 22 @ 14:00 EDT

Copper and Gold Wire Bonding

View Calendar

Popular Posts

  • Capacitor Selection for Coupling and Decoupling Applications

    28 shares
    Share 28 Tweet 0
  • What is a Dielectric Constant of Plastic Materials ?

    4 shares
    Share 4 Tweet 0
  • Ripple Current and its Effects on the Performance of Capacitors

    3 shares
    Share 3 Tweet 0
  • Leakage Current Characteristics of Capacitors

    0 shares
    Share 0 Tweet 0
  • Dielectric Constant and its Effects on the Properties of a Capacitor

    7 shares
    Share 7 Tweet 0
  • Understanding High-Precision Resistor Temperature Coefficient of Resistance

    0 shares
    Share 0 Tweet 0
  • Why Low ESR Matters in Capacitor Design

    0 shares
    Share 0 Tweet 0
  • Filter Q Factor Explained

    0 shares
    Share 0 Tweet 0

Newsletter Subscription

 

PCNS Call for Papers !

Archive

2022
2021
2020
2019
2018
2017

Symposium

Passive Components Networking Symposium

Passives e-Learning

Knowledge Blog

  • Home
  • Privacy Policy
  • EPCI Membership & Advertisement
  • About

© EPCI - Premium Passive Components Educational and Information Site

No Result
View All Result
  • Home
  • News
  • Video
  • Knowledge Blog
  • Preferred Suppliers
  • Events

© EPCI - Premium Passive Components Educational and Information Site

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.