June 2020 – Page 5 – CNC Machining & Turning, Milling, Metal parts

Five links of plastic mold

First, effective management of product data management, process data management, drawing document management: effective mold product data management, process data management, drawing document management, can ensure the comprehensiveness of the file, the consistency of the drawing version; so that the drawings can be effectively shared and effectively used for query. It can establish a complete file management computer database to collect and use the design drawings, scattered, previously scattered and isolated information accumulated by the design department, so as to prevent problems caused by the design drawings, 2D and 3D confusion, confusion of original, design change, maintenance version, inconsistency of 3D model and 2D drawing data, and nonstandard and chaotic design of 2D drawings Find out and correct in time, cause the mold to be modified, reworked, even invalid, increase the manufacturing cost of the mold, lengthen the manufacturing and production cycle of the mold, and affect the delivery time.

Second, keep the consistency and integrity of plastic mold drawings, processing technology and physical data: ensure the consistency and integrity of mold drawings, processing technology and physical data through effective, meticulous and strict detection means.

Third, the design and manufacturing cost of each set of plastic mold must be summarized in time: through the effective control of the issuance of the workshop work order, effective management of tool scrap; Through accurate mold structure design, efficient mold parts processing and accurate parts detection, the additional cost of mold due to design change and maintenance will be effectively reduced, so as to obtain the actual cost of each set of mold and effectively control the mold quality.

Fourth, overall planning: organically organize and integrate the planning, design, processing technology, workshop production, human resources and other information, so as to effectively coordinate the planning and production, and effectively ensure the quality of plastic mold and timely delivery.

Fifth, develop a complete and practical plastic mold production management system: develop a complete mold production management system, realize the computer information management system of product data management, process data management, plan management and schedule management of mold production management process, including plastic mold production plan formulation, mold design, process formulation, workshop task assignment and Product inspection, warehouse management, etc., so that mold manufacturing and related auxiliary information from planning to completion delivery can achieve a full range of tracking management.

Precautions for plastic mold

1、 Don’t just focus on product design, ignore plastic mold manufacturing.

Some users in the development of products or trial production of new products, often focus on product development and development at the initial stage, ignoring the communication with the plastic mold production unit. After the product design scheme is preliminarily determined, there are two advantages to contact the mold manufacturer in advance:

1. It can ensure that the designed product has a good forming process, and it will not modify the finalized design because the parts are difficult to process.

2. The mold maker can make design preparation in advance to prevent improper consideration in a hurry and affect the construction period.

3. To make high quality plastic mould, only when the supplier and the demander cooperate closely can the cost be reduced and the cycle be shortened.

2、 Don’t just look at the price, but consider the quality, cycle and service in an all-round way.

1. There are many kinds of molds, which can be roughly divided into ten categories. According to different requirements of part material, physical and chemical properties, mechanical strength, dimensional accuracy, surface finish, service life, economy, etc., different types of die forming are selected.

2. The die with high precision needs to be processed by high precision CNC machine, and the die material and forming process are strictly required. CAD / CAE / CAM die technology is also needed to design and analyze.

3. Some parts have special requirements when forming, and the mold also needs to use advanced technology such as hot runner, gas assisted molding, nitrogen cylinder, etc.

4. The manufacturer shall have CNC, EDM, WEDM and CNC profiling milling equipment, high-precision grinder, high-precision three coordinate measuring instrument, computer design and relevant software, etc.

5. Generally, large stamping dies (such as automobile covering dies) should consider whether the machine tool has a blank holder mechanism, even edge lubricant, multi position progressive and so on. In addition to the punching tonnage, the punching times, feeding device, machine tool and die protection device should be considered.

6. The manufacturing means and process of the above mould are not possessed and mastered by every enterprise. When choosing a cooperative manufacturer, we must know its processing ability, not only from hardware equipment, but also from management level, processing experience and technical force.

7. For the same set of mould, there is sometimes a big gap in the quotation of different manufacturers. You should not pay more than the value of the mold, but also should not be less than the cost of the mold. Mold manufacturers, like you, should make reasonable profits in business. Ordering a set of molds with a much lower price will be the beginning of trouble. Users should start from their own requirements and measure them comprehensively.

3、 Avoid multiple cooperation, try to make plastic mold and products processing.

1. With a qualified mold (qualified test piece), it is not necessarily possible to produce a batch of qualified products. This is mainly related to the selection of machining machine tools, forming process (forming temperature, forming time, etc.) and the technical quality of operators.

2. With a good mold, but also have a good forming process, the best is one-stop cooperation, try to avoid multi cooperation. If the conditions are not met, it is necessary to select a party who is fully responsible and write clearly at the same time.

Why do two-color mold products appear gray and black spots?

1. The cycle time is short, that is to say, the residual time of molten material in the barrel is short and the cycle time is prolonged.

2. The barrel temperature in the feeding area is too high, which reduces the barrel temperature in the feeding area.

3. Screw speed is too fast, reduce screw speed.

4. Screw back pressure is too low, increase screw back pressure.

In addition, the reason related to the design of the two-color mold is that the unreasonable screw geometry selects the screw with a long feeding section, and the screw groove of the feeding section is deep.

