In industries like electronics, aerospace, and automotive, fire safety is a top priority. As additive manufacturing (AM) commonly known as 3D printing—continues to revolutionize production, selecting the right flame-retardant thermoplastics is essential for ensuring safety, compliance, and reliability.
What is UL 94?
UL 94 is a flammability standard for plastics established by Underwriters Laboratories (UL) in the USA. It evaluates and classifies plastics based on their burning behavior in different orientations and thicknesses. The standard includes six classifications, ranging from the least to the most flame-retardant materials, helping manufacturers select appropriate materials for fire safety compliance.
| UL 94 Rating | Definition of Rating |
| HB | Slow burning on a horizontal part. |
| V-2 | Burning stops within 30 seconds on a vertical part, with flaming drips |
| V-1 | Burning stops within 30 seconds on a vertical part, without flaming drips |
| V-0 | Burning stops within 10 seconds on a vertical part, without flaming drips. |
| 5VB | Burning stops within 60 seconds on a vertical part, without flaming drips. Burn-through (holes) may be present. |
| 5VA | Burning stops within 60 seconds on a vertical part, without flaming drips. No burn-through (no holes). |
The following table compares the attributes of UL 94 V-0 and HB ratings:
When discussing UL 94 flame classifications, the HB and V-0 ratings are frequently used. The main difference between these two ratings is the test orientation (horizontal versus vertical) and the level of flame resistance required. The HB classification measures the burn rate to meet specific standards, but it does not ensure that the material will self-extinguish once the flame is removed..
| Criteria | UL 94 HB attributes | UL 94 V-0 attributes |
| Flame retardant process | No advanced additives: – Longer to put out fires – May drip or spread flames | High-efficiency additives: – Quickly puts out flames – Prevents fire spread |
| Effect on physical properties | More noticeable changes: – Can weaken material due to heat exposure | Minor changes: – Might slightly change strength or flexibility |
| Compliance with safety norms | Meets a basic level of flame resistance, may fall short for stringent fire safety demands. | Complies with the most demanding fire safety norms, suitable for high-risk environments. |
Industrial Applications of Flame Retardant Materials
Automotive Industry
Flame-retardant materials play a crucial role in the automotive industry by ensuring compliance with fire safety regulations. These materials, such as flame-retardant ABS plastics, are commonly used in interior components like dashboards, upholstery, and wiring harnesses. By reducing the risk of fire during collisions or electrical malfunctions, they enhance vehicle safety and durability.
Electronics Industry
Flame-retardant materials are critical in electronics to protect sensitive components and ensure products comply with fire safety standards. These materials are widely used in circuit boards, connectors, and housing materials to minimize fire-related failures and electrical malfunctions, enhancing both safety and longevity.
Consumer Products
Flame-retardant materials are also found in everyday consumer goods such as furniture, appliances, and electronics. For instance, flame-retardant materials in upholstered furniture and bedding help prevent ignition and slow down fire spread, providing an extra layer of safety in homes and workplaces.
Collaborate with 3D printing bureau to choose the best material and optimize build orientation for your project’s needs. Explore our 3D Printing Materials Guide to learn about various plastic and metal materials across technologies.
Discover more about additive manufacturing at projet.my. For assistance, reach out to our applications engineer at [email protected] or +604-2858 335.
