Leading of Liquid Silicone Rubber injection molding (LSR molding) ... In the field of manufacturing LSR molding we have always delivered high precision parts. Ming-Li molded parts made from liquid silicone (LSR) or solid silicone (HTV) are extremely elastic, odorless and tasteless, chemical, UV, ageing and temperature resistant. Numerous fields of application are opened up for those who have mastered the processing methods. Our systems solutions offer you the best possible basis.

At Ming-Li, you get everything from a single source: well-founded process expertise, individually configured electric, hybrid, hydraulic or vertical ALLROUNDER injection molding, including precisely tailored dosage, vacuum and demolding technology as well as automation. For this purpose, we work closely with the applicable leading customers.

• Extensive range for silicone processing: All standard ALLROUNDER machines can be combined with numerous process-specific equipment options
• Continuous bubble-free feed of HTV with the INJESTER tamping device
• High processing quality thanks to carefully adapted cylinder modules, such as the automatically closing disc-type non-return valve for LSR
• Sprueless operation through direct injection by means of a single cold-channel nozzle
• Reliable evacuation with the SELOGICA control system keeps component quality consistently high

Liquid Silicone Rubber (LSR) molding technology finds applications across various industries due to its unique properties and benefits. Some common applications include:

1. Medical Devices: LSR molding is widely used in the medical industry for manufacturing a range of components and devices, including:

   • Surgical instruments and tools with soft-touch grips and ergonomic designs.
   • Medical implants such as catheters, seals, and gaskets for biocompatibility and durability.
   • Respiratory masks, tubing, and connectors for respiratory therapy and patient care.

2. Automotive Components: LSR molding is employed in the automotive industry for producing various components with superior performance and durability, including:

   • Seals, gaskets, and O-rings for engines, transmissions, and fluid systems due to their heat resistance and chemical stability.
   • Grommets, connectors, and cable harnesses for electrical and electronic systems with excellent sealing and insulating properties.
   • Lighting components such as lenses, gaskets, and seals for headlights, taillights, and interior lighting with optical clarity and UV resistance.

3. Electronics and Electrical Encapsulation: LSR molding is used in electronics and electrical applications for encapsulating and protecting sensitive components from environmental hazards such as moisture, dust, and vibration. Examples include:

   • Potting and encapsulation of electronic modules, sensors, and circuit boards for protection against harsh operating conditions.
   • Cable terminations, seals, and connectors for electrical connectors and cable assemblies requiring waterproofing and sealing.

4. Consumer Products: LSR molding is employed in the production of various consumer products for improved performance, comfort, and aesthetics, including:

   • Consumer electronics accessories such as protective cases, grips, and covers with soft-touch surfaces and custom designs.
   • Personal care products such as baby bottle nipples, pacifiers, and toothbrushes with hygienic and hypoallergenic properties.
   • Kitchenware and household goods such as silicone bakeware, utensils, and seals for heat resistance and food safety.

5. Industrial Components: LSR molding finds applications in industrial settings for producing components with superior performance, reliability, and longevity, including:

   • Seals, gaskets, and diaphragms for industrial valves, pumps, and fluid handling systems requiring chemical resistance and durability.
   • Seals, grommets, and bushings for machinery and equipment with high-temperature, high-pressure, or corrosive environments.
   • Vibration dampers, shock absorbers, and isolators for machinery and equipment requiring noise reduction and vibration control.

Overall, LSR molding technology offers versatility, precision, and performance advantages that make it suitable for a wide range of applications across industries, ranging from medical devices and automotive components to consumer products and industrial components.

To ensure successful Liquid Silicone Rubber (LSR) molding, several key considerations must be addressed throughout the process. Here's a step-by-step guide to making LSR molding well:

1. Material Selection: Choose the appropriate LSR material based on the specific requirements of the application, including factors such as hardness, temperature resistance, chemical resistance, and biocompatibility (if applicable). Consult with material suppliers to select the right formulation for the desired properties.

2. Mold Design: Design the mold with careful consideration of part geometry, gating, venting, and cooling requirements. Ensure that the mold design allows for proper filling and venting of the LSR material to prevent air entrapment, voids, and surface defects. Incorporate features such as draft angles, parting lines, and vent channels to facilitate mold release and minimize flash.

3. Tool Fabrication: Fabricate the mold tooling using high-quality materials and precision machining techniques. Ensure tight tolerances and smooth surface finishes on critical mold components such as cavities, cores, slides, and ejector pins. Verify the accuracy of the mold tooling through comprehensive inspection and validation procedures.

4. Injection Molding Process Setup:

   • Prepare the LSR material according to the manufacturer's recommendations, ensuring proper mixing and degassing to remove air bubbles and impurities.
   • Set up the injection molding machine with appropriate barrel temperatures, injection pressures, injection speeds, and cure times based on the LSR material specifications and part requirements.
   • Install the mold tooling securely onto the molding machine, ensuring proper alignment and clamping to prevent leaks and maintain dimensional accuracy.

