Product Descriptions
Case Study Approach in LSR Injection Molding
LSR (Liquid Silicone Rubber) injection molding is one of the most process-sensitive manufacturing technologies within elastomer processing. Two-component silicone systems with very low viscosity undergo chemical vulcanization inside the mold, requiring a fundamentally different process control strategy compared to thermoplastic injection molding.
Key technical requirements for LSR injection applications include:
- Extremely precise dosing and mixing ratio control
- Complete filling of long flow paths at low injection pressure
- Machine stability at elevated mold temperatures
- Reliable demolding of extreme undercuts and complex geometries
- Safe and repeatable processing with cold runner systems
Dr. BOY injection molding machines meet these requirements on an industrial scale through LSR-specific plasticizing units and vibration-free mechanical design. The following case studies are based on real production applications and detailed technical data.
Case Study 1 - Thin-Wall LSR Speaker Housing
Application Description
Production of an LSR speaker housing used in acoustic applications, featuring very thin wall thickness and an exceptionally long flow path. This component represents a boundary application for LSR flow capability.
Technical Data
Part type: Speaker housing
Material: LSR
Wall thickness: 0.4 mm
Flow path length: 240 mm
Part weight: 14.7 g
Shot weight: 17.3 g
Machine: BOY 22 D HV
Screw diameter: 22 mm
Cycle time: 28 s
Number of cavities: 1
Runner system: Side film gate
Process Challenge
Complete filling of a 240 mm flow path at only 0.4 mm wall thickness without cold flow defects or surface degradation.
Dr. BOY Advantage
A finely controlled injection profile and stable clamping system enabled flawless production in a single cycle.
Case Study 2 - LSR Membrane Ring Overmolded on PBT Insert
Application Description
Production of an LSR membrane ring overmolded onto a thermoplastic PBT insert. This application is a typical example of LSR-thermoplastic hybrid technology.
Technical Data
Part type: Membrane ring
Material: LSR
Insert material: PBT
Part weight: 1.78 g
Shot weight: 1.78 g
Machine: BOY 22 A VV
Screw diameter: 18 mm
Cycle time: 20 s
Number of cavities: 1
Runner system: Cold runner
Process Challenge
Achieving homogeneous silicone flow and leak-tight bonding around the insert while preventing air entrapment.
Case Study 3 - LSR Baby Pacifier | 6 Cavities
Application Description
Production of LSR baby pacifiers requiring high hygiene standards, elasticity, and consistent mechanical performance.
Technical Data
Part type: Baby pacifier
Material: LSR 50 Shore A
Part weight: 5.1 g
Shot weight: 30.6 g
Machine: BOY 22 M LSR
Screw diameter: 32 mm
Cycle time: 22 s
Number of cavities: 6
Runner system: 6-cavity cold runner system
Process Challenge
Simultaneous filling of six cavities with uniform vulcanization and exact geometric repeatability.
Case Study 4 - LSR Baby Pacifier with Extreme Undercuts
Application Description
Production of an LSR baby pacifier with very deep undercut geometry, requiring demanding demolding conditions.
Technical Data
Part type: Baby pacifier
Material: LSR 50 Shore A
Part weight: 2.4 g
Shot weight: 9.6 g
Machine: BOY 22 M LSR
Screw diameter: 22 mm
Cycle time: 23 s
Number of cavities: 4
Runner system: 4-cavity cold runner
Process Challenge
Safe demolding without tearing or permanent deformation of the silicone component.
Dr. BOY Advantage
Smooth mold opening characteristics and precise mechanical synchronization ensured reliable demolding.
Case Study 5 - LSR Spark Plug Cap (Difficult Demolding)
Application Description
Production of an LSR spark plug cap for automotive ignition systems, featuring complex geometry and high elastic recovery requirements.
Technical Data
Part type: Spark plug cap
Material: LSR
Part weight: 32.95 g
Shot weight: 35.3 g
Machine: BOY 30 M
Screw diameter: 32 mm (LSR plasticizing unit)
Cycle time: 42 s
Number of cavities: 1
Runner system: Sprue pin with connection
Process Challenge
Preventing tearing in functional areas during demolding of complex geometry.
Case Study 6 - Spark Plug Socket Housing with Machine-Controlled Stripping
Application Description
Production of an LSR spark plug socket housing using a machine-controlled stripping mechanism.
Technical Data
Part type: Spark plug socket housing
Material: LSR
Part weight: 14.2 g
Shot weight: 56.8 g
Machine: BOY 50 A
Screw diameter: 42 mm (LSR)
Cycle time: 35 s
Number of cavities: 4
Runner system: 4-cavity cold runner
Process Challenge
Precise synchronization of the automatic stripping mechanism with the molding cycle.
Overall Evaluation - Results from LSR Case Studies
These LSR injection molding case studies clearly demonstrate the capabilities of Dr. BOY injection molding machines in the following areas:
- Stable filling of thin-wall and long-flow silicone parts
- High process reliability in multi-cavity cold runner systems
- Successful demolding of extreme undercuts and complex geometries
- High quality standards for medical and automotive applications
- Repeatable production performance even at longer cycle times
Conclusion - Why Choose Dr. BOY for LSR Injection Applications?
Dr. BOY injection molding machines are not simply production units for silicone parts. They represent an advanced manufacturing platform delivering high process reliability, precise dosing control, and long-term production stability for complex LSR applications. These real industrial case studies clearly demonstrate why Dr. BOY is a trusted solution for liquid silicone rubber injection molding.
