Electrochemical Aluminum Hot Stamping Common Faults and Solutions (2)

5. Gold falls

Phenomenon: The hot stamping of the printed products removes gold powder dust after a slight friction, which affects the integrity and effectiveness of the hot stamping pattern.
Reason: The hot stamping temperature is too low, the glue layer and the hot stamping material are not well bonded; the pressure is too light, the fixing is not strong; the hot stamping time is too short; after the adhesive is dry, the film is too brittle.

Solution: Try to find the appropriate temperature; Stamping time is slightly longer; Pressure is adjusted to an appropriate level, not too low, to be fixed after hardening firm, pressure is not too great, may be too large gold layer adhesion phenomenon . The adhesive layer is brittle, and only ask the manufacturer to solve it.

6, hot stamping misplaced

Phenomenon: The position of hot-spotting moves more and more serious.

Cause: The displacement of the printing plate has become more severe with time. Paper feeds and other materials that are actually printed are not in the correct position, or the positioning pins are loose or come off.

Solution: Check and correct the position of the plate to make it stick firmly; send the stamped material to the position and keep it pushed every time; the correct position should be appropriate; do not loosen and fall off the positioning pin.
When using anodized aluminum, be sure to store it in a cool, dry place away from direct sunlight. Second, we must use it rationally, make the best use of it, and make full use of anodized aluminum.

7, hot stamping pinhole

Phenomenon: When a wide imprint is printed on a hot stamp, it should be completely covered by gold. There is no regular size hole, that is, the golden film is not hot. Especially when there is a hot ink layer or a smooth surface. Hot stamping temperature is not stable.

Reason: The coating of the galvanized aluminum layer is not uniform, and when the bronzing layer is hot, some of the gold is not bonded. On the surface of a smooth material (such as plastic), the surface has a large degree of local crystallinity, which is not compatible with the adhesive; In one case, the adhesive is not compatible with the resin used in the ink layer (incompatible); in one case, the desiccant in the ink layer is too loose, and it is adhered off during hot stamping.

Solution: According to the hot stamping material selection of aluminum; appropriate increase in stamping temperature; on the surface of the crystallinity of the hair processing; ink layer to make the ink layer dry hot stamping, the ink layer should not be too thick, paper is not good The replacement of the texture of a good paper. In order to prevent the spot stamping of the auto-connected voltage regulator from being locally unstable, a non-contact electronic voltage regulator is used to reduce power consumption and provide uniform and stable heating.

8, cloud atomization

Phenomenon: Gold is not bright, the surface seems to float a light frost.

Cause: Hot stamping temperature is too high; light pressure.

Solution: The hot stamping temperature depends on the nature of the aluminized adhesive layer used. The currently used adhesive layer is divided into two types, a hydrosol layer and a solvent-based adhesive layer.

Water-soluble adhesive layer, adhesiveness using methacrylate (such as methyl ester, butyl ester, ethyl ester), acrylate (such as ethyl ester, etc.), various monomers after emulsification polymerization, and then mixed in a certain proportion, Add leveling agent, thickener, etc., paint and dry. Before applying the water-soluble color layer, apply a thin layer of glue (such as polyvinyl butyral based glue). This glue layer requires a low temperature. At present, the No. 8 and No. 15 anodized aluminum on the market belong to this type.

Solvent-type adhesive layers, ie, various adhesives, are dissolved in a solvent (eg, acetone, ethyl acetate, alcohol, etc.) and then coated. Adhesives such as nitrocellulose, shellac, rosin, acrylate, etc.


Currently, No. 100 and No. 12 galvanized aluminum on the market are solvent-based adhesive layers, which require relatively high temperatures.

Therefore, the fixed stamping temperature may not be suitable for each kind of anodized aluminum. Moreover, unlike the anodized aluminum manufacturers, their adhesive layers may not always be the same. Ocean should ask the manufacturer of anodized aluminum to ask about the temperature requirements of the products it produces. It should not be generalized; adjusting the pressure makes the gold layer more completely transformed.

9, spotting and foaming

Phenomenon: The thickness of the hot gold layer is uneven, with agglomerate and astringent. Some gold layers are foaming. The brightness is not enough.

Reasons: The hot stamping temperature is too high, coupled with great pressure, hot stamping time is long, so that the gold layer is black, even if the substrate is heated and the air rushes out, resulting in metal foaming.

Solution: According to the hot stamping material to grasp the temperature, hot stamping soft plastic, the temperature is generally 70 ~ 80 °C, hot stamping paper, the temperature is generally 100 ~ 120 °C, hot stamping hard plastic, paint cloth temperature should be 110 ~ 130 °C between. According to the thickness and nature of the stamping parts, the variable resistance voltage regulator is adjusted in time to control the temperature, and the pressure grasps the principle of “full and uniform” and the time masters “complete transfer”. It does not affect the principle of gold. It is generally between 0.5 seconds and 1 second.

Source: China Ink Technology Network