In 2003, the Institute of Textiles and Clothing of the Hong Kong Polytechnic University received a grant to develop fabrics with memory effect. As a result of research, the team working on the project created new material with the function of remembering the shape given to it.
The memorial fabric (composition - 100% polyester), which appeared on the market as a result of this breakthrough, found its place in the niche of materials for sewing raincoats, jackets, things for children and adults.
Subsequently, the project resulted in a separate textile industry. Material capable of "remembering" the shape given to it, and then returning to the original, 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.
A way to create a smart thing. History of memory fabric
How was the memorial fabric created? A description of the project should begin with Professor Dzhinlyan Hu from the Institute of Textiles and Clothing. She joined the Hong Kong Polytechnic University in 1994, and by 2001 became the first Asian scientist to receive the Fiber Science Achievement Award.
Everything was realized with the help of the correct production process, resulting in the creation of a material with a symbolic name - memorial fabric. Reviews of clothes from it often include praise like “a nice dull-velvety surface,” “worn perfectly,” “easy to care for, 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 creation of the first memory center in the world at the Hong Kong Polytechnic University.
Memorial Properties
Since the foundation of the Center, many variations of the material with “memory” molecules have been developed. And only one of them is the fabric of the memorial. The description of this material can be reduced to several main points:
- easily erased;
- dries quickly and easily;
- Do not “sit down” during washing and after it (if you follow the manufacturer’s recommendations);
- not stretched;
- not easily soiled;
- not wrinkled.
When treated with a special liquid, it becomes waterproof.
Professor Jinliang Hu
After graduation, Jinlian Hu focused on studying the structure, mechanics, and modeling of memory textiles. It paid off - she created the world's first material with similar properties. It was based on cellulose. Numerous patents of China and the USA were issued for this development.
Success did not stop her career - then Dzhinlyan Hu became the initiator of the creation and scientific director of the Textile Center with the effect of shape memory (in 2003). Currently, the GPU is supporting the development of a fiberglass knit fabric with a shape memory effect, which gives hope for the appearance of new interesting fabrics in the near future.
A few more benefits
Memories, in comparison with "ordinary" materials, are stronger and more resistant to stretching. The fabric of the memorial (does it stretch or not? In certain limits - it is enough that the clothes are comfortable, but incomparable with the stretch) even after many washings it will not turn yellow, it will not become “dimensionless” or hopelessly wrinkled.
In addition, the clothes are spared one more drawback: over time, the material “at the seams” will not turn into burlap, as happens with some other fabrics, and if this happens, then it’s easy to fix it.
Triple memory fabrics
There are other material variations besides those developed by the University of Hong Kong. For example, based on polymers. Such a tissue will restore its original softness and shape after soaking in hot water (+ 60 ° C) or from body temperature, even if it has become very warm 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 when exposed to one temperature and return to their permanent form after applying another, higher t °.
How the shape memory effect arises
Polymers have two states: temporary visible form and “permanent”, which for the time being is hidden. Once the fabric is made, it is given a temporary shape by heating, warping and cooling. She keeps it until the process of returning to the “constant” is started.
The secret to this variability lies in the molecular structure of the tissue. Memorial fabric, the description and photo of which is not so different from “ordinary” textile materials, has, however, an unusual molecular structure.
Cotton Memories - What Fabric?
By adding polymers to other fibers, manufacturers obtain fabrics with a wide range of properties. An example of a mix is Cotton Memories. What fabric is this material?
To be precise, the ratio of cotton to polyester fibers in it varies from 40:50 to 50:50 or more. This fabric is durable, flexible, and well tolerates washing.
From it sew skirts and trousers, dresses, suits. Clothing allows the body to breathe freely, does not wrinkle, holds its shape, is able to absorb moisture well enough and dries quickly. However, despite its positive qualities, Cotton Memories (what kind of fabric is without flaws) is not very accessible from a price point of view.
Memorial Cloth Care
Such material can often be found in the form of raincoats and jackets, things are sewn from it for both children and adults. Specific care recommendations should be consulted with the manufacturer, as they depend on the fabric composition of the garment. However, in general, the care tips are as follows:
- hand or machine wash, at a temperature not exceeding 40 ° C;
- it is undesirable to dry in a drum;
- can be ironed at t ° not higher than 150 ° C;
- Do not use bleaches, chlorine-containing powders;
- it is also undesirable to use solvents and stain removers - the fabric of memori (customer reviews, however, fully reflect the understanding of the situation even without a special warning) is too delicate material.
Other fabrics with a memory effect. Shirt from Italians
The Italian company Corpo Novo has created a men's shirt, which itself rolls up its sleeves when its wearer is hot. The material of this shirt consists of nylon and nitinol - an alloy with shape memory.
Employees at Corpo Novo managed to bring them together. For every five nylon fibers, there is one thin nitinol wire.
As a result, the material turned out with a memory effect. If you give it some form at a certain temperature, and then cool and change this form, the tissue will restore it again when heated to the same preset temperature. The invention of Corpo Novo is capable in this sense of more than memorial fabric. The description of the Asian material does not provide for such significant changes in the material of its state.
For example, it is enough to iron such a shirt with an iron at + 50 ° . Then you can crumple it as you like - after heating to + 50 ° C, it will automatically and independently return to the “smoothed” state.
The same applies to the style - having rolled up the sleeves and heating the fabric, the owner thereby forces the material to “remember” this state. After that, if you cool and straighten everything, the shirt will look quite usual - until it is heated to the same temperature again.
For comparison: memorial fabric (the description of which can be reduced to the phrase “improved material for sewing dresses and cloaks” rather than to the concept “product with shape memory”) cannot be programmed or expanded, 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 Wann. It was originally used for military needs, but eventually found application in the industrial and technological sectors.
A shirt from Corpo Novo, in spite of its unusual properties, could not find a way to the market, since production is too expensive - only one prototype cost the company about $ 3.5 thousand. But numerous pillows, mattresses and blankets containing elements and fabrics with a memory effect are sold quite successfully.