Home > News > Content
Injection Mold Maintenance Knowledge
Aug 03, 2018

Core Tip: Mold is an extremely wide range of process equipment used in the middle of industrial production. The development of modern industry and the improvement of technology level are inseparable from the mold. According to statistics, 75% of rough machining of industrial parts and 50% of finishing machining are completed by mold forming. According to their types can be divided into: cold stamping, injection molds, die-casting molds, rubber molds and so on.

First, injection mold introduction

1.1, the scope of application: plastic injection molds used in thermoplastics such as ABS, PP, PC, POM, etc., and thermosetting plastics such as phenolic plastic, epoxy plastic, etc. are used rubber mold;

1.2, injection mold classification: According to the structure: two-plate mold, three-plate mold; according to the outlet: Dagukou, point outlet, hot water outlet.

1.3, injection mold structure

A, molding parts: that is, we often say before and after the mold CORE, is also the most closely linked with the product;

B. Casting system: the flow path of molten plastic from the nozzle to the cavity can be divided into: the main channel, the runner, the gate, the cold material well, etc.;

C. Guidance system: Determine the relative position of the front and rear molds when closing the mold. Generally, there are guide posts and guide bushes. If necessary, the ejector part also needs guide posts and guide bushes for positioning;

D. Demoulding structure: It is the device that pushes out the plastic parts from the mold. Commonly used are: ejector pin, top plate, and department tube;

E, temperature adjustment system: In order to meet the mold temperature requirements of the injection molding process, cooling water channels added to the front and rear molds;

F, lateral type and lateral core pulling: When the plastic parts have an inverted structure that is inconsistent with the direction of stripping, you must use the line position, the common form: slider, inclined roof, pull core, etc.;

G. Exhaust Structure: There are two common types of exhaust: exhaust slots and gaps between formed parts. In order to eliminate the air in the cavity and the gas generated during the molding process during the injection molding process, an exhaust groove is often provided on the parting surface. The principle of setting up the exhaust groove is to make the exhaust groove as large as possible without affecting the flash and the front edge. Inserts, ejectors, and inserts are exhausted using the gap between molded parts.

Second, mold maintenance

During the normal use of the mold, due to normal or accidental wear, as well as various anomalies that occur in the process of plastic beer, it is necessary to fix the mold.

2.1. Preparation of mold technicians after receiving tasks

A, to clarify the degree of mold damage;

B. Refer to repair model, analysis of maintenance program;

C. Degrees: Our maintenance of the molds is largely carried out under no-drawing conditions. The principle of our maintenance is does not affect the structure and dimensions of the plastic parts. This requires that our modelling mechanics are designing. When you change the size, you should take a few counts and proceed to the next step.

2.2. Precautions for loading and removing the mold

A. Marking: When the repair technician removes the guide post, division tube, ejector pin, insert, pressure block, etc., especially if there is direction requirement, be sure to see the corresponding mark on the mold blank so that it can be seated when loading the mold. . In this process, two things must be kept in mind:

1. The identifier must be unique and must not be repeated;

2. Unmarked mold inserts must be marked with characters;

B, foolproof: In the parts that are prone to misinstallation, do a good job of defiance and ensure that the equipment cannot be installed in the case of anti-fouling;

C. Placement: The removed parts need to be neatly arranged, and the screws, springs, aprons, etc. should be packed in a plastic box.

D. Protection: Make protective measures for the core, cavity and other precision parts to prevent others from accidentally bumping.

2.3. Precautions when Serving Surfaces

A. Machines and Provincial Molds: When the plastic parts are glued, dragged, etc. to be saved, the parts with grained surface should be well protected before they can be repaired. Machines and provinces shall not be allowed to save the pattern of light, in the absence of confidence should be required to drop the mold maintenance;

B. Welding: If the pattern surface is to be welded, it must be noted:

1, the electrode must be consistent with the mold CORE material;

2, after the welding needs to be tempered;

C. Patch pattern: When the mold repair is in need of a factory patch pattern, the repairer needs to protect the pattern surface with a paper cover, and marks the position of the streaking pattern with the pattern of the streaking pattern. When the etched pattern is returned to the factory, the quality of the etched surface should be carefully checked. After confirming OK, the mold can be loaded. If you do not grasp the maintenance effect, you should first try to confirm OK, before the factory can make up the pattern.

Third, mold maintenance

Mould maintenance is more important than die maintenance. The more times the die is repaired, the shorter its life span; and the better the die maintenance, the longer its service life will be.

3.1, the necessity of mold maintenance

A, maintain the normal operation of the mold, reduce unnecessary wear and tear on the active part;

B. Make the mold reach the normal service life;

C. Reduce oil pollution in production.

3.2, mold maintenance classification

A, daily maintenance of the mold;

B, regular maintenance of the mold;

C, the appearance of the mold maintenance.

3.3, mold maintenance content

A, daily maintenance:

1. Various moving parts such as thimble, row position, guide column and guide sleeve refueling;

2, the cleaning of the mold surface;

3, transporting water to clear the road;

B. Regular maintenance:

1, 2, 3, ibid;

4, the exhaust slot clean up, trapped gas burn black position plus exhaust;

5, damage, wear part correction;

C, appearance and maintenance:

1. Paint the outside of the mold to prevent rust;

2. When the mold is dropped, the cavity should be coated with anti-rust oil;

3, should be closed tightly during storage to prevent dust from entering the mold CORE.

3.4, mold maintenance considerations

A, sports parts, daily maintenance must refuel;

B, the mold surface must be clean: Do not stick the label paper on the P/L side, the goods have not been taken out before the mold continues to take the beer, the P/L position glue wire is serious;

C. If abnormalities are found, such as ejecting anomalies, large opening and closing modal noises, etc. must be promptly repaired;

Fourth, safety issues in mold repair and maintenance

To do anything, safety issues must be placed first. Mold repairs and maintenance are related to molds and equipment (steel), and this issue must be highly regarded;

1, when using rings must first check to ensure intact;

2, the use of equipment, especially the production of flying debris, be sure to bring glasses operation;

3. Wear protective clothing and protective glasses when welding;

4. It is forbidden to work on the bottom of the mold;

5. When the machine is in operation, it is necessary to ensure that the injection molding machine is in a stopped state and hangs a good sign.