PLASTIC INJECTION MOLDING MACHINES (INJECTION MOLDING MACHINES AND MANUAL). INJECTION MOLDING COMPANIES IN UKRAINE

Plastic injection molding is a technological process of manufacturing plastic products by processing polymers, melting them, injecting this melt under pressure into a mold and further cooling the products.

More than a third of all plastic products produced are manufactured using the plastic injection molding method. This method is characterized by high productivity and high cost of necessary equipment tooling. That is why plastic injection molding is recommended for high-volume or mass production.

Raw materials, materials for plastic injection molding

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The raw materials for plastic molding are thermosetting powders as well as granules of thermoplastics and thermoplastic and thermoplastic elastomers. All materials have different mechanical and physical characteristics.

The advantage of thermoplastic materials is that they can be recycled after the molding process. Thermosetting materials are subjected to chemical processes during the molding of the product, which lead to the transformation of the raw material into a non-fusible and insoluble material.

Technological process of plastic injection molding

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The pre-prepared casting material enters the screw area of the machine. In the screw area, the raw material is melted and then injected into the molds under high pressure through the sprue channels.

The material completely fills the cavity of the mold and, when cooled, forms the product casting. The material does not cool down immediately, but gradually: first at the cold walls of the mold and then inside the body of the casting.

Special types of plastic injection molding

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The plastic injection molding method is based on the extrusion method – feeding molten material under pressure into a mold. But there are several special injection molding methods:

• Polymer injection molding with gas – inert gas under high pressure is used to seal the polymer, which is injected directly into the product area or near the product. The plastic sealing process is easier and the products are produced with a good surface quality without any imperfections.
• water vapor injection molding – before the start of each cycle, superheated water vapor is injected into the mold channels and the molten plastic is fed into the already heated mold. Then cooling material is fed into the mold channels and the polymer begins to cool down. As a result of this molding method, the product has a perfectly smooth glossy surface.
• water injection molding – after injection of molten polymer into the mold, water is injected under excessive pressure. The water exerts pressure on the material, which ensures its compaction and complete filling of the mold cavity. The method provides rapid cooling of the material. The water casting method is used to reduce the weight of the product, for the production of thin-walled products. Water casting is a very popular method due to its low cost and availability.
• molding with in-mold decoration – a method for decorating the surface of the product with applications, any information carriers with the help of special film carriers. During the production process of a plastic product, the object to be decorated is placed in an open mold and supported there by vacuum or electric slides. Then the mold is closed and molten polymer under pressure is fed into it. The carrier is reliably “fused” into the cooling body of the product and becomes one with it. This method is widely used in the production of cases for cell phones, children’s toys, TV and video products, sporting goods, etc.
• In-mold assembly casting – the method is intended for the production of products with moving elements, such as hinges.

Plastic injection molding machines

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• injection molding machines or injection molding machines;
• and manual plastic molding machines – syringe presses.

Thermoplastic molding machines (injection molding machines)

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An injection molding machine is a machine that is used in the production of plastic parts using the high-pressure molding method. The raw materials used in injection molding machines are thermoplastics (polyamides, polystyrene, polyesters, polyolefins and polyphenylene oxides).

More than a third of all plastic products made from plastics and more than half of all recycled plastic products are produced on injection molding machines. Thermoplastic injection molding machines have a complex construction, which consists of:

• injection mold – which in turn consists of a die and a punch, which are fixed on special plates – one is movable, the other is not. The mold is closed by means of a special electric or hydraulic mechanism.
• hydraulic system – consists of control valves, directional control valves, actuator pump, power cylinders and ejector drive for the mold.
• regulation and control system – control monitors, microprocessor, command and memory device, working hours and cycle counters.
• injection unit – consists of a “worm” press, cylinders and screws.
• safety devices.

Main characteristics of injection molding machines:

• Mass of injected polymer raw material.
• Injection pressure is the maximum pressure of molten polymer that the injection assembly can maintain in a molding cycle.
• Mold Closing Force (the maximum force of the assembly to hold the mold closed).
• Column spacing is the distance between the moving platen guide columns. The column spacing sets the maximum mold width that can be installed on the molding machine.

Classification, types of injection molding machines

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At present, there is a wide classification of injection molding machines.

