88 mold design common basic knowledge

1、Commonly used plastic engineering materials and shrinkage rate?

ABS: 0.5% (super unbreakable glue)

PC : 0.5% (bulletproof glass glue)

PMMa ：0.5%: (plexiglass)

PE ：2% polyethylene

PS ：0.5%(Polyphenylene)

PP：2%(Baizi soft rubber)

PA : 2% (nylon)

PVC : 2% (polyvinyl chloride)

POM ：2%(plug steel)

ABS+PC ：0.4%

PC+ABS ：0.5%

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

2、The mold is divided into those major systems?

Pouring→Ejecting→Cooling→Forming→Exhausting
 

3、What issues should be paid attention to in the process of making mold design?

(1) The wall thickness should be as even and consistent as possible, and the slope of the mold release should be large enough.

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

(3) Gating. The runner should be as wide as possible, thick and short, and the location of the gate should be set according to the shrinkage condensation process, and the cold material well should be added if necessary.

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

(5) Ventilation holes, slots must be sufficient to discharge air and gas in the melt in time.

(6) In addition to PET, the wall thickness should not be too thin, generally not less than 1mm.
 

4、Plastic parts often appear in the obstruction defect?

Lack of glue → cloak → bubble → shrinkage → fusion marks → black spots → stripes → warping → delamination → peeling
 

5、Commonly used plastic mold steel?

45# S50c 718 738 718H

738H P20 2316 8407 H13

NAK80 NAK55 S136 S136H SKD61
 

6、Which kind of outline material is used for high mirror polishing?

Commonly used high hard heat treatment steel, for example, SKD61, 8407, S136.
 

7、What is the structure of the die frame?

Panel → A plate → B plate → square iron → guide pillar → ejector plate → ejector fixing plate → bottom plate
 

8、What are the basic forms of parting surface?

Straight → inclined → curved → vertical → curved
 

9、How to hide each other in UG?

ctrL+B or ctrL+shift+B
 

10、What are the mechanical equipment for mold processing?

Computer gong→lathe→milling machine→grinding machine→drilling machine
 

11、What is 2D and what is 3D?

D English is: Dimension (line degree, dimension) of the prefix, 2D refers to two-dimensional plane, 3D refers to three-dimensional space, in the mold part, 2D usually refers to the planar drawings that are CAD drawings, 3D usually refers to three-dimensional drawings.
 

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

The default precision of pro/e is 0.0012MM

The default accuracy of UG is 0.0254MM
 

13、What are the top four global mold production companies?

Germany: HASCO

Japan: FUTABA (Double Leaf)

USA: DME

China: LKM (Longji)
 

14、What is the default word height of CAD?

The default word height of CAD is: 2.5MM
 

15、What is touch through and what is inserted through?

The male and female die lamination surface parallel to the PL surface is called touch-through surface, and the male and female die lamination surface not parallel to the PL surface is called insertion surface.
 

16、The relationship between strip and filament

Article and silk are both length units, article is the term in Taiwan, 1 article = 0.01MM, silk is the term in Hong Kong, 1 silk = 0.01MM, so 1 article = 1 silk.
 

17、 What is the pillow position?

The edge of the shell-type plastic parts often opens a gap for the installation of various accessories, where the formation of the pillow strong fractal part called the pillow bit.
 

18、What is the crater?

BOOS pillar root reduction part of the mold reflected in the type of volcanic eruption after the shape called mold crater.
 

19、What is the finger?

He refers to the mold kernel, the customary term in Hong Kong.
 

20、What is tiger mouth?

Tiger mouth is also known as the tube position, that is, the part used to limit the position.
 

21、What do you mean by displacement?

The layout of the product on the mold is called a row.
 

22、What is called glue position?

The cavity of the product on the mold is called glue bit.
 

23、What is called bone position?

The tendon on the product is called bone position
 

24、What is called column bit?

The column of the BOSS on the product is called the column bit.
 

25、What do you mean by virtual position?

The gap on the mold is called the imaginary bit.
 

26、What do you mean by buckle bit?

The hook on the product for connection is called the buckle bit.
 

27、What is called spark pattern?

The pattern left after the EDM is called the spark pattern.
 

28、What PL surface?

PL surface, also known as parting surface, snapping surface, refers to the mold in the closure of the front and rear mold contact part.
 

29、What is computer gong?

CNC milling machine and machining center
 

30、What is copper work?

EDM usually uses the easy-to-process copper material to do the discharge electrode, called copper work, also known as the electrode, copper work is generally divided into rough work, rough young work, young work, young work is also known as fine work.
 

31、What is the usual spark level?

During the discharge process, the discharge gap between the copper worker and the steel material is called the spark level, the rough work spark is usually 10 to 50, the young work spark level is usually 5 to 15.
 

32、What is the material level?

Plastic products to avoid the thickness, also known as the meat thickness.
 

33、What is the original body stay?

The original body stay is relative to the cut inserts, the original body stay refers to a whole piece of steel for processing embryo, processing together when processing out.
 