5. Injection Molding Process Optimization:

   • Optimize process parameters such as injection speed, injection pressure, and cure time through iterative testing and adjustment to achieve the desired part quality, consistency, and cycle time.
   • Monitor key process variables during production runs using real-time monitoring systems and perform regular inspections to identify and address any deviations or anomalies.

6. Part Ejection and Deflashing:

   • Eject the molded parts from the mold cavity using the appropriate ejection mechanism (e.g., ejector pins, air ejection) to prevent damage to the parts and mold.
   • Remove any flash or excess material from the molded parts using manual trimming or automated deflashing equipment to achieve the desired part geometry and surface finish.

7. Post-Curing (if necessary):

   • If post-curing is required to achieve the desired physical properties or dimensional stability, follow the manufacturer's recommendations for time, temperature, and post-cure method (e.g., oven curing, UV curing).

8. Quality Control and Inspection:

   • Implement stringent quality control measures throughout the LSR molding process to ensure that the molded parts meet the required specifications and standards.
   • Perform dimensional inspection, visual inspection, and functional testing of the molded parts to verify accuracy, consistency, and performance.

9. Documentation and Traceability:

   • Maintain detailed records of process parameters, material batches, inspection results, and production history to facilitate traceability and troubleshooting.
   • Document any process changes, deviations, or corrective actions taken during production to ensure continuous improvement and regulatory compliance.

By following these steps and paying careful attention to every aspect of the LSR molding process, manufacturers can produce high-quality LSR molded parts with precision, consistency, and reliability for a wide range of applications across industries.

Key elements for successful Liquid Silicone Rubber (LSR) molding include:

1. Material Selection: Choose the appropriate LSR material based on the application requirements, considering factors such as hardness, temperature resistance, chemical resistance, biocompatibility (if applicable), and color options.

2. Mold Design: Design the mold with precision to accommodate the desired part geometry, gating, venting, and cooling requirements. Ensure proper draft angles, parting lines, and vent channels to facilitate mold release and minimize defects.

3. Tool Fabrication: Fabricate the mold tooling with high-quality materials and precision machining techniques to achieve tight tolerances, smooth surface finishes, and durability. Verify the accuracy of the mold components through thorough inspection and validation.

4. Injection Molding Machine: Utilize a well-maintained injection molding machine with appropriate clamp force, shot size, injection pressure, injection speed, and temperature control capabilities for LSR molding.

5. Injection Process Optimization: Optimize process parameters such as injection speed, injection pressure, cure time, and post-curing (if necessary) to achieve consistent part quality, minimize cycle times, and ensure proper curing of the LSR material.

6. Injection Unit: Use a specialized injection unit designed for LSR molding, equipped with precision metering and mixing systems to accurately dispense the LSR material and catalyst (if applicable) into the mold cavity.

7. Cure System: Employ an efficient and reliable cure system to ensure proper curing of the LSR material, whether through thermal curing (oven curing) or UV curing, depending on the material formulation and part requirements.

8. Mold Temperature Control: Maintain precise control over mold temperature through water or oil circulation systems to achieve uniform cooling and curing of the LSR material, preventing defects such as warpage, shrinkage, or surface blemishes.

9. Venting and Degassing: Ensure proper venting and degassing of the mold cavity to eliminate trapped air and gas bubbles during the injection process, preventing defects such as voids, bubbles, or surface imperfections in the molded parts.

10. Part Ejection and Handling: Implement reliable part ejection mechanisms (e.g., ejector pins, air ejection) and handling systems to safely remove the molded parts from the mold cavity without damage or deformation.

11. Quality Control and Inspection: Establish comprehensive quality control measures and inspection procedures to monitor part dimensions, surface finish, and physical properties. Conduct regular inspections and testing to verify part quality and consistency.

12. Training and Expertise: Ensure that operators and technicians receive proper training and have expertise in LSR molding techniques, equipment operation, mold maintenance, and troubleshooting to address any challenges that may arise during production.

By addressing these key elements and optimizing the LSR molding process, manufacturers can achieve high-quality, precision-molded parts with consistent performance and reliability for a wide range of applications.

 

The benfit of LSR molding part

Liquid Silicone Rubber (LSR) molding offers several benefits that make it an attractive choice for manufacturing various parts and components. Here are some key advantages of LSR molding:

1. Versatility: LSR molding can produce parts with intricate designs, complex geometries, and thin-walled sections. It allows for the production of a wide range of parts, from simple gaskets and seals to more complex medical devices and automotive components.

2. High Precision: LSR molding offers high precision and tight tolerances, making it suitable for applications requiring precise dimensions and consistent quality. It enables the production of parts with minimal flash, burrs, or defects, resulting in excellent surface finish and dimensional accuracy.

3. Temperature Resistance: LSR parts exhibit excellent temperature resistance, withstanding extreme temperatures ranging from -50°C to 250°C or higher, depending on the specific formulation. This makes LSR suitable for applications requiring thermal stability, such as automotive components, electrical insulation, and medical devices.

