Water transfer printing process can be described as follows 0000testWater transfer printing process can be described as followsWater 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 next process step.
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.