The all-electric machine increases the precision of the injection molding


by Harald Sambale

The all-electric machine increases the precision of the injection molding

In May 2013, the production of the Romanian plastics processors Plastor has been extended with an all-electric injection molding machine from Sumitomo (SHI ) Demag. With this machine are manufactured parts that meet very very high precision requirements.

Plastor SA is among the leading suppliersof plastics components in Romania for the electronics and automotive industry. In addition, Plastor manufacture finished products for sports item and gardening.

Another important branch of the company is the design and manufacture of injection moulds. "Besides activities on the Romanian home market Plastor maintains close trade relations with companies in other EU countries such as Germany, France, Austria, the UK and the Netherlands," says Managing Director Dr. Eng. Plastor Ion Seres. In the field of automotive, Plastor produces, for example headlamp housings front and rear and small parts of the interior trim, parts for the engine room and little components for closing and locking systems. In addition, the range is completed with blow molded plastic parts, eg. Tanks for windscreen wiper systems or ducts for ventilation and cooling systems.

Plastor has a long experience in the production of components for home appliances. The product range includes control knobs, handles, housings and keypads. The production of these parts is made by using the procedure of injection gas.

Components manufactured at Plastor can be decorated by screen printing, pad printing, hot stamping or by varnishing

"Particularly challenging is the production of end products in the areas of sports equipment and garden machinery," explains Dr. Eng. Ion Seres." These include ski boots for the company Salomon or Atomic and lawn mower for the companies Brill or AL-KO. Here, in addition to product development, injection molding and decorating surfaces, plastics ensures the assembly, packaging and delivery of products."

Plastor was established in 1914 as a manufacturer of hair pins and combs from natural materials. In the fifties and sixties of last century the processing of plastics has gained importance ever higher. In addition to injection molding, Plastor today has introduced also the process of extrusion or the blow-molding of plastic products. In recent years Plastor was restructured as group of companies consisting of eleven companies with specific areas of responsibility.

The product portfolio ranges from brooms and brushes to household products, extruded yarns and technical moldings and recycling of plastics. The parent company of the group Plastor SA, employs about 750 people.

In 1993 began the collaboration between Plastor and Salomon, the French manufacturer of sporting goods . At that time, production capacities were relocated from France to Romania. Among other things, was put into operation at Plastor an injection molding machine manufactured by Demag, with a clamping force of 4200 kN. Due to the positive experiences with the use of this machine, Plastor decided the purchase of additional injection molding machines from Sumitomo (SHI) Demag.

“The injection moulding machines distinguish themselves by a repetitive high precision. The 5 points knees double toggle system provide very precise movements of mold.” Dr. Eng. Ioan Seres,General Manager Plastor S.A.

In close collaboration with Chorus Engineering srl, the Romanian representative of Sumitomo SHI Demag, could found solutions for customer service and maintenance of this injection molding machine. The first two injection molding machines from Sumitomo (SHI) Demag with clamping forces of 4200 kN were purchased in 2003. Meanwhile Plastor has now ten machines from Sumitomo (SHI) Demag with clamping forces 1000-4200 kN. These hydraulic injection molding machines are used at Plastor for the production of component parts for ski boots. "Among other things, simultaneous movements of tool and core pullers are needed," Dr. Eng. Ion Seres says. "The machines can reliably meet these requirements." In addition Plastor benefited from the versatility of the machines. "The plasticizing units are suitable for a wide range of thermoplastic materials and produce a very high quality melt. Thus the processing of TPU material transparent or translucent colored liquid paint get exceptional results," notes Dr. Eng. Ion Seres. He adds: "The machines are also characterized by a very high repeatability lever system with double knees. The Five-point double toggle system ensures very precise tool movements. In addition, the machine controls NC4 and NC5 are very userfriendly, since the parameters for fine-tuning are arranged in groups "

  • From left to right : Marco Codeca, General Manager at Chorus Engineering Srl, Dr. Eng. Ioan Seres, General Manager at Plastor S.A. and Cristian Anghel, Sales Manager at Chorus Engineering Srl

In May 2013 Plastor has purchased an IntElect 100-430 of Sumitomo (SHI) Demag the first all-electric injection molding machine. "This investment was due to extremely strict quality requirements imposed on manufacturing complex parts made up of several components," explains Plastor CEO. "In addition, low power consumption has been an important argument in favor of machine IntEllect". The all-electric injection molding machine is used for the injection molding of small insert parts from TPE, which are then further processed in larger injection molds to 2K or 3K parts. These are parts for ski boots made of translucent TPU. In this form parts soft and elastic parts of TPE are inserted, which must meet very high precision requirements.

  • Plastor S.A. has bought already 14 Injection moulding machines from Chorus Engineering since 2003.


Production takes place automatically or semiautomatically on tools with two or four cavities. The cycle times range between 30 s and a maximum of 50 s. The injection molding machine is equipped with a built-in dust extraction and a gravimetric dosing unit which can dose up to four different components.

The electric injection molding machine is used for both mold parts that have been produced on a hydraulic machine, as well as for a number of new products, which Plastor produces as part of a development project. "During the first few shots in the series production, we found that the machine movements of IntElect can be performed with high precision and high speeds," said Dr. Eng. Ion Seres. "Another advantage is the low noise level of the machine. We also benefit from the possibilities of fine-tuning, for example, when opening and closing the mold, with the ejector or the venting of the mold."

  • Full electric injection moulding machine convinced Plastor S.A. with it’s high accuracy, high speed and a reduced noise level.

In the long run Plastor has the goal to expand the know-how in the business fields in which operates and in parallel to increase the complexity of the products. Thus, in the future will increase the share of injection molding machines equipped with hybrid as well as all-electric drive systems.