screen printing frame tense steps

1. Surface treatment of screen frame

Metal mesh frame before the mesh. Rough and decontamination treatment to increase adhesion.When decontamination grease, must not use oily cleaner.Net frame edge can not have sharp edges and corners, to prevent damage to the screen under the tension of the network.If it is the first use of the mesh frame, need to use fine sandpaper gently friction, make the surface of the mesh frame rough, so easy to improve the adhesion of the mesh frame and screen, also do pretreatment.Sandpaper is also used to clean the mesh frame, remove the last use of the residual glue and other substances.

2. Apply the net glue

After the screen frame surface treatment, immediately on the surface of its sticky net brush a layer of sticky net glue.For the convenience of observation, mesh glue can be added with appropriate dyes, such as alcohol soluble mesh glue can be added in red ballpoint pen oil.Glue can be applied with an oil painting brush, the brush width is about half of the width of the frame.Glue liquid concentration should not be too big, with two besmear become good, besmear first time, after the surface is dry, besmear second time again.

Adhesive method is often called adhesive mesh adhesive, its performance should meet the needs of screen and screen frame bonding firm, should be water-resistant, anti-screen common solvents, temperature change, do not corrode screen and screen frame, and should be fast dry.According to the specific screen frame, screen, ink and plate – making developer and other material characteristics, to choose the appropriate screen adhesive.

The most used is the solvent volatile adhesive mesh adhesive, this kind of adhesive with fast dry solvent, generally 3 to 5 minutes can be glued;

The glue can be “applied immediately” or “pre-coated”.Precoating is before pulling the net, the glue is coated on the frame surface to get a dry adhesive layer: fixed net

When activated with the appropriate solvent to become sticky.The domestic use of this kind of glue are acetal glue, synthetic resin glue, 502 glue, perchloro b

Most of the activators are alcohol, ketone and ester solvents. If gasoline is used as activator, rubber adhesive can be used.

In addition, there are two components of adhesive and uv curing adhesive for adhesive mesh adhesive.The bicomponent glue includes the polymer glue liquid and the curing agent two kinds of components, only then mixes them before USES, after mixes, will produce the chemical reaction and solidifies.

2. Apply the net glue

After the screen frame surface treatment, immediately on the surface of its sticky net brush a layer of sticky net glue.For the convenience of observation, adhesive mesh can be added with appropriate dyes, such as alcohol soluble adhesive mesh can be added in red ballpoint pen oil.Glue can be applied with an oil painting brush, the brush width is about half of the width of the frame.Glue liquid concentration should not be too big, with two besmear become good, besmear first time, after the surface is dry, besmear second time again.

Adhesive method is often called adhesive mesh adhesive, its performance should meet the needs of screen and screen frame bonding firm, should be water-resistant, anti-screen common solvents, temperature change, do not corrode screen and screen frame, and should be fast dry.According to the specific screen frame screen, ink and plate – making developer and other material characteristics, to choose the appropriate screen adhesive.

The most used is the solvent volatile adhesive mesh adhesive, this kind of adhesive with fast dry solvent, generally 3 to 5 minutes can be glued;The glue can be “applied immediately” or “pre-coated”.The precoating is to get the dry adhesive layer before drawing the net.When fixing the network, use appropriate solvent to activate it to become sticky.The domestic use of this kind of glue are acyl glue, synthetic resin glue, 502 glue, vinyl perchloride glue and shellac, etc., most of the activators are alcohol, ketone, ester solvents;If use gasoline kind to do activator, can use rubber type to stick net glue.

In addition, there are two components of adhesive and uv curing adhesive for adhesive mesh adhesive.Two – component glue includes polymer glue solution and solidification as

The two components of the agent are mixed before being used. After mixing, chemical reaction will occur and the curing time will be longer, generally more than 20min.But after curing adhesive layer strength, solvent resistance is good.There are a number of bicomponent gels that can be used as adhesive webs, for example

Phenolic acrylic glue, epoxy glue, polyurethane glue and unsaturated polyester glue.

