Mold


September 5, 2017 Facebook Twitter LinkedIn Google+ Uncategorized



Mold, industrial production for injection molding, blow molding, extrusion, die casting or forging molding, smelting, stamping and other methods to obtain the required products of various molds and tools. In short, the mold is used to make the tools of forming objects, this tool consists of a variety of parts, different molds by different parts. It is mainly through the molding material to change the physical state to achieve the shape of the processing of goods.

In the external force to make the blank into a specific shape and size of the parts of the tool. Widely used in blanking, die forging, cold heading, extrusion, powder metallurgy parts pressing, pressure casting, and engineering plastics, rubber, ceramics and other products of the compression molding or injection molding process. The mold has a specific profile or cavity shape, and the application of a profile with a cutting edge allows the blank to be separated (blanked) by contour shape. The shape of the cavity can be used to obtain the corresponding three-dimensional shape of the blank. Mold generally includes dynamic and fixed mold (or punch and die) two parts, the two can be divided into. Separate the parts removed, close the blank when the mold into the mold cavity forming. The mold is a precision tool, the shape of complex, bear the blank of the expansion force, the structural strength, stiffness, surface hardness, surface roughness and processing accuracy have a higher demand, mold production level of development is one of the important indicators of mechanical manufacturing level.

Table of content

1.Category

2. Classification

3. constitute

4. Mold material

4.1 plastic mold

4.2 Classification of pouring systems

4.3 forming classification

4.4 Other categories

4.5 double shot forming

5. Production process

6. Mold manufacturing

7. Mold selection

7.1 Requirements

7.2 Process performance

8. Use performance

9. Maintenance

10.Other references

11.List of Mold manufacturers

1.Category

Many types of mold, according to the processing object and processing technology can be divided into: ① processing metal mold. ② processing non-metallic and powder metallurgy mold. Including plastic mold (such as two-color mold, compression mold and extrusion die, etc.), rubber mold and powder metallurgy mold.

According to the structural characteristics of the mold can be divided into flat punching die and a cavity with a cavity.

Mold is generally single, small batch production.

2. Classification

Depending on the material being molded

Metal mold, plastic mold, and its special mold.

Metal molds are divided into: including stamping die (such as punching die, bending mold, drawing die, hole mold, shrinkage mold, ups and downs, bulging mold, plastic mold, etc.), forging die (such as die forging die Forging die, etc.), extrusion die, extrusion die, die casting mold, forging mold;

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 mold and people’s lives are closely related. Plastic mold can be divided into: injection molding die, extrusion molding die, gas-assisted molding die, and so on.

3. constitute

In addition to its own mold, but also need mold seat, mold, mold core parts caused by the device, these components are generally made of general-purpose.

4. Mold material

The most important factor in mold material is thermal strength and thermal stability, commonly used mold material: working temperature forming material mold material

4.1 plastic mold

4.2 Classification of pouring systems

According to the different types of gating system can be divided into three categories of plastic mold:

(1) large outlet mold: the flow channel and gate in the parting line, and the product in the mold when the mold release, the design of the most simple, easy processing, low cost, so more people use the water system operation. Plastic mold structure is divided into two parts: dynamic and fixed mold. With the injection part of the active part of the dynamic mode (mostly for the top side), the injection device in the injection of the general activity is called fixed. Due to the mold part of the mold is generally composed of two steel plate is also known as such a structure of the mold for the “two plate model.” The two molds are the simplest structure in the mold.

(2) fine water mold: the flow channel and the gate is not parting line, generally directly on the product, so to design a group of water nozzle sub-line, the design is more complex, more difficult processing, generally depending on product requirements and use Fine water system. The mold part of the mold is usually made up of three steel plates, which are also called “three plates”. The three-plate mold is the simplest structure in the mold.

