LSR Injection Molding Service
Z.S.R Group is your source for high-quality, custom silicone injection-molded parts that transform your product drawing into vital components in today’s high-tech industrial devices. We offer our partners in industrial, consumer, commercial to medical high-quality custom Liquid Silicone Rubber injection molding with our 12 sets LSR injection molding machines.
Z.S.R LSR injection molding Capacities
Z.S.R offer two different types of custom Liquid silicone molding: (Liquid Silicone Injection Molding) and LSR over molding: LSR over molding with different materials (silicone, Metal, plastic, etc). While both processes are great options your part geometry and complexity will likely determine which process to use.
LSR molding
LSR over-molding
LSR Multi-Shot
Tooling
Prototype Tooling: 100-1000pcs;
Production Tooling: over 10.000 pcs
Materials
Standard Silicone
Medical-Grade Silicone
Optical-Grade Silicone
Fluorosilicone (fuel and oil resistant)
Machines
Single, multi. cavity, and family molds: 50 to 300 press tonnage, side actions, including hand-loaded
Precision Tolerances
±0.01 mm machining tolerance with ±0.05 mm shrink rate control.
Part-to-Part Repeatability
Less than 5 mm
Parts size
1mm-400mm
After your files are received, we’ll review them to identify and communicate any potential Design for Manufacturability (DFM) Feedback to save money through the manufacturing process.
The Process of Injection Moulding
LSR molds are specifically designed for the injection molding process of Liquid Silicone Rubber (Part A and Part B, typically mixed in a 1:1 ratio)—also known as Liquid Injection Molding (LIM). The core principle of this process involves achieving precision molding through a combination of high-pressure injection and thermal curing.
- Metering and Mixing: Components A and B are metered precisely via high-precision pumps and thoroughly blended using a static mixer.
- Cold Runner Transport: The mixed LSR is conveyed to the mold through a cold runner system while maintained at a cooled temperature (10–20°C) to prevent premature vulcanization.
- High-Pressure Injection: Using a screw or plunger mechanism, the LSR is injected at high velocity into the mold cavity, which has been preheated to 170–200°C.
- Rapid Vulcanization: Under high-temperature conditions, the LSR undergoes a platinum-catalyzed addition reaction, completing the curing process within 20–120 seconds.
- Demolding: Once cooled, the finished part is automatically ejected. Typically, this process generates no waste material (as cold runner designs allow for gate-less molding).
Where Are LSR Molded Parts Used?
Due to silicone’s unique set of properties, it has become one of the most popular elastic materials. You can find custom LSR molding across many industries.
Medical Industry
Catheters Implantable cartridge
O-rings, Gaskets and Plugs
Storage devices
Automotive Industry
Valve Membranes
O-rings and gaskets
Vibration dampeners
Food/Appliance Industry
Silicone baking dishes
Flexible ice cube trays
Baby bottle nipples
Electronics Industry
Cell phone cases
Gaskets and dampeners
Tactile buttons
Materials & Specifications
Choose the right LSR material for your application. We support custom material selection based on performance, regulatory, and budget requirements.
Standard Silicone
30, 40, 50, 60, 70 Shore A
Medical-Grade Silicone
FDA / ISO 10993 compliant
Optical-Grade Silicone
High transparency, UV stable
Fluorosilicone
Fuel and oil resistant
Available Mold Types
Steel (tool steel, carbon steel) and aluminum molds. Production grades range from Class S50C (prototype) to S136 (extremely high production). Single, multi-cavity, and family molds with side actions including hand-loaded. Tighter tolerances can be requested and may increase tooling cost due to additional sampling. Z.S.R mills to a steel-safe condition on critical features.