34、What is the fusion mark?

The line formed by the meeting of two strands of plastic is called a fusion mark.
 

35、What is the jet stream?

The plastic from the inlet into the cavity after the formation of curved folded like snake flow marks is called a jet.
 

36、What does LKM mean?

LKM refers to Longji mold embryos, commonly used mold embryos are: LKM, Fudeba, Mingli, Huansheng, Changhui, Desheng.
 

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

DME and LKM are both standards of standard parts, DME is the American system, HASCO is the European system.


 

38、What do you mean by inverted buckle?

The part of the product that cannot be directly demolded from the front and rear mold becomes inverted.
 

39、What do you mean by dummy-proof?

Anti-dull is a kind of idiom, that is, to prevent a very simple error, to prevent dull! For example, an insert in the sky and the earth side have the same size as the hanging table, the site assembly is likely to put the sky and the earth side of the reverse, but he did the hanging table in the side of the insert, then, if the sky and the earth side of the reverse can not be installed, want to install the wrong are impossible, this action to prevent the emergence of dullness and error is called anti-dull.
 

40、What is the name of the beer machine?

Beer machine is a local customary term, which is often referred to as injection molding machine and molding machine.
 

41、What do you mean by stop?

Stop port is the art line of clamping mouth, also known as ugly line.
 

42、What do you mean by flying mold?

The flying mold is the matching mold or standard mold.
 

43、What is called a light knife?

CNC finishing action is called light knife, that is, in the open rough based on the processing in place.
 

44、What do you mean by open frame?

The action of processing the position of the mold kernel on the mold embryo is called opening the frame.
 

45、What is the word "sun"?

The word "sun" is placed in the film and then the processing font to add the font.
 

46、What do you mean by anti?

The normal situation of the front and back of the mold material position in reverse to open the mold method is called anti-hope.
 

47、What do you mean by floating?

Part of the inverted place using small inserts to pop out of the mold method is called floating.
 

48、What do you mean by eating the front mold?

When opening the mold, the product stays in front of the mold called eat front mold.
 

49、What is called top white?

Top out the required die force is larger, the thimble is not enough to force, so that the product is partially top bad, from the front of the product, there is a clear white for the top white, also known as the top of the high water mouth.
 

50、What do you mean by baking?

When diving into the water point in the system point appearance of the surface left traces called baking marks.
 

51、What is called code boy?

Code boy belongs to the clamping tool, a triangular beveled opening bit slot of the pad block.
 

52、What is called overcutting?

Overcutting refers to excessive cutting, that is when processing the workpiece does not need to process the part also processed, overcutting is not good.
 

53、What is the school cup?

The front mold pops out the inner line of the mold bit.
 

54、What is the tooth tapping?

Tapping and thread tapping is called dental tapping.
 

55、When do I need to make a two-color mold?

When a product contains two different materials or different colors of the same material, design a two-color mold molding.
 

56、What is the process of mold design in the factory?

The customer provides product drawing→analysis of product→confirm plastic species→confirm mold material→transfer engineering drawing→multiply shrinkage for mirroring→perfect assembly drawing→order mold embryo→order mold insert material→drawing mold→3D parting→determine flow channel/gating method→refer to displacement drawing for structure design→disassembly insert→correct 3D→engineering drawing (including mold embryo/insert/mold embryo/bulk parts)→do BOM table→proofreading audit
 

57、How many ways are there for molding?

Smooth and strong off
 

58、What are the ways of glue feeding?

Direct glue → lap glue → side glue → ring glue → sheet glue → submerged → point glue → bullhorn glue → fan glue
 

59、What are the forms of runners?

There are round runner → semi-circular runner → T-shaped runner → hexagonal runner
 

60、Mold designer's manuals and books?

Steel books, plastic books, mold standard parts books.
 

61、What is the role of spring?

To produce rebound force when external use appears.
 

62、Why should the mold be pulled out?

To prevent the product from being strained when it comes off the mold.
 

63、The role of screws and the determination of the length of fit?

The main role of the tight fixing, with the length of the general, takes 1.5 to 2 times the diameter of the screw.
 

64、How much is the slope of the slider generally taken, and how much is the slope of the inclined guide column generally taken?

The slope of the slider is generally taken as 20 degrees, and the slope of the inclined column is generally taken as 18 degrees.
 

65、The role of cold material well?

The role of the cold material well is: to store the first to enter the mold of the small part of the temperature is relatively low plastic material.
 

66、The role of the positioning ring?

The role of the positioning ring is: to ensure that the mold and the injection machine maintain the correct relative position.
 

67、Relative position of the fit?

The fit is mainly divided into three categories: gap fit, transition fit, interference fit.
 

68、What is the role of inserts?

Facilitate processing, prevent carbon accumulation, facilitate polishing, save material, help exhaust, facilitate replacement, and reduce the processing machine.
 

69、What are the indicators of hardness?

Hardness indicates the ability of the material to resist the pressure of hard objects into its surface, the common hardness indicators are Brinell hardness, Rockwell hardness, and Vickers hardness.
 

