In 2003, the Hong Kong Polytechnic University Institute of Fabrics and Clothing received a grant to develop memory-effect fabrics. As a result of research, the team working on the project created a new material with the function of remembering the shape given to it.
Memory fabric (composition - 100% polyester), which appeared on the market as a result of this breakthrough, has found its place in the niche of materials for sewing raincoats, jackets, clothes for children and adults.
Subsequently, the project turned into a separate branch of the textile industry. A material that can "remember" the shape given to it, and then return to its original shape, under the influence of heat or other triggers, has become very popular as the basis for sewing jackets, raincoats, skirts, pillows and other fabric products.
The way to create a "smart" thing. The History of Memory Fabric
How was the memory fabric created? The description of the project should start with Professor Jinliang Hu from the Institute of Fabrics and Clothing. She joined the Hong Kong Polytechnic University in 1994 and by 2001 became the first Asian scientist to receive the Fiber Science award.Achievement Award.
Everything was realized with the help of the correct production process, resulting in the creation of a material with a symbolic name - memory fabric. Reviews of clothing made from it often include praise such as "nice matte velvety surface", "wears well", "easy care, but looks luxurious."
In 2003, the project received funding of 6.3 million from the Innovation and Technology Fund (ITF). In addition, four private companies sponsored the establishment of the world's first memory tissue center at Hong Kong Polytechnic University.
During the time that has passed since the founding of the Center, many variations of the material with "memory" molecules have been developed. And only one of them is memory fabric. The description of this material can be reduced to several main points:
- easy to wash;
- dries quickly and easily;
- does not "shrink" during washing and after it (if you follow the manufacturer's recommendations);
- does not stretch;
- not easily soiled;
- does not wrinkle.
When treated with a special liquid, it becomes waterproof.
Professor Jinliang Hu
After graduating from the institute, Jinlian Hu concentrated her interests on studying the structure, mechanics and modeling of memory textiles. This paid off - she created the world's first material with similar properties.It was based on cellulose. Numerous Chinese and US patents have been issued for this development.
Success did not stop her career - then Jinliang Hu became the initiator and scientific director of the Center for Shape Memory Textiles (in 2003). The GPU is currently supporting the development of shape memory fiberglass knitted fabric, which gives hope for new interesting fabrics in the near future.
Memory, compared to "normal" materials, is stronger and more resistant to stretching. Memory fabric (does it stretch or not in general? Within certain limits - enough to make the clothes comfortable, but incomparable with stretch) even after many washes it will not turn yellow, become "dimensionless" or hopelessly wrinkled.
In addition, the clothes are spared one more drawback: over time, the material "along the seams" will not turn into burlap, as happens with some other fabrics, and if this happens, then everything is easy to fix.
Triple Memory Fabrics
There are other material variations besides those developed by the University of Hong Kong. For example, based on polymers. Such a fabric will restore its original softness and shape after soaking in hot water (+60°C) or from body temperature, even if it was heavily wrinkled before.
Although most manufactured fabrics can only "remember" two states (permanent and temporary), there are materials that have a triple "memory". These products pass from one temporary state to another whenexposed to one temperature and return to a permanent form after applying another, higher t °.
How the shape memory effect occurs
Polymers have two states: a temporary visible form and a "permanent" form, which is hidden for the time being. Once the fabric is made, it is temporarily shaped by heating, warping and cooling. She keeps it until the process of returning to "permanent" is started.
The secret of such variability lies in the molecular structure of the tissue. Memory fabric, the description and photo of which is not so different from "ordinary" textile materials, nevertheless has an unusual molecular structure.
Cotton memory - what kind of fabric?
By adding polymers to other fibers, fabricators obtain fabrics with a wide range of properties. An example of a mix is cotton memory. What kind of fabric is this material?
To be precise, the ratio of cotton and polyester fibers in it varies from 40:50 to 50:50 and more. This fabric is durable, stretchy and washable.
Skirts and trousers, dresses, suits are sewn from it. Clothing allows the body to breathe freely, does not wrinkle, keeps its shape, is able to absorb moisture quite well and dries quickly. However, despite its positive qualities, cotton memory (what kind of fabric without flaws) is not very affordable in terms of price.
Memory fabric care
Such material can often be found in the form of raincoats and jackets, things are sewn from it for both children and adults. See the manufacturer for specific care instructions.since they depend on the fabric composition of the clothing. However, in general, care tips are as follows:
- hand or machine wash, at a temperature not exceeding 40°C;
- undesirable to tumble dry;
- can be ironed at t° not higher than 150°C;
- do not use bleach, chlorine powders;
- using solvents and stain removers is also undesirable - memory fabric (customer reviews, however, fully reflect the understanding of the situation even without a special warning) is too delicate material.
Other memory fabrics. Italian shirt
Italian firm Corpo Novo has created a men's shirt that rolls up its sleeves when the wearer is hot. This shirt is made from nylon and nitinol, a shape memory alloy.
Corpo Novo employees managed to put them together. For every five fibers of nylon, there is one thin wire of nitinol.
As a result, the material turned out with a memory effect. If it is given some form at a certain temperature, and then cooled and this form is changed, then the fabric will restore it again when heated to that same temperature. The invention of Corpo Novo is capable of more in this sense than the memory fabric. The description of the Asian material does not provide for such significant changes in its condition.
For example, it is enough to iron such a shirt with an iron at +50°С. Then you can crumple it as you like - after heating to + 50 ° C, it automatically andwill automatically return to the "ironed" state.
The same applies to the style - by rolling up the sleeves and heating the fabric, the owner thereby forces the material to "remember" this state. After cooling and straightening everything, the shirt will look quite normal - until it is heated to the same temperature again.
For comparison: memory fabric (the description of which can rather be reduced to the phrase “improved material for sewing dresses and raincoats” than to the concept of “shape memory product”) cannot be programmed and straightened, although it was created specifically for the textile industry.
Nitinol is an alloy of titanium and nickel, in a ratio of 55:45. It was first obtained in 1958 in the US military laboratory by William Bueller and Frederick Vann. Initially used for military needs, but over time it has found application in the industrial and technological sectors.
The shirt from Corpo Novo, despite its unusual properties, did not find its way to the market, as the production turns out to be too expensive - only the production of one prototype cost the company about 3.5 thousand dollars. But numerous pillows, mattresses and blankets containing memory elements and fabrics are selling quite well.