Silkscreen Printing 

A screen is made of a piece of mesh stretched over a frame. A stencil is formed by blocking off parts of the screen in the negative image of the design to be printed; that is, the open spaces are where the ink will appear on the substrate.

Before printing occurs, the frame and screen must undergo the pre-press process, in which an emulsion is ‘scooped’ across the mesh and the ‘exposure unit’ burns away the unnecessary emulsion leaving behind a clean area in the mesh with the identical shape as the desired image. The surface to be printed (commonly referred to as a pallet) is coated with a wide ‘pallet tape’. This serves to protect the ‘pallet’ from any unwanted ink leaking through the screen and potentially staining the ‘pallet’ or transferring unwanted ink onto the next substrate. Next, the screen and frame are lined with a tape. The type of tape used in for this purpose often depends upon the ink that is to be printed onto the substrate. These aggressive tapes are generally used for UV and water-based inks due to the inks’ lower viscosities. The last process in the ‘pre-press’ is blocking out any unwanted ‘pin-holes’ in the emulsion. If these holes are left in the emulsion, the ink will continue through and leave unwanted marks. To block out these holes, materials such as tapes, speciality emulsions and ‘block-out pens’ may be used effectively.

The screen is placed atop a substrate. Ink is placed on top of the screen, and a floodbar is used to push the ink through the holes in the mesh. The operator begins with the fill bar at the rear of the screen and behind a reservoir of ink. The operator lifts the screen to prevent contact with the substrate and then using a slight amount of downward force pulls the fill bar to the front of the screen. This effectively fills the mesh openings with ink and moves the ink reservoir to the front of the screen. The operator then uses a squeegee (rubber blade) to move the mesh down to the substrate and pushes the squeegee to the rear of the screen. The ink that is in the mesh opening is pumped or squeezed by capillary action to the substrate in a controlled and prescribed amount, i.e. the wet ink deposit is proportional to the thickness of the mesh and or stencil. As the squeegee moves toward the rear of the screen the tension of the mesh pulls the mesh up away from the substrate (called snap-off) leaving the ink upon the substrate surface.

   

  

A Poety Education for Kemp Hospice

Kidderminster College Poetry Competition is being held to raise money for Kemp Hospice a local cancer charity, these are a couple of entries from students.

studying

Diversity

What is diversity?

The difference between you and me

The difference between he or she

The avoidance of perversity

What is diversity?

More than black or white

More than wrong or right

More struggling against adversity

We want diversity

We want to be free

We want a committee

We all agree

Diversity in college goes hand in hand with knowledge.

 

 

Education

 

Off to get an education

A college level vocation

Waiting at the bus station

Overflowing with anticipation

It’s 32 week duration

Looking forward to graduation

What if there’s been a cancellation?

What if there’s a problem with the application?

Have a done enough preparation?

Enough of my active imagination

I’ll check with student information

They can give me explanation, mediation without hesitation

And soon I be in a new occupation

All thanks to my college education.