4. Chemical Resistance: LSR materials have excellent chemical resistance, making them resistant to oils, solvents, fuels, and other harsh chemicals. This property makes LSR parts suitable for applications in automotive, industrial, and medical environments where exposure to chemicals is common.

5. Biocompatibility: LSR materials are biocompatible and can be formulated to meet various regulatory standards for medical and healthcare applications. LSR parts are widely used in medical devices, implants, and pharmaceutical packaging due to their biocompatibility, sterilizability, and non-reactivity with bodily fluids.

6. Elasticity and Flexibility: LSR parts exhibit high elasticity and flexibility, allowing them to withstand repeated deformation and stretching without permanent deformation or loss of mechanical properties. This property makes LSR suitable for sealing and gasketing applications, as well as overmolding onto rigid substrates.

7. Optical Clarity: Some LSR formulations offer excellent optical clarity and transparency, making them suitable for optical and lighting applications such as lenses, light guides, and LED encapsulation. LSR parts can transmit light efficiently without significant loss or distortion, making them ideal for demanding optical requirements.

8. Sterilizability: LSR parts can be easily sterilized using various methods such as autoclaving, gamma irradiation, or ethylene oxide (EtO) sterilization. This makes LSR suitable for use in medical and healthcare environments where sterilization is required to maintain cleanliness and safety.

9. Longevity and Durability: LSR parts are known for their durability and long service life, even in demanding operating conditions. They exhibit excellent resistance to aging, weathering, UV exposure, and mechanical wear, making them suitable for outdoor, automotive, and industrial applications.

10. Overmolding and Bonding: LSR can be overmolded onto a wide range of substrates, including metals, plastics, and textiles, to create integrated components with enhanced functionality and performance. LSR also offers excellent adhesion properties, allowing for strong bonds between LSR and substrate materials.

Overall, LSR molding offers numerous benefits, including versatility, precision, temperature resistance, chemical resistance, biocompatibility, elasticity, optical clarity, sterilizability, longevity, and overmolding capabilities. These advantages make LSR a preferred choice for manufacturing a wide range of parts and components in industries such as automotive, medical, electronics, aerospace, and consumer goods.

 

The elements of P(plastic injeciton) +R(LSR) molding

Combining plastic injection molding (P) with liquid silicone rubber (LSR) molding (R) offers several advantages and allows for the production of complex parts with unique properties. Here are the key elements of P+R molding:

1. Hybrid Molding Process:

   • P+R molding combines the traditional plastic injection molding process with LSR molding techniques in a single manufacturing process.
   • The process involves injecting thermoplastic material (such as ABS, PC, or nylon) for the initial part structure, followed by overmolding with liquid silicone rubber to add features or properties not achievable with plastics alone.

2. Design Integration:

   • Design engineers must carefully integrate both plastic and silicone rubber components into the part design.
   • Considerations include part geometry, material compatibility, bonding between plastic and LSR, and functionality requirements.

3. Material Compatibility:

   • Selecting compatible materials is crucial for successful P+R molding.
   • The thermoplastic used for the base structure must bond well with the LSR during overmolding.
   • Compatibility testing may be necessary to ensure proper adhesion and performance.

4. Overmolding Process:

   • The overmolding process involves injecting liquid silicone rubber over the pre-formed plastic substrate.
   • It typically requires specialized injection molding equipment capable of handling both thermoplastics and LSR, as well as molds designed for overmolding applications.

5. Injection Sequence:

   • The sequence of injection is critical to ensure proper bonding between the plastic substrate and the LSR.
   • Factors such as injection speed, pressure, and temperature profiles must be optimized for both materials.

6. Adhesion and Bonding:

   • Achieving strong adhesion between the plastic and LSR layers is essential for part integrity.
   • Surface treatment techniques or bonding agents may be employed to enhance bonding between the two materials.

7. Part Quality Control:

   • Quality control measures must be implemented to ensure consistent part quality throughout the P+R molding process.
   • Inspection techniques may include dimensional checks, visual inspection, adhesion testing, and functional testing.

8. Material Properties:

   • By combining plastics with LSR, parts can benefit from a wider range of properties, including hardness, flexibility, chemical resistance, temperature resistance, and biocompatibility.
   • Material selection should be based on the specific requirements of the application.

9. Complex Part Design:

   • P+R molding enables the production of complex parts with multiple materials and features.
   • Designers can incorporate features such as soft-touch grips, seals, gaskets, overmolded threads, and encapsulated electronics into a single part.

10. Applications:

    • P+R molding is commonly used in industries such as automotive, medical, consumer electronics, and industrial manufacturing.
    • Typical applications include seals, gaskets, grips, handles, connectors, electronic enclosures, and wearable devices.

By leveraging the advantages of both plastic injection molding and LSR molding, P+R molding offers manufacturers the ability to create innovative, high-performance parts with unique properties and functionalities. This hybrid approach opens up new possibilities for product design and development across various industries.