By the number of raw materials used for casting:

• Molding machines for molding with one type of raw material;
• Molding machines for molding with multi-component raw materials.

By location of the injection unit:

a) horizontal injection molding machines – injection of material into the mold is performed horizontally, the mold parting plane is located vertically;

c) vertical injection molding machines – injection of material into the mold is carried out vertically from top to bottom, the mold parting plane is horizontal;

b), d) angular injection molding machines with vertical or horizontal press part (used most often for molding products that have certain difficulties with their removal from the mold).

By type of mold closing system:

• crank-and-lever injection molding machines;
• hydraulic injection molding machines.

By design of the actuator:

• electrical;
• electromechanical;
• hydromechanical.

By the number of mold closing (locking) units:

• one-liners;
• bicomposite;
• multicomposition (rotary and carousel).

Thermoplastic molding machines are complex and expensive equipment, which is constantly being improved by modern technical solutions. In order to mold a plastic product exactly on the injection molding machine, it is necessary to have a rational feasibility study: a large production run, geometric complexity of the product to be manufactured, the possibility of using in the molding technology on the injection molding machine the raw material that has been selected for production.

All possible injection molding machines differ in characteristics, dimensions, capabilities and, of course, price. Today the Ukrainian and Russian market is represented by injection molding machines from manufacturers of Europe, America, Asia and CIS countries.

The most popular injection molding machine manufacturers:

• Khmelnitsky (Ukraine);
• Krasmashzavod, Savma, Tula NITI, Souvenir (Russia);
• Atlant (Belarus);
• Arburg, Demag, Krauss-Maffei, Battenfild (Germany);
• Netstal (Switzerland);
• BM Biraghi (Italy);
• Haitian, Kaiming (China);
• LS (South Korea);
• Ferromatik (USA);
• Husky (Canada).

Device injection molding machine. How is the injection molding machine built?

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As already mentioned, the most popular method of plastic injection molding is injection molding machines. Any injection molding machine consists of two main parts:

1. mold clamping/unclamping unit (crank lever mechanism or hydraulic unit);
2. plasticizing unit (rotating heated screw cylinder working on the principle of a piston). The most common name for the screw is worm.

These units are driven by hydraulic drives. The pressure in the hydraulic system is provided by an electric motor.
The injection molding machines have a CNC unit, which can be used to set the parameters of each molding cycle, control the molding process, as well as control external devices – hydraulic drives, electric motor, heaters, etc.

The figure shows a simplified schematic diagram of the injection molding machine:

Detailed schematic diagram of the injection molding machine:

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{\t\t\t\t\t1. Bunker. \t\t\t\t2. Material cylinder. \t\t\t\t\t3. Rotating auger. \t\t\t\t4. Outdoor zone heaters. \t\t\t\t\t5. Hydraulic drive. \t\t\t\t\t6. Check valve. \t\t\t\t\t7. Worm tip. \t\t\t\t\t8. Mouthpiece. \t\t\t\t\t9. Front rack plate.

\t\t\t\t\t10. Column of the injection molding machine. \t\t\t\t\t11. Moving part of the mold (punch). \t\t\t\t\t12 — Fixed part of the mold (die). \t\t\t\t\t\t13. Slider. \t\t\t\t\t14. Column of the injection molding machine. \15.16. Lever-hydraulic mechanism. \t\t\t\t17. Rear rack plate. \t\t\t\t\t18. Electric motor. \t\t\t\t\t

\t\t\t\t\t\t19. Pump unit. \t\t\t\t\t20. High-pressure piping \t\t\t\t21. Low pressure piping. \t\t\t\t\t22. The rigid frame on which all the devices of the injection molding machine are mounted. \t\t\t\t\t23. Gear transmission of the hydraulic motor. \t\t\t\t\t24. Worm hydraulic motor. \t\t\t\t\t25. Hydraulic drive for axial movement of the “worm”. \t\t\t\t26. 27. Limit switch. \t\t\t\t\t\t

Technology of plastic molding on injection molding machines:

The prepared raw material is poured into the feed hopper and enters the material cylinder. The rotating screw moves the polymer material towards the nozzle. Thanks to the external zone heaters, the material starts to melt and is completely melted under pressure. The melt is then injected into the closed mold and the screw returns to its original position. In order to prevent the polymer material from flowing back into the hopper the screw is equipped with a check valve, which also performs the function of material dosing.

