Silicone is one of the most stable and versatile elastomers available. It withstands extreme temperatures, maintains elasticity for years and resists chemical conditions that degrade other materials. But behind a technical seal, tube or extruded profile lies far more complex engineering than it appears.
Manufacturing silicone is not "mixing rubber and shaping it." It requires controlling a complete chain of variables: formulation, mixing, calendering, extrusion or molding, vulcanization, cooling, cutting, splicing and final validation. A minimal deviation at any point changes hardness, tolerance, thermal aging or even product lifespan.
And when there is a parent company certified in ISO 9001 and ISO 13485 behind it, that level of control affects the entire factory, not just the medical sector. Quality ceases to be a requirement and becomes a structural obligation.
Below we explain, with technical rigor, how an industrial silicone component is actually manufactured.
1. Compound Formulation: Where Everything Begins
Silicone does not arrive ready for extrusion. First, a compound adapted to the application is formulated.
There are two main families:
Solid Silicone HCR / HTV
Firm mass mixed on rollers or kneaders. Ideal for extrusion, compression and transfer molding.
Liquid Silicone LSR
Two-component, low-viscosity system injected into closed molds and crosslinked with platinum. The reference for medical, electronic and precision applications.
The chemical structure—silicon-oxygen chain—provides chemical inertness, thermal stability and elasticity at elevated temperatures. But an industrial compound is not just polymer: it includes fumed silica, catalysts, pigments, curing agents (peroxide or platinum), thermal additives, functional fillers and behavior modifiers.
2. Mixing and Calendering: Homogeneity Before Shape
For HCR, the compound passes through calendering rolls. This is one of the most critical processes, although rarely explained publicly.
Here the following are controlled:
- Plasticity
- Mixing temperature
- Microbubble elimination
- Silica dispersion
- Preparation for extrusion or molding
3. Extrusion: Shaping with Millimetric Precision
Extrusion works as follows:
- Material is fed into the extruder
- A screw compresses it
- It passes through a die
- Enters a curing tunnel
- Cools, stabilizes and is cut
But what truly makes the difference is controlling physical phenomena such as:
Die Swell
Material expansion upon exiting the die (5–20% depending on hardness and formulation).
Shrinkage
Contraction during curing.
Warping
Twisting due to irregular mixing or thermal imbalances.
Dimensional stability depends on pressure, temperature, die geometry, composition, line speed and curing time. Any variation means the profile will not meet ISO 3302-1.
4. Molding: Geometries Impossible to Extrude
When the part is not a continuous profile, the following methods are used:
- LSR Injection
- Compression
- Transfer
LSR injection always follows the same cycle:
- Controlled A+B mixing
- Injection into closed mold
- Platinum crosslinking
- Cooling and demolding
5. Vulcanization: The Moment Silicone Becomes Silicone
Unvulcanized silicone is not a stable elastomer.
There are two curing mechanisms:
Peroxide
Typically 140–180°C, may require post-cure.
Platinum
Clean, stable and without by-products; dominant in LSR and critical applications.
6. Cutting, Splicing and Finishing: Transforming a Profile into a Functional Seal
A seal rarely comes out as a single piece. It is cut, spliced and vulcanized into a frame shape.
Common processes:
- Cut to size
- Hot bonding
- Mold-vulcanized splices
- Food-grade or technical adhesives
- Specialized lubrication
- Visual defect inspection
For inflatable seals or railway applications, assembly requires specific processes, tolerances and geometric validations.
7. The Quality System: When the Factory Defines the Product
This is where the difference between a real manufacturer and a distributor becomes enormous.
ISO 9001 – Industrial Quality Management
Document control, calibration, standardized processes.
ISO 13485 – Manufacturing Under Medical Standards
Complete traceability, environmental control, process validation.
ISO 8 Clean Room
Continuous particulate and microbiological control.
EN 45545-2
Strict fire behavior requirements: oxygen, smoke and toxicity.
Normative Tests
- ISO 3302-1 (dimensional tolerances)
- ISO 48 (hardness)
- ISO 37 (tensile)
- ISO 815 (compression set)
- ISO 1817 (chemical resistance)
The result: every batch is controlled, recorded and validated with traceability equivalent to healthcare sectors.
Conclusion
Industrial silicone manufacturing is a discipline where chemistry, processes, materials physics and high-level standards converge. Each seal, tube or technical profile is the result of a chain of controlled decisions that determine its final performance.
When there is a parent factory certified in ISO 9001, ISO 13485, with ISO 8 clean room processes and formulations capable of meeting EN 45545-2, the manufacturing standard ceases to be "industrial" and becomes "critical."
This is what allows a simple profile or seal to function with precision for years in medical equipment, trains, industrial machinery or advanced sealing systems.
Need to manufacture a profile or seal with technical validation?
Our team designs and produces extruded profiles and technical seals with comprehensive process control. We review plans, propose stable geometries and validate materials for your application.
Contact now →