(3) hot runner mold: This mold structure and the water outlet is roughly the same, the biggest difference is the flow channel in one or more constant temperature of the hot runner plate and hot mouth, no cold material stripping, Mouth directly on the product, so the flow channel does not need stripping, this system is also known as the waterless system, can save raw materials for more expensive raw materials, products require a higher situation, design and processing difficulties, high mold costs. Hot runner system, also known as hot runner system, mainly by the hot sprue sets, hot runner board, temperature control box composition. Common hot runner systems are available in single hot gates and multi-point hot gates. The single-point hot gates are used to inject molten plastic into the cavity directly with a single hot-gourd sleeve. It is suitable for plastic molds with single-chamber single gates. Multi-point hot gates are used to distribute the molten material through the hot runner. Sub-hot gate sets and then into the cavity, it is suitable for single-chamber multi-point feed or multi-cavity mold.

4.3 forming classification

(1) injection molding
Is the first plastic to the injection machine into the heating cylinder, the plastic heat and melt, in the injection machine screw or plunger driven by the nozzle and die casting system into the mold cavity, due to physical and chemical effects and hardening stereotypes into injection Products. Injection molding by the injection, holding pressure (cooling) and plastic parts of the process of forming the cycle cycle, so injection molding has a cyclical characteristics. Thermoplastic injection molding molding cycle is short, high production efficiency, the melt on the mold wear and tear, can be large quantities of complex shape, the surface pattern and marking clear, high precision plastic parts.

(2) compression molding
Commonly known as pressing molding, is one of the earliest molding of plastic parts. Compression molding is the plastic directly added to a certain temperature of the open mold cavity, and then close the mold, under the action of heat and pressure plastic melt into a flow state. Due to physical and chemical effects, leaving the plastic hardened into a certain shape and size of the room temperature to keep the same plastic parts. Compression molding is mainly used for forming thermosetting plastics, under normal circumstances, often press the film on the mold, the mold with the structure, the compression model is divided into overflow type, not overflow type, semi-overflow type three.

(3) extrusion molding
Is a molding method in which a plastic in a viscous flow state is formed at a high temperature and a constant pressure through a die having a specific cross-sectional shape and then molded at a lower temperature into a continuous profile of a desired cross-sectional shape. Extrusion molding process is to prepare molding materials, extrusion molding, cooling stereotypes, traction and cutting, extrusion of post-processing (quenching or heat treatment). In the extrusion process, pay attention to adjust the extruder barrels of the heating section and the machine head die temperature, screw speed, traction speed and other process parameters in order to get qualified extruded profiles. Particular attention should be paid to adjusting the rate at which the polymer melt is extruded from the die die.

(4) pressure molding
Also known as casting molding. The plastic material is added to the preheating feeding chamber, and then the pressure column into the feeding chamber to lock the mold, through the pressure column to the plastic pressure, the plastic at high temperature, high pressure melting into the flow state, and through the pouring system into the cavity Gradually solidified into plastic parts. This molding method, also known as transfer molding. Pressure molding for the lower than the solid plastic, in principle, can be compression molding of plastic, can also be used pressure molding. But requires the molding material below the curing temperature, the molten state has good flow, higher than the curing temperature, a greater curing rate.

(5) hollow molding
Is made by the extrusion or injection, is still in the plastic state of the tubular or sheet material tend to be fixed in the molding mold, immediately through the compressed air, forced the billet expansion and affixed to the mold cavity wall After cooling the mold release, that is, the required hollow products of a processing method. According to the different types of parison molding methods, hollow molding is divided into extrusion blow molding hollow molding and injection blow molding hollow forming two.

(6) die-casting mold
Die-casting mold, also known as transfer molding die. The plastic raw material is added to the preheating feeding chamber, and then pressure is applied to the pressure column. The plastic melts under high temperature and high pressure and enters the cavity through the pouring system of the mold, and is gradually hardened. This molding method is called die casting, Called die-casting mold. This mold is used for the formation of thermosetting plastics.

In addition, there are foam molding mold, glass fiber reinforced plastic low-pressure molding die and so on.

