1. Commonly used plastic engineering materials and their shrinkage rates?
ABS: 0.5% (super unbreakable rubber)
PC: 0.5% (glue for bulletproof glass)
PMMa: 0.5% (plexiglass)
PE: 2% (polyethylene)
PS: 0.5% (polystyrene)
PP: 2% (100% soft rubber)
PA: 2% (nylon)
PVC: 2% (polyvinyl chloride)
POM: 2% (steel)
ABS+PC: 0.4%
PC+ABS: 0.5%
Engineering materials: ABS PC PE POM PMMA PP PPO PS PET
2. How many systems are molds divided into?
Pouring → Ejecting → Cooling → Forming → Exhausting
3. What problems should be paid attention to during the mold design process?
(1) The wall thickness should be as uniform as possible and the draft angle should be large enough.
(2) The transition part should be gradual and smooth, avoiding sharp corners.
(3) Door. The flow channel should be as wide and short as possible, and the position of the door should be adjusted according to the shrinkage and condensation process. If necessary, a cold well should be added.
(4) The mold surface should be smooth and clean, with low roughness (preferably less than 0.8).
(5) Exhaust holes and slots should be sufficient to discharge air and gases from the melt in a timely manner.
(6) Except for PET, the wall thickness should not be too thin, generally at least 1mm.
4. What are the common defects of plastic parts?
Lack of glue → Cape → Bubbles → Shrinkage → Solder marks → Black spots → Scratches → Lifting → Layering → Peeling
5. Commonly used plastic mold steels?
45#S50c718738718H
738H P20 2316 8407 H13
NAK80 NAK55 S136 S136H SKD61
6. What type of material is used for high mirror polishing?
Commonly used very hard heat treated steels, such as: SKD61, 8407, S136
7. What structures does the mold holder have?
Panel → Panel A → Panel B → Square iron → Guide post → Ejector plate → Ejector pin fixing plate → Base plate
8. What are the basic shapes of joint surfaces?
Straight surface → inclined → curved surface → vertical → curved surface
9. How to hide in UG?
ctrl+B or ctrl+shift+B
10. What are the mold processing machines and equipment?
Computer gong → Lathe → Milling machine → Grinder → Drill
11. What is 2D and what is 3D?
The English word D is the prefix for Dimension. 2D refers to the two-dimensional plan and 3D refers to the three-dimensional space, 2D generally refers to the plan view or CAD drawing, and 3D generally refers to the three-dimensional space. three-dimensional drawing.
12. What is the default accuracy of pro/e? What is the default precision of UG?
The default precision of pro/e is: 0.0012 mm, and the default precision of UG is: 0.0254 mm.
13. Among the world’s top four mold holder manufacturers?
Germany: HASCO Japan: FUTABA (Double Leaves) United States: DME China: LKM (Longji)
14. What is CAD’s default font height?
The default height of CAD characters is: 2.5 mm.
15. What is penetration and penetration?
The joining surface of the male and female molds which is parallel to the PL surface is called the penetration surface, and the joining surface of the male and female molds which is not parallel to the PL surface is called the insertion surface.
16. The relationship between bands and silk
Strips and threads are units of length. Strips are used in Taiwan, 1 strip = 0.01mm, and silk is used in Hong Kong, 1 thread = 0.01mm, so 1 strip = 1 thread.
17. What is the position of the pillow?
There are often notches on the edges of the plastic parts of the hull, which are used to install various accessories. The pillow-like part formed here is called pillow position.
18. What is a crater?
The shape of the glued part at the root of the BOOS column reflected on the mold after the volcanic eruption is called the mold crater.
19. What is finger?
Ha refers to Mo Yan, a Hong Kong idiom.
20. What is the tiger’s mouth?
The tiger’s mouth is also called: position tube, which is the part used to limit the position.
21. What is ranking?
The arrangement of the product on the mold is called grading.
22. What is the position of the glue?
The product cavity on the mold is called: glue level.
23. What is bone position?
The tendons present on the product are called: bone positions.
24. What is the position of the spine?
The BOSS column on the product is called: column position.
25. What is virtual position?
The gap on the mold is called: virtual position.
26. What is deduction?
The hook used for connection on the product is called a loop.
27. What are spark lines?
The lines left after EDM are called spark lines.
28. Which side PL?
The PL surface, also called: parting surface and pop-up surface, refers to the part where the front mold and the rear mold come into contact when the mold is closed.
29. What is a computer gong?
CNC milling machines and machining centers.
30. What is copper working?
Electric sparks generally use easy-to-process copper materials as discharge electrodes, called copper workers, also called electrodes. Copper workers are generally divided into: raw workers, raw workers, and young and young workers. good workers.
31. What is the usual position of the spark?
During the discharge process, the discharge gap between copper and steel materials is called spark position. Raw sparks are usually 10-50 and young sparks are usually 5-15.
32. What is the material level?
The thickness of plastic products is also called flesh thickness.
33. What remains of the original body?
Compared with cutting inserts, original body retention refers to a whole piece of steel as the blank to be processed, which is processed together during processing.
