FAQ
Water transfer printing process can be described as follows
Water transfer printing process can be described as follows:
Primer Coat on Products------pretreatment:Removal of surface
impurities by polishing------Net closure on the products----Load the
products on a jig frame------Spreading the film on water-------apply
activator on film by spraying-----Pattern transfer------Washing------
Drying(air dry or oven dry)-------finishing :coat a glossy finish on
products-----Drying(oven dry)------Inspection and packing-----Ex work
Pretreatment on products
Surface clean without grease or other impurity is of vital importance
to successful WTP process, Experiences show many failures come from
poor pretreatmend on the products.
Detail requirements on pretreatment as follows:
1.First inspect the products if there is obvious impurity on surface
of the products, polish the surface with 800-1000 mesh sand paper, care
no to polish too hard to leave scrapes on the surface.
2.Hand-touch the products if the surface is smooth,if the surface is
rough with sandy feeling, polish the surface with 800-1000 mesh sand
paper.
3.Observe the products if there is oil stains, dusts or other
impurities on the surfaces, Remove the oil stains or dusts by proper
methods, for examples, remove the dust with a clean rag or the stains
with suitable solvent.
4.To remove the inferior pattern from the WTP process, you have to use
the special pattern remover,or if the area of defects is small, you can
use 800-1000 mesh sand paper to remove the defects and trim with a
paint brush.
5.The products must keep clean after pretreatment.
6.The products must keep dry after pretreatment,use an air dryer,or
blower to remove the moisture on surface of the products,or just leave
the products in clean and dry place (air-dry).
7.Place the pretreated products in a clean and dry location for the
1.1Check the products from the last process step.return the off-
quality products to the last process.
1.2Material preparation1:the products must be well prepared before
water dipping .
1.3material preparation 2:a metal door may need to dip two times,
each with different pattern, so preparation had to be made on the door
for such purpose.
1.4take a metal door, which needs to be coated on double side with
different pattern, for example, the uncoated side should be close with
a nylon net.
1.5make a nylon closure:the closure is made of 300 mesh nylon net,
the size of the net is a little larger than the door dimensions, round
the net are attached (by sewing)with magnetic bars.
1.6Close the uncoated side of the door with above mentioned nylon
net.Note:The above measure is only an example to close the uncoated
area of a metal door, anyway you have to find a solution for your
particular products, use adhesive type to seal the uncoated area is
also simple and very popular.
1.7Fix the metal door to a jig frame, the jig frame,together with the
metal door, maybe hanging from the ceiling or an iron structure, the
jig frame must be lowered down below the water surface.try several
times until you are satisfactory with the dipping procedure.
1.8if the size of the products is very small, you have to arrange the
small pieces in the jig frame , fix the pieces tightly with fixtures
or clips attached to the jig frame,the pieces must fix tight not to
move during the dipping procedure.
Operation instructions and hints on dipping.
2.1. Before dipping, the products must keep clean and free from
static electricity.
2.2 the water surface must be clean, free from remains left from the
last dipping, expel the remains to the far end of the water tank with a
scraper,(or simply a wood piece).Expel gently and slowly, do not stir
the water or this may bring forth bubbles on water surfaces.
2.3 You have to distinguish the face side and reverse side of the
film, if you are not sure, touch with a wet finger to the film surface,
the sticky side is the face side and the face side must be laid on top
and the reverse side on bottom, don’t splash water on the film
spreading on water, the film must be spread evenly on water
surface,tryto remove the curved edge of the film with you finger,
remove the bubbles between the film and water with you finger by gently
expelling the bubble out of the film.
2.4Whn to start spray the activator?
Timing for spraying of activator is also a trick for successful
dipping, after the film laying on water, you,not only need to wait for
some time(1-2minuts,)you have to observe the film change as well, in 1
-2 minutes,the film is spreading flat with light glimmering, this is
the right time you apply activator, or you may make a small test.apply
a little activator one corner of the film .
How much activator spray to the film?