4.4 Other categories

(1) hot runner mold
With the heating device so that the plastic system in the casting system will not solidify, nor with the product stripping, so also known as no flow mold. Commonly used hot runner there are two: 1) heating flow mode 2) adiabatic flow channel mode.

(2) hard mold
The inner plate used in the steel plate, bought back after the need for heat treatment, such as quenching carburizing, in order to meet the requirements, such injection mold called die.

(3) soft mold
The inner module used in the steel, buy back after the need for heat treatment, will be able to meet the requirements, such injection is called soft mold.

4.5 double shot forming

Double shot molding mainly to double injection molding machine with two sets of molds with two sets of molds in the order of two times made of double-shot products.

5. Production process

Mold is a model, according to this model to make the product.

Modern mold production process:

1) ESI (Earlier Supplier Involvement): This stage is mainly between customers and suppliers on product design and mold development and other aspects of technical discussion, the main purpose is to allow suppliers to clearly understand the product designer’s design Intent and precision requirements, but also to the product designers to better understand the mold production capacity, product performance, and thus make a more reasonable design.

2) Quotation: Including the price of the mold, the life of the mold, the turnover process, the tonnage of the machine requirements and the delivery time of the mold. (More detailed quotation should include information such as product size weight, mold size weight, etc.)

3) Order: customer orders, deposit issued and the acceptance of supplier orders.

4) Production Planning and Schedule Arrangement: This stage requires a response to the customer for the specific date of delivery of the mold.

5) mold design: may use the design software Pro / Engineer, UG, Solidworks, AutoCAD, CATIA, etc.

6) Purchasing materials

7) Machining: The processes involved are vehicle, gong (milling), heat treatment, grinding, computer (EDM), wire cutting (WEDM), coordinate grinding (JIG GRINGING), Laser engraving, polishing and so on.

8) Mold assembly

9) Trial Run

10) Model evaluation report

11) Model evaluation report approved

6. Mold manufacturing

The design requirements are: size is accurate, smooth surface; reasonable structure, high production efficiency, easy to automate; easy manufacturing, high life, low cost; design in line with the needs of the process, the economy is reasonable.

Mold structure design and parameter selection should take into account the rigid, guiding, discharge mechanism, positioning method, the gap size and other factors. The wearing parts on the mold should be easy to replace. For plastic molds and die-casting molds, also need to consider a reasonable pouring system, molten plastic or metal flow state, into the cavity position and direction. In order to improve the productivity and reduce the loss of the flow channel, a multi-cavity mold can be used to complete the same or different products simultaneously in a mold. In high-volume production should be used high efficiency, high precision, high life mold.

Stamping die should be multi-station progressive die, can be used carbide inlay progressive die to improve life. In small batch production and new product trial production, should use simple structure, manufacturing fast, low cost simple mold, such as combination die, sheet die, polyurethane rubber mold, low melting point alloy mold, zinc alloy mold, superplastic alloy mold. Mold has begun to use computer-aided design, that is, through a computer-centric system to optimize the design of the mold. This is the development direction of mold design.

Mold manufacturing according to the structural characteristics, divided into flat punching die and a cavity with a cavity. Blanking die using punch and die size of the exact match, and some even no gap with. Other forging die, such as cold extrusion die, die casting mold, powder metallurgy mold, plastic mold, rubber mold and so on belong to the cavity mold, for forming three-dimensional shape of the workpiece. Cavity mold in the long, wide, high three directions have size requirements, complex shape, manufacturing difficulties. Mold production is generally single, small batch production, manufacturing requirements strict, accurate, and more use of sophisticated processing equipment and measuring devices.

