Skip to main content
UploadLanguage (EN)Support
BusinessMobileSocial MediaMarketingTechnologyArt & PhotosCareerDesignEducationPresentations & Public SpeakingGovernment & NonprofitHealthcareInternetLawLeadership & ManagementAutomotiveEngineeringSoftwareRecruiting & HRRetailSalesServicesScienceSmall Business & EntrepreneurshipFoodEnvironmentEconomy & FinanceData & AnalyticsInvestor RelationsSportsSpiritualNews & PoliticsTravelSelf ImprovementReal EstateEntertainment & HumorHealth & MedicineDevices & HardwareLifestyle
AB
Uploaded byankit bhatt
PPTX, PDF2,662 views

flame retardents by ankit

This document discusses flame retardants in textiles. It begins by outlining the needs for flame retardants, such as protecting consumers and workers from fires. It then discusses the different types of flame retardant fabrics and provides a brief history of flame retardant usage. The document focuses on the mechanisms of flame retardancy, including disrupting the combustion cycle through heat sinks, insulating layers, and producing less flammable gases. It also covers testing methods and factors that affect flame resistance. Specific applications for protective firefighter clothing are discussed at the end.

Engineering◦
Downloaded 177 times
1 STUDENT NAME -ANKIT KUMAR BHATT
INTRODUCTION 2  Flame-retardant finishes provide textiles with an important performance characteristic that is it stopped the propagation of fiber when it comes in contact with fire.  NEEDS OF FLAME RETARDANTS  Protection of consumers from unsafe apparel  Firefighters and emergency personnel require protection  Floor coverings, upholstery and drapery protection  The military  the airline industry
Types of F.R. Fabric In Industry 3 Fabric which has to be padded with F.R. chemical Fabric which is made flame retardant at the time of manufacturing of yarn
HISTORY 4 About 450 BC EGYPTIANS used ALUM to reduce flammability of wood In 1638 clay & gypsum used for theater curtains. 1821 GAY-LUSSAC mixture of borax & ammonium salt of phosphoric acid for linen 1913 Perkin gives FR treatment for cotton by using so. Stannite & ammo. Sulphate.
Mechanisms of flame retardancy 5  Combustion: is an exothermic process that requires three components, Heat oxygen suitable fuel.
Mechanisms of flame retardancy  Pyrolysis temperature, TP,  At this temperature, the fiber undergoes irreversible chemical changes, producing  non-flammable gases (carbon dioxide, water vapor and the higher oxides of nitrogen and sulfur),  carbonaceous char,  tars (liquid condensates) and  flammable gases (carbon monoxide, hydrogen and many ox disable organic molecules). 6
Mechanisms of flame retardancy  the combustion temperature, TC,  At this point, the flammable gases combine with 7 oxygen in the process called combustion,  which is a series of gas phase free radical reactions.  These reactions are highly exothermic  and produce large amounts of heat and light.
Some combustion Cycle Disruption Techniques 8 1. Heat Sink on / in the fiber 2. Insulating Layer 3. Condensed Phase: reaction to produce less flammable volatiles and more residual char.
Combustion Cycle Disruption Techniques 9 1. Heat Sink on / in the fiber by use of materials that thermally decompose through strongly endothermic reactions.  If enough heat can be absorbed by these reactions, the pyrolysis temperature of the fiber is not reached and no combustion takes place. Examples of this method are the use of aluminum hydroxide or ‘alumina rehydrate’ and calcium carbonate as fillers in polymers and coatings
Combustion Cycle Disruption Techniques 10 2. Insulating Layer  to apply a material that forms an insulating layer around the fiber at temperatures below the fiber pyrolysis temperature. Boric acid and its hydrated salts function in this capacity. When heated, these low melting compounds  release water vapor  and produce a foamed glassy surface on the fiber, insulating the fiber from the applied heat and oxygen.
Combustion Cycle Disruption Techniques 11  Condensed Phase: reaction to produce less flammable volatiles and more residual char. This ‘condensed phase' mechanism can be seen in the action of phosphorous-containing flame retardants which, after having produced phosphoric acid through thermal decomposition, crosslink with hydroxyl-containing polymers thereby altering the pyrolysis to yield less flammable by-product.
Combustion Cycle Disruption Techniques 12  The ‘condensed phase’ strategy includes the described mechanism of removal of heat and the enhancement of the decomposition temperature as in heat resistant fibers.
Testing of flame retardants The visual timing test- vertically The 45 degree test – 5 inch distance at such angle Hoop test- semi circular frame 13
LOI  LIMITED OXYGEN INDEX is give us some information about flame retardancy  It is the minimum % of oxygen in oxy- nitro atmosphere require to sustain combustion L.O.I. = (O2)/(O2+N2)* 100 HIGHER THE LOI MEANS MORE THE FLAME RETARDENT 14
Factor affecting the f. resistance Fiber content Fabric structure weight 15
Problems with flame retardant Toxicity Irritated towards skin Durability Flexibility 16
17
18
Protective clothing for fire fighter (APPLICATION) NATIONAL FIRE PROTECTION ASSOSIATION has set a fundamental requirement that it’s TPP value must be 35 minimum. According to NFPA each far. cloth ,, contain three component – Outer shell Moisture barrier Thermal barrier 19
Protective clothing for fire fighter  As an example LOS ANGELOUS fire department used-  outer shell –nomex/kevlar in a rip stop weave Thermal insulator Moisture barrier 20
21
22
23