Uv curable adhesives are solvent-free and have the advantages of fast drying, strong adhesion and good solvent resistance. However, they can only be dried by the irradiation of portable high-power UV light sources (such as UV lamps and dysprosium lamps, etc.), which limits their application.

The strength of the mesh, in addition to glue, but also related to the performance of the frame, that is, the mesh frame bonding surface to clean, large surface area.For this reason, the metal frames with too smooth surface, especially aluminum frames, should be roughened by anodic oxidation electrolysis, rough sandpaper or grinding wheel machinery.To prevent oxidation on roughened surfaces, it is best to cover and protect them with a two-component adhesive.The clean work of frame surface, should be carried out before coating sticky net glue, with appropriate solvent (such as ethanol, acetone and refined gasoline, etc.) or detergent will be the dust and grease of frame surface thoroughly washed, dry can be coated sticky net glue.

The commonly used adhesives for stretching network include polyvinyl acyl adhesive, polyvinyl acetate copolymer adhesive, chloroprene rubber type adhesive, cyanoacrylate adhesive, epoxy resin adhesive, etc.Glue a variety of models, the selection should be detailed reading speed

The instructions.

3. Cut the screen

Note that the cutting edge should be parallel to the warp and weft of the screen.

4. The distribution network

According to the size of the mesh frame, the size and number of mesh clips should be configured and selected, that is, the total length of each side should be shorter than the length of the inner side of the mesh frame is about 10cm.When arranging the network clip, the two opposite side of the network clip number, length and position should be symmetrical;Leave 5cm at each end of each side of the net cabinet (i.e. the corner) to avoid the risk of Angle tearing when pulling the net: The gap between the clamping ends of the net should be small:

5. Net

When the mesh clip inside, to be very careful, to ensure that the screen of warp and weft lines and mesh edge to maintain parallel, and as straight as possible, avoid cable-stayed net.

6. At the beginning

A pull that is stretched only to 60% of the rated tension is called a primary pull.Mesh due to the characteristics of weaving, the need to stretch slowly, in order to facilitate the mesh shape adjustment and tension relaxation of acceleration, but also to prevent a tension to high tension when the danger of breaking the net, so step by step or incremental pull.The operation of the pneumatic pull net is as follows.

(1) Adjust the air compressor pressure value, should be greater than the network pressure value of about 30%.

(2) Open air compressor air valve and air source controller air valve.

Adjust the pressure gauge on the air source controller to the initial tension pressure value.

(4) Open two three-way valve, compressed air through the distributor to each cylinder, push the piston, complete the initial pull.

At first drawing, carefully check the warp and weft of the net. If it is not parallel with the net clamp, loosen the wire mesh and double clamp and pull.

7. Let stand for

After about 10min of initial tension, make the screen as loose as possible under the initial tension.

8. Heavy

Increase the air pressure to the rating and measure the tension with a tensiometer (compensate for the loss of tension every 5 to 10min 1

The pneumatic thin mesh will automatically compensate: the other tension mesh must be manually replenished, that is, tensioned repeatedly until the tension stabilizes at the rating

So far.Generally need to be repeatedly tensioned more than 3 times.

9. The fixed network

Spray to the adhesive surface or brush adhesive mesh adhesive active solvent, then with cotton brush pressure mesh frame of the close, according to the entire adhesive mesh surface appears more dark and uniform color, adhesive is sufficient.If there is a light color area, it means that the area is not coated enough and should be recoated.Or the frame and the network contact is not good, can be pressed iron screen, contact sufficient and then bonding, to the adhesive part of the glue thoroughly dry, close the two three-way network, cut off the air source, pull the air inlet and the atmosphere, live damage by spring return, you can loosen the mesh clip.Take off the screen.

10. The whole edge

Cut out excess silk screen, wrapping, marking, and use tape or coating to protect adhesive parts from harmful solvents.

After taking the stretched screen from the stretching screen equipment, in order to make the screen durable and clean, also need to cut the excess screen and repair: cut the remaining net edge should be able to cover half of the outside of the frame, and stick it to the frame.