We have discussed about the basic methods of fabric printing that are widely applied in Textile sector.
If you missed that session, you may go through the following link: Basic Printing Methods
Today we will discuss about the special Printing method termed as Flock Printing.
Flock Printing
Flock printing is a method of fabric ornamentation where fabric is printed with an adhesive & then finely chopped fibres/flocks are applied by means of dusting-on, air-blast or electrostatic attraction.
Fibres adhere only printed areas & removed from unprinted areas.
It is also called flocking or pile process.
What is Flock
Flock is a material obtained by reducing textile fibres to fragments by cutting, tearing or grinding.
Flock is made from monofilament fiber of viscose, cotton, wool, polyester, acetate etc.
Flocks range 0.9-22 dtex & 0.5-2 mm.
Flocks may be white or colored. The use of flocks gives pile effect.
Basic Principle of Flock Printing
- Application of adhesive: Adhesive is applied to fabric by squeeze, roller, screen or spray method. Synthetic resins is the best adhesive for flock printing. A typical recipe for the application of adhesive-
- Paralac = 50 parts
- White spirit = 34 parts
- China clay = 15 parts
- Lead naptholate (3%) = 0.8 parts
- Cobalt (8%) = 0.3 parts
- Water = x parts
- Total = 1000 parts
Flock application: The flock is applied by means of dusting-on, air-blast or electrostatic attraction from above the material or against the force of gravity, from below the material.
Drying: The drying conditions are dependent on the requirements of particular bonding agent used. Drying is carried out at 700oC for 3-8 mins. Suitable drying unit has steam heated tunnel driers as well as infra-red radiation.
Excess Flock removal: At last excess flocks from unprinted areas are removed by brushing with brush rollers together with a mechanical suction unit.
Methods/Types of Flock Printing
Dusting-on Method: Flocks are applied by shaking, dusting or sprinkling either by hand or through a fine sieve. It produces random flocking.
Air-blast Method: Flocks are applied by a spray gun, lied in a disordered state on fabric. Various sizes guns are available.
Electrostatic Method: Flocks are applied using electrostatic forces. This is the best one method as the flocks are shot into the fabric vertically by using 2 insulated pole-plates. It creates velvet-like appearance that isn’t achieved by other methods.
Advantages of Flock Printing
Create high quality & exclusivity with exceptional tactile & visual experience.
The surface can be entirely or partially flocked.
Flocks are available in various thicknesses, colors & lengths.
Fabric hold a good grip.
Disadvantages of Flock Printing
Very thin line & contours are difficult to execute.
Long flock fibers tend to swell & complicate the production of sharp edge.
Multi-colored motifs are rarely applied due to high workload & cost.
Flock surface may affect the machine processing.
This is Tariqul Islam , I am Lecturer of a recognised Textile Engineering College in Bangladesh. You may follow me to get posts about textiles, fashion and others..