Microencapsulation is a process that coats tiny particles or droplets with a protective shell to form capsules that are typically 2-2000 micrometers in size. It can be used to encapsulate fragrances, phase change materials, fire retardants, and other active ingredients for textile applications. Microencapsulation allows for controlled release of ingredients over time and protects unstable materials. Some common uses of microencapsulation in textiles include adding fragrances that last through multiple washes, incorporating phase change materials for thermal regulation, and providing antimicrobial properties for medical textiles.

2. MEHRAN UNIVERSITY Of ENGINEEING AndTECHNOLOGY JAMSHORO
Department of Textile Engineering
TOPIC: MICROENCAPSULATION
PREPARED BY : DANISH RAJA
Danish_raja1@hotmail.com

3. Structure and Mechanism2
CONTENTS
Constituents and Benefits3
Introduction1
Application inTextiles5
Techniques4
Conclusion6

4. Introduction…….
History
 The origins of the process of microencapsulation lie in the
pharmaceutical and paper industries of the 1940s. However, the textile
industry started introducing encapsulated products, in its articles
between 1980 and 1990.
 The pharmaceutical industry has long used microencapsulation for the
preparation of capsules containing active ingredients.
 During the past 10 years this approach has been explored widely by the
agricultural, food, cosmetic, and textile industries.

5. What is MICROENCAPSULATION……???
 Micro-encapsulation is a process in which tiny particles or droplets
are surrounded by a coating to give small capsules many useful
properties.
 Micro-encapsulation may also be defined as the process of surrounding or enveloping
one substance within another substance on a very small scale, yielding capsules ranging from
less than one micron to several hundred microns in size.
 The potential size range of the microcapsules produced is enormous,
with typical diameters being between 2 and 2000 µm.
 Capsule walls are typically 0.5-150 µm thick, although walls
measuring less than 0.5 µm can be achieved.
 The proportion of core material in the capsule is usually between 20
and 95% by mass.

6.  The substance that is encapsulated may be called the core material, the active ingredient or
agent, fill, payload, nucleus, or internal phase.
 The material encapsulating the core is referred to as the coating, membrane, shell, or wall
material .
 Microcapsules may have one wall or multiple shells arranged in of varying thicknesses around
the core.

7.  Microencapsulation involves the production of microcapsules which act as tiny containers of
solids. Microcapsules have walls less than 2 μm in thickness and 20–40 μm in diameter is
useful in fiber applications.
Fig. Microencapsulation: Paraffinic PCM core material individually with a hard
polymeric shell.

8. Structure of a Microcapsule
 Microcapsules basic structures. (Courtesy of RonaldT. Dodge 2009)

9.  A close view of Microcapsules…

10.  MECHANISM ….
How itWorks…..???
Microencapsulation can have two distinct objectives.
 On one side, to block the substance within the microcapsule, necessarily
rigid, when the diffusion of a product is not desired.
 The second objective is the progressive liberation of the active ingredient
within the microcapsule which, in this case should have a more fragile wall.
This second option is the most used in case of the functional or active
textiles.

12.  CONSTITUENTS & BENEFITS ……..
Microcapsules may contain…
 A perfume, scents
 A cosmetic product(moisturizer, freshener, toner, etc.)
 An odor absorbing product
 Insect repellents
 A combination of ingredients(e.g., perfume+ bactericide)
 X chromes (pigments whose color changes to X environment)
 Dyes or ink
 PCM (Phase Change Materials)
 Vitamins, Nutrients, ..
 Drugs, pharmacological products, …
 Bacteria, virus,ADN, …
 Enzymes
 Living cells.
 Others …

13. Benefits of Microencapsulation……….
 Protection of unstable, sensitive materials from their environments prior to use.
 Better processability
 Self-life enhancement by preventing degradative reactions (oxidation, dehydration).
 Controlled, sustained, or timed release.
 Safe and convenient handling of toxic materials.
 Masking of odor or taste.
 Controlled and targeted drug delivery.
 Handling liquids as solids

14. Techniques to apply onTextiles…….
 In the polymer
 On fabric by padding
 In a coating
 Spraying
 Transfer print
 Injecting into the yarn

