A perforated insulating part can fail between holes while the original film still meets its tensile specification. For buyers considering PEEK Film, the relevant question is how much material remains to carry the actual load after conversion. An intact laboratory strip does not reproduce the narrow connections, edge condition or local stress created by a repeated hole pattern.
Dafu identifies high-crystalline PEEK film in Dafu's engineering film range and provides mechanical reference information for a laboratory specimen. The supplied engineering-film brochure also includes PEEK. These sources support material screening, but neither establishes the strength of an arbitrary perforated drawing. The proposed gauge, pattern and conversion process need to be evaluated as a specific component.
Explain why the holes are required
Start with the function of the openings. They may provide clearance, access or another design feature, each with a different constraint on position and size. Identify which dimensions can change and which are fixed by neighboring components. This allows the designer to consider a better load path instead of assuming that every failure must be solved by a stronger base polymer.
Mark the direction in which the part is pulled, bent or restrained during assembly and use. A hole pattern that appears regular on a drawing may leave very different remaining widths in different directions. Also include handling loads before installation. A thin part can encounter its most demanding pull while it is removed from a carrier or positioned, rather than after it is supported in the product.
Map the remaining connections
Measure the material between adjacent holes and between each hole and the outside edge. These narrow connections are part of the load path. The overall width of the uncut sheet does not describe them. A drawing review should identify the most restricted locations, especially where several openings align across the direction of the applied load.
Open-area percentage alone cannot establish strength. Two patterns with the same removed area may arrange the remaining material differently. Likewise, a nominal remaining width is only one aspect of the response; hole shape and local edge condition also require review. Use the geometric information to select meaningful specimens, without claiming that a simple area calculation predicts every failure.
Do not apply strip data without its scope
A tensile reference for intact PEEK film describes the stated specimen and test arrangement. It is not a perforated-part rating. Preserve the film grade, gauge, test direction and method when using that information in a comparison. If another morphology or thickness is proposed, request the applicable evidence rather than treating every PEEK product as mechanically identical.
The supplier's high-crystalline designation is useful for identifying the offered film. It does not establish a universal advantage for every opening pattern or forming step. Select the material form against the actual component requirements. Where the pattern is the main uncertainty, test the pattern rather than repeatedly requesting another intact-film strength number.
Inspect the edges produced by conversion
The drawing defines an ideal opening, while the cutting process produces the real edge. Examine holes at the required scale for damage or geometry that could influence subsequent tearing. Identify the cutting route and relevant tooling condition. A clean prototype and a production part made by another process should not be assumed equivalent without comparison.
Check repeated features across a production-representative sample. A single well-made hole cannot establish consistency for a large pattern. If tears begin at one location repeatedly, retain and inspect those locations. Record whether the initial defect was visible before loading or appeared during the trial. This helps distinguish conversion damage from the response of an otherwise intact geometry.
Test the component in its loading arrangement
Prepare specimens with the actual pattern and gauge. Where the installed support influences deformation, reproduce that support. Pulling an unsupported coupon may answer a different question from a film clamped around several openings. State the loading direction, attachment points and inspection objective before comparing samples, so the result can be related to the design.
Observe initiation and propagation, not only the final failure force. A small tear that remains local may have a different implication from one that rapidly connects adjacent holes. If the part must remain electrically isolating, a visible crack may matter before complete mechanical separation. Choose acceptance criteria that reflect the required function and retain the failed specimens for review.
Include relevant temperature and repetition
An application may expose the component to heat, repeated movement or both. Define those conditions from the design brief. Do not infer perforated-part performance from PEEK's general heat-resistant description. A material that remains suitable as an intact film still needs evaluation where holes concentrate movement or where assembly restraint changes with temperature.
Avoid adding a temperature or cycle count merely because it is easy to run in the laboratory. The comparison should represent a requirement the part actually has. Keep a baseline and identify which exposure produced a change. This lets the team decide whether to revise the pattern, the process or the material, rather than attributing every difference to thermal capability.
Compare design changes independently
If wider connections or revised hole spacing improve the result, document that as a geometry change. If a different gauge is used, review fit and flexibility as well as strength. Changing the film, pattern and cutting route together may produce a workable part but leave the reason uncertain. A staged comparison creates a clearer basis for production control.
Send Dafu the perforation drawing, film direction, proposed gauge and the observed failure location. Include the conversion route and the relevant assembly load. Ask for representative film samples and applicable reference data, while qualifying the converted component through its own trial. The material purchase can then be tied to a defined PEEK film and a verified remaining load path, rather than an intact-strip value used outside its scope.