34. What are weld marks?
The line formed when two strands of plastic meet is called a weld mark.
35. What is a jet plane?
Once the plastic enters the mold cavity from the plastic entrance, it forms a curved and bent snake-shaped flow mark called a jet.
36. What does LKM mean?
LKM refers to Longji mold base. Commonly used mold bases include: LKM, Fudeba, Mingli, Huansheng, Changhui and Desheng.
37. What does DME mean and what does HASCO mean?
DME and LKM are both standards for standard parts, DME is American made and HASCO is European made.
38. What is undercut?
The parts of the product that cannot be directly demolded from the front and rear molds become undercuts.
39. What is infallibility?
Infallible is an idiom, which means to avoid a very simple mistake and avoid being dazed! For example: an insert has hangers of the same size on the sky and on the ground. When installing on site, it is very likely that the top and bottom sides are installed upside down, but it makes the hangers on one side only. the insert. At this time, if the upper and ground sides are installed upside down, it cannot be installed and it is impossible to install it incorrectly. This action to avoid errors caused by blurring is called foolproof.
40. What is a beer machine?
Beer machine is a local idiom, it is what we often call injection molding machine and molding machine.
41. What is silence?
The stop is the artistic line of the mouth, also known as the ugly line.
42. What is a flying model?
The flying molds are assorted molds or standard molds.
43. What is a light knife?
The action of CNC finishing is called light knife, which is to complete the machining in place from a rough cutting.
44. What is open frame?
The action of processing the position of the mold core on the mold support is called frame opening.
45. What is the word “Sha”?
Publishing involves putting the fonts on the film and then adding fonts to the fonts.
46. What is opposition?
The method of opening the mold by reversing the front and rear positions of the mold material under normal circumstances is called reverse.
47. What is fuhe?
The mold ejection method of using small inserts to reveal parts with undercuts is called Fuhe.
48. What is eating away at the front mold?
When the mold is opened, the product remains in the front mold, which is called eating the front mold.
49. What is Dingbai?
When ejecting, the required molding force is large and the ejector pin is not strong enough, resulting in the product being partially ejected. When viewed from the front of the product, there is an obvious white mark called ejection white, also known as ejection. nozzle.
50. What is pastry?
The marks left by the point of water entry on the surface of the point made during diving are called cooking marks.
51. What is a coder?
The pliers are a clamping tool, a pad with a triangular bevel and an opening slot.
52. What is overexploitation?
Overcutting refers to excessive cutting, that is, when processing the workpiece, parts that do not need to be processed are also processed.
53. What is the school cut?
The front mold pops up and opens the inner mold position.
54. What is Yata?
Tapping, tapping on the thread is called thread.
55. When should a two-tone mold be made?
When a product contains two different materials or the same material in different colors, a two-color mold is designed.
56. What is the factory’s mold design process?
Customer provides product drawings → analyzes the product → confirms the plastic variety → confirms the mold material → converts the technical drawing → multiplies and shrinks to create a mirror image → completes the assembly drawing → orders the mold base → order the mold core material → draw the mold → 3D separation → determine the flow channel / Gate method → refer to the layout diagram for the structural design → disassemble the inserts → correct the 3D → produce the project drawings “including: mold core/inserts/mold base/parts” → create a list of parts lists → reread and revise.
57. How many ways are there to eliminate mold?
Soft and forced ejaculation.
58. What are the glue supply methods?
Direct gluing → Lap gluing → Side gluing → Circular gluing → Sheet gluing → Latent type → Dot gluing → Horn type gluing → Fan gluing.
59. What are the shapes of flow channels?
There are circular flow channels → semicircular flow channels → T-shaped flow channels → regular hexagonal flow channels.
60. What are the permanent manuals and books for mold designers?
Steel books, plastic books, mold standard parts books.
61. What is the function of the spring?
Rebound when used outdoors.
62. Why does the mold need to be sketched?
Prevent product from dripping when removed from mold.
63. What is the function of screws and how to determine the corresponding length?
It mainly plays the role of tightening and fixing. The corresponding length is generally 1.5 to 2 times the diameter of the screw.
64. What is the general slope of the slider and the slope of the inclined guide column?
The slope of the slider is generally 20 degrees, and the slope of the inclined guide column is generally 18 degrees.
65. What is the function of the cold well?
The function of the cold material well is to store the small portion of plastic material at relatively low temperature that first enters the mold.
66. What is the function of the positioning ring?
The function of the positioning ring is to ensure that the correct relative position between the mold and the injection machine is maintained.
67. The relative position of coordination?
Fits are mainly divided into three categories: undercut fit, transition fit, and tight fit.
68. What is the function of inserts?
It facilitates processing, prevents carbon deposition, facilitates polishing, saves materials, facilitates exhaust, facilitates replacement, and reduces the size of the processing machine.
69. What are the hardness indicators?
Hardness indicates a material’s ability to resist hard objects pressed against its surface. Commonly used hardness indicators include Brinell hardness, Rockwell hardness and Vickers hardness.
70. Can curved surfaces be drawn? Can the group be drafted? Can the duvet be replaced?
Curved surfaces cannot be stripped, group surfaces can be stripped, and quilt groups can be replaced.