This is something of skill or experience , we just run the spray gun
crosswise from left to right and from top to bottom and then
lengthwise, also from left to right and from top to bottom, the sprayed
area between two passages may have 1/2overlap,never run repeatedly on
activated surface because this may disturb the pattern waves, do not
move the gun to fast or too slow.
2.5 Notes on dipping operation.
Make a trial dipping to ensure a successful dipping procedure:
2.5.1 Do not cut the film too big or too small, cut the size of the
just enough for dipping
2.5-2Dip the product to water at an angle about 30-40 degrees.to
water surface.
2.5-3Observe the wave direction especially the pattern of wood wave,
or you may decide to turn the film 90-180 degrees on water .the dipping
is a continuous one-step procedure, never stop lowering the product
down until it totally merged in water, any stop in middle of dipping
procedure will damage the pattern.
2.5-4When the product dropped to water, swing it gently in water and
take it, also in a tilted manner out from water surface without
touching the floating film remains, do not allow the product fall down
to bottom of the tank.
2.5-5Each time when you finished dipping, check if there is any
defect on the pattern (bubbles or cracks on the pattern, for
instance),this may give you idea for improvement on next dipping, if
the remains stick to the products , washing it away with water.
2.5-6The water in the tank must be maintained at certain level, in
WTP process , water is not only used as media to give pressure for
coating, it also washes way the remains , the water need to change if
you find the water is sticky or there are bubbles or lots of remains
floating on surface.
2.5-7 In normal operation, change water once a day and drain the
water from air dryer of the compressor once a day.
3.Instructions on Washing
3.1Take care not to touch by finger the product just out of water.
The ink layer at this time is very fragile any such touch may damage
the just coated pattern.
3.2The purpose of washing is to remove the sticky later on the
surface. Do not apply too heavy a pressure for washing. Water under
heavy pressure may damage the just coated pattern.
3.3 After washing ,touch the product by our finger. If you feel
sticky on the product, then the washing is not enough. The sticky layer
must be thoroughly washed away or the adhesion for the finish coating
will be a problem!
3.4 You may also need to wash the other side(uncoated side) of the
product because usually this side also need to dip for another pattern
or apply finish coat.
4. Instructions on Trimming
4.1 Before finish coating, the defected pattern need to be trimmed.
The trimmer should prepare film.
4.2 Use the paint brush soaked with activator to erase the defected
area.
4.3Trimming is only carried out on defects of small area. If defects
on large area are found. This should report to the management to take
proper measures in dipping procedure.
4.4 The trimmer should each product before delivering to products to
the spray room.
4.5 Remove dusts or impurity on the trimmed products. Place the
trimmed products in a dry and clean place.
Which are ready to move to the spray room for finish-coat.
5. Instructions on Baking
5.1Temperature control is essential for baking process. The product
may be deformed or degraded under elevated temperatures
5.2Baking temperature for drying: thermoplastic and non-metal
products: less than 60℃；metal products： Max.180℃,because the primer
can not stand higher temperature；if the products is coated with two-
component PU paint as primer，you should observe exactly the paint
manufacturer’s operational instructions. The purpose of drying after
washing is no other than remove moisture from the products.
5.3Curing temperature for Finish coat: baking temperature and time
depend on nature of finish coat. Finish coat or transparent lacquer or
varnish has two types: baking type and non-baking type. Please follow
the manufacturer’s instructions for curing time and temperature.
6 Instructions on finish coat: the finish coat is a kind of
transparent lacquer. Paints of different type may be used for finish:
two-component PU paint, one-component lacquer, baking lacquer, baking
lacquer, gross finish and dull finish.
7 Instructions on finish coat application
7.1 Preparation: the amount of transparent lacquer prepared depends
on the amount of products
7.2 The prepared lacquer must be filtered with 300 mesh nylon screen.
7.3 The spray room must be clean, free from dusts. The floor and the
floor round the spray area must be wet to prevent dusts form flying
over in the air.