After the material is injected into the mold, high pressure is maintained by the screw while the product is cooling. If the pressure is too high, the mold halves may move apart slightly, resulting in material leakage, product failure and mold damage.
In the final stage of cooling and taking the finished product out of the mold, the screw starts to rotate again and the next batch of polymer melt for molding is prepared.

When the workpiece cools, the movable platen moves back and the mold opens. As a rule, molds are designed so that the finished product remains on the moving part of the mold. The part is removed from the punch by special pushers.

Manual plastic injection molding machines (hydraulic syringe press)

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Plastic injection molding technology on manual machines is similar to injection molding technology on injection molding machines, but the pressure on the syringe press is created manually by a piston using a lever.

In addition, the scheme of a manual syringe press is similar to the scheme of a vertical injection molding machine. The syringe press also consists of a loading chamber where the polymer material is poured in, a fixed cylinder, a rubber piston and a head with a die.

Advantages and features of the hydraulic syringe press (HSP):

• syringe presses are designed for small or medium-sized production runs;
• lower power consumption;
• simple design and easier process control eliminates the need for highly qualified personnel;
• possibility to use recycled polymer materials;
• The syringe press has smaller dimensions and weight;
• when casting on a syringe press it is possible to put metal parts of different shapes – used in the production of scissors, screwdrivers, etc. products;
• the requirements for molds for injection molding machines are lower than for molds for injection molding machines. Moulds for injection molding machines may be made of less durable material (e.g. aluminum), because the pressure in the syringe press is not as high as in an injection molding machine. This also affects the cost of the molds: they are much cheaper for injection molding machines.

Due to all these advantages, GSHPs are widely used in small batch production.

Companies engaged in plastic injection molding in Ukraine

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We would like to note that this list does not carry any advertising character and is created for introductory purposes. If any company has been omitted or incorrect data is indicated, please contact us by e-mail info@koloro.ua with the appropriate note, or write your additions in comments to the article through the proposed comment form.

To go to the website of the business you are interested in, just click on the name of the business!

