Co-design of plastic injection molding and liquid silicone injection molding parts
Co-designing parts for plastic and liquid silicone injection is the fundamental strategy for aligning functional requirements with production realities from the earliest stages.
In industrial product development, the difference between an innovative idea and a viable product lies not just in conceptual design, but in its ability to be manufactured efficiently, repeatably, and profitably.
What is part co-design for plastic injection molding and liquid silicone injection molding
From an industrial perspective, co-design is not generic product design; it is a collaborative process between the client, the engineering team and the manufacturer to transform a functional need into an injectable, repeatable, and viable part.
This model integrates specialized manufacturing knowledge—such as thermoplastic and LSR (Liquid Silicone Rubber) injection—into the design phase. The goal is to ensure technical feasibility, avoiding deviations and optimizing mass production through a real manufacturing-oriented approach.
Difference between designing a part and co-designing it with the manufacturer
Designing in isolation typically focuses on aesthetics or theoretical function, whereas co-design involves projecting with the injector in mind.
Collaborating with the manufacturer allows for the early consideration of critical factors like material behavior, mold complexity, realistic tolerances, necessary geometry for demolding and production scaling.
Why co-design reduces redesigns, failed tests and delays
An early review based on Design for Manufacturing (DFM) criteria detects issues before the mold—one of the highest initial costs—is even built.
Co-design helps prevent:
- Aesthetic and structural defects: Warpage, sink marks, and burrs.
- Filling issues: Using simulation to optimize material flow distribution.
- Cost overruns: Identifying excessively complex geometries that inflate mold costs or increase cycle times.
When to involve the manufacturer in the part design process
For technical managers and industrial procurement departments, the ideal moment is before closing the final CAD, defining the definitive blueprint or purchasing the material.
Involving the manufacturer early allows for the anticipation of injection process limitations and mold requirements, facilitating a fluid transition to industrialization.
Technical requirements that must be defined before designing the part
Before drawing the first line of the design, it is essential to provide the manufacturer with clear information to ensure the co-design process is effective.
Part function, operating environment and expected service life
It is necessary to define whether the part will be subjected to pressure, extreme temperatures, chemical contact, friction wear, or continuous vibration.
These factors determine whether structural rigidity, sealing flexibility, or electrical insulation is required.
Tolerances, critical dimensions and functional areas
Not all areas of a part require the same level of precision.
It is vital to identify assembly zones, sealing surfaces, and control points.
DFM design for silicone and plastic focuses on these critical dimensions to ensure functionality without adding unnecessary costs for unfeasible tolerances in non-critical areas.
Regulatory, healthcare or safety requirements
Depending on the sector (medical, automotive, industry,...), the part may require certifications for biocompatibility, total traceability, sterilization or flame retardancy.
Material selection in the co-design of injection-molded parts
Material selection is the most critical technical decision, as it dictates the geometry, the mold, and the final cost.
Engineering plastics for rigid or structural parts: PA, PC, PP and PPS
Biocompatible thermoplastic materials are used for housings, supports, and connectors requiring mechanical and thermal resistance.
Co-design helps evaluate if these options meet the expected durability for demanding industrial components.
Technical elastomers: EPDM, SEBS and PUR
Ideal for gaskets, vibration absorption, and flexible parts.
For projects requiring high thermal stability or very complex geometries, co-design helps decide between these elastomers or the use of liquid silicone (LSR).
Fluorinated materials: ETFE, PTFE and PFA for demanding applications
These materials ETFE, PTFE y PFA are selected for environments with aggressive chemicals or very high temperatures where other plastics would fail.
Their use strongly influences part design due to their unique flow and friction properties.
Flame-retardant plastics for industry, automotive and electrical components
When fire safety is required, self-extinguishing or Flame-retardant plastics materials with UL 94 (HB, V-2, V-1, V-0) classifications are used.
The choice of retardancy grade directly affects part wall thickness and surface finishes.
Applications of co-design in the medical, industrial and automotive sectors
Co-design adapts to the specific technical needs of each industry, always seeking maximum precision. Something essential in the medical, industrial, and automotive sectors, among others.
Parts for the medical, pharmaceutical and veterinary sectors
Focused on liquid silicone (LSR) components for fluid contact, sealing parts, and consumables requiring extreme cleanliness, biocompatibility and stability.
Industrial components made with engineering plastics or special materials
Design of insulators, wear-resistant parts and technical supports with tight tolerances that must withstand severe operating conditions.
Parts for automotive and technical mobility applications
Gaskets, grommets and connectors that must resist vibration and chemicals while meeting safety and flame retardancy standards.
What to consider when choosing a manufacturer that participates in part co-design
To guarantee success, an industrial partner must provide more than just injection capacity.
They must demonstrate:
- Technical expertise and guidance: Ability to optimize thicknesses, ribs, and structural reinforcements.
- Deep material knowledge: Advice on selection based on final application.
- Validation and simulation: Use of tools to predict material behavior within the mold.
- Traceability and quality: Strict process control from prototype to series production.
A solid collaboration model with a specialized industrial partner transforms a technical need into an industrializable, efficient, and market-competitive product.
If you would like more information on how to optimize your injection-molded parts or require technical guidance for your next project, please do not hesitate to contact us.