Application Checklist: What Information You Should Prepare Before Starting a Custom Silicone Project

Having a well-prepared brief prior to reaching out to a silicone manufacturer can significantly accelerate the quoting process, facilitate design for manufacturing (DFM) feedback and minimize the revision iterations. In many projects, unforeseen delays and cost overruns occur because important information regarding the actual application of the part was missing at the beginning. Use this handy checklist to ensure that the product engineer, brand owner and OEM buyer have all the necessary information in hand, to enable the manufacturer to make the correct recommendations and deliver a high-quality product from the first sample.

Using a structured checklist can help you prepare your custom silicone application project more effectively and reduce the risk of costly mistakes later. 

Core Application Information – What the Part Is and What It Does

The key to any successful custom silicone project is understanding the part. Consider these very basic but important questions first: 

• What is the part? A seal, gasket, sleeve, grip, bumper, valve, mat, or overmolded part (e.g., seal, gasket, sleeve, grip, bumper, valve, mat, or overmolded part).
• Where does it go in the finished product?
• What does it do? 

Defining the Functional Role of the Silicone Part

Describe the function using words. Some examples are suitable for project briefs, such as: 

• “Key characteristics of this gasket is the ability to stop water entering into an electronics casing.”
• “The sleeve will protect a bottle from drops and offer a soft touch grip.”
• “This pet mat should be easy to clean after use and it must also be non-slip.” 

The engineering team can use clear function statements to recommend the best geometry, material characteristics, and manufacturing processes. 

Environmental Conditions – Where the Part Will Actually Live

Silicon performance is very sensitive to its operating environment. Describe actual uses in as much detail as possible.

Here are some questions to consider in making this decision: 

• What range of temperatures (min, max, continuous or cyclic) is expected?
• Will part be in contact with liquids, oils, chemicals, cleaning or food products?
• Are there any exposures to UV, outdoor weather conditions, vibration or shock?
• Indoor or outdoor? Would you rather it be a sealed room or completely exposed? 

Temperature, Chemicals and UV as Key Environment Factors

For under-hood components, often the combination of high heat and oil and coolant exposure leads to certain high-temperature grades. Products used outside, for pets or gardens require good UV and weather resistance. Products such as medical or personal-care products are subjected to multiple situations of sterilization or skin contact. Adequate documentation of these factors at an early stage enables selection of the most appropriate material and prevent failures in the field. 

Dimensions, Geometry and Interface Requirements

Any sort of basic information regarding size and shape is useful at the outset of a custom silicone task checklist.

Share:

• Length, width, height and wall thickness (approx)
• The dimensions and tolerances that are critical to the function of a product or process.
• Items that are mounted, holes, slots, interfaces with other elements etc.
• All undercuts, thin walls or changing thickness. 

Rough Concept vs Final Design – What You Need at This Stage

Don’t need to have a final CAD file for initial discussion. Often a diagram or picture of similar component or dimensions will suffice. Be clear about the dimensions that are hard or soft. This assists the manufacturer to give realistic DFM feedback and tooling suggestions. 

Performance Requirements – What the Part Must Achieve

Specify the desired behavior of the part for its life.

Key performance data features: 

• Shore A range (required hardness)
• Compression set resistance
• Life in cycles (flex or compression)
• Ability to resist abrasion, tearing or impact.
• Surface finish specifications (smooth, matte, textured etc.) 

Quantifying Performance Where Possible

If you have data, then you will have a target for it, for example: “maintain sealing force after 10,000 cycles at 120°C” or “withstand repeated drops from 1.5 m”. If there are no test data, it is still useful to have rough estimates. These detail information inform material selection and design changes. 

Material Grade and Compliance Requirements

Not all silicone compounds are the same. Define the requirements that the part should fulfill. 

Common requirements: 

• Food contact (FDA, LFGB)
• Medical/biocompatibility (ISO 10993)
• Baby products or skin contact.
• ROHS, REACH or other Regulatory requirements 
• The flame retardancy or electrical properties are also taken into account. 

When Medical, Food-Grade or High-Temperature Grades Are Required

The kitchenware used in food processing must be made of certified material used in the kitchen to preserve the full traceability of the product. For automotive applications or for chemicals or other applications that demand higher temperatures or chemically resistant formulations, special materials may be needed such as fluorosilicone. If these requirements are listed early, there will be no changes to the specification later which can impact cost and timeline. 

Production Volume, Lead Time and Budget Constraints

Scale is a significant factor in manufacturing process and tooling decisions. 

Provide:

• The number of forecasts of the volume anticipated during the year or life of an animal.
• Set the prototype, pilot, and mass production dates.Specify the prototype date, the pilot date and the mass production date.
• The cost range and the unit price of the tooling
• Any supply-chain preferences or restrictions 

How Volume Affects Process and Tooling Choices

Small volumes may be best compression molded with simpler tools, while larger volumes may benefit from the liquid silicone rubber (LSR) injection molding process which can be more expensive but offers faster cycle times and tighter tolerances. By stating the volume, the manufacturer can then suggest the most efficient way to do it. 

Visual and Branding Requirements (If Relevant)

Appeal is important especially for consumer products.

Consider: 

• Colour matching to brand standards.
• The feel of the surface (matte, shiny, soft touch).
• Placement and method of logo on product (printed, embossed or co-molded)
• Restrictions in visible area (parting line, flash) 

When Appearance Drives Design and Process Choices

Hidden parting lines and exact colour consistency might be needed if you are designing a kitchen sleeve or promotional mat. These looks can affect the design of the tools and the secondary operations. 

Risks, Challenges and Known Issues with the Current Part (If Any)

When replacing an existing component, let us know what is broken.

Helpful details include: 

• Failure modes (cracking, hardening, leaking, wear)
• The circumstances in which failures are seen is described.Conditions in which failures are observed.
• The materials of the present part and their limitations. 

Using Failure History to Guide Material and Design Changes

The ability to clearly describe the problem, such as “After 6 months in hot oil, existing rubber seal is hard and becomes less elastic”, helps the team to make recommendations for improvement and to prevent repeating the problem. 

Your Project Checklist – A Simple Summary

Before the next supplier discussion, use this ready to copy checklist: 

1. Describe part type and core functions.
2. Summarize the conditions under which the process will be operated (temperatures, chemicals, UV, etc.).
3. Give approximate sizes and interfaces.
4. Set performance specifications (hardness, cycles, compression set).
5. Describe the specifications for materials by grade and compliance.
6. Provide anticipated volume, time and cost.
7. Note visual/branding requirements if any.
8. Outline any problems or limitations that are known of existing solutions. 

The time you spend preparing your custom silicone application project with this information will pay off in many ways, including quicker responses, better technical proposals and ultimately better parts that are performing well in the field.

Every year we receive hundreds of briefs for projects, and we’re ready to assist you with your next silicone customization project at HT Silicone & Rubber.At Dongguan HT Silicone & Rubber Co., Ltd., we are constantly reading about project briefs, and we are ready to help you with your next custom silicone development project. Present your ready-to-go list and let’s make your concept a production-ready solution!