The 16 CFR 1610 is a burn test that checks the flammability of clothing textiles. This test specimen of 2 × 6 inches is mounted at 45 degrees. A flame of 16 mm is applied to the lower end of the specimen for 1 sec. Then, we monitor the fabrics’ burning behavior. In this article, we will explore this flammability test method further.
16 CFR 1610 Fabric Flammability Testing
16 CFR part 1610 is often called a 45 degree flammability test. The flame test chamber consists of a stainless steel apparatus with a glass closure to check the test.
Inside the chamber, the specimen holder is placed on a 45-degree platform. The apparatus has gauges for controlling flame height, a release button to activate flame impingement, and a timing device.
Flammability Tester Types
To perform 16 CFR 1610 tests, 3 types of testing equipment are used in the textile lab.
- Vertical Flammability Tester
- Horizontal Flammability Tester
- 45-Degree Flammability Tester
Typically, a 45-degree Flammability tester is used. Other testers also use the same methodology. It depends upon the customer’s requirements.
45-Degree Flammability Tester
Here, we take Fabric Flame Retardant Tester YG (B) 815D-IV by Darong Company China to perform the 16 CFR 1610 flammability standard.
Equipment and Accessories
Here is the list of test equipment and accessories required for flame retardant tests.
- Automatic washing machine and dryer
- Ballast for dry cleaning
- Brushing device and stop thread number 50
- Circulating oven, Thermometer, Butane
- Desiccator
- Gloves, Scale, Timer, Regulator, scissors, marking pens, and tape
- Specimen holders, clip, and holding rack
- Specimen template, 50 by 150 mm (2 × 6 Inch)
Calibration & Safety Measures
Before starting fabric tests, check the machine’s performance by calibrating it. Maintain safety measures in the lab.
45-Degree Flammability Tester CalibrationsTrained lab technicians with safety protocols can perform tests effectively. Insulated gloves are mandatory when taking samples from the flammability chamber.
Sample Preparation
Equipment List:
- Brushing Device
- Specimen Holder, clips, and holding rack
- Specimen preparation accessories, scissors, pen, and tape
- Specimen template 2 × 6 inches (50 × 150 mm)
Before any flammability testing is performed, preliminary tests are done to determine which fabric direction, length, or width burns fastest.
The sample for testing is taken as 2 × 6 inches with a long specimen direction.
Sample Preparation for Flammability TestFor Plain Surface Fabrics
Plain surface fabric samples are cut out 2 × 6 inches (50 × 150 mm) from directions, warp, and weft. Then, through preliminary testing, you can determine which direction burns the fastest.
Plain fabric samples do not need brushing.
For Raised Surface Fabrics
For raised surface fabrics such as corduroy, Chenille, fleece, and Velvet, we have to find the fastest direction of burning and the fabric side that burns the most rapidly, either the front or the back.
The raised surface fabrics must be brushed before the flammability test using the brushing device.
Brushing Device
It is used in cloth testing laboratories. This device consists of a base platform over which a hinge brush is attached to a carriage that allows the brush to be pulled on the surface of the specimen mounted in a test holder.
We will use the faster-burning side of the raised fabric as the uppermost side.
The specimens are brushed from the open end of the specimen holder to the closed end of the holder to raise the surface fibers to their highest level.
Specimen Mounting
The specimen holder consists of a tip and bottom U-shaped metal frame. The top piece has hooks or thread guides for positioning the stop thread.
Specimen Mounting in Flammability Tester HolderThe upper and lower portions of the specimen are secured between the two pieces of metal frame with clips.
Specimen Drying & Conditioning
The specimens are mounted in testing holders and then exposed in a circulating air laboratory oven at 105 + 3 oC for 30 minutes.
Then, samples are placed in a desiccator, which allows the specimen to cool but does not change its moisture content.
16 CFR 1610 Test Procedure
Equipment List:
- Butane
- Stop Thread # 50
- Test Chamber
- Regulator
- Timer
After conditioning the specimen in a desiccator, it is immediately placed on the inclined platform inside the test cabin.
The cotton thread is pulled through the guides on the upper front to secure the thread across the specimen on the upper end of the specimen holder.
Specimen Placed on Inclined Platform inside Flammability TesterA weight is attached to the thread. The chamber door should be closed before starting the test. Press the start button to begin the test.
Closing Flame Chamber Door before Beginning the TestIf the flame starts to burn and continues to the top of the specimen, then the thread will break.
