What is injection molding? Injection molding is a process in which thin-walled parts are made of non-ferrous metals, plastics, and steel using automated equipment. This technology characterizes by high performance. When creating parts, a liquid melt obtained from these materials is fed at high speed into a special mold, after which casting of a given configuration obtains under pressure.

Features of metal injection molding technology

This device is casting equipment, the design of which provides for movable and fixed parts. The first move along with the guide cylinders and the second is mounted on a stationary plate.

What is injection molding?  Before the start of the technological process, the movable part of the mold was tightly fixed to the fixed parts with the help of a hydraulic cylinder. Then, to prevent the movement of these parts, the latter fastens with special locks.

After pouring and solidifying the molten material, the movable part of the device shifts to the side, and the workpiece obtained under high pressure removes from the equipment using mechanical pushers.

This composition is used to eliminate the negative impact of high temperatures on the steel parts of the equipment.

What is injection molding?

The main unit of this equipment is the chamber in which the material presses. This structural element is of two types: cold and hot. Structurally, the first chamber presents in the form of a horizontally laid cylinder, inside of which there is a funnel piston used for pouring the molten material.

Moreover, the process of manufacturing parts in such equipment is as follows: after filling the installation with metal, a piston starts, which, moving inside the cylinder, pumps the melt into the mold. After filling the latter, the pressure inside the chamber increases. This happens by increasing the force on the piston, which leads to the crystallization of the metal.

The function of Hot Chambers In Injection molding

What is injection molding? The hot chamber of the molds presents in the form of a bath located in a cast-iron crucible, which constantly heats during the creation of blanks. In such installations, a piston is also used, which pushes the melt out of the crucible while moving.

Further, the metal rises through a special channel with a heated mouthpiece (which prevents the solidification of the material), through which it enters the mold. At the end of the process, the remains of the melt return to the bath.

Moreover, hot chamber molds are used to create blanks from zinc and magnesium alloys.

What is injection molding? Material heating temperature

The temperature to which the material heats and is selected considers two parameters. The grade of the alloy and the geometric parameters of the part create. Failure to comply with this rule leads to serious consequences.

Moreover, due to overheating of the material during mold pouring, splashes fly out that block the ventilation holes, as a result of which gas removal disturbs, which leads to the appearance of pores in the workpiece after the latter has hardened.

Exceeding temperature increases the duration of metal crystallization

Exceeding the permissible temperature leads to an increase in the duration of metal crystallization, this is why it takes more time to complete the process.

What is injection molding? This leads to an increase in the load on the equipment, which increases the wear of the mold. In such conditions, the risks of welding metal to the inner walls increase. As a result, the probability of damage to the part during ejection increases.

Moreover, this technological process involves pressing at a minimum temperature. Non-ferrous metals heat 10-300 degrees above the point at which the alloy begins to solidify.

At the same time, if the technical task requires the manufacture of parts with a thin wall, the heating temperature increases. When creating castings of a simple configuration, the opposite approach uses. In such cases, the material heats to a temperature slightly above the melting point.

Manufacturing of high-strength parts

If high-strength parts are manufactured during this technological process, then the metal pours into the mold in a solid-liquid state. This approach achieves the following results:

• Eliminate the appearance of a shrinkage effect in the created workpiece;
• Reduce the negative impact of high temperature on equipment;
• Reduce the duration of the casting hardening process;
• Reduce the risks of welding metal to the inner walls.

Moreover, metal with hard phase inclusions is pressed exclusively in cold chamber machines. This explains by the fact that when manufacturing parts from this material in other equipment. What is injection molding? Then the risks of melt solidification in the supply channel increase.

In particular, during aluminum injection molding, the volume of solids should be 40-60%, providing that the molds are easily filled and the quality of the casting remains at a high level.

Molten material feed rate

The speed at which the piston compresses the molten material determines by taking into account the characteristics of the alloy and the geometry of the part to manufacture:

Detail of a complex geometric shape and with thin walls. When creating such a workpiece, the melt should be pressed at high speed. This requirement explains by the fact that the liquid material must have time to fill all the cavities before solidification begins.

Moreover, exceeding the permissible pressing speed leads to the fact that the supplied jet scatters into small drops, as a result of which air enters the melt. If the design provides for an insufficient number of channels intended for the removal of gases, or they clog, voids will remain in the cast billet.

In order to avoid such consequences, injection molding carries out in a vacuum in which the mold is placed.

The speed determines the quality of the casting

The speed at which the pressing carries out determines the quality of the castings and the life of the equipment. If the melt is fed too quickly, then because of this, the lubricant that the bath has been treated with is washed off. Because of this, the metal sticks to the inner walls, which, when pushed out, leads to damage to the workpiece.

If the speed is too slow, the quality of the part deteriorates. In this case, the metal begins to solidify before the pressure inside the equipment increases. A smaller parameter selects when creating blanks from steel and copper alloys. Molten tin and zinc fed at a faster rate.