Plane punching die can be used to start forming EDM, and then forming grinding, coordinate grinding and other methods to further improve the accuracy. Forming grinding can be used for optical projection curve grinder, or with a blending, grinding wheel mechanism of the surface grinder, but also in the precision surface grinding machine grinding with a special forming grinding tools. Coordinate grinding machine can be used for precision positioning of molds to ensure precision pore size and pitch. You can also use the computer numerical control continuous track coordinate grinding machine grinding any curved shape of the punch and die. Cavity mold multi-purpose copy milling machine processing, EDM and electrolytic processing. The use of copy milling and CNC combined applications and in the EDM to increase the three-way flat head device, can improve the processing quality of the cavity. Increasing the charge electrolysis in electrolytic processing can improve the production efficiency.

7. Mold selection

Mold selection is the whole mold making process is a very important part.
Mold selection needs to meet the three principles, mold to meet the wear resistance, toughness and other work needs, mold to meet the technical requirements, while the mold should meet the economic applicability.

7.1 Requirements

1) abrasion resistance
When the blank is deformed in the mold cavity, it flows and slides along the surface of the cavity, causing severe friction between the cavity surface and the blank, which causes the mold to fail due to wear. So the wear resistance of the material is one of the most basic and most important performance of the mold.
Hardness is the main factor affecting wear resistance. Under normal circumstances, the higher the hardness of mold parts, the smaller the wear, wear resistance is also better. In addition, the wear resistance is also related to the type, quantity, shape, size and distribution of carbides in the material.

2) toughness
Mold working conditions are mostly very bad, and some often bear a greater impact load, resulting in brittle fracture. In order to prevent the mold parts in the work suddenly brittle, mold to have a high strength and toughness.
The toughness of the mold depends mainly on the carbon content of the material, grain size and tissue state.

3) Fatigue fracture performance
Mold work in the process, the long-term role in the cyclic stress, often lead to fatigue fracture. Its form has a small energy multiple impact fatigue fracture, tensile fatigue fracture contact fatigue fracture and bending fatigue fracture.
The fatigue fracture properties of the mold are mainly determined by its strength, toughness, hardness, and the content of inclusions in the material.

4) high temperature performance
When the mold temperature is higher, will make the hardness and strength decreased, leading to early wear or plastic deformation of the mold and failure. Therefore, the mold material should have a high resistance to tempering stability, to ensure that the mold at the operating temperature, with a high hardness and strength.

5) resistance to hot and cold fatigue performance
Some molds are in the process of repeated heating and cooling, so that the surface of the cavity by the tension, the role of stress stress, causing the surface cracking and peeling, increased friction, blocking plastic deformation, reducing the size of the accuracy, resulting in Mold failure. Hot and cold fatigue is one of the main forms of hot die failure, to help this type of mold should have a high resistance to hot and cold fatigue
The
6) corrosion resistance
Some molds such as plastic mold at work, due to the presence of chlorine in the plastic, fluorine and other elements, heat decomposition after the decomposition of HCI, HF and other strong corrosive gases, erosion mold cavity surface, increase its surface roughness, exacerbate wear failure.

7.2 Process performance

Mold manufacturing generally have to go through forging, cutting, heat treatment and other processes. In order to ensure the quality of mold manufacturing and reduce the production cost, the material should have good malleability, machinability, hardenability, hardenability and grindingability. It should also have small oxidation, decarburization sensitivity and quenching Deformation Cracking tendency.

1) malleable
Has a low hot forging deformation resistance, good plasticity, wide forging temperature range, forging cracking and precipitation of creep carbide tendency is low.

2) annealing process
Spherical annealing temperature range is wide, the annealing hardness is low and the fluctuation range is small, the spheroidizing rate is high.

3) Machinability
Cutting the amount of large, low tool loss, low surface roughness.

4) oxidation, decarburization sensitivity
High temperature heating when the antioxidant Huai good, decarburization slow, not sensitive to the heating medium, resulting in pits tend to small.

5) hardened
After quenching with uniform and high surface hardness.

6) hardenability
After quenching can get a deeper hardened layer, the use of moderate quenching medium can be hardened.

