The principle of membrane microencapsulation or « core-shell »
- Membrane microencapsulation, also known as « core-shell », contrasts with matrix capsules, which are homogeneous. They are really made up of a « wall ».. This makes it possible to change the size of the pores of the membrane to obtain waterproofness, considerably improving the retention of the active ingredient that it must release mechanically.
- This is the method we use in the microencapsulation we do, because the drop of fragrance that will make up the inside of the microcapsule placed in a detergent or softener will be surrounded by a membrane that will serve as protection until the release of this active particle.
- The membranes in the detergent products will be large enough to allow easy breaking of the capsule by friction or rubbing; the brittleness of the microcapsules can be controlled according to the expectations of our customers in the cleaning products industry.
In 2010, we developed double-walled microcapsules, made of silicone and aminoplast, which we have improved according to our customers’ demands. They are generally used in detergent products, particularly liquid and solid detergents, but also softeners, showing excellent ageing properties with respect to the fragrance they contain.
- Our machines capable of producing emulsions by the core-shell or membrane method create these tiny droplets in a stable way, at a lower energy cost. Our work on emulsion polymerization and on surfactants compatible with microcapsules allows us to obtain this result, with diameters of about 20 μm.
- Technical expertise in microcapsules with effective properties
- The microcapsules produced can contain various active ingredients, while being protected by the membrane. There are several methods of membrane microencapsulation: the first, historically, is complex coacervation, also called « phase separation », followed by interfacial polymerization and in situ polymerization.
- These methods make it possible to create a resistant membrane that can then serve as a shield for the fragrance until it is released.
In addition, the membrane will allow, through surface modifications, to improve the cling of the microcapsules to the linen and thus to release the active ingredients which are there at the desired place.