Pressure on the melt during solidification

After filling the mold with metal, the pressure on the piston increases many times. The material experiences such an impact until it hardens. Through pressure:

• The density of the workpiece increases;
• Improved mechanical characteristics of the casting;
• The formation of shrinkage defects excludes;
• The quality of the casting improves;
• The risk of marriage reduces;
• The surface finish of the metal part increases.

What is Injection molding?

What are the advantages of injection molding? The essence of this method lies in the fact that the molten metal is fed into a steel split mold under pressure. The working pressure on the melt is carried out directly by compressed air (gas) or by a piston, which moves under the action of compressed air (gas), emulsion, or oil.

The pressure can reach several hundred atmospheres, which ensures good filling of the mold and the production of castings of the 3-5th accuracy class and with a surface roughness corresponding to the 5-8th class. This provides great performance.

Injection molding is carried out on compressor and piston machines. Piston machines are made with vertical and horizontal pressing chambers. Chambers can be cold or hot.

The scheme of injection molding on a machine with a vertical chamber is as follows. Melt 2 is poured with a measuring spoon into the pressing chamber 3.

Moreover, the upper piston 1, descending, exerts great pressure on a portion of the melt, which transfers pressure to the lower piston 8. The piston, moving, open the gate channel 11, through which the melt fills the mold cavity.

The procedure of molding machine

a – with a cold vertical pressing chamber,

b – with a cold horizontal pressing chamber;

c – position before pouring,

d – during pouring,

e – after pouring

Moreover, the mold consists of two half-molds 4 and 5. After the melt solidifies, the half-mold 4 moves aside, and the casting 7 together with the sprue 10 pushes out by pushers 6. Excess metal 9, which has not entered the mold cavity, pushes out of the chamber by piston 8 and goes to the smelter.

Injection molding on a machine with horizontal chamber proceeds in the same sequence.

What are the advantages of injection molding?

Injection molding allows you to solve one of the most important tasks of foundry production: to bring the dimensions of the casting as close as possible to the dimensions of the finished part.

Moreover, castings obtained in metal molds have a clean and smooth surface, which significantly reduces the surface finish of parts (grinding, polishing, etc.). This method uses to cast critical parts with thin walls and complex configurations.

In addition, injection molding is used to connect several parts or to obtain castings with fittings from other metals. Castings obtained by injection molding have a fine-grained structure and high mechanical properties.

The most advanced methods for manufacturing castings

What are the advantages of injection molding? It is also economically advantageous that a large number of castings can produce in a single mold in a short time. The high productivity of this casting method and the minimum allowances reduce the cost of production both in the foundry and in the machine shops.

In addition, injection molding eliminates the use of sand, so sanitary production conditions are better than in conventional foundries.

Moreover, on the other hand, injection molding is a complex technological process that requires knowledge of alloy metallurgy, casting technology, special knowledge of tool production in the manufacture of molds, and, finally, mechanics in the operation of injection molding machines.

Injection molding has some drawbacks

Injection molding has some drawbacks, such as the appearance of small air pockets (porosity) in castings. The air in the cavity of the mold does not have time to completely go out and partially mixes with the melt.

The gases dissolved in the metal do not have time to leave the casting; due to the porosity of the casting, it is impossible to heat treat it, since swellings appear when heated. Moreover, it is difficult, and sometimes impossible, to cast a part with an undercut and internal cavity in this way.

The machines and molds that exist in modern production are suitable only for the manufacture of castings from alloys with a melting point below 1000 ° C. Special experimental casting machines and molds have been made for casting steel.

Die casting can produce castings, not from all alloys

The most suitable are zinc alloys, some aluminum, and brass. Moreover, it is more difficult to obtain parts from steel and cast iron in this way. Bronze parts are not cast under pressure.

The high cost of equipment and molds makes it not always profitable to produce small batches of castings by injection molding, so the injection molding method is widely used in serial and mass production.

The 6 advantages of plastic injection molding

Injection molding allows the production of large quantities of plastic products and components in a short time. Moreover, it guarantees the dimensional repeatability of the pieces and reduces production costs thanks to the automation of the production process.

What are the advantages of injection molding? The molding of plastic materials is one of the most widespread techniques in the transformation processes of plastic materials.

It is a procedure whereby the techno plastic material melts and injects at high pressure inside the closed molds. It opens once the material has solidified and the product is ready.

Moreover, the wide diffusion of this technique can explain by its important advantages. It brings in terms of production efficiency and cost reduction.

But that’s not all: there are numerous other advantages of plastic injection molding that make this technique a viable solution for the production of plastic components.

It is precisely for this reason that we use injection molding of plastic materials to provide its customers with quality products that best meet the needs of various companies.

The 6 advantages of plastic injection molding.

Injection molding of plastic materials means obtaining large quantities of products in a short time. Moreover, this advantage accompanies by the consequent possibility of reducing production costs. Thanks to the automation of the entire procedure.

Production of complex design components

The versatility of injection molding involves, among other advantages. The possibility of obtaining parts with complex geometries is impossible to obtain with different techniques. In this way, injection molding makes it possible to respond to any need, making possible a high degree of customization of the products.

