Plastic Oxygen Index Determination

Determination of Oxygen Index for PlasticsThis instrument not only serves as a means to identify the flame retardancy of polymers but also acts as a research tool, providing a powerful testing method for laboratory studies on flame retardant formulations and the development of new flame retardant materials.
Suitable for flammability testing of solid materials, laminated materials, foam plastics, fabrics, soft sheets, films, and other materials.
Scope of Application
Applicable for determining the combustion performance of plastics, rubber, fibers, foam plastics, soft sheets, films, textiles, and other materials.
Related Technical Parameters
Equipped with imported oxygen sensors, digitally displays oxygen concentration without calculation, offering higher precision and accuracy, range 0–100%.
Digital resolution: ±0.1%
Overall measurement accuracy: Class 0.4
Flow regulation range: 0-10L/min (60-600L/h)
Response time: <5S
Quartz glass cylinder: Inner diameter ≥75 mm, height 480mm
Gas flow velocity in combustion cylinder: 40mm±2mm/s
Pressure gauge accuracy Class 2.5, resolution: 0.01MPa
Flow meter: 1-15L/min (60-900L/H) adjustable, accuracy Class 2.5
Test environment: Ambient temperature: room temperature to 40℃; relative humidity: ≤70%;
Input pressure: 0.2-0.3MPa
Working pressure: Nitrogen 0.05-0.15Mpa, Oxygen 0.05-0.15Mpa. Oxygen/nitrogen mixed gas inlet: includes pressure stabilizing valve, flow regulating valve, gas filter, and mixing chamber.
Sample holder applicable for soft and hard plastics, textiles, fire doors, etc.
Propane (butane) ignition system, flame length adjustable from 5mm to 60mm
Gases: Industrial nitrogen and oxygen, purity >99%; (Note: Gas sources and connectors must be provided by the user). Tips: For oxygen index testing, one bottle each of industrial-grade oxygen and nitrogen with purity not less than 98% is required as the gas source. Due to these gases being high-risk transport items, they cannot be provided as accessories for the oxygen index tester and must be purchased from local gas stations. (To ensure gas purity, purchase from reputable local gas stations.)
Power requirements: AC220 (+10%) V, 50HZ
Maximum power consumption: 50W
Igniter: Made of a metal tube with a nozzle of inner diameter Φ2±1mm at the end, capable of inserting into the combustion cylinder to ignite the sample, flame length: 16±4mm, adjustable.
Self-supporting material sample holder: Can be fixed at the axis of the combustion cylinder and vertically clamp the sample.
Non-self-supporting material sample holder: Can simultaneously fix both vertical edges of the sample onto the frame (optional, suitable for textiles, films, etc.)
Overall dimensions: 650mm×400mm×830mm
Chassis structure
Control box: Processed by CNC machine, electrostatic spray-coated steel box, control and test sections are separately controlled.
Combustion cylinder: High-temperature resistant high-quality quartz glass tube (inner diameter ￠75mm, length 480mm), outlet inner diameter: φ40mm
Sample fixture: Self-supporting fixture, capable of vertically clamping the sample; (optional non-self-supporting sample holder available), two sets of sample holders meet different test requirements; sample holders are plug-in type, making sample placement easier.
Long rod igniter end tube hole diameter ￠2±1mm, igniter flame length (5-50)mm arbitrarily adjustable.
Applicable standards
Design standard: GB/T 2406.2-2009
Compliant standards: ASTM D 2863, ISO 4589-2, NES 714, GB/T 5454, GB/T 10707-2008,
GB/T 8924-2005, GB/T 16581-1996, NB/SH/T 0815-2010, TB/T 2919-1998, IEC
61144-1992, ISO 15705-2002, ISO 4589-2-1996

Determination of Oxygen Index for PlasticsStandard Operating Procedures and Precautions for Pre-oxidized Fiber Oxygen Index Tester, Integrating Laboratory Safety Norms and Textile Material Testing Essentials:

