1. There is color difference in the wood grain of the two batches of aluminum materials
Cause: the temperature control of the rotary charging furnace is abnormal, and the temperature sensing probe falls off.
Solution: control the transfer furnace temperature well, and do not change the fixed process temperature at will; ensure that the temperature sensing probe is firmly attached before entering the transfer furnace.
2. The wood grain on the aluminum surface is not clear
Cause: the set transfer furnace process temperature is too high and the curing time is too long.
Solution: reduce the set value of transfer furnace process temperature and control the temperature and baking time in a proper range.
3. The wood grain on the aluminum surface is too dark
Cause: the set transfer furnace process temperature is too low, the curing time is too short or the temperature sensing probe falls off halfway.
Solution: increase the set temperature of the transfer furnace, extend the baking time, stabilize the temperature sensing probe, and return to the furnace for baking if necessary.
4. There is no wood grain on the surface of aluminum
Cause: the vacuum degree of transfer furnace is not enough, and the wood grain film is perforated and air leaks.
Solution: carefully check whether the lamination is crooked and air leakage, and use high temperature resistant adhesive paper to subsidize the perforation position or replace the wood grain film cover.
For the above aluminum products which have serious defects of wood grain quality and need to be reworked, the aluminum products with quality defects can be baked in the rotary printing furnace until the color of the wood grain has faded out, and then the heat transfer printing can be carried out again.
5. Process I: paste transfer with heat transfer glue, suitable for large area or special-shaped substrate
Step 1: select the substrate that has been sprayed or electrophoresis.
Step 2: use heat transfer glue to stick the front side of the wood grain heat transfer paper to the transferred surface of the transferred substrate (select manual operation mode of brushing and pasting, or select mechanical operation mode of brushing and pasting with universal wheel wrapping machine). The purpose of using heat transfer glue is to make the wood grain heat transfer paper cling to the transferred surface of the transferred substrate.
Step 3: send the wrapped substrate to the oven for baking. The baking temperature and time should be adjusted according to the characteristics of the substrate to be transferred, the depth of the texture to be transferred and the specific performance of the oven. Generally, the transfer temperature is 160-180 ℃, and the time is 5-8 minutes.
Step 4: take out the transferred substrate from the oven, tear off the heat transfer paper and clean the surface.
6. Process II: applicable to large area or special-shaped base materials
Step 1: select the substrate that has been sprayed or electrophoresis.
Step 2: wrap the transferred substrate with wood grain heat transfer paper, and fix the paper interface with high temperature resistant adhesive paper to prevent the wood grain heat transfer paper from loosening. (Note: the front of wood grain heat transfer paper should be pasted with the transferred surface of the transferred substrate.)
The third step: the tubular plastic bags with high temperature resistance and good sealing performance are sheathed on the base material which has been wrapped by the wood grain heat transfer paper, and then vacuum from both ends of the plastic bags until the plastic bags can fully and effectively adhere to the base material. The negative pressure of the vacuum should be adjusted according to the characteristics of the substrate to be transferred and the negative pressure that the plastic bag can bear, usually between 0.3 and 0.8MPa. (Note: the purpose of using plastic bags is to force the wood grain heat transfer paper to fully and effectively adhere to the substrate through the negative pressure
Step 4: send the wrapped substrate to the oven for baking. The baking temperature and time should be adjusted according to the characteristics of the substrate to be transferred, the depth of the texture to be transferred and the specific performance of the oven. Generally, the transfer temperature is 160-180 ℃, and the time is 5-8 minutes.
Step 5: take out the transferred substrate from the oven, pull off the plastic bag from one end of the transferred substrate, tear off the heat transfer paper, and clean the surface.
7. Process 3: applicable to plane base material
Step 1: select the substrate that has been sprayed or electrophoresis.
Step 2: lay the front of wood grain heat transfer paper against the front of the substrate to be transferred.
The third step: press and heat the plate heat transfer machine, usually the transfer temperature is 160-180 ℃, the time is 18-25 seconds.
Step 4: tear off the heat transfer paper.
8. Transfer with pet heat transfer film
A process I: applicable to special-shaped substrate
Step 1: select the substrate that has been sprayed or electrophoresis.
Step 2: wrap the transferred substrate with pet heat transfer film, and seal the pet heat transfer film into a tubular bag with ultrasonic sealing machine. (Note: the front of pet heat transfer film should be pasted with the transferred surface of the transferred substrate.)
Step 3: vacuumize the two ends of the tubular pet heat transfer film bag until the pet heat transfer film can fully and effectively adhere to the substrate. The negative pressure of vacuum should be adjusted according to the characteristics of the substrate to be transferred and the negative pressure that pet heat transfer film can bear, usually between 0.3 and 0.8MPa.
Step 4: send the wrapped substrate to the oven for baking. The baking temperature and time should be adjusted according to the characteristics of the substrate to be transferred, the depth of the texture to be transferred and the specific performance of the oven. Generally, the transfer temperature is 160-180 ℃, and the time is 5-8 minutes Step 5: take out the transferred substrate from the oven, and remove the pet heat transfer film by manual or mechanical air blowing (that is, blow the pet heat transfer film tubular bag with air blowing).
B process II: applicable to plane substrate
Step 1: select the substrate that has been sprayed or electrophoresis.
Step 2: lay the front of pet heat transfer film against the front of the substrate to be transferred.