7.4 Never touch or allow any object to touch the uncured surface.
7.5 The operator must clean the spray gun before leaving the shift job.
Primer Coat on Products------pretreatment:Removal of surface
impurities by polishing------Net closure on the products----Load the
products on a jig frame------Spreading the film on water-------apply
activator on film by spraying-----Pattern transfer------Washing------
Drying(air dry or oven dry)-------finishing :coat a glossy finish on
products-----Drying(oven dry)------Inspection and packing-----Ex work
Pretreatment on products
Surface clean without grease or other impurity is of vital importance
to successful WTP process, Experiences show many failures come from
poor pretreatmend on the products.
Detail requirements on pretreatment as follows:
1.First inspect the products if there is obvious impurity on surface
of the products, polish the surface with 800-1000 mesh sand paper, care
no to polish too hard to leave scrapes on the surface.
2.Hand-touch the products if the surface is smooth,if the surface is
rough with sandy feeling, polish the surface with 800-1000 mesh sand
paper.
3.Observe the products if there is oil stains, dusts or other
impurities on the surfaces, Remove the oil stains or dusts by proper
methods, for examples, remove the dust with a clean rag or the stains
with suitable solvent.
4.To remove the inferior pattern from the WTP process, you have to use
the special pattern remover,or if the area of defects is small, you can
use 800-1000 mesh sand paper to remove the defects and trim with a
paint brush.
5.The products must keep clean after pretreatment.
6.The products must keep dry after pretreatment,use an air dryer,or
blower to remove the moisture on surface of the products,or just leave
the products in clean and dry place (air-dry).
7.Place the pretreated products in a clean and dry location for the
next process step.
Control Points and Hints
operation instructions1.1Check the products from the last process step.return the off-
quality products to the last process.
1.2Material preparation1:the products must be well prepared before
water dipping .
1.3material preparation 2:a metal door may need to dip two times,
each with different pattern, so preparation had to be made on the door
for such purpose.
1.4take a metal door, which needs to be coated on double side with
different pattern, for example, the uncoated side should be close with
a nylon net.
1.5make a nylon closure:the closure is made of 300 mesh nylon net,
the size of the net is a little larger than the door dimensions, round
the net are attached (by sewing)with magnetic bars.
1.6Close the uncoated side of the door with above mentioned nylon
net.Note:The above measure is only an example to close the uncoated
area of a metal door, anyway you have to find a solution for your
particular products, use adhesive type to seal the uncoated area is
also simple and very popular.
1.7Fix the metal door to a jig frame, the jig frame,together with the
metal door, maybe hanging from the ceiling or an iron structure, the
jig frame must be lowered down below the water surface.try several
times until you are satisfactory with the dipping procedure.
1.8if the size of the products is very small, you have to arrange the
small pieces in the jig frame , fix the pieces tightly with fixtures
or clips attached to the jig frame,the pieces must fix tight not to
move during the dipping procedure.
Operation instructions and hints on dipping.
2.1. Before dipping, the products must keep clean and free from
static electricity.
2.2 the water surface must be clean, free from remains left from the
last dipping, expel the remains to the far end of the water tank with a
scraper,(or simply a wood piece).Expel gently and slowly, do not stir
the water or this may bring forth bubbles on water surfaces.
2.3 You have to distinguish the face side and reverse side of the
film, if you are not sure, touch with a wet finger to the film surface,
the sticky side is the face side and the face side must be laid on top
and the reverse side on bottom, don’t splash water on the film
spreading on water, the film must be spread evenly on water
surface,tryto remove the curved edge of the film with you finger,
remove the bubbles between the film and water with you finger by gently
expelling the bubble out of the film.
2.4Whn to start spray the activator?
Timing for spraying of activator is also a trick for successful
dipping, after the film laying on water, you,not only need to wait for
some time(1-2minuts,)you have to observe the film change as well, in 1
-2 minutes,the film is spreading flat with light glimmering, this is
the right time you apply activator, or you may make a small test.apply
a little activator one corner of the film .
How much activator spray to the film?
