At TOPSIL GLOBAL we work with two groups of materials: silicones and thermoplastic elastomers. We process them using two main technologies: injection and extrusion. We are also able to combine different types of materials in one product, thanks to two-component extrusion or injection moulding technology.
We manufacture the tools for our production lines on our own, especially the moulds for liquid silicone injection – the most complex and advanced plastic processing technology.
We formulate and prepare silicone compounds on our own, so that we can be more flexible to meet specific customer’s needs.
Find out more about our main process lines:
Liquid silicone injection moulding (LSR)
Lines for the production of Liquid Silicone Rubber (LSR) products consist of dosing equipment, cold runners, injection moulding machines equipped with extensive control systems and specialised injection units and moulds. We process LSR with both well-known techniques, using both open and needle shut-off nozzles. The production process is fully automatic, and the manufactured products do not require any finishing. This technology is extremely environmentally friendly, as no waste is generated during production.
Injection moulding of thermoplastics (TP, TPE, TPV,…)
In the processing of thermoplastics we use both cold channel and hot channel injection moulding technologies. This technology complements our basic injection moulding product range – which includes silicone products – with articles made from various types of thermoplastic materials: TPE, TPO, TPV, TPU, etc.
2-Component LSR + TP injection moulding
We can also offer the production of two-component products from thermoplastic components combined with LSR silicone. Alternatively, the component made of TP can be supplied by the customer. We will only inject the silicone part.
There are 3 factors that fundamentally distinguish LSR injection moulding technology from thermoplastic (TP) injection moulding:
– Cold material is injected into a hot mould (contrary to TP).
The accuracy of the sealing of the mould cavities is between 0.003 and 0.005 mm, as liquid silicone would flow into larger gaps and form flashes which would have to be removed (additional processing of the products). Moreover, the formation of flashes would make it impossible to run the process in automatic cycles.
– Thorough sealing of the cavities would in turn increase the risk of air closing in the products.
It would then be necessary to remove the air from the cavities with a vacuum pump, before filling them or to build a venting system that is tight for liquid silicone but fully permeable for the air.
– Silicone products stick to the moulding surfaces, which in combination with their elasticity, makes automatic demoulding difficult. Bolt ejectors, the most common in the case of emptying TP mould cavities, are not practical. This problem poses an additional challenge for designers of LSR processing tools.
Modern, fully integrated extrusion lines consist of extruders specially designed for silicone, thermal shock zones and vulcanisation tunnels, horizontal or vertical, heated by infrared or high-speed hot air stream. The extrusion lines are divided into production lines, which also include the preparation of compounds according to the type of vulcanisation (peroxide or polyaddition one). Each line is equipped with a precise control system enabling the achievement of high dimensional accuracy of the extruded products.
They are continuously controlled with special laser devices. In order to ensure dimensional accuracy, we use an automatic feedback system. We also provide our customers with the possibility of automatic in-line cutting of finished products into sections of any length, starting from 0.7 mm, as well as laser printing, execution of ventilation holes or punching of the profile, e.g. for window lock.
Co-extrusion of silicone
We offer our customers co-extruded silicone products with different properties, e.g. of different hardness, in different colours, or with different thermal and electrical conductivity. This is a technology largely developed by means of our internal resources.
Extrusion and co-extrusion of thermoplastic materials
We manufacture extruded products from TPE materials on fully automated lines using extruders manufactured by Cincinatti and Metalchem. It is possible to combine the equipment in lines for the extrusion of two-component products. The lines are equipped with a fully automated laser dimension control system. We offer the possibility of automatic cutting of products into specified lengths or automatic winding on spools. All drives in the line are fully synchronized and controlled by PLC. The lines are adapted to the manufacturing of thermoplastic elastomer products with any characteristics.
Co-extrusion of polyamide and silicone
This is the original polyamide and HTV silicone co-extrusion technology. The polyamide part of significant rigidity is usually the element used for mounting the sealing profile – the so-called foot – while the silicone part of high elasticity is responsible for sealing. This technology is used to produce two-component seals, which are resistant to high temperatures and provide a more durable mounting than seals made only from silicone.
Press moulding using vulcanising presses
This is our longest-used traditional technology. At present, it is used primarily for the manufacture of prototypes and low volume production.
HTV silicone compounding
We produce a wide range of silicone compounds based on raw materials supplied by the best manufacturers, such as Wacker Chemie, Dow Silicones, Shin-Etsu, Momentive, and others.
Based on our own knowledge and experience, we introduce numerous additives to improve the properties of finished products. HTV compounds can be vulcanised (cross-linked) using peroxides or by addition in the presence of a platinum catalyst. We have our own know-how regarding crosslinking by addition. For the production of compounds, we use two-roller mills and an extrusion mixer, which enables the introduction of loose components. All compounds are subjected to rheometric control. We produce the compounds mainly for our own needs, but also for external customers.
Our own tool-making facility, equipped with state-of-the-art, high-precision machines allows us to manufacture all the tools necessary to start the production on the TP and silicone extrusion lines, as well as injection moulds for LSR and TPE. Within our spare production capacity, we also offer manufacturing of injection moulds for external customers. Here some of the equipment available in our tool-making unit:
- Sodick CNC wire EDM (linear drives)
- Sodick CNC plunge EDM (linear drives)
- HERMLE 5-axis CNC milling centre, type C 40 U Dynamic
- HERMLE 3-axis CNC milling centre
- Studer cylindrical grinder, type S 30
- JUNG surface grinder
- HAAS CNC lathe
- A set of conventional machine tools for metal
The machine tools operators have many years of experience in tool making and are among the best in the industry.