FIRE-RESISTANT SYNTHETIC TENSION MEMBERS
A load-bearing assembly according to an example of the present disclosure includes at least one tension member. The tension member has a resin, reinforcement fibers, and at least one additive that provides a fire-resistance to the tension member. A jacket material covers the at least one tension member. An alternate load-bearing assembly and a method of making a load-bearing assembly are also disclosed.
This application claims priority to U.S. Provisional Application No. 62/487,673 filed on Apr. 20, 2017.
BACKGROUNDThere are various uses for elongated flexible assemblies such as for elevator load bearing members or roping arrangements, drive belts for machines such as a passenger conveyor and handrails for passenger conveyors, for example. Such elongated flexible assemblies may comprise one or more tension members encased in a jacket material. Such assemblies may be designed with fire resistance performance in order to meet existing building codes. Such assemblies must also meet mechanical performance requirements, such as tensile strength and stiffness requirements.
SUMMARYA load-bearing assembly according to an example of the present disclosure includes at least one tension member, the at least one tension member comprising a resin, reinforcement fibers, and at least one additive that provides a fire-resistance to the tension member. The load-bearing assembly also includes a jacket material covering the at least one tension member.
Another example load-bearing assembly according to an example of the present disclosure includes at least one tension member, the at least one tension member comprising a self-fire-resistant resin and reinforcement fibers, and a jacket material covering the at least one tension member.
An example method of making a load-bearing assembly includes providing reinforcement fibers to a die, providing a resin precursor to the die, curing the resin precursor and fibers to form at least one synthetic tension member comprising a resin having a fire-resistance, and covering the at least one synthetic tension member in a jacket material.
Various features and advantages of at least one disclosed example embodiment will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
The load bearing assembly 26 supports the weight of the elevator car 22 and the counterweight 24 and facilitates movement of the elevator car 22 into desired positions by moving along sheaves 28 and 30. One of the sheaves will be a traction sheave that is moved by an elevator machine in a known manner to cause the desired movement and placement of the elevator car 22. The other sheave in this example is an idler sheave.
An example rope used as part of the load bearing assembly 26 is schematically shown in
As shown in
The example of
In some embodiments, the tension members 32 comprise synthetic material, or more particularly, a fiber-reinforced polymer resin. Synthetic tension members 32 are lighter than metal-based tension members, which can be advantageous in some situations. Synthetic materials do not typically have an inherent fire-resistant quality or characteristic.
Tension member 132 includes fibers 136 that enhance the mechanical properties of the synthetic tension member 132. The fibers 136 are encased in the resin 134 in this example. Though the fibers 136 in
The resin 134 also includes one or more additives. In a particular example, the synthetic tension member 132 includes a first additive 138 that provides fire-resistant properties and a second additive 140 that provides smoke-suppressant/char-forming properties. Example fire-resistant first additives 138 include phosphorous-containing or nitrogen-containing compounds or polymers. Example smoke-suppressant and/or char-forming second additives 140 include metal-exchanged clays, zeolites, zinc molybdate, zinc borate complex, zinc molybdenate, magnesium silicate complex.
In the illustrated example, the synthetic tension member 132 includes an optional nanofiller 142. The optional nanofiller 142 allows for improved mechanical properties and customization of the synthetic tension member 132. Example nanofillers 142 include materials with one or more of the following functional groups: glycidyl, silane, hydroxyl, carboxyl, amine, isocyanate, ethylene, and amide. More particularly, example nanofillers include magnesium hydroxide and aluminum trihydrate. In some examples, the nanofiller 142 is chemically treated.
The injection box 150 provides the resin 134 and fibers 136 to a die 152. In one example, the die 152 is at a different temperature than the injection box 150. More particularly, the die 152 is cooled. The die 152 forms the resin 134 and fibers 136 into the shape of a tension member 132. The shaped tension member 132 travels through one or more zones 154, 156, and 158 which are at various temperatures selected to cure the resin 134.
An example self-fire-resistant resin 234 is a rigid thermoset carbon-epoxy composite. Example epoxy resin precursors include diglycidylmethylphosphonate, diglycidylphenylphosphonate, triglycidylphosphite, and triglycidylphosphate. Example curing agents include aliphatic polyether triamine (such as JD-FAMINE® T-403, available from Huntsman Corporation), bis(4-aminophenyl)phenylphosphine oxide, bis(3-aminophenyl)methylphosphine oxide and bis(4-aminophenyl)methylphosphonate.