If the measurement process of the two-color mold injection process starts too early, and the air wrapped in the particles in the screw feeding area does not overflow the feeding port, the air will be squeezed into the melt. However, the pressure in the feeding area is too low to move the air to the rear. The air squeezed into the molten material in the barrel will cause grey black spots in the products. Just like what happens in the compression ignition diesel engine, the coking phenomenon caused by the air squeezed into the barrel is sometimes called “diesel engine effect”. The coking phenomenon can explain the high temperature produced by compression at the junction of the molten material and the extruded bubble, and the fracture of the molten material caused by the oxidation of oxygen in the air. The melting process should be started in the middle of the feeding area when the injection process of the two-color mold is debugged, where the melting pressure is high, forcing the air between the particles to move backward and overflow the material mouth.

The preferred apparent gray black markings may occur near the gate, in the middle of the runner and away from the gate. This phenomenon can only be seen in transparent parts, and is often found in two-color mold injection products made of PMMA, PC and PS materials.

All kinds of machine tools in machining

With the development of industrial modernization, the processing and manufacturing of various parts are gradually from manual processing to mechanical processing. The development in the middle is rather tortuous. The first to realize mechanization is the textile industry in ancient China. The loom was the first processing equipment to replace the manual at that time. But in the stage of capitalist development, the industrial revolution in Britain rose because of the steam engine, and the machines in various industries of the steam engine were invented one after another. Later, the refining of oil promoted the development of engines, more mechanical products were produced one after another, and the operation speed and efficiency of machinery were greatly improved. Later, with the gradual improvement of electromagnetic theory, generators were also produced, and human beings began to use electricity, and various industries were booming. To the modern computer and other intelligent products operation and calculation has replaced a lot of human heavy work, the development of the machinery industry has also appeared the situation of the whole machinery. Baoding Honglian machine roll Co., Ltd. introduces the operation principle and development of various machine tools in detail.

The main processing in the mechanical processing industry includes turning, milling, planing, grinding and boring. But now the machining center basically contains these machining. The so-called turning is lathe machining, which uses the rotation movement of chuck and the feed movement of turning tool to cut workpiece. It mainly cuts some circular axis and symmetrical workpiece, and the machining accuracy is greatly improved. Milling is the most important machining method in mechanical processing. It processes the workpiece surface through the rotation and feed motion of milling cutter. Now, the diversification of milling machine adds more technology to milling. Both planer and grinder are used for planing and grinding the plane, groove and other processing surfaces of the workpiece to achieve a smoother and smoother surface. Boring machine is similar to drilling machine in hole processing, which is also essential in mechanical operation..

Features of sheet metal parts

1. Sheet metal has the characteristics of light weight, high strength, conductive (can be used for electromagnetic shielding), low cost, large-scale mass production performance and so on. At present, sheet metal has been widely used in the fields of electronic appliances, communication, automobile industry, medical devices and so on. For example, in computer case, mobile phone, MP3, sheet metal is an essential part.

2. With the application of sheet metal more and more widely, the design of sheet metal parts has become a very important part in the process of product development. Mechanical engineers must master the design skills of sheet metal parts, so that the designed sheet metal can not only meet the requirements of product function and appearance, but also make the stamping die manufacturing simple and low cost.

3. Sheet metal is sometimes used as trigger gold. The word comes from English sheet metal. Generally, some sheet metal is pressed by hand or die to produce plastic deformation, forming the desired shape and size, and further forming more complex parts by welding or a small amount of machining, such as the chimney, tin furnace, and car shell are sheet metal parts.

4. Modern sheet metal technology includes: filament power winding, laser cutting, heavy processing, metal bonding, metal drawing, plasma cutting, precision welding, roll forming, metal plate bending forming, die forging, water jet cutting, precision welding, etc.

Advantages of copper zinc alloy in sheet metal processing

Among the materials of sheet metal processing, copper has many outstanding physical and chemical properties. For example, its thermal conductivity and conductivity are very high, its conductivity is second only to silver, and its thermal conductivity is second only to silver and gold. Chemical stability is strong, easy to dissolve, in the atmosphere, fresh water, sea water has a good corrosion resistance.

Copper zinc alloy, the color changes from yellow red to yellow with the increase of zinc content. The mechanical properties of brass are higher than that of pure copper, and it will not rust or be corroded under the same conditions. It has good plasticity and is widely used in the mechanical manufacturing industry to make various structural parts.