The third step: press and heat the plate heat transfer machine, usually the transfer temperature is 160-180 ℃, the time is 18-25 seconds Precautions (take the wood grain heat transfer paper and pet heat transfer film produced by our company as examples, for reference only)
9. How to compare the color of heat transfer paper or film?
A generally, when comparing the color of heat transfer paper or film, we should select the same texture and position of the contrast sample, and use the same transfer conditions, transfer on the same substrate of the same background color, and make comparison under the same light source. Because the way of directly using the paper sample or film sample surface color before transfer for comparison is not accurate.
B. when selecting the base material for color comparison pressing plate, try to be consistent with the base material base color used in mass production.
10. Will heat transfer change the original characteristics of the substrate?
A. products with decorative texture are processed by heat transfer printing, which will not change the original luster, wear resistance, weather resistance, acid and alkali resistance of the products due to heat transfer printing. Heat transfer printing only plays a surface decoration effect.
B the surface treatment of the transferred substrate is very important, such as smoothness, glossiness, color, etc., which will directly affect the surface effect of the substrate after transfer. If the surface of the transferred substrate is high gloss, the transferred product is also high gloss.
11. After heat transfer, what is the reason for the phenomenon of bad paper or film removal?
The wood grain heat transfer paper and pet heat transfer film produced by our company have taken into account the production process that users can easily take off paper or film. If there is still bad phenomenon of taking off paper or film, the possible reasons are as follows:
A. There are quality problems on the surface of the transferred substrate, such as high temperature resistance, paper sticking or mucosal phenomenon.
B. after powder spraying, the powder spraying layer on the surface of the transferred substrate is not fully cured, resulting in re curing during heat transfer.
C if the heat transfer glue is used, the quality of the heat transfer glue, the ratio concentration and the brushing amount and other factors will directly affect the off paper.
D if the heat transfer glue is used, it is recommended to add the release agent (also known as silicone oil) into the heat transfer glue properly to solve the problem of paper stripping.
12. After heat transfer, why is the heat transfer paper or film fragile or zooming?
It is usually caused by aging of heat transfer paper or film due to too high temperature or too long time of transfer baking.
13. Why does the same heat transfer paper or film produce the color difference of transfer products?
A. when comparing colors, the comparison conditions of "selecting the same texture and position of the contrast samples, using the same transfer conditions, transferring on the same substrate of the same background color, and comparing under the same light source" are not observed.
B. there is color difference in transfer substrate.
C. unstable performance of transfer equipment.
D. during the heat transfer processing, the temperature and time of transfer are not well controlled. Generally, when the transfer temperature is between 120 ℃ and 190 ℃, the transfer temperature and time are in direct proportion to the depth of the transfer texture color. Otherwise, when the transfer temperature is lower than 120 ℃, it cannot be transferred; when the transfer temperature is higher than 190 ℃, it will gradually make the color of the texture transferred to the substrate lighter with the passage of time Transfer color depth curve and transfer time, temperature diagram:
14. After transfer, what is the reason for the uneven color on the surface of the product or the deep and light color?
A. the surface contact between transfer paper or transfer film and substrate is not close or sufficient, such as warping of transfer paper during baking, or air leakage of tubular bag during vacuum pumping, etc.
B the temperature in different positions of the oven is different or uneven.
C. when the base material is put into the oven, different positions are not put into the oven at the same time, so that some parts of the base material have a longer transfer time than other parts.
D. when the company is carving the printing plate roller, it intends to make the texture with a deep and shallow style, so customers should pay attention to the original style of the printing plate roller when selecting plates.
15. After heat transfer, what is the reason for the spot or foggy block of the product?
A. the surface of the transferred substrate has spots or foggy blocks.
B. the surface of the transferred substrate is not resistant to high temperature, and there is paper sticking or mucosal phenomenon.
C the powder spraying layer on the surface of transferred substrate is not fully cured.
D. if the heat transfer glue is used, the quality, ratio concentration, brushing amount and other factors of the heat transfer glue will cause this phenomenon. The normal heat transfer glue will volatilize automatically after high temperature without leaving any trace.
E. if this phenomenon is caused by the use of heat transfer adhesive, it is suggested to wipe the transferred substrate with water or send it to the oven for short-term baking according to the actual situation.
F if this phenomenon is caused by the use of hot transfer membrane, it is suggested to use low concentration acetone and other organic solvents to scrub to remedy it.
16. Is the heat transfer product easy to be discolored or discolored?
A. the quality of the base material finish of transfer products will directly affect the transfer effect and weatherability of the final transfer products. When spraying powder, the powder with good weatherability shall be selected, which is generally polyester, followed by polyurethane, with the spraying thickness of more than 50 μ M.
B the company selects the imported printing ink, which is high-grade in light fastness. Generally, after transfer printing under normal conditions, the pigment on transfer paper or transfer film will penetrate to the surface of the substrate about 50 μ m deep, so it is not easy to decolorize.
17. How to improve the production efficiency of heat transfer printing?
There are differences between wood grain heat transfer paper and pet heat transfer film in the operation process and transfer equipment of heat transfer printing, the production efficiency of using PET heat transfer film transfer printing will be higher, and each transfer surface of different or complex shape substrate can be transferred with texture.
18. What are the advantages of heat transfer over other transfer methods?
A. compared with water transfer printing, heat transfer printing has the advantages of high production efficiency and low cost.
B less equipment and fewer operators.
COMPANY:Fujian MingLv Aluminum Co., Ltd.
Contact:Mr. ZHENG
Tel:+86-0592-5718928
Phone:+86-13779947258
Email:120514135@qq.com
Add:No.44 hongcuoli, Dongren Road, Jimei District, Xiamen, China