PADS

If you vary any one of these characteristics, the print quality will change. You must take these points into account when you plan the job and order pads from your suppliers. Shape is the most important variable in selecting a pad. Four basic shapes are as follows:

• Round (conical also)


• Rectangular/Square


• Printing of fine detailed images, words, logos, graphics


• Bar(tapered or half rounds)


• V-Shaped

At PARAM INTERNATIONAL Although hundreds of pad shapes are available, most are based on these Four shapes: round, rectangular, bar shaped or v-shaped. Regardless of what pad shape you choose for a job. For best printing results use the largest pad size that is practical for the item to be printed.

Try to avoid flat-bottomed pads, as they have a tendency to trap air when they come in contact with the cliche, hampering ink pickup.
Another important variable to consider is pad size relative to image size. The larger the pad, the less the image is likely to distort. Often, the distance between the cliche and the body of the machine will determine the maximum pad size you can use.

We guide you to use these following measures when choosing a pad shape for a particular job:

• First, at your end try your standard pads that you think would do the job for this particular product. Then do a trial print to verify that the proposed print area is imaged accurately.


• The round and the square pads are considered the most popular pads because these two shapes can print the same object many a times and cover variety of products.


• If the pad shape you have chosen provides a satisfactory print over just a part of the area, look for similar pad shapes that extent the profile in a way that will cover the entire image. Distortion at the image edges is almost always caused by undersized pads.


• Whenever possible, ensure that the lower point or apex of the pad does not come into contact with the image area of the clinch. This tends to thin the link at that point, causing an inconsistent ink deposit.


• If the pad is "overstressed" (that is, too small for the image) or the image is too close to the edge of the pad, distortion is likely to occur. Always use as little pressure as possible to pick up and print the image. If the machine is running too fast, excessive pad pressure can cause distortion as well as poor ink transfer.

Hardness of the pad:
The Hardness of the pad is normally determined by the amount of silicon oil used when the pad is made, Mainly four different hardness are standard in the industry and cover most applications. As a general rule, the harder the pad, the better the performance. However, a hard pad may be impractical in some applications, such as when using a low-power machine or printing onto a delicate item. Choosing the proper pad hardness for a job is a matter of experimentation and experience.

• Hard pads are most suitable for textured surfaces.


• Use softer pads when printing onto heavily contoured surfaces. Also use them when printing onto fragile items.


• You must use a softer pad if you are using the electrical powered machines to achieve a satisfactory action.


• Avoid using pads of different hardness on the same application, or the thickness of the ink deposit will vary on the substrate.

Top Surface finish of pads:
You get Pads with high gloss finish when you buy, you should remove excess silicon oil that creates the glossy appearance, to enable the pad to pick up and transfer proper ink during the printing process. Typically, pad printers will use a strong solvent for cleaning which damages the pad and shortens its life.

After you satin finish the pad till its finish becomes nearly matte, the only other step that must be taken prior to production is to gently wipe the pad with an alcohol-based pad-cleaning fluid. This removes any free silicone oil. Once you have used the pad, however, the best way to remove solid debris, dried ink, and dust is with a quality brown packaging adhesive tape. By following this simple procedure, you will improve your print quality, reduce downtime, and prolong the pad's life.

To Retain Quality of PADS:
The better you treat them, the longer they will last. Mechanical damage, aggressive solvents, and poor storage all take their toll. But the real killer is a careless operator. If you make your staff aware of how much pads cost, they may treat them with more care. Use a softer pad if the power of your machine can't compress the pad sufficiently to achieve a satisfactory rolling action. Although no hard and fast guidelines regarding pad life are available, you can take a number of steps to get the most life from all your pads:

• Use a strong solvent only for first time initial removal of the silicone oil on the super surface.


• Use a very mild solvent such as alcohol, or preferably an adhesive tape, if the pad must be cleaned during production.


• Always use an brown packaging adhesive tape to remove debris and dried ink before starting a production run.


• Never use too much of pad pressure during printing process.


• Ensure that the substrate is free of dust, particularly the sharp particles, before you start printing.


• When possible, avoid printing near sharp-substrate edges. For that never print on to an empty nesting fixture.


• With wood-backed pads don't let the screws penetrate into silicon rubber.


• Use as large a pad as is reasonable for the job.


• Never store a pad on top of other pad.


• If pads are supplied in a protective shell, use it when storing the pads in your shop.


• If you continuously use strong solvents on printing pads they will cause them to permaturely wear out.


• Please Handle and store the pads very carefully.

One other point about pad life is that many inks have aggressive solvents that will be absorbed by the pad during printing. This absorption of solvents will cause the image to "grow" on the super surface of pad, to the point that it will eventually affect the print quality. At this point, you must stop the machine and replace the pad with another pad of same shape and size. This isn't a permanent condition, though: If you allow the original pad to stand for some time, the solvents that have penetrated into it will evaporate, returning the pad to its normal surface finish. You can accelerate this process by warming the pad. Then you can use this pad again after some time.

CONCLUSION ON PADS:
Although the importance of pads is sometimes overlooked in the field, remember that the process derives its name from these silicone-rubber image carriers from plate to the substrate. Correct selection and care of pads is essential. As with any process, pad printing has its limitations and it's best to understand those before you choose a pad. Common sense and experimentation will guide you. Overall, keep pad in good condition, and it serve you well.

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