15. APPLICATION INTEXTILES …….

16.  1-PHASE CHANGE MATERIALS
 The intention of microencapsulation of phase-change materials is to reduce the influence of extreme
variations in temperatures.
 Phase-change materials are materials that change the aggregation from solid to liquid within certain
range of temperature.
 In this way the thermoregulation of clothing is achieved and the constant temperature is provided.
 PCM capsules were first applied by the NASA in the early 1980s for use in space suits.Today these
kinds of microcapsules are applied to different materials, vests, snowsuits, blankets, mattresses etc

17.  2-Fragrance finishes
 Numerous trials have been made at adding fragrances directly to fibre and fabrics, but the
aroma vanished after one or two wash cycles.
 By the use of microencapsulation fragrances are able to remain on fabric for a longer
period of time.
 Microcapsules may contain essential oil flavors like lavender, rosemary, pine and other for
the effect of aromatherapy.This is used mainly to help with insomnia, headache, and to
prevent bad odor.
 The Slovenian producer Aero Celje has developed microcapsules with essential oil that
were applied to shoe sock.
 Vitamins and moisturizers are also applied to all types of textile substrates, including
hosiery and baby wears.

18.  3- FIRE RETARDANTS
 Fire retardants applied to textile products often cause the reduction of softness.
 To conquer these problems microcapsules with fire retardant core were developed.They
are applied to fabrics used in military applications like tentage.

19.  4- PHOTOCHROMIC ANDTHERMOCHROMIC MICROCAPSULES
(COLOUR-CHANGINGTECHNOLOGY)
 The application of photo chromic and thermo chromic microcapsules can be found in
textiles like product labeling, medical and security applications.
 One of the colour changing systems changes colour in response to temperature, this is
thermo chromatic and the other changes colour in response to UV light, the photo
chromatic.
 Today even microencapsulated thermo chromatic dyes are produced that change colour at
specific temperature - in response of human contact.

20.  5- ANTIMICROBIALS
 Bacteria are often related to the notion of bad smell or disease and in textile industry the loss of
useful properties of fabric often refers to microbiological decay of fibers.
 To prevent this problem the importance and demands of antimicrobial finishes continue to grow,
especially for textiles for medical and technical use.
 To realize these functionalities, nanotechnology offers a lot of new Possibilities.Antimicrobial
finishes can be applied to textiles also by microencapsulation.
 The release of active substances of microcapsules with antimicrobial agent is slow or sustained.
 Textiles with antimicrobial finishes are known in the market by different names, like Bacterbril,
Biofresh,Terital,Trevia Bioactive,Amicor etc

21.  6- COUNTERFEITING
 Microencapsulation can be used to deal with the problem of illegal copying in high added
value textiles and in branded and designer goods with providing a hidden yet clear marking
system.
 Microcapsules applied to label contain a colour former or an activator.
 By the use of UV light or a solvent, microcapsules break open, the content is released,
colour is developed and in this way detection is achieved

22. INTERESTING ASPECTS !!!

23. CONCLUSION
 The possibilities of application of microcapsules to textiles discussed are
just some of the most interesting.
 Today there is almost no field where microcapsules would not be presented.
 Encapsulation became a very powerful tool, because it is invisible and comes
to life at the slightest touch.

24. REFERENCES
 1- G. Nelson (2002) Application of microencapsulation in textiles.International Journal of
Pharmaceutics 242 (2002) 55-62
 2- http://www.celessence.co.uk/micro.htm (2000)
 3- M. Leskovšek et al. (2005) Microcapsules in Medical and Hygienic Products.Textilec 48
(2005) 37-42
 4- http://pro.wanadoo.fr/euracli/en/textile.htm (2000)
 5- M. Kukovič et al. (1998) Microcapsules forTextile Industry.Tekstilec 41 (1998) 225-230
 6- http://www.flok.ru/news/FLOCK%20News_7.2006_e.pdf (2006)
 7- Nelson, G.,Wales D.S., Sagar, B.S., 1991.Treating Materials. European. Patent, EP
0511 258 B1.
 8- Nelson, G., 1991. Microencapsulation in textile coloration and finishing. Rev. Prog.
Color 21, 72–85.