The use and selection of screen printing squeegee
1. The squeegee has four functions
1. Make the ink flow through the screen.
2. The screen can be contacted with the printing material.
3. It can ensure that the screen is compatible with the printing and material surface.
4. It can remove the excess ink on the screen.
There are two criteria for choosing a squeegee

1. Squeegee hardness

The hardness of the squeegee is usually expressed by Shore hardness, and the hardness ranges from 55 Shore to 95 Shore.
In the screen printing industry this-range is also used as a measure of hardness. Squeegee hardness from highest to lowest 5 Shore
The hardness is equal and decreasing, which ensures the stability of printing quality. The hardness of the squeegee affects the degree of deformation and bending of the squeegee,
The squeegee’s performance coefficient will vary from squeegee manufacturer to different manufacturers, and this point can only be manifested during printing.
The hardness value of the squeegee affects how the squeegee aligns with the substrate and determines how much pressure
Ink flows over the screen. The softer the squeegee, the better the compatibility between the squeegee and the screen surface, and the smaller the required printing pressure.
On the contrary.
2. The shape of the cut surface of the squeegee
The shape of the cut surface of the squeegee refers to the shape of the cross-section at the end of the contact between the squeegee and the screen, which is determined by the shape of the cut surface.
The amount of pressure on the surface of the substrate material. Different cutting planes can make the ink flow more or less, thus affecting the affects the thickness of the printing ink layer. The shape of the cut surface of the squeegee also determines the compatibility of the squeegee with the surface of the substrate.
And directly affect the amount of printing ink and the fineness of the printed image. The sharper the printing end of the squeegee, the less the excess ink flow, and the printing The better the resolution of the brushed image and the better the printing clarity, the thicker the printing ink layer will be.

3. How to choose the right squeegee
The working part of the squeegee is the printing end of the squeegee, and the printing end of the squeegee contacts the screen during the printing process. glue
The hardness or softness of the scratch is critical to the entire printing process. It is not to say that the squeegee determines the printing quality
quantity.
1. The hybrid squeegee has a solid support, and the hardness of the printing end of the squeegee can be changed. because glue
Scraping will bend during printing, which reduces the screen pressure, increases the contact area with the surface of the substrate material, and reduces the printing oil.
The ink is applied more uniformly on the surface of the substrate. Hybrid squeegees are ideal for high-speed presses and can
By printing flat glass and solder resist, the multi-color printing ink layer and UV varnish layer are uniform. Some prints are not
This hybrid squeegee is needed, but as customer demand for high quality prints increases, choose the right squeegee
Very necessary.
2. Flat-mouth squeegee is widely used in the printing of common materials such as paper and textile printing. This kind of squeegee and printing
The adaptability of the material is moderate, the pressure generated is the greatest, and the ink is scraped off the screen instead of flowing through under pressure
Screen printing, so ink excess is minimal, flat-mouth squeegee is ideal for thick and thin line printing and halftone printing. ink
The smaller the ink layer, the finer the printed image.
3. The sharp-mouthed squeegee can control the amount of ink flow well when printing glass and plastic bottles. Double blunt glue
The squeegee can better control the printing angle, and the pointed squeegee is also suitable for fine printing on textiles.
4. Groove type squeegee is used in container printing. The contact recombination with the surface of irregular objects is particularly good,

The hardness of the squeegee is divided into three categories
1. Soft squeegee
Generally, soft squeegee is used under the conditions of moderate squeegee pressure, large screen opening and low ink viscosity.
It is the best choice for printing irregular objects and uneven printing platforms. Use soft squeegee printing, ink build up
Large quantity, moderate printing image fineness, – generally used for large area printing and glass and ceramic printing.

2. Medium hardness squeegee
When the printing pressure is high, use the medium hardness squeegee, any mesh and ink can choose the medium hardness glue
Scrape and print. Make medium hardness squeegee printing, and the ink accumulation amount is good. Good image resolution, suitable for all kinds of printing
Material printing.
3. Hard rubber scraper
Use a hard squeegee when printing pressure is at its highest and when ink viscosity is high. Small ink accumulation, image resolution.Fairly good, usually fine screen printing can choose a hard squeegee, which produces a very thin layer of ink.
5. The difference between Shore degree and squeegee hardness
1. 55 Shore to 65 Shore is a soft squeegee.
2. 65 Shore bottom to 75 Shore degree is medium hard squeegee.
3. 75 Shore to 95 Shore is a hard squeegee.

6. Grinding of squeegee
The squeegee print end will eventually be damaged and deformed due to frequent friction with the screen. Use a scraper to make glue
The scraped edges are sharpened again. There are a few things to keep in mind when we do squeegee grinding:
1) Grind with a finer grinding wheel to minimize the loss of squeegee material during scraping. Guarantee the squeegee edge
Clean, non-spotting, non-melting, and the wheel spins at a low speed.
2) When it needs to be worn out quickly – large pieces of squeegee material can be scraped with a coarse grinding wheel.
3) If you only need to scrape the glue smooth, you can use very fine sandpaper.

4) When using a cutting knife to cut off a part of the squeegee and need to be re-sharpened – be sure to ensure that the squeegee after cutting
Clean without gaps.
5) After the squeegee is printed, the squeegee should be scraped immediately. After printing, the squeegee should be placed for 24 hours until the solvent is completely evaporated.
Scratching after it has fallen off.
6) In addition to ensuring that the edge of the squeegee is straight, make the free height of the squeegee along the entire length of the squeegee.
be consistent.
7. Maintenance and storage of squeegee
1) When in stock, the squeegee should be placed flat, not in rolls.
2) After opening the whole roll of scraper, it should be placed for 24 hours so that the scraper is stretched and flat before use.
3) When storing the squeegee without the handle removed, use the squeegee facing upwards, and the squeegee cannot touch anything.
4) The temperature of storing the squeegee should be in a dry environment of 200C- 250C, away from the ink, because the squeegee can absorb moisture and solvents in the air.
5) Squeegee or handle with ink cannot be stored overnight.