Capabilities
Injection moulding, extrusion and in-house compounding
50 people, 16 injection machines, 3 extrusion lines and 3 compression presses in Curitiba, Brazil. All parts are produced to customer drawing. The tables below are our working envelope. If your part sits outside it, tell us — we will say plainly whether we can make it.
Processes
Injection moulding is our main process. Extrusion and compression run alongside it for parts where they are the better route. The table below is a selection guide, not a product list — see How a part is developed below.
| Process | Machines | Range | Suited to |
|---|---|---|---|
| Injection moulding | 16 | 80–240 t clamping | Repeat series, tight dimensional repeatability, complex geometry, minimal flash |
| Extrusion | 3 | Hot air tunnel vulcanisation | Continuous sections cut to length — tube, cord, profile |
| Compression moulding | 3 | — | Thick sections, larger parts, short runs and prototypes |
Compounding
Compounds are mixed in-house. Elastobras develops and adjusts its own formulations rather than buying ready-mixed compound.
| Mixing equipment | 1 internal mixer (Banbury type) and 2 open mills |
|---|---|
| Batch size | up to 30 kg |
| Batch release testing | Rheometer curve and hardness, on every batch |
Formulation development is carried out in-house, and the compounding activity is inside the scope of our ISO 9001:2015 certificate.
Dimensional tolerances
We work to DIN ISO 3302-1, the standard tolerance classes for rubber products. Stating a class is how a drawing and a quotation agree on what is achievable before tooling is committed.
| Process | Standard | By agreement |
|---|---|---|
| Injection moulding | Class M2 | Class M1 on functional dimensions |
| Extrusion | Class E2 | Tighter on request, after feasibility review |
| Compression moulding | Class M3 | M2 on selected dimensions |
M1 on functional dimensions is not a claim on paper: we are in series production on silicone parts holding sealing diameters to ±0.10 mm and membrane thickness of 0.70 mm to ±0.10 mm.
Tolerance is worth spending where it does work. On most parts, the functional dimensions justify a tight class and the general outline does not — tell us which dimensions matter and we will quote accordingly, rather than pricing the whole part at its tightest feature.
Materials
Compounds are produced across a hardness range of 25 to 90 Shore A. Because we formulate in-house, the elastomer is chosen against the service condition of the part — the substances it will meet, the temperature it will see, the colour and the mechanical requirement. The same part can be produced in different families for different customers.
| Family | Designation | Chosen when the part meets |
|---|---|---|
| Nitrile | NBR | Oils, fuels and hydrocarbons |
| Ethylene propylene | EPDM | Weather, ozone, UV, hot water and steam — outdoor housings |
| Silicone | VMQ | Wide temperature range, low compression set, chemically inert |
| Styrene butadiene | SBR | Abrasion and general dynamic service |
| Natural rubber | NR | High resilience, tear strength, dynamic loading |
| Chloroprene | CR | Moderate oil resistance combined with weather resistance |
How a part is developed
Elastobras holds no catalogue and no shelf stock. Every part is customer-specific on two axes at once: a dedicated tool, and a compound formulated for that application.
- Drawing, sample or problem. A part can start from a technical drawing, from a physical sample to be reproduced, or from a component that is failing in service.
- Compound selection. We propose an elastomer family and formulation against the service condition — media, temperature, hardness, colour, mechanical requirement.
- Tooling. Moulds are designed and produced with partner toolmakers to the approved geometry.
- First article. Sample parts with dimensional report and material data for customer approval.
- Series production. Under a frozen formulation, with the rheometer curve of every batch on record.
The parts shown across this site are examples of work done, not products offered. What we supply is the development and the series that follows it.
Tooling and the initial investment
We only do development and localisation work, so every new part requires a dedicated tool. That means an initial tooling investment, quoted separately from the piece price, before any series production.
Tooling cost depends on geometry, cavitation and process. We quote the tool together with the manufacturability review, so the decision is made with the figure in hand rather than afterwards.
In many cases the investment can be avoided: existing tooling held at another supplier can be transferred and requalified, usually faster and cheaper than starting from a drawing.
Tooling pays back above a certain annual volume. If your volume does not reach that point we will say so plainly — we would rather lose an enquiry than sell a tool that cannot justify itself.
Finishing
Deflashing, dimensional inspection and packaging to customer specification. Extruded parts are cut to length on automated equipment with 100% inline inspection.
Capability sheet
Download the capability sheet (PDF, 2 pages) — process selection, material property matrix, compounding, quality and what to send with an enquiry.
Series
Series run from 30 pieces to continuous high-volume production. The low end is a development run on the compression presses. The high end is series production on the extrusion lines, shipped monthly for export.
Minimum order quantity depends on the tooling and the compound, not on a fixed policy. A short development run and a multi-million series are both normal here.