Custom Silicone Sealing and Dust Plug Design Guide: No CAD Skills? How Can the Factory Help and What Is a Reasonable Design Fee?
1. No Design Background? What Can the Factory Actually Do for You?
Many start-ups or project owners struggle when customizing silicone sealing and dust plugs because they “can’t draw technical drawings” or “lack design experience”. In practice, most silicone product factories can provide an end-to-end service from requirement to design. In general, they can help you with the following:
1. Requirement Translation: Turning Ideas into Drawings
- If you only have the intended use (for example, “used as a dust plug for an electronic device port, diameter 10 mm, relatively soft”), the factory can work backwards from the application to propose a structure (such as recommending silicone with Shore A 40–50 hardness and adding a slightly raised sealing lip at the edge to improve sealing performance), and then generate 2D/3D drawings.
- If you have a reference sample (even an old plug or hand sketch), the factory can use reverse engineering (scanning and dimensional measurement) to recreate the design, or optimize details (for example, restoring worn radii or correcting distorted profiles).
2. Visualized Communication: Solving the “Abstract Description” Problem
- Providing material/hardness samples: the factory can send silicone blocks with different hardness levels in advance (for example, Shore A 30/50/70) so you can physically feel and confirm the tactility, avoiding vague descriptions like “as soft as an eraser” that easily lead to misunderstanding.
- Using simple tools to assist: using a tablet drawing tool so you can mark dimensions directly, or using clay to make a rough hand model, plus 3D-printed quick prototypes to confirm the shape visually (very suitable for craft creators, personal brands, and other scenarios where design capability is limited).
3. Compliance and Optimization: Ensuring Manufacturability and Performance
- Structural optimization: for example, if you want to make a sealing plug with vent holes (hole diameter 1 mm), the factory can use CAE analysis to verify whether the vent layout affects sealing performance, or adjust wall thickness to avoid deformation.
- Industry standards and regulatory fit: if the plug is used in medical devices, the factory can recommend FDA-compliant silicone grades and incorporate compliance details into the design (such as smooth surfaces without dead corners and resistance to repeated disinfection and chemical cleaning).
2. What Is a Reasonable Design Fee? Cost Breakdown and Typical Ranges
There is no universal standard for design fees. The core depends on design complexity, service scope, and whether the design is original. Based on real industry cases (feedback from clients on platforms such as Zhihu, Taobao, and Maimai), you can refer to the following ranges and components:
1. Base Design Fee (Excluding Physical Sampling): RMB 300–2,000
- Simple designs (such as cylindrical dust plugs with no complex features): around RMB 300–800, typically including 2D drawing creation and basic dimensional annotations (suitable for B2C individuals and small-batch customization, such as DIY scented candle plugs or pet product plugs).
- Medium complexity (such as sealing plugs with lips or non-standard geometries): around RMB 800–1,500, typically including 3D modeling and basic structural feasibility checks (suitable for SMEs, such as smart home waterproof components or sports bottle stoppers).
- High complexity (such as medical-grade sealing plugs or multi-component dust plug assemblies): RMB 1,500–2,000 and above, often including material testing (temperature and chemical resistance) and compliance evaluation (suitable for special industries such as laboratory reactors or medical device interfaces).
2. Additional Services: Items That Affect the Total Cost—Confirm in Advance
- Sampling/prototyping fee: charged separately, typically RMB 100–500 per run for simple designs and RMB 500–1,000 per run for more complex parts. Some factories may offset or refund this after a mass production order is placed.
- Number of revisions: usually includes 1–2 rounds of free revisions by default. Additional revisions may cost RMB 200–500 per round (agreeing on the number of free iterations in advance helps avoid hidden charges such as “pay again after three revisions”).
- Reverse engineering / non-original copy: copying an existing product (non-original design) is typically 30%–50% cheaper than fully original design work, but you must pay attention to IP and copyright risks (for example, character IPs or branded products require proper authorization).
3. Beware of Very Low Prices: Designs Under RMB 300 Can Be Risky
- Ultra-low design fees may skip critical steps (such as structural optimization or complete dimensional annotations), which can result in samples that cannot be assembled properly (for example, “tapered interface mistakenly designed as a straight cylinder”, or “hole diameter undersized by 3 mm”). In the end, this increases rework and overall project cost instead of saving money.
3. Three Practical Tips: Information to Provide the Factory to Help Reduce Design Costs
Design fees are not fixed. Clear, precise requirements communication can reduce the factory’s communication and trial-and-error costs, and, in turn, lower your design expense. How to do this in practice?
1. Provide “Reference Anchors”: Reduce the Time Spent Guessing Your Needs
- Send physical samples / high-resolution photos: much more effective than text alone. For example, send an old plug and mark “keep dimensions unchanged, reduce hardness by 10 Shore A points”, or share a clear photo of a similar product and note “follow this shape, but change the hole diameter to 2 mm”.
- Clarify use case and environment: instead of saying “I want it soft”, specify “for baby products, needs food-grade silicone with Shore A 40 to avoid scratching the baby’s skin”; instead of saying “waterproof”, specify “for outdoor lighting interfaces, requires IP67 sealing and a working temperature range of –30℃ to 80℃”.
2. Simplify the Design: Remove “Non-Essential Complexity”
- Complex surface textures and irregular protrusions increase 3D modeling workload and sampling difficulty. For example, a scented mold with embossed patterns usually costs about 50% more in design fees than a plain mold. If the function is not affected, consider simplifying to “local texture + basic geometry”.
- Prioritize standard modules: ask the factory whether they have “standard silicone sealing/dust silicone plug families” (such as basic round or square geometries). Suppose you only need to change dimensions or add a logo. In that case, the design fee can be reduced by around 40% (very suitable for small-batch customization such as theatre merchandise or corporate gifts).
3. Define the “Service Scope” in Advance: Avoid Future Disputes
- Before signing, confirm: whether the design fee includes 3D models, how many rounds of sampling are covered, and whether material test reports are provided. Also agree on the refund or adjustment policy if the design proves non-manufacturable (for example, cannot be mass-produced as drawn).
- Use a “visual checklist” to align requirements: create a simple table listing “dimensions (ID/OD/height), material grade (food-grade/industrial), temperature range, special requirements (such as vent holes or anti-slip texture)”. Ask the factory to confirm this list before starting detailed design work.
Summary
When customizing silicone sealing and dust plugs, “not being able to design” is not a real barrier—most factories can provide design services from requirement definition to engineering drawings. A typical design fee ranges from about RMB 300 to 2,000, depending mainly on the design’s complexity and the scope of services. If you want to control costs, the key is to reduce the factory’s “guesswork cost”: provide reference samples, clearly specify application parameters, simplify non-essential structures, and define the service scope in advance. Doing so helps you avoid the trap of “design fees more expensive than the product itself”. It enables the factory to deliver a solution that meets your needs faster and more accurately.