I. Preliminary Preparation

‌Environmental Requirements‌

Fume hood or independent laboratory (waste gas emission must meet standards)

Temperature and humidity control: 10-30℃/30%-80% RH (cotton textiles require 20℃/65% RH equilibrium for 24 hours to eliminate static electricity)

Gas source preparation: Oxygen/nitrogen purity ≥98%, cylinder pressure stabilized at 0.25-0.4MPa

‌Equipment Calibration‌

After startup, flush the gas pipeline first to discharge residual air

Use standard gas to calibrate the oxygen sensor (zero calibration with nitrogen, range calibration with standard mixed gas)

Check airtightness: After closing valves for 30 minutes, the pressure gauge reading should show no change

II. Test Operation Steps

‌Sample Treatment‌

Cutting dimensions: 150mm×58mm (sample taken 1/10 width from the cloth edge)

Conditioning treatment: Balance for 8-24 hours according to GB 6529 standard

‌Initial Oxygen Concentration Setting‌

For unknown samples: Select 18% for rapid combustion in air, 21% for slow combustion, ≥25% for non-combustible

Refer to Appendix B for corresponding oxygen/nitrogen flow ratio (total flow 10-11.4L/min)

‌Ignition Test‌

Vertically clamp the sample in the center of the combustion cylinder

Adjust flame length to 16±1mm, ignite the top end and immediately remove the ignition source

Observe after-flame time and damage length; 40%-60% of samples must exceed standard limits

III. Conclusion Process

‌Data Recording‌

Record the minimum oxygen concentration that sustains combustion (accurate to 0.1%)

‌Equipment Maintenance‌

Close gas cylinder → exhaust gas lines → return valves to initial positions

Quarterly calibration of sensors (annual drift must be <3%)

IV. Key Precautions

‌Safety Warnings‌

Must use explosion-proof pressure reducing valves; direct connection to high-pressure gas sources is prohibited

ABS and other plastic samples require 48 hours to relieve stress

‌Precision Control‌

Recommended digital mass flow meter (error ±0.4%)

For high-frequency testing, consider models with hot-swappable oxygen sensors

Pre-oxidized Fiber Oxygen Index Tester

61144-1992, ISO 15705-2002, ISO 4589-2-1996

Adjust the gas control device to regulate gas mixing and flow control, so that the oxygen concentration in the mixed gas is the determined oxygen concentration, flowing through the combustion cylinder at 10±10mm/s, and wash the combustion cylinder for at least 30 seconds.

Gas sources use oxygen as specified in GB 3863 and nitrogen as specified in GB 3864, along with the required oxygen and nitrogen cylinders and regulating devices. The pressure of gas used should not be less than 1 MPa.

Non-self-supporting material sample holder: Can simultaneously fix both vertical edges of the sample onto the frame (optional, suitable for textiles, films, etc.)

Identification characteristics of the material, name and grade, batch number, manufacturer, production date, etc., sample preparation method, type, dimensions, conditioning status, sample ignition method, type of ignition gas, oxygen index OI and step size d, combustion characteristics,

Control box: Processed by CNC machine, electrostatic spray-coated steel box, control and test sections are separately controlled.

Determination of "○" and "×" reactions: After igniting the sample, start timing immediately, observe the burning length and behavior of the sample. If combustion stops but spontaneously reignites within 1 second, continue observation and timing.

Igniter glass combustion cylinder. Burning sample; sample holder; combustion cylinder support; metal mesh; temperature measurement device; base stand with glass beads; gas premixing node; shut-off valve; connector; pressure gauge; precision pressure controller; filter; needle valve; gas flow meter; glass combustion cylinder; flow limiting cover

Fuluo County Composite Materials Co., Ltd. Beijing Bowen Shixun Technology Co., Ltd.

Applicable for determining the combustion performance of plastics, rubber, fibers, foam plastics, soft sheets, films, textiles, and other materials.

Change the oxygen concentration by repeating the operation with the initial oxygen concentration ψa, record the corresponding "×" reaction or "O" reaction at ψ. This becomes the first value of the N series.