The technical challenge
A hosiery manufacturer sought to enhance its women’s hosiery line – focused on wellbeing and named Antistress – with lavender essential oil, well known for its calming and relaxing properties documented in aromatherapy literature.
The solution initially adopted – application of the fragrance in free form – proved inadequate: the volatile aromatic compounds evaporated rapidly upon contact with air, making the functional effect imperceptible after only a few uses. The product was unable to sustain the promises of the Antistress line over time.
The technical challenge was structured across three levels:
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Fragrance stability
Ensuring an olfactory duration significantly superior to that achievable with free fragrance, preserving the integrity of the essential oil during the production process and throughout the useful life of the finished product. -
Process compatibility
Integrating the solution into the existing yarn production process, without structural modifications to the production line and without impact on the physical properties of the fabric: elasticity, breathability, handle and surface appearance. -
Homogeneous distribution on the yarn
Ensuring uniform deposition of the active ingredient across the entire fibre surface, avoiding agglomerates or irregularities that could have compromised the quality of the finished product.
Analysis of microencapsulation options
During the technical evaluation phase, IPS analysed the two main microencapsulation solutions for textile finishing applicable to this type of process: slurry microcapsules and Microgel.
Slurry Microcapsules
Aqueous suspensions with core-shell structure – active core protected by a gelatin membrane – with particle sizes between 20 and 500 µm. An established solution for impregnation, coating and padding processes in textile finishing. The active ingredient is released by mechanical rupture of the membrane, ensuring a gradual response and a very long olfactory duration.
Microgel IPS
A hydroalcoholic formulation in which microparticles of lipophilic active ingredient – free of any coating membrane – are dispersed in a gel matrix. The particles have sizes below 10 µm, significantly smaller than standard microcapsules. Release occurs immediately, amplified by the evaporating action of the alcohol present in the formulation.
For this specific application on hosiery yarns, Microgel proved to be the most suitable technical choice for three reasons:
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Particle size below 10 µm
It ensures fine penetration and uniform distribution on the fine yarn, without altering its feel or surface structure. Dimensions in the hundreds of µm range, typical of slurry microcapsules, could have introduced perceptible irregularities in the fiber. -
Gel formulation
Directly compatible with the yarn production process, with no need for adaptations to existing equipment. -
No gelatin membrane
Microgel contains no animal-derived components, unlike microcapsules produced by coacervation. This makes it a vegan-friendly solution, a requirement of increasing importance for fashion and wellness brands—and consistent with the needs of the personal care and repellent sectors, where clean label composition is often mandatory.
The technology: Microgel IPS
Microgel IPS is a hydroalcoholic formulation with acid pH, designed for textile finishing applications by coating or immersion.
Unlike traditional microencapsulated systems with core-shell structure – such as slurry microcapsules or dry microcapsules – in Microgel the droplets of lipophilic active ingredient are stabilised directly within the hydroalcoholic matrix, without a polymeric shell.
Technical parameters relevant to this application:
| Values | |
|---|---|
| Physical form | Hydroalcoholic gel with acid pH |
| Microparticle size | < 10 µm |
| Structure | No membrane - no polymeric shell |
| Active ingredient | Lavender essential oil |
| Components of animal origin | None - vegan friendly |
| Application process | Yarn immersion |
The ultrafine particle size is the critical parameter that differentiates Microgel from standard microcapsules: it allows for homogeneous distribution and fine penetration into the yarn, ideal for applications on fine fibers such as those used in women’s hosiery. For a complete overview of the product’s technical parameters, please refer to the Microgel technical data sheet.
The application process
The Microgel is introduced directly into the existing and consolidated yarn production process of the client. The integration requires no equipment modifications or changes to the production sequence – one of the key characteristics IPS evaluates during new microencapsulation project development.
During the immersion of the yarn in the bath, the Microgel microparticles deposit homogeneously on the fiber surface. Once the drying process is completed, the treated yarn keeps the essential oil microparticles stably anchored to the fiber. During the use of the tights, body heat and contact with the skin promote the gradual and continuous release of the fragrance.
Simplified process overview
- Preparation of the treatment bath with Microgel IPS
- Immersion of the yarn in the bath
- Homogeneous deposition of microparticles onto the fibre (< 10 µm)
- Drying with standard process
- Standard textile processing of the treated yarn
- Finished product: hosiery with microencapsulated lavender fragrance and gradual controlled release
Results and benefits
-
Fragrance duration
Significantly superior compared to fragrance applied in free form, owing to the stabilisation of microparticles within the hydroalcoholic matrix and their adhesion to the yarn. -
Homogeneous distribution
The ultrafine particle size (< 10 µm) ensures uniform deposition across the entire yarn surface, with no agglomerates or irregularities. -
Production line compatibility
Microgel was integrated into an existing production phase without modifications to equipment or process sequence. -
Unchanged physical properties of the fabric
Elasticity, breathability and handle of the hosiery were not compromised by the treatment. -
Vegan friendly formulation
No components of animal origin, in line with the positioning requirements of the Antistress line.
Reference sector and related applications
This application falls within the field of functional textile finishing with microencapsulation, an area in which IPS operates with solutions based on Microgel and slurry microcapsules for impregnation, coating, padding and immersion processes on natural and synthetic fabrics.
Related applications developed by IPS in the same field:
- Antibacterial finishes for technical fabrics and medical materials
- Treatments on non-woven and tissue paper with fragranced active ingredients
- Fragranced textile accessories for applications in the personal care and repellents sector
FAQ — Microencapsulation for textile finishing on yarn
What is the difference between Microgel and slurry microcapsules for textile finishing?
Microgel IPS is a hydroalcoholic formulation with active ingredient microparticles below 10 µm, free of any membrane - ideal for fine yarns where larger particle sizes would introduce perceptible irregularities on the fibre. Slurry microcapsules have a core-shell structure with sizes between 20 and 500 µm and a gelatin membrane - preferred for padding or coating processes on heavier fabrics where a very long olfactory duration is required.
Is Microgel compatible with the existing yarn immersion process?
Yes. Microgel IPS is designed to integrate directly into the yarn treatment bath already present in the production line, without modifications to equipment or process sequence. The hydroalcoholic gel formulation is compatible with the standard immersion processes used in hosiery production.
Does Microgel contain components of animal origin?
No. A differenza delle microcapsule in slurry prodotte per coacervazione - che utilizzano gelatina come materiale di parete - il Microgel non contiene involucro polimerico né componenti di origine animale. Si tratta di una soluzione vegan friendly, requisito di crescente rilevanza per i brand del settore moda, benessere e personal care.
How long does the fragrance last on yarn treated with Microgel?
The olfactory duration is significantly superior compared to fragrance applied in free form. Microgel microparticles anchor stably to the fibre during the drying process and release the active ingredient in a gradual and continuous manner through the effect of body heat and skin contact during use. For a complete overview, see the IPS microencapsulation technology section.
Does Microgel treatment alter the physical properties of the fabric?
No. The ultrafine particle size - below 10 µm - ensures homogeneous deposition onto the fibre without introducing perceptible irregularities. Elasticity, breathability and handle of the yarn remain unchanged after treatment. Compatibility with the physical properties of the fabric is one of the parameters evaluated by IPS during the development and prototyping phase.