The tension member 232 comprising the self-fire-resistant resin 234 is, in one example, formed by a system similar to the system 144 of
Though the fibers 136 in
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.
Claims
1. A load-bearing assembly, comprising:
- at least one tension member, the at least one tension member comprising a resin, reinforcement fibers, and at least one additive that provides a fire-resistance to the tension member; and
- a jacket material covering the at least one tension member.
2. The load-bearing assembly of claim 1, wherein the load-bearing assembly is configured to support the weight of an elevator car.
3. The load-bearing assembly of claim 1, wherein the load-bearing assembly is a handrail for a passenger conveyor.
4. The load-bearing assembly of claim 1, wherein the resin comprises at least one of epoxy, polyurethane, vinyl ester, ethylene propylene diene monomer (EPDM), and melamine.
5. The load-bearing assembly of claim 1, wherein the reinforcement fibers comprise at least one of liquid crystal polymer, carbon fiber, glass fiber, ultra high molecular weight polyethylene fiber, ultra high molecular weight polypropylene fiber, fiber, polybenzoxazole fiber, aramid fiber and nylon.
6. The load-bearing assembly of claim 1, wherein the at least one additive comprises a first additive that provides fire-resistant properties and a second additive that provides another property that is at least one of smoke-suppressant and char-forming properties.
7. The load-bearing assembly of claim 6, wherein the first additive comprises at least one of a phosphorous-containing compound or polymer and a nitrogen-containing compound or polymer and the second additive comprises at least one of metal-exchanged clays, zeolites, zinc molybdate, zinc borate complex, zinc molybdenate, magnesium silicate complex.
8. The load-bearing assembly of claim 1, wherein the tension member further comprises at least one nanofiller.
9. The load-bearing assembly of claim 8, wherein the at least one nanofiller comprises at least one of the following functional groups: glycidyl, silane, hydroxyl, carboxyl, amine, isocyanate, ethylene, and amide.
10. The load-bearing assembly of claim 9, wherein the at least one nanofiller includes at least one of magnesium hydroxide and aluminum trihydrate.
11. A load-bearing assembly, comprising:
- at least one tension member, the at least one tension member comprising a self-fire-resistant resin and reinforcement fibers; and
- a jacket material covering the at least one tension member.
12. The load-bearing assembly of claim 11, wherein the self-fire-resistant resin comprises at least one functional group that provides fire-resistant properties.
13. The load-bearing assembly of claim 12, wherein the at least one functional group is one of a nitrogen-based and a phosphorous-based functional group.
14. The load-bearing assembly of claim 11, wherein the resin comprises at least one of epoxy, polyurethane, vinyl ester, ethylene propylene diene monomer (EPDM), and melamine.
15. A method of making a load-bearing assembly, the method comprising:
- providing reinforcement fibers to a die;
- providing a resin precursor to the die;
- curing the resin precursor and fibers to form at least one synthetic tension member comprising a resin having a fire-resistance; and
- covering the at least one synthetic tension member in a jacket material.
16. The method of claim 15, wherein the resin is a self-fire-resistant resin.
17. The method of claim 16, wherein the self-fire-resistant resin comprises at least one functional group that provides fire-resistant properties, and the at least one functional group is introduced to the resin precursor during the curing step via a curing agent.
18. The method of claim 17, wherein the curing agent comprises at least one of aliphatic polyether triamine, bis(4-aminophenyl)phenylphosphine oxide, bis(3-aminophenyl)methylphosphine oxide, and bis(4-aminophenyl)methylphosphonate.
19. The method of claim 15, comprising providing at least one additive to the resin precursor, wherein the at least one additive comprises a first additive that provides fire-resistant properties and a second additive that provides at least one of a smoke-suppressant and a char-forming property.
20. The method of claim 19, wherein the first additive comprises at least one of a phosphorous-containing compound or polymer and a nitrogen-containing compound or polymer, and the second additive comprises at least one of a metal-exchanged clay, zeolite, zinc molybdate, zinc borate complex, zinc molybdenate and magnesium silicate complex.
Type: Application
Filed: Apr 13, 2018
Publication Date: Oct 25, 2018
Inventor: Chen Qian Zhao (Newark, DE)
Application Number: 15/952,581