Printing machine and scraping the looks be like simple, actually the stencil is fairly complex part of screen printing.Screen printing machine strip commonly known as plastic (glue) choose wrong, silk screen printing product happens scraper has depth, silk
Article printed logo, printed out, blow not durable, screen printing machine printed stencil material is polyurethane, solvent resistance, good wear resistance, specification size, more extensive all kinds of screen printing machine.
When strip screen printing products:
1. Transfer the ink by screen printing screen to substrates.
2. Scrape off the redundant ink on silk screen.
3. Keep the screen with substrates line contact.
4. Able to shape different substrates of printing.
Only the printing machine and scraping the above four function to get a good play, print high quality print.And the physical properties of the scraper is crucial to the above function.(e.g., high hardness
Glue can shave off excess ink, but not well meet the requirements of various substrates shape).Therefore, when choosing the stencil should fully take into account the above factors on the function of the stencil performance
Ring, avoid the bad influence on printing effect.
A, when choosing appropriate performance of the stencil, need to consider the following four factors:
1. Hardness:
The stencil is usually made of polyurethane, with hardness tester to measure the hardness of the stencil.The hardness of the stencil, size and blade shape determines the bending of the stencil, flexibility and stress.Hardness of the van
Wai from 55 to 90 degrees (shore A).Hardness value measured with shore A hardness tester.55-65 - a is a low blow hard rubber, hard, in 66 a - 75 - a is more than 75 a is high.
High hardness rubber to glue shave first three function is very good, will ink into the screen and pressure will transfer from fine screen ink onto substrates, and keep the screen line contact with the substrates.High hardness of the rubber
Scrape the only defect is can't satisfy the different shapes of substrates printing, the printing when the rough surface and uneven surface of the stencil is also high quality requirements.
2. The effective width:
Refers to the stencil into aluminum handle, from aluminum handle out the stencil width.The width is very important, determines the stencil bending under pressure.Bending is the effective width of cube values.Such as two times
The effective width is greater than 23 = 8 bending.
The stencil bending causes changes in two aspects: the stencil and screen Angle change;Printing pressure is passed on to the substrates.Compared the stencil to a set of spring, for example, when the spring into a certain Angle
Force, spring began to bend, the preaching of smaller and smaller.The stencil printing Angle decreases, and lack of printing pressure, printing effect is not ideal.Printing small Angle, pressure decreases, and the large amount of ink, the ink
Layer thickening.(in this case, increases the printing pressure, printing operators stencil bending increases, the ink layer is still not ideal.Solution is to glue scraping increased hardness, adhesive Angle increases.
) it is glue scrape the effective width of the glue to the influence of the four major functions.
Usually the stencil the effective width of between 20 mm to 30 mm.Based on the selection of optimal effective width substrates flatness, network map as resolution and other printing parameters such as: plastic scraping Angle, speed
Degrees and types of ink.On the substrates of flat/smooth printing of images of high resolution power, the effective width is small (less than 20 mm), high hard, using suitable ink for printing.In the uneven, coarse
Rough substrates, to increase the effective width (sometimes more than 30 mm), lower hardness, low hardness and adhesive scraping the adaptation ability is poor, not excessive bending, can also be used on both sides of the middle hard soft three layers
Or double blow.Usually, the effective width increases, the printing speed and to increase the Angle.
3. The shape of the stencil:
The stencil shape refers to the cross section of the stencil.Most of the shape of the stencil is simply blow square, other shapes of adhesive used in specific printing conditions.Hard rubber, for example, scraping the performance is better than soft glue scrape,
But the poor adaptability of substrates.Use slanting blowing, printing edge easy deformation (similar to soft glue).
There are three kinds of the shape of the stencil printing workers can choose: party (or square edge blowing), various inclined and round shave (horn).Party has a wide applicable scope, can provide the largest printing pressure, printing
Brush Angle on effective width.Oblique blow to provide maximum flexibility, reduce printing pressure, printing Angle smaller than set point.Circle the adaptability of the worst, provide minimum printing pressure, printing Angle can be
As a free set (often is the smallest Angle).These reasons will influence the amount of ink.
Second, silk-screen printing machine scraping gum maintenance can prolong the life of article silk screen scraping, can drop the printing cost, in use and maintenance methods are:
1 cleaning method: use weak washing diluted solution;Article will blow in from soaking in the solution do not use cyclohexanone, acetone, MEK, VYNIL, PYROLDORE, carbon oxide, water Ding Bing esters such as cleaning.
2 storage methods: after use and cleaning, article scraping knife holder, blade should be facing up;Not a long time in the sun light, in constant temperature, and humidity;To avoid dust and dirt.
Three, silk-screen printing machine the stencil in use should pay attention to:
1 in the process of using clean every 4 hours, the flat for about 3 hours after solution volatile again after use.
2 do not use used in printing ink dry, or in the ink dry on the strip, should be cleaned as soon as possible.