Moreover, it has high plasticity and can bear all kinds of cold and hot pressure sheet metal processing well. The disadvantage is that the strength and hardness are low. Generally, it does not make structural parts. Pure copper is also known as red copper, which is light rose or light red. After the copper oxide film is formed on the surface, its appearance is purple red

Source of sheet metal processing

Sheet metal processing is sometimes used for pulling metal processing. Generally, some metal sheets are pressed by hand or die to produce plastic deformation, forming the desired shape and size, and further forming more complex parts through welding or a small amount of machining, such as the chimney commonly used in the family, tin furnace, and automobile shell are sheet metal parts. Sheet metal processing is called sheet metal processing. For example, using plates to make chimneys, iron buckets, oil tanks, ventilation pipes, elbows, Tianyuan places, funnel-shaped and so on. The main processes are cutting, bending and buckling, bending and forming, welding, riveting and so on, which requires certain geometric knowledge. Sheet metal parts are sheet metal parts, which can be processed by stamping, bending, stretching and other means. A general definition is the parts with constant thickness in the process of processing. The corresponding parts are casting parts, forging parts, machining parts, etc. for example, the outer iron shell of the car is sheet metal parts, and some cabinets made of stainless steel are sheet metal parts..

Knowledge of machining

For processing of deformed and eccentric parts, the workpieces are generally fixed with a flower plate. Therefore, first of all, pay attention to the card. The claw and pressing plate shall not extend beyond the diameter of the disc, and it is better to install a shield. Secondly, pay attention to the counterweight of eccentric parts. It is important and appropriate. The clearance between the inner hole diameter of the counterweight and the screw diameter should be small. The rotating speed of the machine tool shall not be too high, so as to prevent the counterweight from moving outward under the centrifugal force during the rotation, colliding with the guide rail of the machine tool, breaking the screw and damaging the operator.

What safety requirements should the control system of machine tool equipment meet?

1. Easy to operate, reduce walking back and forth, avoid unnecessary bending and tiptoe.

2. The positioning is accurate and reliable to prevent misoperation due to slight vibration.

3. The movement direction of the operating parts and the movement direction of the operated parts of the machine tools shall meet the requirements, and shall be marked with simple symbols.

4. The necessary interlock mechanism shall be installed to prevent the uncoordinated action of the operating parts and the accidents caused by the uncoordinated operation of multiple persons.

5. The structure and arrangement position of handle, hand wheel and button shall meet the requirements. The start button shall be installed in the casing or equipped with a guard ring to prevent accidental touch. The handwheel and handle installed on the shaft rod will hurt people when rotating with the shaft during automatic feed, so the automatic release device shall be installed.

Basic knowledge of machining process

Basic knowledge of machining technology i. production process and production process of products refer to the whole process of transforming raw materials into finished products. The production process of mechanical products generally includes:

1. Preparation of production and technology, such as process design and design and manufacturing of special process equipment, preparation of production plan, preparation of production data, etc;

2. Manufacturing of blanks, such as casting, forging, stamping, etc;

3. Machining, cutting, heat treatment and surface treatment of parts;

4. Product assembly, such as general assembly, component assembly, commissioning inspection and paint, etc;

5. Production services such as the supply, transportation and storage of raw materials, purchased parts and tools;

The process of changing the shape, size, relative position and property of the production object in the production process to make it a finished product or semi-finished product is called process. For example, the manufacturing, machining, heat treatment and assembly of rough are all technological processes.

In the process of machining, if the shape, dimension and surface quality of the production object are directly changed by the method of machining, it is called machining process. Similarly, the process of assembling the processed parts into a machine to achieve the required assembly accuracy and obtain the predetermined technical performance is called the assembly process.

Machining process and assembly process are two main contents in the research of mechanical manufacturing technology.

2、 Composition of machining process

The machining process is composed of one or several sequential processes, which can be divided into several installation, working position, working step and cutting.

Several important steps in sheet metal processing

Sheet metal is sometimes used as trigger gold, which comes from the English word plate metal. Generally, some metal sheets are pressed by hand or die to produce plastic deformation, forming the desired shape and size, and further forming more complex parts through welding or a small amount of machining, such as the chimney commonly used in the family, tin furnace, and automobile shell are sheet metal parts.

Sheet metal processing is called sheet metal processing. For example, using plates to make chimneys, iron buckets, oil tanks, ventilation pipes, elbows, Tianyuan places, funnel-shaped and so on. The main processes are cutting, bending and buckling, bending and forming, welding, riveting and so on, which requires certain geometric knowledge.

Sheet metal parts are sheet metal parts, which can be processed by stamping, bending, stretching and other means. A general definition is the parts with constant thickness in the process of processing. The corresponding parts are casting parts, forging parts, machining parts, etc. for example, the iron shell outside the car is sheet metal parts, and some cabinets made of stainless steel are sheet metal parts.

Modern sheet metal technology includes: filament power winding, laser cutting, heavy processing, metal bonding, metal drawing, plasma cutting, precision welding, roll forming, metal plate bending forming, die forging, water jet cutting, precision welding, etc.

The surface treatment of sheet metal parts is also a very important part of the sheet metal processing process, because it can prevent parts from rusting and beautify the appearance of products. The function of surface pretreatment of sheet metal parts is mainly to remove oil, oxide skin, rust, etc. it is to prepare for surface post-treatment, and the latter treatment is mainly to spray (bake) paint, spray plastic and plating antirust layer, etc