71. What is the difference between the first angle method and the third angle method?
① Any drawing method that places an object in the first quadrant and projects the view into the relationship (point of view) (observer) → (object) → (projection surface) is called the first angle method, also known as of the first quadrant method. .
②Any drawing method that places an object in the third quadrant and projects the view into the relationship (point of view) (observer) → (projection plane) → (object) is called the third angle method, also known as third quadrant method.
Note: The difference between the first angle drawing method and the third angle drawing method is the placement of the item in the view.
How to draw the first corner: put the view from left to right, the view from right to left, the view from top to bottom, and so on…
Third angle drawing method: put the view from left to left, the view from right to right, the top view to top, and so on…
72. What are the means of transporting water?
Commonly used types for water transportation include: straight type, wraparound type, water tower type, and spiral type.
73. What are the basic principles of three points of view?
The basic principles of three views are: length is aligned, height is equal, and width is equal.
74. What are the categories of injection machines?
According to appearance, they are divided into: vertical and horizontal According to the injection volume, they are divided into: ultra-small injection molding machine, small injection molding machine, medium-sized injection molding machine, large injection molding machine and super large injection molding machine; according to the clamping force of the mold, they are divided into: several tons to several thousand tons.
75. What is the relationship between clamping force and mold support force?
The clamping force of the injection molding machine should be greater than the opening force of the mold, otherwise the mold will be opened by the pressure inside the mold.
76. What are the methods of positioning male and female molds?
There are two types of positioning methods for front and rear molds: one is jig positioning and the other is mold core positioning.
77. What is the appropriate wall thickness for commonly used plastics?
The suitable wall thickness of ABS is: 1.8 ~ 3mm, the suitable wall thickness of PC is: 2 ~ 3.5mm, the suitable wall thickness of POM is: 1.5 ~ 2.5mm, the suitable wall thickness of NoryL is: 2~3.5mm. .
78. What is overflow value?
The overflow value refers to the space under which the plastic product will overflow. The overflow value of ABS is 0.04mm. The overflow value of PC is 0.06mm, the overflow value of PA is 0.015mm, the suitable wall thickness of POM is 0.04mm, the overflow value of PBT+15%GR is of 0.03mm, the overflow value of PBT+30% is 002mm, PM The overflow value of MA is 0.065mm, the overflow value of PVC is 0.07mm, the overflow value of AS is 0.05mm, the overflow value of PS is 0.05mm, the overflow value of PP is 0.03mm and the overflow value The PE is 0.02 mm.
79. How big is a standard picture frame?
Commonly used photo frames are: A0, A1, A2, A3, A4. The photo frame size of A0 is: 1189m x 841m, the photo frame size of A1 is: 841m x 594mm, the photo frame size of A2 is: 594mm x 420mm, the photo frame size A3. The frame size is: 420mm x 297mm, and the A4 photo frame size is: 297mm x 210mm.
80. Planning mold size?
Each company has different standards for planning mold sizes, but the common standards are as follows: molds of 15 to 30 series mold bases are classified as small molds, molds of 30 series mold bases are classified as small molds, to 50 are classified as medium molds and molds from 50 to 50 mold bases are classified as medium molds. The mold base mold is listed as a large mold.
81. What is elastic deformation? What is plastic deformation?
An object deforms under the action of an external force. When the external force disappears, the object can return to the deformation before deformation, called elastic deformation. When the external force disappears, the object cannot return to the deformation before deformation. is called plastic deformation.
82. What materials are commonly used for mold bases?
Mold bases are often made of Trump steel (called in Hong Kong), which is medium carbon steel and 45 steel.
83. What is the difference between CAD drawing workspace and layout space?
Model space is the space reserved for graphic entities and layout space is the space intended for drawing layouts.
84. What is the function of water transport?
The function of water transportation: controlling the temperature of the mold core.
85. What is a mold?
In industrial production, various presses and special tools mounted on the press are used to manufacture parts or products of the required shape from metallic or non-metallic materials by pressure. These special tools are collectively called molds.
86. Classification of molds?
Molds can generally be divided into plastic molds and non-plastic molds. Non-plastic molds include: casting molds, forging molds, stamping molds, die casting molds and plastic molds. According to different production processes and products, they are divided into: injection molding mold, blow molding mold, compression molding mold, transfer molding mold, extrusion molding mold, thermoforming mold and heat molding mold. rotation. According to the different types of door systems, molds can be divided into three categories: large nozzle molds, fine nozzle molds and hot runner molds.
87. What is a casting system?
The plastic flow channel from the nozzle of the injection machine to the mold cavity is called the gate system. The gate system includes: main channel, diversion channel, gate and cold well.
88. What is reverse engineering?
Reverse engineering uses a high-speed three-dimensional laser scanner to scan existing samples or models accurately and at high speed to obtain their three-dimensional contour data, then performs curve reconstruction with inverse software and performs analysis and online accuracy assessment of the reconstruction. Surface After constructing the effect and finally generating IGES or STL data, rapid prototyping or CNC machining can be achieved in one step.
Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.