7) quenching deformation cracking tendency
Conventional quenching volume change is small, shape warpage, distortion is slight, abnormal deformation tendency is low. Conventional quenching cracking sensitivity is low, the quenching temperature and the shape of the workpiece is not sensitive.

8) Grindable
Grinding wheel relative loss is small, no burn limit grinding large amount of grinding wheel quality and cooling conditions are not sensitive, less prone to wear and grinding cracks.

8. Use performance

1) Small density: small plastic density, to reduce the weight of mechanical equipment and energy conservation is of great significance, especially for vehicles, ships, aircraft, spacecraft in terms of space.

2) Specific strength and specific rigidity: The absolute strength of plastic is not as high as that of metal, but the plastic density is small, so the specific strength (σb / ρ) and the specific stiffness (E / ρ) are quite high. Especially in a variety of high-strength fibrous, flaky and powdery metal or non-metallic filler made of reinforced plastic, the specific strength and specific stiffness than the metal is also high.

3) Chemical stability: the vast majority of plastic has a good acid, alkali, salt, water and gas properties, under normal conditions, they do not react with these substances chemical.

4) electrical insulation, insulation, excellent sound performance.

5) wear and self-lubricating: plastic friction coefficient is small, good wear resistance, good self-lubricating, coupled with high strength, transmission noise, it can be in the liquid medium, semi-dry or even dry friction Conditions to work effectively. It can be made into bearings, gears, cams and pulleys and other machine parts, very suitable for the speed is not high, the load is not the occasion.

6) strong bonding ability.

7) good shape and coloring performance.

9. Maintenance

1) mold for a long time after use must be grinding edge, grinding edge must be demagnetized, can not be with magnetic, or easy to block material. The use of the mold to do the company to do a detailed record of the use of its care, lubrication (cleaning, cleaning, rust) and damage, which can be found which parts, components are damaged, the degree of wear and tear to provide information to find and solve the problem, As well as the molding process parameters of the mold, the product used to shorten the mold test time, improve production efficiency. Should be in the injection molding machine, the normal operation of the mold, the test mold a variety of performance, and the final shape of the plastic parts measured by this information can determine the existing state of the mold to find the cavity, core, cooling system and Sub-surface and other damage, according to the information provided by the plastic parts, you can determine the damage to the mold state and maintenance measures.

2) spring and other flexible parts in the course of the most vulnerable to damage the spring, usually the phenomenon of fracture and deformation. Take the approach is to replace the spring in the replacement process must pay attention to the specifications and models, spring specifications and models through the color, diameter and length of three to confirm that only in the same three cases can be replaced. The quality of the spring is better for the import.

3) the use of molds in the process of punching prone to break, bend and bite bad phenomenon, punch sets are generally bite bad. Punch and punch the damage is generally the same specifications of the parts to be replaced. Punch the main parameters of the working part of the size, installation part of the size, length and size.

4) fasten the parts, check the fastening parts are loose, damaged, the way is to find the same specifications of the parts to be replaced.

5) pressing parts such as pressing plate, gifted of plastic, such as stripping parts, such as stripping board, pneumatic, such as materials. Maintenance, check the parts of the accessories and the relationship between the damaged, the damaged part of the repair, pneumatic materials to check whether the leak phenomenon, and the specific circumstances to take measures. Such as tracheal damage to replace. To focus on several important parts of the mold to track the detection: the role of ejection, guide parts to ensure that the mold opening and closing movement and plastic parts of the top, if any part of the damage due to injury and stuck, will lead to shutdown, it should always keep Mold thimble, guide column lubrication (to choose the most suitable lubricant), and regularly check the thimble, guide column, etc. whether the deformation and surface damage, once discovered, to be replaced; complete a production cycle, the mold work surface , Movement, guide parts coated with professional anti-rust oil, with particular emphasis on gears, rack mold bearing parts and spring mold elastic strength protection to ensure that it is always in the best working condition; with the production time , The cooling channel easy to deposit scale, rust, sludge and algae, so that the cooling channel cross-section smaller, narrow cooling channel, greatly reducing the coolant and mold heat exchange rate between the increase in production costs, so the flow of the clean-up Should pay attention to; for hot runner mold, the heating and control system maintenance is conducive to prevent the occurrence of production failures.

