Monday 28 June 2021

C

 


Remarkable New Fabric Efficiently Transfers Heat – Could Help Keep You Cool Even Without A/C

Cooling Fabric

Air conditioning and other space cooling methods account for about 10% of all electricity consumption in the U.S., according to the U.S. Energy Information Administration. Now, researchers reporting in ACS Applied Materials & Interfaces have developed a material that cools the wearer without using any electricity. The fabric transfers heat, allows moisture to evaporate from the skin and repels water.

Cooling off a person’s body is much more efficient than cooling an entire room or building. Various clothing and textiles have been designed to do just that, but most have disadvantages, such as poor cooling capacity; large electricity consumption; complex, time-consuming manufacturing; and/or high cost. Yang Si, Bin Ding and colleagues wanted to develop a personal cooling fabric that could efficiently transfer heat away from the body, while also being breathable, water repellent, and easy to make.

The researchers made the new material by electrospinning a polymer (polyurethane), a water-repelling version of the polymer (fluorinated polyurethane) and a thermally conductive filler (boron nitride nanosheets) into nanofibrous membranes. These membranes repelled water from the outside, but they had large enough pores to allow sweat to evaporate from the skin and air to circulate. The boron nitride nanosheets coated the polymer nanofibers, forming a network that conducted heat from an inside source to the outside air. In tests, the thermal conductivity was higher than that of many other conventional or high-tech fabrics. The membrane could be useful not only for personal cooling, but also for solar energy collection, seawater desalination, and thermal management of electronic devices, the researchers say.

###

Reference: “Thermoconductive, Moisture-Permeable, and Superhydrophobic Nanofibrous Membranes with Interpenetrated Boron Nitride Network for Personal Cooling Fabrics” by Xi Yu, Yang Li, Xianfeng Wang, Yang Si, Jianyong Yu and Bin Ding, 1 July 2020, ACS Applied Materials & Interfaces.
DOI: 10.1021/acsami.0c04486

The authors acknowledge funding from the National Natural Science Foundation of China, the Interdisciplinary Studies Program for the Central Universities and the Fundamental Research Funds for the Central Universities.

American Chemical SocietyBiotechnologyMaterials ScienceNanotechnologyPolymers
 Comments ( 1 )
Add Comment
  • Ron McCune 

    Can it be put on walls, furniture, beds, car seats and other things and do any good for us.

Tuesday 22 June 2021

What Color is your Parachute ?

 


What Materials are Used to Make Parachutes?

 

EDITORIAL FEATURE

What Materials are Used to Make Parachutes?

Image Credits: Photos.com

Parachutes are designed to slow the movement of an object or personal as it falls through the air; they were initially used by the aviation industry for rescue purposes and in the military for troop deployment. Today, parachuting has become a popular recreational activity, and horizonal parachutes are employed to slow fixed wing aircraft and drag racing cars. These are activities where there is no place for error.

There are two types of parachutes; the first is a dome canopy which traps the air inside creating a region of high pressure that slows down movement in the opposite direction to the air flow. Their shape ranges from a hemisphere to a cone. The second is a rectangular parafoil or ram-air canopy; it is a series of tubular cells that act as a wing allowing the jumper to direct his/herself towards a target. The parachute’s descent depends on the material, and hence it is important that the material is light, flexible, and windproof. It has to be able to handle high altitude winds and other environmental elements. The material’s density, rigidity, and texture are the other key factors that will control the speed and provide a swing-free descent.

This article will look at the key materials used in parachute manufacture.

Materials used to make Parachutes

Leonardo Da Vinci is credited with the first design for a parachute; his drawings show a pyramid-shaped linen canopy held open by a square wooden frame and was designed as an escape device to be used by someone escaping from a burning building.

Canvas - The first choice for the parachute’s canopy was canvas. It is a very heavy-duty plain-woven fabric.

Silk – Canvas was replaced by silk, as silk happened to be lighter, stronger, thinner as well as fire resistant and easy to fold and pack. Silk was first used by J.P Blanchard in 1785 to make the first parachute without a rigid frame.

Nylon - Nylon replaced silk during the WW2 when supply of silk diminished. Nylon has since become a popular choice, as it has excellent wind resistance, good elasticity, mildew resistance, and is comparatively cheaper. The material is also lightweight and dries quickly. It is resistant to abrasion and chemicals. Due to its exceptional strength, it is also used to make straps of the parachute harness, reinforcing tape, and suspension lines.

Nylon fabric for parachutes is woven in a specialized manner with extra thick threads to create a pattern of small squares – this is known as ripstop nylon. When small tears occur in the canopy, these small squares prevent the tears from becoming bigger.

Kevlar – This is an extremely strong synthetic fabric that can be used in bullet-proof clothing. It is heat and flame resistant, therefore it does not lose its strength or deform at high temperatures. The tensile strength remains intact even when stored away for long periods.

Terylene - A type of polyester fabric that is now being used as a material for parachutes as it is very strong and heat resistant.

Other materials used include:

  • Forged steel-plated with cadmium for metal connectors to prevent rusting
  • Stainless steel cable for ripcords.

Conclusion

Parachute manufacturers are looking for ways to improve their products with better materials and designs. Fascinating research being performed involves creating a parachute with the ability to control the emergency descent of an entire aircraft. The fabric is being designed to have extremely low-porosity and high strength. With the rapid advancement in the materials world, we can hope to see some innovative materials in the future to make parachuting safer and more fun.

Sources and Further Reading

This article was updated on 13th August, 2018.

Read in:

Comments

  1. Hope KniselyHope Knisely Australia says:

    Would a plastic bag be a good material for a parachute, like in a school assignment?

  2. George DingleyGeorge Dingley United Kingdom says:

    Would normal felt be a good material for a parachute?

  3. cameron braycameron bray Australia says:

    amazing

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of AZoM.com.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
 
 
 
Submit

ReUse 📌