The secret of long life of injection mold is here

1、 Manufacturing mold No

1. The mold number must be processed with a milling machine above the outer end face of the mold blank (square iron). The characters are 40mm high and 0.5mm deep, and the characters are in the form of equal lines.

2. Each template must be marked with the mold number in a uniform direction.

3. All screws, lifting ring holes and mold components of the mold must be metric specifications, while the mold accessories to be processed must be standard specifications. It is prohibited to make them locally.

2、 Skid position

1. Each set of mold shall be milled at four corners of B plate (movable template) for the purpose of FIT mold and mold repair.

3、 Die pit

1. All non I-shaped mold blanks need to be milled out of the coding groove in the front and back mold, and the specific size depends on the design size of the mold.

4、 Code die screw hole

1. Each set of mold shall be provided with coded mold holes on the moving mold base plate and fixed mold panel.

2. The hole spacing shall be determined according to the injection model

5、 Top rod hole

1. The bottom of the movable formwork must be provided with a large jacking hole with a diameter of Φ 25～40mm

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

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

6、 Locating ring

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

2. The size of the locating ring shall be determined according to the hole diameter of the wallboard of the injection molding machine,

3. The diameter tolerance of locating ring is 0.2~0.4mm, and the height of protruding die plate is 8~10mm smaller,

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

7、 Reset device first

1. When the ejector sleeve is related to the row position ejector device, a first reset device must be set on the mold. Do not rely on the spring to reset the ejector plate, so as to avoid future spring failure and collision between the row position (core pulling) and the ejector sleeve.

2. A travel switch must be installed between the ejector plate and the movable template to ensure that the reset device is effective before the mold can be energized and closed.

8、 Ejector plate guide post guide sleeve

1. The ejector plate is 12 or more long, or the tooling alignment is off center

2. More small thimbles with diameter less than 2mm

3. More drivers (more than 10) are equipped,

4. In the above three cases, four guide pillars and guide sleeves must be added to the ejector plate to ensure that the ejector pin can eject the rubber parts evenly and stably.

9、 Ejector plate spring bow

1. Four reset slingshots must be installed on the upper thimble plate of all moulds to help the thimble retract evenly,

2. The blue slingshot specially used for plastic mold is used, and both ends of the reset slingshot are polished,

3. The reset slingshot cannot be compressed by more than 40% of the free length. Four ejecting limit nails shall be made on the ejector pin panel when the rubber part is effectively ejected

4. To fix the reset slingshot, there must be fixed counterbores at both ends. It is prohibited to use unreliable methods of one end counterbore and the other end grinding flat.

10、 Automatic dehydration device

1. The fine nozzle mold (three plate mold) must be equipped with pull rod, brace or return pin to ensure that the movable nozzle of nozzle plate and A plate will fall off automatically.

2. The thickness of the material for bracing is 10mm or more than 12mm,

3. The diameter of brace screw shall not be less than 8-14mm,

4. Four nylon nails (nylon puller) are installed on the surface of B plate (movable formwork), which is safe, reliable, economical and practical.

11、 Ejector action

1. It shall be ensured that the beer parts can be ejected reliably in any occasion, and that they will not be reset in connection with other mold parts before mold closing,

2. When ejecting, the beer piece shall not be deformed, the white top and clamping stagnation shall be ejected rapidly, and the thimble trace shall not affect the appearance quality of the beer piece.

3. The ejection shall be balanced and smooth, without any inclination of the thimble plate, and without noise

4. After ejecting, the ejector pin shall automatically retract (except for special molds).

12、 Row position action

1. The action of the slider (row position) shall be smooth to ensure that the shape piece does not move, and there shall be no dead action, uneven, loose and other phenomena;

2. The guide surface of large sliding block shall be provided with oil groove;

3. The large sliding block must have a cooling channel;

4. HVE6 shall be used for the combination of sliding block and sliding seat, which shall not be too loose;

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

6. A clearance of more than 0.2mm must be left between the inclined guide pillar hole and the inclined guide pillar. It is prohibited to fit with the same size;

7. The angle of the slope guide post is 2 degrees less than the slope of the wedge tightening surface of the row position. The wedge tightening block of the large slider must extend into the lower mold for 15-20mm, and the interlocking back pressure shall be conducted with a 10 degree slope.

8. For the cavity of circular slider combination, the angle of longitudinal and wedge tightening surface of the wedge slider and the angle of the slope column differ by 2 degrees respectively. It is prohibited to use the same degree. The final positioning of the slider above the mold must be pushed or pulled by a slingshot, and the form of wave beads cannot be used to prevent the slider from hitting the wedge tightening block and the slope guide column when closing the mold.

9. The rubbing surface of all rows must be equipped with wear-resistant plates, with the length ≥ 30mm and width ≥ 50mm. The thin row position and row position pressing plate shall be hardened by more than 52 degrees, and the large row position shall be nitrided or hardened according to the requirements before mold opening.

13、 Formwork hole

1. The upper and lower sides of small mold A and B plates are provided with mold lifting screw holes;

2. All formworks of large moulds shall be provided with mould hanging screw holes or both sides.

14、 CAVNO.:

1. The parts with multiple cavities in the first mock examination must be marked with CAVNO on the non exposed surface and the mating surface to show the difference. The CAVNO must be marked before the previous mold test.

2. The CAVNO mark position should be marked after contacting the design engineer.

15、 Material channel shape

1. In principle, O-shaped (round) material channel is adopted;

2. In special cases, trapezoidal chute is used;

3. The section size of the material pass is usually determined according to the size of the product and the number of faces in the cavity of the mold. The specific size is determined according to the mold design drawing;

4. There are many shapes and styles of the material crossing, usually including flat joint, flat joint, point casting, submersible, three or four claw point casting. The specific size of the material crossing is positive or negative to the actual product size. When opening the material crossing, the flow should be evenly distributed. Generally, the material crossing increases gradually as it is farther away from the main stream. The fine nozzle is point casting. In principle, the belly button hole should be reserved. Generally, the inclined position of the material crossing should be opened when the flat joint enters the water, To avoid the increase of auxiliary labor after the product glue leaves the water outlet.