70、Can a curved surface be pulled out of a mold? Can a group be pulled? Can a surface group be replaced?

The surface can not be pulled, the group can be pulled, and the group can be replaced.
 

71、What is the difference between the first angle method and the third angle method?

①、Where the object is placed in the first quadrant, the method of drawing the projected view is called the first angle method, which is also called the first quadrant method, with the relationship of {viewpoint}(observer) → (object) → (projection surface).

②, where the object is placed in the third quadrant, {point of view} (observer) → (projection surface) → (object) relationship and the projection of the view of the drawing method, that is, the third angle method, also known as the third quadrant method.

Note: The difference between the first and third angle drawing methods is the article of view placement.

The first corner drawing method: the left view is placed on the right, the right view is placed on the left, the upper view is placed below, and so on.

The third corner drawing method: the left view is placed on the left, the right view is placed on the right, the top view is placed on top, and so on.
 

72、What are the ways to transport water?

Water transport commonly used are: straight through, around the type, water tower type, spiral type.
 

73、What is the basic principle of the three views?

The basic principles of the three views are: long to square, high flush, width equal.
 

74、Injection machines are divided into those categories?

According to the shape, there are vertical and horizontal injection machines (these two are most commonly used).

According to the injection volume, there are super small injection molding machines, small injection molding machines, medium injection molding machines, large injection molding machines, and super large injection molding machines. That is, the injection volume ranges from a few milligrams to tens of kilograms, and the clamping force is divided into a few tons to several thousand tons.
 

75、What is the relationship between clamping force and clamping force?

The clamping force of the injection molding machine should be greater than the clamping force, otherwise, the mold will be opened by the pressure inside the mold.
 

76、What are the positioning methods of male and female molds?

There are two types of positioning methods for front and rear molds: one is template positioning, and the other is mold kernel positioning.
 

77、What is the suitable wall thickness of commonly used plastics?

ABS: 1.8-3mm

PC: 2-3.5mm

POM: 1.5-2.5mm

NoryL: 2-3.5mm
 

78、What do you mean by overflow value?

The edge spill value is a value that refers to how big the gap of the plastic product will spill out (also known as running burr).

ABS: 0.04mm

PC: 0.06mm

PA : 0.015mm

POM : 0.04mm

PBT+15%GR：0.03mm

PBT+30%：002mm

PMMA ：0.065mm

PVC ：0.07mm

AS ：0.05mm

PS ：0.05mm

PP ：0.03mm

PE : 0.02mm
 

79、What is the size of the standard drawing frame?

Commonly used frames are: A0, A1, A2, A3, A4

The size of A0 frame is 1189mx841m

The size of A1 frame is 841mx594mm

A2's frame size is 594mmx420mm

The size of the frame of A3 is 420mmx297mm

The size of A4 frame is 297mmx210mm
 

80、Planning of mold size?

Each company has different criteria for planning mold size, but the common criteria are as follows: 15-30 series mold germ is classified as small mold, 30-50 series mold germ is classified as medium mold, and over 50 series mold germ is classified as large mold.
 

81、What is meant by elastic deformation? What is called plastic deformation?

The object is deformed under the action of external force, when the external force disappears, the object can return to the deformation before the deformation is called elastic deformation, when the external force disappears, the object can not return to the deformation before the deformation is called plastic deformation.
 

82、What materials are commonly used for mold embryos?

The mold embryo is often made of Wang steel (called in Hong Kong), which is also known as medium carbon steel and 45 steel.
 

83、What is the difference between the model space and layout space in CAD drawing work?

Model space is the space for graphic entities, layout space is the space for the layout of drawings.
 

84、What is the role of water transportation?

The role of water transportation is: to control the temperature of the mold kernel.
 

85、What is a mold?

In industrial production, with various presses and special tools mounted on the press, through the pressure of metal or non-metallic materials to make the required shape of parts or products, this special tool is collectively known as the mold.
 

86、Classification of moulds?

Moulds can be generally divided into plastic moulds and non-plastic moulds.

Non-plastic molds are: casting mold, forging mold, stamping mold, die-casting mold

The plastic mold according to the production process and production products are divided into injection molding mold, blow mold, compression molding mold, transfer molding mold, extrusion molding mold, thermoforming mold, rotary molding mold

According to the different types of pouring systems, the molds can be divided into three categories: large spout molds, fine spout molds, hot runner molds.
 

87、What is the pouring system?

The plastic flow channel from the injector nozzle to the cavity is called the pouring system. The pouring system includes the main flow channel, manifold, gate, and cold material well.
 

88、What is reverse engineering?

Reverse engineering is the accurate and high-speed scanning of existing samples or models by the high-speed laser scanning machine, to get its three-dimensional profile data, with the inverse software to reconstruct the curvature, and online accuracy analysis of the reconstructed surface, to evaluate the construction effect, and finally generate IGES or STL data, according to the time can be rapid prototyping or CNC machining.