Basic knowledge commonly used in mold design

In addition to the mold itself, the mold also needs a mold base, a mold seat, a device for ejecting parts caused by the mold core, and the like. These parts are generally made into universal models. Mold enterprises need to be bigger and better, and determine product positioning and market positioning according to market demand, technology, capital and equipment. These practices are especially worth learning and learning from small mold enterprises, and concentrate on gradually forming their own technical advantages and product advantages. Therefore, mold enterprises in China must actively learn from the experience of these foreign advanced enterprises in order to develop better in the future.

The classification of molds depends on the different materials formed.

Hardware mold, plastic mold and its special mold.

Hardware dies are divided into: punching dies (such as punching dies, bending dies, drawing dies, hole-turning dies, shrinking dies, undulating dies, bulging dies, shaping dies, etc. ), forging die (such as forging die, upsetting die, etc. ), extrusion die, extrusion die, die casting die, forging die, etc.

Non-metallic molds are divided into plastic molds and inorganic non-metallic molds. According to the different materials of the mold itself, the mold can be divided into sand mold, metal mold, vacuum mold, paraffin mold and so on. Among them, with the rapid development of polymer plastics, plastic molds are closely related to people's lives. Plastic molds can generally be divided into injection molding molds, extrusion molding molds, gas-assisted molding molds, etc.

Basic knowledge of mold design 88 1, common plastic engineering materials and shrinkage?

ABS:0.5% (unbreakable rubber)

Pc:0.5% (bulletproof glass glue)

PMMa:0.5% (plexiglass)

Polyethylene: 2% polyethylene

Polystyrene: 0.5% (polystyrene)

Polypropylene: 2%( 100% soft rubber)

Nylon: 2% (nylon)

PVC: 2% (PVC)

Polyformaldehyde: 2% (plug steel)

ABS+PC:0.4%

PC+ABS :0.5%

Engineering material: ABS PC PE POM PMMA PP PPO PS PET

2. How many systems is the mold divided into?

Dump and eject? Cooling? Molding? unleash

3. What problems should be paid attention to in the process of mold design?

(1) The wall thickness should be as uniform as possible, and the demoulding slope should be large enough.

(2) The transition part should be smooth and smooth to prevent sharp corners.

③ the gate. The runner should be as wide and short as possible, the gate position should be set according to the contraction and condensation process, and cold material wells should be added if necessary.

(4) The surface of the mold should be smooth with low roughness (preferably 0.8).

(5) Exhaust holes and grooves must be enough to exhaust air and gas in the melt in time.

(6) Except for PET, the wall thickness should not be too thin, generally not less than1mm..

4. What are the common defects of plastic parts?

Lack of glue? Cloak? Bubbles? Shrinkage? Welding marks? Black spots? Stripes? Tilt up? Hierarchy? shed a skin

5. What are the commonly used plastic die steels?

45# S50c 7 18 738 7 18H

738H P20 23 16 8407 H 13

nak 80 nak 55s 136s 136h SKD 6 1

6. What steel is used for high mirror polishing?

Commonly used high hardness heat-treated steels, such as SKD6 1, 8407, S 136.

7. What is the structure of the template?

Panel? A board? B board? Square iron? Guide? Thimble disk? Thimble fixing plate? sole

8. What are the basic forms of parting surface?

Straight man? Tilt? Surface? Vertical? cambered surface

9. How to hide each other in UG?

CtrL+B or ctrL+shift+B

10, what are the mold processing machinery and equipment?

Computer gong? Lathe? Milling machine? Grinder? Drilling machine

1 1. What are 2D and 3D?

D is the prefix of dimension, 2D refers to two-dimensional plane, and 3D refers to three-dimensional space. In the mold part, 2D usually refers to plan, that is, CAD drawing, while 3D usually refers to 3D drawing.

What is the default precision of 12 and pro/e? What is the default precision of UG?

The default precision of pro/e is 0.0012mm, and that of UG is 0.0254mm..

13. What are the top four enterprises in the world in terms of formwork production?

Germany: Hasko, Japan: Shuang Ye, USA: DME, China: LKM (Ji Long)

14. What is the default word height of CAD?

The default word height of CAD is: 2.5 mm

15, what is touching and what is inserting?

The mating surface of the male die and female die parallel to the PL surface is called the contact surface, and the mating surface of the male die and female die not parallel to the PL surface is called the insertion surface.

16, the relationship between sliver and silk

Stripe and silk are both units of length. The strip in Taiwan Province Province is 1 = 0.0 1 mm, and the silk in Hong Kong is 1 = 0.0 1 mm, so 1 = 1.

17, where is the pillow?

There is often a gap on the edge of the plastic part of the shell for installing various accessories. The pillow-shaped parting part formed here is called pillow position.

18, what is a crater?

The shape of the root of BOOS column reflected in mold is called mold crater after volcanic eruption.

19, what do you mean?

Oh, it refers to the core, a Hong Kong idiom.

20. What is a tiger's mouth?

The tiger's mouth is also called: pipe position, that is, the position used for limiting.

2 1, what is ranking?

The product layout on the mold is called ranking.

22. Where is the glue?

The cavity of the product on the mold is called the gluing position.

23. What is the bone position?

The tendon on the product is called: bone position.

24. What is the column position?

The column of BOSS on the product is called: column position.

25. What is a virtual location?

The gap in the mold is called a dummy position.

26. What is the position of the buckle?

The hook used for connection on the product is called the buckle position.

27. What is the fire mode?

The pattern left after EDM is called fire pattern.

28. What PL surface?

PL surface, also called parting surface and Lamian Noodles, refers to the part where the front mold and the back mold contact when the mold is closed.

29. What is a computer gong?

CNC milling machine and machining center

30. What is a copper worker?

EDM usually uses easy-to-process copper material as discharge electrode, which is called copper worker, also known as electrode. Copper workers are generally divided into rough workers, rough young workers, young workers and young workers, also known as Seiko.

3 1. What is the spark position?

In the process of discharge, the discharge gap between copper workers and steel materials is called spark potential. The spark potential of rough workers is generally 10 to 50, and that of young workers is generally 5 to 15.

32. What is the material level?

Avoid the thickness of plastic products, also known as the thickness of meat.

33. What is the original body?

The retain force of that original body is relative to the blade. Original body retention means that a whole piece of steel is a processing blank and is processed together during processing.

34. What are the welding marks?

The line formed when two strands of plastic meet is called weld mark.

35. What is a jet plane?

After the plastic enters the cavity from the glue inlet, it forms a serpentine flow mark, which is called jet flow.

36. what does LKM mean

LKM refers to the Ji Long embryo, and the commonly used embryos are: LKM, Fordba, Li Ming, Huansheng, Changhui and Desheng.

37. What does DME mean and what does HASCO mean?

DME and LKM are standard parts, DME is made in America and HASCO is made in Europe.

38. What is reverse buckle?

Parts of the product that cannot be directly demoulded by the front and rear molds become inverted.