Lab-Scale Digital Printing Machine

• Printing width: Min. 600 mm
• Media.Vvidth: Min. 500 mm
• Number of Ink Channels/Colors 4-8
• Inksystem type : 1-2 litre
• Take Reel: Yes

Printing Related Defects/Problems

Incomplete Curing of Pigment Prints-

Definition and Causes:

In order to ensure color fastness and wash durability of a pigment printed fabric a complete curing process must take place. Read also Printing and Packaging Machine Spare Parts

This is achieved after the printing process and in the drying stage where the print paste, through the binder’s fusion process, binds with the surface of the fabric.An incomplete curing will cause one or a combination of the following: Cracking of the printed areas, particularly if thicker pigment paste is used Flaking of the pigment paste Poor crocking in both dry and wet state Poor wash fastness and durability

Preventive Suggestions:

The curing temperature often depends upon the type of the base fabric, the extent of the coverage, the thickness of the paste and the type of binders used.However, as a general rule, for an effective curing to take place, the printed areas need to be exposed to temperatures of no less than 360 degrees Fahrenheit for approximately 8 to 10 seconds. 

Corrective Measures

For this problem no corrective measures are available.Incomplete Steaming and Fixing of Wet Prints-

Definition and Causes

When using the wet print process it is important to ensure a thorough and complete steaming process is carried out. This is done to facilitate the dye absorption and establish sharp print definition. Failure to do this will result in one or a combination of the following:

• Lack of full dye exhaustion
• Poor crocking
• Poor color fastness and wash durability

Preventive Suggestions

Correct steaming process must be used. Prior to printing the fabric must be checked for the presence of An-ionic softener residue. Any left-over residue might affect the steaming procedure.

Corrective Measures

For this problem no corrective measures are available.Incomplete Removal of Base Color in Discharge Printing-

Definition and Causes

The basic premise of discharge printing, which is done on an already dyed fabric, is to remove the dyed base, in pre-determined areas, and to replace it with a new color thus creating a printed pattern. This type of printing is normally done on synthetic and cellulose fabrics where lighter shades need to be printed on a darker ground color. The incomplete removal of the base color will result in a lack of print sharpness and definition.

Preventive Suggestions

The use of appropriate chemicals and at correct conditions is essential.The chemicals that are used are of the” reducing” types and must be used, in most cases, in an alkali stable condition. Any presence of acid based components may lead to the decomposition of the reducing agents.

Corrective Measures

For this problem no corrective measures are available. Incomplete Pattern Transfer in Heat Paper Transfer Printing-

Definition and Causes

Heat paper transfer printing is a common process predominantly used on synthetic fabrics. It is a delicate process but it can be performed at very high rates of production. It is done by placing the especially constructed patterned papers on to the surface of the fabric and through the application of heat cause the transfer of the patterns from the paper to the surface of the fabric.

The most common problem with this process is the incomplete transfer of patterns which is due to the inappropriate finish of the fabric.

Preventive Suggestions

If the fabric is contaminated with certain silicone softeners and resins, this transfer process may be adversely affected.

Corrective Measures

For this problem no corrective measures are available.