It will drop the weight, which stops the timer and ends the test. Each specimen burn time is recorded in the same way.
Stop Thread Breaks, ends the Flammability Test
Time is recorded after each specimen test.
Flammability Test TimeRefurbishment for 16 CFR 1610
Title 16 CFR part 1610 describes the fabric flammability method. This test requires that fabric be tested as it is and after refurbishing.
Refurbishment means fabric must be treated with one home laundering and dry cleaning before flammability testing.
Fabrics Burning Behaviors in Flammability Test
The preliminary classification is based on the average burn time of the five specimens’ fabric flammability chart. Sometimes, specimens exhibit a surface flash that may or may not burn through the thread.
Base Burn
Some fabrics may or may not burn through their structure. But when fabrics burn through their structure, it is called the base burn.
Burning Behavior Criteria
The criteria for the classification of burning behaviors are:
- Average Burn Time
- Observations of burning characteristics
- Surface Flash
- Base Burn
These parameters determine whether the fabric falls under class 1, 2, or 3.
Here are the flammability testing standards for flame resistance to check physical testing of fabric.
Class 1 – Normal Flammability
Plain surface fabrics with an average burn time above or equal to 3.5 seconds are classified as a Class 1 Normal flammability category.
Fabrics with raised surfaces are also called normal flammability if they have a burn time greater than 7 seconds with no base burn and may exhibit rapid surface flash.
Class 2 – Intermediate Flammability
This does not apply to plain fabrics. Raised fabrics have an average burn time of 4 to 7 seconds with a base burn.
Class 3 – Rapid & Intense Flammability
Plain fabrics have an average burn time of less than 3.5 seconds. Raised fabrics have less than 4 seconds of burn time with a base burn.
Fabrics Burning Behavior Codes
Codes For Plain Surface Fabrics
Three burning behavior codes and the burn time of each specimen are reported for plain surface fabrics.
DNI = did not Ignite
IBE = Ignited but Extinguished
IPE = Ignited at point of Impingement but extinguished
The actual burn time, the time it takes to burn the thread, is measured and recorded by the timing device to the 10th of a second.
Codes for Raised Surface Fabrics
Burning behavior possibilities for raised surface fabrics are more complicated. Some examples of burning behavior codes for pile, napped, fleece, and other raised surface fabrics that must be reported with a time of a burning hour.
SFBB poi = surface flash with base burn starting at the point of Impingement
SF uc = Surface Flash under the stop thread
SF poi = surface flash at the point of Impingement only
Several other burning behavior codes describe surface flash behavior and locations over the fabric burned or not burned.
The burning behavior of 5 specimens must be noted to prepare a fabric lab test report for the flammability test.
Average Burn Time of the 5 Specimens TestedIn the US, it is legal to sell class 3 clothing, although it is not illegal to sell clothing classified as class 2. Textile companies usually do not want to assume the risk of possible injuries, so only class 1 items are sold.
Similar standards on 16 CFR 1610 Flammability Test in Textile
These tests are also used to test the flammability of textile fabrics.
- ASTM D6413
- NFPA 701
Conclusion
The 16 CFR 1610 test is also known as the 45-degree flammability test. It determines the clothing flammability and burning behavior of plain and raised-surface fabrics.
This test helps to determine the flammability class of clothing fabric and ensures the user’s safety from serious injury.
FAQs
What is the 16 CFR 1610 flammability standard?
16 CFR 1610 test is done to check the flammability of textile fabrics. Specimen of 2 × 6 inches is mounted at 45 degrees. A flame of 16 mm is applied on the lower end of the specimen for 1 sec. Then, results are conducted based on flammability behavior and time of combustion.
What is the function of the stop thread in the flammability test?
Stop thread number 50 is attached to the weight. When the thread is burned, the weight drops to stop the timing mechanism of the test apparatus.
What is the Normal Flammability Standard?
Plain surface fabrics with an average burn time greater than or equal to 3.5 seconds are classified as a Class 1 Normal flammability category.
Why Flammability Test in Textile is Important?
Some textile fabrics are inherently flammable, so using such fibers in clothing is a serious concern for customers’ safety.
To avoid these concerns, the U.S. Consumer Product Safety Commission (CPSC) established 16 CFR part 1610 as a Standard for the Flammability of Clothing Textiles.
Which type of fabric has a 16 CFR 1610 flammability exemption?
Hats, gloves, footwear, and interlining fabrics are exempt from 16 CFR 1610 requirements.