Injection mold maintenance methods

Molds have an extremely important role in modern industry, and their quality directly determines the quality of the product. Improve the service life and precision of molds.

Shortening the manufacturing process cycle of molds is a technical problem that many enterprises urgently need to solve, but failure forms such as collapsed corners, deformation, wear and tear, and even fractures often occur during the use of molds.

Although it is in the selection of injection molding materials, molding equipment, and mold design under the expected injection molding process conditions, people’s understanding is often imperfect, so it is necessary to carry out a trial mold test after the mold processing is completed, to see how the quality of the injection molded parts. After finding always, carry out the mold repair to exclude the error nature.

There are many kinds of bad plastic parts, and the reasons are very complicated, there are reasons for the mold, and there are also reasons for the injection molding process conditions, and the two are often intertwined.

Before repairing the mold, we should analyze and study the defect in detail according to the actual situation of the injection molded part, find out the cause of the defect and propose remedial methods.

Because the molding conditions are easy to change, so the general practice is to change the molding conditions first, when changing the molding conditions can not solve the problem, then consider repairing the mold.

Repair the mold should be more cautious, not very sure not to take rash action. The reason is that once the mold conditions are changed, it is not possible to make a major transformation and restore the original state.

Therefore, the repair of the mold is also necessary. There are many methods to repair the mold, such as the EDM process, argon arc welding repair, laser welding technology, and the electric brush plating method.

Argon arc welding repair

The use of continuous feeding of the wire and the workpiece between the burning arc as a heat source, by the torch nozzle spray gas protection arc, to carry out welding.

Argon arc welding is currently the most commonly used method and can be applied to most major metals, including carbon steel, and alloy steel.

Dissolved electrode inert gas shielded welding for stainless steel, aluminum, magnesium, copper, titanium, zirconium, and nickel alloys, due to the low price, is widely used in mold repair welding, but the welding heat affected area, large welding joints, and other shortcomings, the current in precision mold repair has been gradually replaced by complementary laser welding.

The electric brush plating repair

Brush plating technology is a special DC power supply equipment, the positive side of the power supply is connected to the plating pen, as the anode when brushing; the negative side of the power supply is connected to the workpiece, as the cathode when brushing, the plating pen usually uses high-purity fine graphite block as the anode excess material, graphite block outside wrapped in cotton, and wear-resistant polyester cotton cover.

When working, the power supply component is adjusted to a suitable voltage and the plating pen is dipped in the plating solution with a certain relative movement speed on the surface contact of the repaired workpiece.

The metal ions in the plating solution diffuse to the surface of the workpiece under the action of electric field force and gain electrons on the surface to reduce to metal atoms, thus these metal atoms are deposited and crystallized to form the plating layer, that is, to obtain the required uniform deposition layer on the working surface of the repaired plastic injection mold cavities.

Laser welding repair

Laser welding is the use of high-power coherent monochromatic photon streams focused on a laser beam as a heat source for welding. This welding method usually has continuous power laser welding and pulsed power laser welding.

The advantage of laser welding is that it does not require a vacuum, but the disadvantage is that it does not penetrate as well as electron beam welding. Laser welding allows precise energy control, which makes it possible to weld precision devices.

It can be used for many metals, especially for difficult-to-weld metals and dissimilar metals. It has been widely used in the repair of injection molds.

Laser welding is performed by using a high-power coherent monochromatic photon stream to focus a laser beam as a heat source. This welding method is usually available in continuous power laser welding and pulsed power laser welding.

The advantage of laser welding is that it does not require a vacuum, but the disadvantage is that it does not penetrate as well as electron beam welding. Laser welding allows precise energy control, which makes it possible to weld precision devices.

It can be used for many metals, especially for welding difficult metals and dissimilar metals. It has been widely used for the repair of molds.