Can it bear "a huge weight"? Sisal wire rope core: the "behind-the-scenes hero" of elevator safety

1. What is sisal?

Sisal is a perennial tropical hard-leaf fiber crop, mainly distributed in Guangdong, Guangxi, Hainan and other southern China regions. As a member of the hemp crop family, its leaves are long and hard, like green swords, hence the name "sisal". Sisal fiber is very tough, like the "Iron Man" of nature, and can withstand great tension. Because of its wear resistance, salt and alkali resistance, and corrosion resistance, it is widely used in various industries such as transportation, fishery, petroleum, and metallurgy. In particular, in elevator wire ropes, sisal fiber plays an important role as a high-quality core raw material.

Harvesting Sisal Leaves

Sisal in flowering

Planting sisal in severe rocky desertification areas to stabilize soil and conserve water

2. What is sisal wire rope core?

Sisal wire rope core is an important part inside the elevator wire rope. It is made of sisal fiber or Manila hemp fiber. It is a material clearly specified in the national standards "GB/T 8903-2018 Elevator Wire Rope" and "GB/T 15030-2021 Sisal Wire Rope Core". It is like the "spine" of the wire rope, playing a supporting and lubricating role to help the wire rope work better. The elevator wire rope is like the "hanging rope" of the elevator, and the sisal wire rope core is the "core" of the hanging rope. The core made of sisal fiber is like a "super assistant" to help the wire rope work better.

Several kinds of steel wire rope cores for elevators

Make the wire rope more durable: Sisal fiber is very strong, just like putting "armor" on the wire rope, making it less likely to be damaged in repeated pulling and longer service life. The fatigue resistance of the traditional sisal rope wire rope can reach 1.3 million times, and the new composite sisal rope core can even reach 3.84 million times.

Sisal wire rope core

Make elevators safer: The sisal rope core can store and transfer lubricating oil, just like a "small oil depot", allowing the lubricating oil to be evenly distributed between the steel wires, reducing friction, preventing steel wire breakage, and ensuring the smooth operation of the elevator.

3. The current situation and development of sisal rope core in China

my country's annual demand for elevator steel wire ropes is about 300,000 tons, of which the demand for sisal rope cores is about 20,000 tons. However, my country has not yet been able to independently produce high-grade sisal fiber raw materials (such as UG grade and 3L grade), and the raw materials mainly rely on imports, which limits the development of the elevator steel wire rope industry. In the future, new composite rope cores will be developed, such as PET filament/sisal island phase structure composite rope cores, combining the advantages of sisal fiber and synthetic fiber to improve performance. Breakthroughs in high-quality sisal fiber production technology, optimize planting and processing processes, and gradually achieve independent supply of high-grade sisal fiber. Although the sisal steel wire rope core is small, it plays an important role in elevator safety. The next time you take an elevator, think about this little "behind-the-scenes hero", it is silently guarding our safety!

Author: Zhao Haohan