Flame Retardant Finishing

Fabric Flame Retardancy is testing equipment which is sale by Testing Equipment Systems Limited. Flame resistant fabrics have different degrees of ability to stop flame spread. After leaving the flame source, burning of the fabrics can be quickly stopped. Most of the textiles are flammable. The fire caused by textiles also occurs from time to time. Usually, different textile materials have different chemical structures, their combustion performances are also various. Therefore, we should select different types of flame retardants and flame retardant methods for different types of fibre.

Flame Retardant Finishing Agent

Flame retardant finishing agent exerts the effect of flame retardant mainly through the next several approaches:The flame retardant forms a barrier on the surface of the fabrics, preventing the contact between the oxygen and the surface of the comburent.The flame retardant causes the cellulose fiber fabric to dehydrate and restrains the pyrolysis reaction to some extent.The flame retardant can be used as a transfer of free radicals under the heating conditions to prevent the radical reaction from proceeding, so as to achieve the purpose of flame retardant.

Due to different types of textiles,flame retardant finishing agent can be divided into cotton flame retardant, wool flame retardants, silk flame retardant, synthetic fiber flame retardant, and blended fabric flame retardant,etc..According to the durability of flame retardant finishing agent，it can be divided into: temporary flame retardant finishing agents, it mainly refers to inorganic salts such as borax – boric acid (1: 1 or 7: 3), ammonium polyphosphate, phosphate, oxidized paraffin- antimony oxide and so on; Semi-durable flame retardant finishing agents such as halophosphorus compounds, urea-phosphoric acid (1: 1) and so on; Durable flame retardant finishing agents, such as THPC, the fabric can withstand more than 50 times of washing after it is treated with durable flame retardants, moreover, the fabric still retains well. According to the composition of different elements of flame retardant finishing agent, it can be divided into: phosphorus-based flame retardant, phosphorus is its main compound and it also includes halogen and nitrogen. (The synergistic effect of phosphorus and halogen is stronger than that of the flame retardant including only one element. Compared with the use of phosphorus alone, the synergistic effect of nitrogen and phosphorus synergies is stronger. Nitrogen can promote the carbonization of the fiber and prevent combustion). Ammonium polyphosphate, phosphates, tetrakis (hydroxymethyl) phosphonium chloride are the common phosphorus-based flame retardants; Halogen-based flame retardant mainly includes bromine. It has the advantages of high efficiency, low dosage, low price, etc. The common halogen-based flame retardant includes hexabromocyclododecane, aromatic bromine compounds, chlorinated paraffin and so on; Boron-based flame retardants mainly include inorganic boric acid and borate, such as sand and boric acid: mixed use by the proportion of 1: 1 or 7: 3. This kind of flame retardant is applied earlier than the others. It is easy to handle and its flame retardant effect is good, but not washable; Nitrogen-based flame retardants includes melamine, phosphate and so on; Blended flame retardants includes phosphorus based-nitrogen based flame retardants, phosphorus-boron based flame retardants and so on.

Flame Retardant Finishing Process

Flame retardant finishing process is a process of preparing flame retardant finishing liquid, which contains flame retardants and other additives, in a certain temperature, time and other process conditions, to make the flame retardant and fabric have chemical reaction or the flame retardant deposition fix on the fabric surface to obtain the effect of flame retardant. If flame retardant and the fabric finished is different, the flame retardant finishing process will be different. It mainly includes padding-baking method, impregnating-drying method, organic solvent method, coating method, etc.. Padding-baking method is the most widely used method in flame retardant finishing process. The flame retardant effect obtained in padding-baking method can resist to washing for several times, which is a durable finishing process. Take cotton fabric flame retardant finishing as an example:

Process: pad flame retardant finishing liquid (two times of dipping and two times of rolling, the picking-up rate is 70% -80%) → drying (80-100 ℃) → baking (160 ℃, 3 min) → washing → drying.

Padding finishing liquid is generally composed of flame retardants, catalysts, additives, penetrant and some other ingredients. Confect it to aqueous solution or emulsion to finish. The picking-up rate can be adjusted according to the demand of flame retardant performance. Drying is usually carried out at about 100 ° C. The baking temperature is determined by different types of flame retardants, catalyst and fiber.

Test the Flame Retardant Finishing Effect

(1) Vertical method

  1. Testing instruments and materials vertical flammability tester, stopwatch, fabrics, dividing ruler. Front Door
  2. Sample Holder Support
  3. Sample Holder
  4. Sample Holder Fixture Flame Height Measure Device
  5. EDM Device Igniter 8. Vent Doors
  6. Heat and Corrosion Resistant Material Board
  7. Safety Switch Roof Panel 12. Control Panel

(2) Testing principle

The vertical method is carried out on a vertical burning tester. Use the samples of certain size which have had the flame retardant finishing to do the combustion test. To measure its combustion performance according to the burning time, smoldering time and damage length.

(3) Testing method

  • Sample preparation: take the samples of latitude direction and longitude direction respectively 5 pieces which have had he flame retardant finishing, the size is 300 mm × 80 mm.
  • Place the sample in a sample holder of a vertical burning tester and fix it vertically.
  • Connect the air supply, press the ignition button, and then the ignition is on, adjust the flame, so that it is in a stable height of 40 mm ± 2 mm.
  • The igniter turns off automatically after 12 seconds of ignition and resets.
  • Test the continued burning time, the smoldering time of the sample (accurate to 0.1s)
  • Remove the sample holder, remove the sample and fold it in two along the length direction, hang on the required heavy hammer on one lower end side of the sample, slowly lift another lower end side of the sample to measure the damage length, that is charcoal length (accurate to 1mm)
Testing Equipment Systems Limited
Add Daojiao, Dongguan city, P. R. China
Tel +86 769 2329 4842
Mob +86 158 7646 8074
Email marketing3@tes.hk
Web : www.TestexTextile.com