Synthetic rope made with Dyneema fibre made its debut in the crane industry back in 2014, in the construction crane sector: US-based manufacturer Manitowoc launched the Grove RT770E at industry trade show ConExpo, fitted with KZ100, a synthetic rope developed with manufacturer Samson.
The headline benefits did not necessarily seem transferrable to
overhead crane and hoist applications: the weight savings, of around 80% compared to wire rope, would not translate into a huge weight reduction with the relatively short fall of typical factory cranes, and the torque-neutral construction that eliminates load spin again related to an issue more often caused by long rope falls.
However, a raft of other benefits mentioned suggested that synthetic rope could become a good fit for hoists: easier handling, corrosion resistance, and the ability to operate without lubricants.
DSM Protective Materials, inventor and manufacturer of HMPE fibre branded as Dyneema has been working with Wuxi, China-based Vulcan Cranes since 2016 to integrate Dyneema fibre into hoisting lines for overhead cranes, for use in clean industries. “These include the production of pharmaceuticals, semi-conductors, food, chemicals, and the aerospace, defence and solar power industries,” says Dietrich Wienke, business develop manager at DSM Protective Materials. “Oil used to lubricate conventional wire ropes can contaminate clean operations; some cranes incorporate shields to catch oil drips, which make the cranes more expensive and complex. Synthetic ropes do not need lubricating.”
Yong-Le Liu, regional technical manager at DSM Protective Materials, says: “Compared to steel wire hoist rope, rope made with Dyneema DM20 is rustfree.
It is self-lubricated by having a low co-efficient of friction (CoF) at 0.05–0.07, compared to the CoF for steel of 0.74, or 0.16 if lubricated with oil. That synthetic hoist line avoids damage costs and production losses from contamination by steel particles and oil pollutions.”
Cleanroom applications and clean industries are only one application that can benefit from the use of synthetic running ropes in place of steel wire ropes, adds Wienke: “The ropes are chemically stable, so better resist the effects of corrosive atmospheres such as coastal climates and in waste processing facilities, where there is a high ammonia content.
“In some of these applications, wire ropes in hoists have to be replaced every six months, which is costly and necessitates downtime. We had enquiries from biomass plants who want to have to undertake less maintenance.”
DSM is now making the move into various specialised applications in the hoist industry