What are Duplicating Machines?
Duplicating is a process in which the desired number of copies is prepared from a master copy with the help of a duplicator. Duplicating differ from copying and reproduction. Copying or reproduction means preparation of one copy or few copies from the original. Duplicating is followed when the number of copies required is more than the capacity of the typewriter. Duplicating machines or duplicators are used for preparing circulars, price lists, reports, office forms etc., with speed and accuracy.
Types of Duplicators or Methods of Duplicating Machines
A wide range of duplicators or duplicating machines is available in the market. Some of them are briefly explained below:
1. Gelatine Duplicator
This duplicator contains gelatins in a tray on which the master copy is pressed. The master copy is prepared with the help of special machine ink. Now, the copying paper is pressed on the gelatins with a dampened roller to take a copy. The cost of the gelatine duplicator is very cheap. However, it is very difficult to take a copy. Only 20 to 25 copies may be taken from a single master copy.
2. Stencil Duplicator or Mimeograph
This type of duplicator is highly used in every business office. A stencil is cut by a typewriter or by hand. The stylus pencil is used to cut a stencil by hand. The matter is to be typed within the frame marked in the stencil. The stencil is to be cut directly with the letters. The mistakes and errors are to be corrected by using correcting fluid. The correcting fluid will dry soon and after that the correct letter or word can be typed on it.
The cut stencil is fixed in a duplicating machine. Duplicating ink is pasted on the surface of the cylinder of the machine. The cylinder is rotated still the ink spread over the rollers. There are two trays on each side of duplicator. One side tray carries the papers for taking copies and other side tray is used for keeping the copying papers.
The machine can be operated by hand or by power. If the machine is switched on, the papers are automatically feeded and leave the copying papers. In the latest models, the required number of copies can be fixed (set). Then, the machine will stop automatically after taking required number of copies. The stencil is removed and kept for use. The cost of the duplicator is very low.
Advantages of Mimeograph
1. Up to 5000 copies can be taken with the help of Stencil duplicator.
2. Correcting fluid can be used to make alteration or corrections.
3. The cost of stencil paper and duplicating paper is very cheap.
4. Stencils can be stored and reused.
5. The stylus pen is used to draw graphs and diagrams.
6. Photographic reproduction is possible with electronic duplicators.
Disadvantages of Mimeograph
1. White paper cannot be used for legible looking of letters.
2. Multicolour copies cannot be taken in a single run.
3. The drum in the machine should be changed to take copies in different colours.
4. A small business office cannot afford the cost of stencil, paper and machine.
3. Electronic Stencil Duplicator
This type of duplicator is a marked improvement over the ordinary stencil duplicator. The original document is electronically scanned while contents are produced accurately on a stencil in another cylinder in the machine. The copies can be reproduced on the stencil duplicator. Only a few minutes are enough to produce a stencil.
Photographic copies of any document whether hand written, typed, cyclostyled or printed can be obtained easily. Speed and accuracy are the main advantages of this machine. However, the cost of machine is high.
4. Multigraph or Typeset Duplicator
It is like a small printing press. This machine uses letterpress type. Motor is used to operate the machine. Sometimes manual operation is also done. The type is set by hand round the outside drum. The printing is done through an inked ribbon, which reproduces a copy similar to the true copy.
Up to 4000 copies can be produced per hour with a multigraph. The high quality of the work is done with the help of this duplicator. The cost of the duplicator is also high.
5. Letter Press Printing Duplicator
The face of the duplicator seems like a typewriter. The type set is fixed on to the machine. The paper is fed into the machine. The copies are obtained when printing types are pressed against the paper. The duplicator can be operated at high speed and obtained more than thousand copies per hour. Hence, the cost per copy is very low. However, the cost of this duplicator is very high. More space is required to keep the duplicator; copies are neat and clean and obtained in different colours.
6. Offset Lithography Machine
The matters are prepared on these metal sheets as master copy. This machine is operated by power. The machine is of rotary type. There is no mixing of oil or grease and water since the machine works on the offset litho printing principles. The master copy is fixed to a drum after producing a greasy image on it. The roller meets the inked cylinder and water. Then, the image is offset on a rubber blanket; it is imprinted on the paper form.
Advantages of Offset Lithography Machine
1. Ordinary paper is used for copying. Hence, it is economical.
2. Large number of copies can be obtained very easily.
3. The quality of reproduction is very good.
4. Master copy can be stored for future use for an indefinite period.
5. Up to 6000 copies can be obtained in an hour.
Disadvantages of Offset Lithography Machine
1. Trained operators are necessary to operate the machine
2. The cost of the machine is high.
3. More storage space is necessary to keep the machine
4. Separate runs are necessary for different colours.
Choice of Selection of Method of Duplicating Machines
No method of duplicating machine is suitable to all types of business office. The following factors should be considered while selecting a suitable duplicating machine.
1. Number of copies required.
2. The frequency of need of copies.
3. Speed of reproduction.
4. Quality of paper is to be used.
5. The cost of paper, materials and operator.
6. The kind of image needed.
7. Enlarged, reduced, or same size of the original document is reproduced.
8. Number of colours required.
9. Durability of the matter and image.
10. Type of appearance preferred.