The machine based on transfer printing are essentially hot pressing unit in which the temperature is maintained in the desired range. The machine are of-
- Flat bed transfer printing machine
- Continuous transfer Printing Machine
- Vacuum Transfer Printing Machine
A short description is now describing here giving the working procedure of each machine.
- Flat Bed Transfer Printing Machine :
- It is suitable to print the garment
- It is suitable to print both side of the fabric
- Time of printing is settled to the machine
- The number of printed garments per hour is 50-100
- Heating is carried out by electricity or super steam
Working Procedure : In this machine working is carried out in three steps.
- At first fabric to be printed is carried out to the endless blanket
- In this step fabric comes to the press bed and per-printed paper is placed on the fabric in press bed. In this step, temperature keeps 180 to 200 degree centigrade normally and pressing time keeps 30-40 seconds by a pair of cylinder with air.
- The press bed or heated plate is then lifted and this printed fabric is stored by moving through blanket. In the moment the another cycle is starts.
2. Continuous Transfer Printing Machine : In this machine design is transferred from printing paper to fabric. After printing by this machine no need of fixation or wet treatment.
Working Principle : In this machine working is carried out as following steps.
- In this machine, since preprinted paper and fabric contact to each other passes through, design is transferred to fabric which is done in a biggest heated cylinder.
- Here cylinder is heated at 220 degree centigrade internally and design is transferred due to the pressure of cylinder and preprinted paper.
- A tension device is used for pressure of printing paper to fabric
- Required time for printing is 15-60 s
- Backing paper is used for uniform pressure fabric and transfer paper.
- The speed of machine is 1300 m/hr
- the speed of machine varies between 6-15 m/min depending on the diameter of the heated cylinder.
3. Vacuum Transfer Printing : Both continuous and unit transfer printing machine have been redesigned to provide vacuum assisted transfer. The drawing of dye in to the fabric from the printing paper is achieved by means of vacuum produced in a cylinder the cylinder is manufactured from a finely perforated steel mantle with surface profile and perforation. Due to this even vacuum the paper and the fabric are wrapped around the cylinder.
Working Procedure: The steel mantle of the drum is covered witha heat resistant padding material. The paper ususally extends about 1 inch beyond each selvedge of the fabric. The projecting edge of the paper are sealed off by adjustable perforated Teflon tapes which reject the dyestuffs and protect the drum edge from getting soiled. Heating is done by infra-red heating, filled in a special reflecting chamber.