In TOPSIL GLOBAL we work with two groups of materials: silicones and thermoplastic elastomers. We process them by means of two main technologies: injection and extrusion moulding. For trials, tests and prototypes we still use the traditional technology of compression moulding on vulcanisation presses. At the same time we experiment with the newest 3D printing technology, which in the near future can revolutionise the industry.
We make the tools for our production lines in-house, including the LSR injection moulds – the most complex and advanced technology of plastics processing.
We develop and prepare the silicone mixes according to our needs, thanks to which we can show greater flexibility in meeting our customers’ expectations.
Below you can learn more about our main technological lines:
Injection of liquid silicone (LSR)
Lines for production of liquid silicone articles consist of dispensing equipment, cold channel distributors, injection moulding machines equipped with an advanced control system and specialized injection unit and moulds. LSR processing is conducted using both known techniques – open nozzles and nozzles with needle valves. The production process is fully automatic, and manufactured goods do not require any post-finishing. This technology is very environmentally friendly because the manufacturing process does not produce waste.
Injection moulding of thermoplastic materials (TP, TPE, TPV,…)
TOPSIL GLOBAL owns a machine park enabling the manufacture of products from thermoplastic materials, particularly thermoplastic elastomers: TPE, TPO, TPV, TPU, etc. To process thermoplastic materials we use both cold channel injection technology, as well as hot channels. This technology complements our core range of injection products made of silicone.
2K LSR + TP
We can also offer the production of two-component thermoplastic elements (also supplied by client) combined with LSR silicone.
There are three factors which substantially distinguish LSR injection moulding technology from injection moulding of thermoplastics (TP):
- Cold material is injected into the hot mould (in contrast to the TP method).
- The accuracy of the closure of the mould cavity is 0.003 – 0.005 mm, because a larger gap would cause the liquid silicone to form beads, which should be removed (additional post-finishing of products). In addition, the forming of beads would prevent processing in automatic cycles. More precise closing would increase the risk of sealing air in the products. It would then be necessary to remove the air from the sockets before they are filled with a vacuum pump or build a venting system tight for liquid silicone and completely passable for air.
- Silicone products adhere to the surface of the mould. Because of that and their flexibility they are difficult to remove automatically from moulds. There is no practical application for pin ejectors – the most prevalent form of emptying sockets – in TP. This issue presents an additional challenge for designers of tools for LSR processing.
TOPSIL GLOBAL owns the very modern, fully integrated extrusion lines. They consist of extruders specially designed for silicone, thermal shock zones and curing tunnels – vertical or horizontal, heated with infrared or a fast stream of hot air. Lines are separated into production process lines, which include the preparation of compounds with regards to the type of vulcanization (peroxide or polyaddition). Each line is equipped with a precise control system that ensures the dimensions of extruded products are reproduced with high accuracy. They are controlled continuously using special laser equipment. In order to ensure dimensional accuracy, we use an automatic system of self-regulation. We also provide our customers with the option to automatically cut the finished products in line into sections of any length larger than 0.7 mm. As well, we can perform laser marking, ventilation hole drilling and punching, all in line.
We offer our customers co-extruded silicone products with different properties, such as different hardness, different colours, different thermal and electrical conductivity, etc. It is a technology mostly developed by TOPSIL GLOBAL and many of its elements are used only in our company.
Extrusion and coextrusion of thermoplastic materials
Extruded TPE materials are manufactured on fully automated lines using extruders produced by Cincinnati and Metalchem. It is possible to connect devices in a line for extrusion of two-component products. Lines are equipped with a fully automated laser system for dimension control. We offer the ability to automatically cut products to specified length or automatically coil them on spools. All drives in the line are fully synchronized and controlled by a PLC controller. Lines are suitable for production of thermoplastic elastomers with any characteristics.
Extrusion of polyamide and silicone
TOPSIL GLOBAL owns a proprietary technology for co-extrusion of polyamide and HTV silicone. Polyamide part characterized by high stiffness is usually the component used to attach the sealing profile – the so-called foot – and the highly flexible silicone is responsible for the sealing. This technology is used to produce two-component, high temperature resistant sealing that enables mounting with durability beyond that of pure silicone seals.
Compression moulding using curing presses
This traditional technology has been used in TOPSIL GLOBAL for the longest period of time. Nowadays it is used primarily for production of prototypes and small batches of products.
Preparation of HTV silicone blends
TOPSIL GLOBAL produces a wide range of silicone blends based on raw materials supplied by the best manufacturers, such as Wacker Chemie, Dow Corning, Shin-Etsu, MPM and others. Basing on our knowledge and experience, we introduce a number of additives to improve the properties of finished products. HTV blends can be cured (cross-linked) using peroxides or by addition in the presence of a platinum catalyst. For production of blends we use two-roller mill stands and a pressing and mixing machine that makes possible to feed them with loose components. All blends are rheometrically controlled. We produce blends mostly for our own needs, but also by request from customers.
TOPSIL GLOBAL can independently manufacture all the tools necessary to run production lines for extrusion of TPE and silicone, as well as injection moulds for LSR and TPE. Utilizing our spare output, we can also manufacture injection moulds for external clients. We have a state-of-the-art machinery, which consists of the following devices:
- CNC wire EDM by Sodick (linear drives)
- CNC sinker EDM by Sodick (linear drives)
- 5-axis CNC machining center by HERMLE, of type C 40 U Dynamic
- Cylindrical grinder by Studer, type S-30
- Manual surface grinders by JUNG
- CNC lathes by HAAS
- A set of conventional machining tools for metal.
Machine operators have vast experience in the manufacture of tools and are some of the best in the industry.