Here is the secret of long life of injection mold

1. Make mold numbers

1. The mold numbers must be processed by milling machine on the upper side of the outer end surface of the mold blank (square iron), with a height of 40mm, a depth of 0.5mm, and a uniform font.

2. The mold numbers must be printed on each template with a letter code, and the direction must be uniform.

3. All screws, hanging ring holes and mold parts of the mold must be metric specifications, and the accessories of the processing mold must be standard specifications. Self-made molds are prohibited.

2. Prying mold positions

1. Each set of molds has prying mold positions milled on the four corners of the B plate (moving mold plate) for FIT mold and mold repair.

3. Code mold pits

1. Non-I-shaped mold bases need to have code mold grooves milled on the front and rear molds. The specific size depends on the mold design size.

4. Code mold screw holes

1. Each set of molds must open code mold holes on the movable mold bottom plate and the fixed mold panel.

2. The hole spacing size must be determined according to the injection machine model

V. Ejector hole

1. The bottom of the movable mold must have a sufficiently large ejector hole with a diameter of Φ25~40mm

2. Small molds only need to open one ejector hole, medium-sized molds must open more than three ejector holes, and large molds need to open five holes.

3. The ejector hole diameter and position are based on the actual size (design size) of the injection machine model

VI. Positioning ring

1. Each set of molds must be equipped with a positioning ring (i.e. positioning flange) to facilitate mold positioning,

2. The size of the positioning ring should be determined according to the hole diameter of the injection machine wall panel,

3. The tolerance of the positioning ring diameter is 0.2~0.4mm, and the height of the protruding mold panel is 8~10mm,

4. The standard size of the positioning ring (flange) between the mold and the machine plate is 100mm-0.20^-0.40mm,

VII. Pre-reset device

1. When the ejector sleeve and the slide ejector interfere with each other, a pre-reset device must be installed on the mold, and the ejector plate must not be reset solely by the spring to prevent the spring from failing in the future and the slide (core pulling) from colliding with the ejector sleeve.

2. A travel switch must be installed between the ejector plate and the moving plate to ensure that the pre-reset device is effective before the mold can be powered on.

VIII. Ejector plate guide pin and guide sleeve

1. The ejector plate is 12 or more in length, or the mold is centered

2. A large number of small ejectors are configured with a diameter of less than 2mm

3. A large number of ejectors (more than 10) are configured,

4. In the above three situations, four guide pins and guide sleeves must be added to the ejector plate to ensure that the ejector ejects the plastic parts in a balanced and stable manner.

IX. Ejector plate spring bow

1. All molds must be equipped with four reset springs on the ejector plate to help the ejector retract evenly.

2. Use a blue spring specially made for plastic molds, and grind both ends of the reset spring flat.

3. The reset spring cannot be compressed by more than 40% of the free length. Four ejection limit pins must be made on the ejector panel when the plastic part is effectively ejected.

4. The reset spring must be fixed with fixed countersunk holes at both ends. The unreliable practice of countersunk holes on one end and grinding flat surfaces on the other end is prohibited.

X. Automatic dehydration device

1. Fine gate molds (three-plate molds) must be equipped with tie rods, pull bars or return pins to ensure that the gate plate and A plate move to the gate and automatically fall off.

2. The thickness of the pull rod material is 10mm or more than 12mm.

3. The diameter of the pull rod screw cannot be less than 8-14mm.

4. The B plate (moving template) is equipped with 4 nylon nails (nylon puller), which is safe, reliable, economical and practical.

11. Ejector action

1. It should ensure that the beer parts can be ejected reliably in any occasion, and reset without interfering with other mold parts before closing the mold.

2. The beer parts should not be deformed during ejection, and the ejector white and jamming phenomena should be ejected quickly, and the ejector marks should not affect the appearance quality of the beer parts.

3. The ejection should be balanced and smooth, and the ejector plate should not be tilted, and there should be no noise during ejection.

4. After the ejection is completed, the ejector should automatically retract (except for special molds).

12. Slide action

1. The slider (slide) should move smoothly to ensure that the parts do not move, and there should be no dead movement, unevenness, looseness, etc.;

2. The large slider guide surface should have an oil groove;

3. The large slider must have a cooling water channel;

4. The slider and the slide seat are matched with HVE6 and should not be too loose;

5. When the slider sliding stroke is too long, the guide must be increased on the mold base. Usually, the length of the sliding part should be about 1.5 times the width. When pulling the core, the matching part of the slider in the guide groove should have 2/3 of the slider sliding part in the guide groove;

6. The matching of the inclined guide column hole and the inclined guide column must leave a gap of more than 0.2mm, and the same size matching is prohibited;

7. The angle of the inclined guide column is 2 degrees less than the inclination of the slider wedge surface. The wedge block of the large slider must extend into the lower mold 15-20mm, with a 10-degree inclined surface interlocking back pressure.

8. For the cavity of the circular slider combination, the angle of the wedge surface of the longitudinal and wedge sliders and the angle of the inclined column are 2 degrees different, and the same degree is prohibited. The slider above the mold must be pushed or pulled by a slingshot for final positioning, and a wave ball cannot be used in form to prevent the slider from hitting the wedge block and the inclined guide column when closing the mold.

9. Wear-resistant plates must be installed on the rubbing surfaces of all sliders, and the length of the rubbing surface is ≥30mm and the width is ≥50mm. Fine sliders and slider pressure plates must be quenched and hardened to more than 52 degrees, and large sliders must be nitrided or hardened according to the requirements before mold opening.

13. Hanging mold holes

1. There are hanging mold screw holes on the upper and lower sides of the A and B plates of small molds;

2. All templates of large molds are made with hanging mold screw holes, or both sides.

14. CAVNO.:

1. One-mold multi-cavity parts must be marked with CAVNO. on the non-exposed surface and the mating surface to distinguish them, and they should be marked before the first mold trial.

2. It is advisable to contact the design engineer before marking the position of CAVNO.

15. Channel shape

1. In principle, O-shaped (circular) channel is used;

2. Trapezoidal channel is used in special cases;

3. The cross-sectional size of the channel opening is usually determined according to the product size and the number of faces in the inner cavity of the mold. The specific size is determined according to the mold design drawing;

4. The channel opening has many shapes and styles, usually flat, flat, point-casting, diving, three-four-claw point-casting. The specific channel opening size is positive or negative with the actual product size. When opening the channel opening, the flow rate should be evenly distributed. Usually, the farther away from the main channel, the larger the channel opening is. For the fine water outlet point-casting type, in principle, the navel should be retained. Generally, the flat water outlet should be opened at an oblique position to avoid increasing the auxiliary labor workload after the product glue leaves the water outlet.