Quality
Assurance
Vihan employs cutting-edge technologies for ensuring highest product quality at every production stage, namely:
- Weaving (mainly for liquid filtration products)
- Needle Felt (mainly for gas filtration products)
Weaving
- Yarn
- Warping & Weaving
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- Fabrics
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- Finishing
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- Assembly
Yarn
At Vihan, we use basic raw material like polypropylene, polyamide (nylon), polyester, cotton which are available in staple, multi and monofilament yarns. Various yarns give different filtering properties to the fabrics when combined in different weaving patterns.
Staple Yarns
- Low tensile strength
- Excellent retention of the finest particulates
- Greater active surface
Multi-filament Yarns
- Good tensile strength
- Good retention capacity
Mono-filament Yarns
- Smooth and optimal release of the material
- Avoids the risk of clogging
Warping and Weaving
At Vihan, we use advanced and efficient warping and weaving equipment to ensure high quality of our products.
Fabrics
Different yarns can be weaved in different constructions. The most widely used construction patterns are:
Plain
- Guarantees high retention capacity
- Simple structured fabric
- Same appearance on both sides
Twill
- Excellent mechanical resistance
- Diagonally structured fabric
Satin
- Guarantees excellent release of the cake
- Smooth and shiny appearance
- Structure prevents clogging
- Sides are different
Broken Twill (chain):
- A derivative of twill weave
- Obtained by breaking twill line or a regular twill
- Gives a stripe like effect
- Provides better retention capacity and can sustain more pressure
Finishing
At Vihan, whenever necessary, the grey fabric is treated to bring dimensional stability, reduce air permeability, increase retention capacity, enhance the life cycle and reduce material loss. Some treatments that we provide are:
- Hydraulic treatment
- Thermal stabilization
- Chemical treatment
- Calendaring
Assembly
At this stage, the product is ready for the last stage of process, which are laser cutting and stitching. Our products will enable you to create precise and high-quality products with maximum efficiency even at a large scale.
Needle Felt
- Fibre
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- Scrim
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- Needle Felt
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- Finishing
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- Assembly
Fibre
Various fibres can be combined in different proportions to optimise the desired performance. Wide range of fibres with different resistances (to temperature, corrosion, oxidizing environments) are used to enable high performance under any possible operating condition. The needle punched felts majorly use Polyester, Polypropylene and Polyacrylonitrile.
Scrim
Our weaving technology makes scrim with the same polymer as that of the felt. Inserted reinforcements guarantee dimensional stability and strengthen the felt.
Needle Felt
With years of expertise, our production process has evolved to ensure highest product quality by practising strict quality controls at every stage. We produce wide range of felts for varied needs of markets.
Finishing
At this stage, various treatments are performed to improve the properties of the felt, making it the fundamentally important phase. Any desired application can be easily customized.
Heat Setting
Every needle felt is heat set. An optimum combination of quality decisive factors like temperature, dwell time and cooling phase reduce the residual shrinkage to a minimum. During the cooling phase, the controlled process ensures excellent form stability of filter bags even under most difficult conditions.
Thermal Surface Treatment
The surface of every needle felt influences its:
- Structure of filter cake
- Cleanability
- Pressure drops
- Emission
We provide two thermal surface treatments as defined below:
- Singed
Three variations are possible
- Smooth – For adhesive and moist dust
- Medium – For universal treatments
- Rough – For low agglomeration or fine dust
- Calendaring
Calendaring achieves a more compact fibre structure, allowing more surface separation of dust with lower emission.
Protective Impregnation
- Fluoric Carbon
This treatment makes it more difficult for moisture to penetrate the needle felt. This reduces the risk of excessive dust deposits and caking. The water-repellent treatment also enhances cleaning and separation efficiency.
- Protection against Acids and Hydrolysis
The special impregnation based on PTFE, coats the fibre surface and provides anti-adhesive character of a PTFE finish. The oil and water repelling effect produced, effectively protect the fibre against acid and hydrolysis attack.
Coatings
The filter-active coating like silicon coating, separates the dust from the surface. It also helps in reducing the adhesive force between the filter medium and dust cake.
Antistatic Constructions
Optimum discharge of electrostatic changes is suitable for potentially explosive areas as well as for electrostatic and strongly chargeable / charged dusts.
- Epitropic Fabric
Permanent electrical conductivity is gained by adding stainless steel and carbon fibres into the fibre mass.
- Metal Wire Impregnated Fabric
The Metal wire is impregnated in the scrim at a fixed distance.
Assembly
Our dedicated packaging department performs Laser Cutting and stitching. They also customize products for any and various client needs.