Printing on many types of substrates, and customers in providing material can only say it is "plastic", "white", "polymeric materials" and other information, so screen printing is only to find out exactly what it is material and choose the right ink.The purpose of this paper is to introduce common plastic and POP materials.
styrene
Styrene is widely used in indoor and posters, in retail and exhibition galleries can be seen everywhere, it can also be used for making bottles and packaging.Styrene material hard, brittle, thermoplastic material, it is sensitive to solvent, if use excessive solvent can appear crack, the thickness of the thinner styrene can rip, harsh voice.When a large roll of styrene shaking up sound like thunder.
Styrene can also be identified through simple solvent test.Styrene with ketones and aromatic solvents will become soft, add a few drops on styrene screen cleaning agent will clear in a few minutes to soften.Using fingertips touch gloves to soften surface will produce fine plastic stripe.A few drops of aromatic hydrocarbons can also make a styrene to soften.
Can also identify the styrene combustion test.Styrene after burning flame orange, crackle, releasing a thick black smoke, when away the styrene from burner will continue to burn.
polypropylene
Of pp thermoplastic hard material rigidity, good durability, suitable for making signs, containers/bottles, boxes and coated film.Common polypropylene as the groove type single, have different shapes.Sign at the bottom of the container has a recycling mark Code5 or PP, and other products such as cups, pen don't recycle marking.
Polypropylene cutting clean, can float in water, can be repeated bending without tearing or damaged.
Since polypropylene is very resistant to solvents, solvent test signifies little.Combustion test can provide a lot of information.Blue and yellow flames of fire, no smoke, when the polypropylene away from the burner will continue to burn.To soften the plastic transparent, like other polyolefin polymers, polypropylene without ignition point, polypropylene combustion flame cannot spread quickly.
polyethylene
Polyethylene is often used for containers, solvent resistance, water pipes and packing.It also has a single form.There are different types of polyethylene, low density, dense, hard leaflet, banner for flexible polyethylene, and so on.Substrates suppliers usually provide polyethylene rolls and the single type.
Polyethylene material is qualitative light, strong, special solvent resistance, it has wax feeling, which makes it can distinguish with polypropylene.Polyethylene sheet before tearing stretch.Polyethylene as polypropylene cutting clean, also can float in water.Solvent and burning test results and polypropylene are exactly the same.
In order to get the ideal printing ink viscosity, appropriate printing process is indispensable.Container decorator online to fire the bottle before printing, banner printer usually use corona discharge on the material pretreatment.
ethylene
Ethylene substrates is the most widely used plastics in the screen printing, can be used to sign, tape, decals, bottles, labels, advertising posters, and so on.Screen printing is common with pressure-sensitive ethylene vinyl, static, rigid PVC, PVC plate expansion, vinyl banner material, polishing ethylene vinyl, friction resistance, etc., there are many other types.Ethylene can be coarse divided into flexible and rigid, can be subdivided according to use purpose.
Flexible ethylene include oily flexibility agent, is that it makes the material with flexibility and scalability.Ethylene contained in the flexibility agent is not part of the ethylene strictly.Have flexible agent can usually smell measured, can also see from the surface of the oil film, many flexible agent has the smell of identification, for many people is sweet.The longer the life of ethylene, flexible agent smell is strong.Hard vinyl no flexibility, so there is no smell.
In the cyclohexanone ethylene rather than soft aromatic solvents.Ethylene present a bright green flame flame test, release the dirty black smoke.When remove from heat immediately go out.Vinyl film is hard to tear, cut clean.
Polycarbonate and polyester
Polycarbonate and polyester film is generally used in membrane switch panel, instrument panel, label and nameplate.Two kinds of materials are transparent and frosted.Polycarbonate and polyester have important differences, screen printing, it is very important to distinguish them, because their differences will affect the convex printing, die-cutting, pressure and other operations.
Often contact screen printing of these two kinds of material can be distinguished by feeling it them, possibly through sound, touch, or tear at appearance.
The simplest is a chemical test, polyester resistance to solvents and polycarbonate is not.Knowing this, put a drop on the polycarbonate cyclohexanone over 15 min ~ 30 min will be obvious softening, while polyester is not affected.
Polycarbonate combustion test will find it difficult to ignite and burn sometimes sputter, orange flame, scented, black smoke.Polycarbonate carbonized in the combustion process, remove from heat will continue to burn, it cut clean, ethyl ketone in ring become soft, aromatic solvent is not.
Polyester combustion test will find it fast burning, bluish light yellow flame, burning when meeting from heat, the above mentioned polyester is very resistant to solvents.
test
The initial test begins with the observation, only to have to solvent and combustion chemistry tests, through processability could clear a variety of plastic, without the need for further chemical test.
The first step is to log color, texture, feel, feel is including rough, smooth, fabric, fiber, wax, oil.Smell plastic determine whether there is a smell, odor may be softening agent.Shake it listening to the sound, it easy to bend?Or it brittle?Can you easily tear?Cut a small piece of material to observe it is tidy or have burrs, put it in the water it is floating or sinking.
Further testing is the solvent and combustion experiments.When making these tests should be ventilated good environment, the operator test any industrial chemicals are put on the gloves and safety glasses.
Simple solvent testing is dripping solvent on material, put 30 min, and then use a gloved fingers touch drops of solvent, check the plastic softening or inflation.Used for testing the commonly used solvents is ketones and aromatic solvents, most thermoplastic don't resistance to solvent, but commonly used solvent resistant screen printing materials, including polypropylene, polyethylene, polyester.