1. Factory “UkrDetal” is engaged in plastic injection molding, casting of non-ferrous metals (products from aluminum, CAM, brass, copper, bronze), casting of iron and steel.The company also offers services in mechanical processing of products. Донецк,+38-(062)-208-99-11,+38-(067)-646-01-56.
2. Gorizont Ltd. – manufacture, development and evaluation of molds; services in plastic molding on molding machines.Kharkov, +38-(057)-712-90-41, +38-(057)-712-90-61, +38(057)-712-90-71.
3. Galsoft-service.The company is engaged in molding of plastic products on molds of clients, design and manufacture of molds for molding, as well as supply of new or used injection molding machines; Lviv,+38-(032)-224-75-96,+38-(032)-242-11-03.
4. LLC “Promservice”is engaged in the manufacture of molds and dies, as well as the production of polymer products, as well as low-voltage and high-voltage equipment; Chernigov,0462-651-544,+38-098)-20-100-87.
5. ARTEGO LTD: injection molding, molding, milling, laser cutting. Харьков,+38-(057)-781-71-34,+38-(066)-127-92-72,+38-(057)-756-58-57.
6. Electrotechnical plant (RELSiS)offers its services on plastic molding and metal working. Киев,+38-(044)-406-61-52 (-53,-54),+38-(044)-406-62-16.
7. Zherok-Alpha – serviceson molding of plastic products using customer’s tooling, services on processing of polymeric materials; Zhytomyr,+380412418512,+380412418513.
8. Forma-Plus – moldingplastics, mechanical processing of products, design and manufacture of molds.Kharkov,+38-(057)-735-23-29,+38-(050)-575-71-75.
9. Bdzhilka”– a full range of services for the production of plastic products, design and manufacture of molds, sale and supply of injection molding machines; Khmelnitsky,+38-(038)-278-51-82,+38-(038)-278-51-85.
10. Company Gefestpredlagaetservices on molding of products from plastics and rubber by injection molding on injection molding machines.Chernigov,+38-(050)-3131791.
11. Artemovskiy electrotechnical plant is engaged inplastic injection molding, metal cutting and mechanical, milling processing and cold stamping of metal products.Artemovsk, Donetsk region,+38-(0627)-44-65-68,+38-(0627)-44-65-74,+38-(0627)-44-65-75.
12. The company “MTT” (Magnetoprovod Transformers Tory)is engaged in manufacture of electrotechnical production (including plastic cases); Nikolaev,+38-(0512)-58-13-38,+38-(0512)-44-56-08,+38-(0512)-49-50-40,+38-(093)-368-05-72.
13. The firm SANTAN offersplastic injection molding, manufacture of plastic parts. Kharkov, +38-(057)-757-9-757, +38-(067)-570-64-64.
14. Laboratory of vacuum molding Marabu – production of plastic products, parts, cases; injection molding. Kiev, +38-(044)-537-34-60.
15. PE “Nick” – casting of polymers, plastics under pressure, manufacturing of molds. Киев,+38-(067)-464-84-08,+38-(044)-227-00-47, +38-(067)-600-92-42,+38-(044)-227-00-37.
16. Plasma – moldingpolymers under pressure using tpa.Kharkiv,057-781-37-38,057-781-14-40,057-781-36-35,057-715-17-26.
17. Electrochemical coatings plant is engaged inmanufacturing of molds for plastic injection molding, production of plastic products; Kiev,+38-(044)483-69-95,+38-(067)-441-69-19,+38-(067)-608-88-27,+38-(095)853-29-06.
18. Viaplast – injection molding ofplastic products on injection moldingmachines; Kharkiv,057-768-02-57,057-752-01-17.
19. Scientific-production enterprise “ES Polymer“ – servicesinclude designing and manufacturing of plastic products for electrical equipment; Artemovsk, Donetsk region,+380-627-44-65-71.
20. Firm Nomitek provides acomplex of services from designing and manufacturing of molds to manufacture of plastic products; Kiev,+38-(044)233-27-06,+38-(044)-209-23-49.
21. State enterprise “Plant named after Malyshev”.One of the activities of the enterprise is the casting of plastics, casting on injection molding machines, investment casting, precision casting of blanks, aluminum and iron casting; Kharkiv,057-739-31-01,057-766-47-20.
22. AMBOX – manufacture and realization of plastic products; Makeevka, Donetsk region,+38-(095)-348-46-13,+38-(097)-388-55-94.
23. Production enterprise “Gears”is engaged in manufacturing ofdetails (gears, springs, gear wheels, etc.) for various equipment.Dnepropetrovsk,+38-(056)-722-04-45,+38-(067)-441-51-04.
24. Firm Stalex.Manufacturing of molds and dies, services tpa, turning and milling processing of metal.Kharkiv,057-715-17-30,050-982-77-03,096-273-22-73,066-373-22-73.
25. The company “Stankoplast”is engaged in repair and modernization of injection molding machines, as well as manufacturing of plastic products; Khmelnitsky,+38-(0382)-78-43-49,+38(067)-575-59-25,+38-(096)-304-07-14,+38-(050)-376-42-25.
26. The company “Park” provides a range of services from 3D-modeling of the product to its casting on the syringe press; Dneprodzerzhinsk,+38-(093)-033-33-66,+38-(066)-499-25-95,+38-(093)-277-82-82-82.
27. Services of the company Amper:metalworking on CNC machines: – 3D, 4D milling; turning works; engraving works; production of foundry tooling; manufacture of molds for casting EVA copolymers.Kharkiv,050-325-89-14.
28. In.Kol- manufacture of molds and dies, manufacture of tooling, designing tooling, dies and molds, machining parts.Kharkiv,057-728-12-78,057-728-12-79.
29. Northern Trading Company Ltd – design, evaluation and manufacture of molds; services in plastic molding on injection molding machines. Chernigov, 0462-65-15-44, 067-64-63-882.

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KOLORO company is engaged in designing of molds. If you need to make a small run of plastic products, please contact us by:+38-(057)-760-26-05, +38-(057)-760-26-06, +38-(099)-618-87-50 (Kharkiv).We are engaged in manufacturing of silicone reverse molds for casting (small-scale production), creation of prototypes and prototypes.