10.Other references

Stamping Machine
Mould Design
Injection Moulding Machine
CNC Engraver
Gantry Milling Machine
Milling Cutter
CNC Turning Machine
Universal Milling Machine
Horizontal Milling Machine
Vertical Milling Machine
Tapping Machine
Water Jet Cutting Machine
Plasma Cutting Machine
EDM – Electrical Discharge Machining
ERP – Enterprise Resource Planning
CAM – Computer Aided Manufacturing
CAD(Computer Aided Design)
cnc-milling-machine
cnc router
cnc-lathe-machine-buyers
3d-printer
cnccomputer-numerical-control
cnc-grinding-machine
cnc-drilling-machine
cnc-machining-center
5-axis-cnc-machine
cnc-machining

11.List of Mold manufacturers

ManufacturerHQProducts Built
MeusburgerAustriamanufacturer of molds and accessories for injection molding.
Unique Tool & Gauge Inc.Canadamanufacturer of die and mold.
True North Molds Ltd.Canadamanufacturer of mold for automotive sealing systems.
Sigma Engineering Inc.Canadamanufacturer of dies, molds.
Schmolz+Bickenbach Canada Inc.Canadamanufacturer of cutting tools, mould, non ferrous tooling materials.
Protectolite Composites Inc.Canadamanufacturer of dies, molds, patterns, models.
H.S. EnterprizesCanadamanufacturer of plastic tooling and plastic products.
H. J. Machine & Pattern Ltd.Canadamanufacturer of tools, dies, molds, pattern equipment for wood, metal, plastic industry.
H D Patterns & Matchplates Inc.Canadamanufacturer of patterns, models, molds, pressure cast match plates for foundry and pattern industry.
Glider Guard Tool & Die Inc.Canadamanufacturer of tooling, dies, molds.
Crest Mold Technology Ltd.Canadamanufacturer of dies and molds.
Classic Tool & Die Inc.Canadamanufacturer of tools and dies, progressive dies, transfer dies, line dies.
Cana-Datum Moulds Ltd.Canadamanufacturer of tools, dies, molds, especially large tooling for magnesium and aluminium components.
Anchor DanlyCanadamanufacturer of tool & die, die sets, steel plates, die & mold components.
Aluminum Mold and Pattern Ltd.Canadamanufacturer of die and mold: flexible urethane molds, vacuum form molds, rotational molds, blow molds, bead foam molds, compression molds, RIM molds, part validation equipment.
Accurate Machine & Tool Ltd.Canadamanufacturer of tools, dies, molds.
Autania Grinding TechnologiesGermanymanufacturer of fine grinding machines for die and mold, tool.
F. Zimmermann GmbHGermanymanufacturer of CNC portal type milling machines, bed type milling machines, milling heads, die & mold milling machines, die & mold grinding machines, for automotive industry, and aircraft industry.
PRIMACON Maschinenbau GmbHGermanymanufacturer of precision milling machines for watch and jewelry industry, dental and medical industry, tool and mold making.
AURATRONICGermanymanufacturer of machining centers and machining head for die and mold, wood, plastic, and aluminum materials.
Pfister Werkzeugbau AGSwitzerlandmanufacturer of plastic injection molds, mold, plastic parts.
WILLEMIN MACODEL SASwitzerlandmanufacturer of precision milling machines, machining centers, jig boring machines for watch making, jewelry, medical devices, dental instruments, aviation, die & mold.
Quaser Machine Tools, Inc.Taiwanmanufacturer of 5 axis machining centers, machining centers for die and mold making.
Unipunch Products IncUSmanufacturer of modular press tooling, punches, dies, press mounting accessories, templates, dies, molds.
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