Moreover, the experience and competence of the supplier certainly contribute to this advantage.

The strength and stability of the pieces produced

Thanks to their stability, the plastic components have excellent durability over time. Thus, contributing to the quality of the final product itself.

What are plastic injection molds?

What products are made from injection molding? Many injection molding machines are sold in the global market every year, which work with special molds (molding molds, forming equipment).

A mold is a metal device good to use for the production of plastic products by injection molding. They are good to use for mass production. Production should be supervised by experienced engineers who will develop design documentation for the manufactured product, as well as the device itself.

Let’s look at each option:

The application of the technology involves several stages

Initially, the matrix with the powder is exposed to high temperatures until it becomes plastic. What products are made from injection molding? Further, a special punch puts pressure on the plastic, due to which it acquires the necessary shape. Despite its simplicity, this technology has its drawbacks.

Models for direct pressing, designed to work exclusively with simple materials, allow the production of simple products. Another disadvantage is the high cost of production, which makes it unprofitable to produce large batches.

For injection molding

The mold has 3 plates and a more complex device, it is multifunctional. Here, the matrix and gates locate independently in relation to each other. What products are made from injection molding? This allows you to design parts of different sizes. Due to the multifunctionality, many companies produce injection molded products, while the production requires relatively low costs.

The operation is only possible for professionals

The operation of injection molding models is only possible for professionals, as they are difficult to work with, are not easy to maintain, as well as expensive to repair.

According to the number of parts produced at a time, the molds are single and multi-place. The use of the latest molds allows the production of many parts at the same time, thereby increasing productivity and reducing the cost of production.

Mold material for casting: aluminum alloys, various steel grades, zinc alloys, and copper alloys. Aluminum plastic injection molds are common and are affordable and also have excellent performance.

What products are made from injection molding? machine for plastic panels

All owners of modern offices, shops and cafes, exhibition halls, and restaurants would like to make their premises clean, beautiful, and comfortable, but they do not want or do not have the financial opportunity to do so.

Today, it is absolutely not necessary to buy expensive finishing materials, since there is a large amount of finishing materials on the market that will look great and even solid. The best option, in this case, is plastic panels, which produce on a modern injection molding machine. It is worth noting that this finishing material will look great on your insulated loggia or balcony.

What products are made from injection molding? Plastic panels are indeed the most economical and simple finishing materials at the moment, which can be good to use in rooms of various types. Such a panel produces on an injection molding machine from solid polyvinyl chloride and from a softener.

The finishing material does not contain any harmful substances

The plastic panel can be good to use for interior decoration of kitchens, corridors, bathrooms, and loggias, as well as swimming pools, cafes, and restaurants.

Such panels are advantageous for finishing the interior of an office and various cultural and leisure facilities, sports and recreation complexes, and so on.

What products are made from injection molding?

This finishing material is quite popular in the domestic building materials market, it is much cheaper than siding and, moreover, natural wood. However, the panels are easy to produce not only in the classic white color, the manufacturer today has production technologies to imitate the texture and color of natural precious wood.

It must be said that when carrying out finishing work, cladding with plastic panels is easy to attribute to the most “clean” ways of finishing rooms. After its installation, no dust, no dirt, no waste, and no other construction debris will remain in the room. During installation, there are no problems with sizing, it perfectly cuts both along and across with a fine-toothed saw.

Proportional valves

In the process of molding plastics, exact proportions of the base material to the additional one are sometimes required. This makes it possible to achieve the requirements for molded products flexibly, mixing primary material with secondary material. To make this process simple and economical, a proportional valve for injection molding machines is good to use. 

This equipment interacts with a vacuum loader and controls through a small controller. When using loaders of the SAL-U series, control occurs from the loader panel. It will make operation even more convenient.

Proportional valve operation

By means of the PV and PVN valve, a proportional loading of recyclables together with primary raw materials in certain proportions ensures. What products are made from injection molding? It is good to use with a vacuum loader. The proportional valve controls by its own control panel or vacuum loader.

When loading raw materials, while reaching a predetermined period of time, the supply of primary material is cut off by means of a pneumatic valve, after which the supply for recyclables opens. 

After the specified time for supplying the secondary material, the pneumatic valve switches, and the supply of primary raw materials resumes. At the moment of stopping the loading of raw materials, the proportional dispenser stops.

The operation of the valve is based on pneumatic switching

The operation of the valve is based on pneumatic switching by external sources of compressed air. What products are made from injection molding? To operate a proportional valve, a pressure of 6-8 atmospheres is most often required. In operation, one of the loading channels always remains open and the other closed. Among the advantages of the device:

• Loading with one vacuum loader of two different materials, which have different fluidity and bulk density.
• There is no need to install a separate dispenser for crushed materials.
• Dosing carries out proportionally

What products are made from injection molding? Due to the stable operation of the magnetic valve, the precise operation of the pneumatic cylinder ensures strict proportions maintained between new and recycled material.