This is something of skill or experience , we just run the spray gun
crosswise from left to right and from top to bottom and then
lengthwise, also from left to right and from top to bottom, the sprayed
area between two passages may have 1/2overlap,never run repeatedly on
activated surface because this may disturb the pattern waves, do not
move the gun to fast or too slow.
2.5 Notes on dipping operation.
Make a trial dipping to ensure a successful dipping procedure:
2.5.1 Do not cut the film too big or too small, cut the size of the
just enough for dipping
2.5-2Dip the product to water at an angle about 30-40 degrees.to
water surface.
2.5-3Observe the wave direction especially the pattern of wood wave,
or you may decide to turn the film 90-180 degrees on water .the dipping
is a continuous one-step procedure, never stop lowering the product
down until it totally merged in water, any stop in middle of dipping
procedure will damage the pattern.
2.5-4When the product dropped to water, swing it gently in water and
take it, also in a tilted manner out from water surface without
touching the floating film remains, do not allow the product fall down
to bottom of the tank.
2.5-5Each time when you finished dipping, check if there is any
defect on the pattern (bubbles or cracks on the pattern, for
instance),this may give you idea for improvement on next dipping, if
the remains stick to the products , washing it away with water.
2.5-6The water in the tank must be maintained at certain level, in
WTP process , water is not only used as media to give pressure for
coating, it also washes way the remains , the water need to change if
you find the water is sticky or there are bubbles or lots of remains
floating on surface.
2.5-7 In normal operation, change water once a day and drain the
water from air dryer of the compressor once a day.
3.Instructions on Washing
3.1Take care not to touch by finger the product just out of water.
The ink layer at this time is very fragile any such touch may damage
the just coated pattern.
3.2The purpose of washing is to remove the sticky later on the
surface. Do not apply too heavy a pressure for washing. Water under
heavy pressure may damage the just coated pattern.
3.3 After washing ,touch the product by our finger. If you feel
sticky on the product, then the washing is not enough. The sticky layer
must be thoroughly washed away or the adhesion for the finish coating
will be a problem!
3.4 You may also need to wash the other side(uncoated side) of the
product because usually this side also need to dip for another pattern
or apply finish coat.
4. Instructions on Trimming
4.1 Before finish coating, the defected pattern need to be trimmed.
The trimmer should prepare film.
4.2 Use the paint brush soaked with activator to erase the defected
area.
4.3Trimming is only carried out on defects of small area. If defects
on large area are found. This should report to the management to take
proper measures in dipping procedure.
4.4 The trimmer should each product before delivering to products to
the spray room.
4.5 Remove dusts or impurity on the trimmed products. Place the
trimmed products in a dry and clean place.
Which are ready to move to the spray room for finish-coat.
5. Instructions on Baking
5.1Temperature control is essential for baking process. The product
may be deformed or degraded under elevated temperatures
5.2Baking temperature for drying: thermoplastic and non-metal
products: less than 60℃；metal products： Max.180℃,because the primer
can not stand higher temperature；if the products is coated with two-
component PU paint as primer，you should observe exactly the paint
manufacturer’s operational instructions. The purpose of drying after
washing is no other than remove moisture from the products.
5.3Curing temperature for Finish coat: baking temperature and time
depend on nature of finish coat. Finish coat or transparent lacquer or
varnish has two types: baking type and non-baking type. Please follow
the manufacturer’s instructions for curing time and temperature.
6 Instructions on finish coat: the finish coat is a kind of
transparent lacquer. Paints of different type may be used for finish:
two-component PU paint, one-component lacquer, baking lacquer, baking
lacquer, gross finish and dull finish.
7 Instructions on finish coat application
7.1 Preparation: the amount of transparent lacquer prepared depends
on the amount of products
7.2 The prepared lacquer must be filtered with 300 mesh nylon screen.
7.3 The spray room must be clean, free from dusts. The floor and the
floor round the spray area must be wet to prevent dusts form flying
over in the air.
7.4 Never touch or allow any object to touch the uncured surface.
7.5 The operator must clean the spray gun before leaving the shift job.