Meaning
Dimensional measurement of a flexible part occurs while it is clamped into a fixture that simulates its final assembly position. This restrained state inspection evaluates whether the part will fit and function correctly once secured in its housing. This process isolates the part’s actual dimensions from free state warpage.
Fixturing Requirements
The fixture used for evaluating flexible parts must apply localized clamping force without permanently distorting the polymer material. During a restrained state inspection, the clamping sequence must be executed in a specific order to ensure measurement repeatability. This repeatability is essential for calculating process capability indices.
Dimensional Analysis
Molded components like plastic grilles or door trims can display significant twist when sitting on a inspection bench. Utilizing restrained state inspection allows the metrology team to verify that the mounting bosses and clip towers are correctly positioned. This measurement confirms that the assembly clips will align with the sheet metal.
Manufacturing Control
Molders must distinguish between cosmetic warp and critical dimensional failures to avoid scraping functional parts. Implementing restrained state inspection provides a realistic assessment of part quality and reduces the rate of unnecessary part rejections. The data collected from these runs helps the tooling team decide whether to adjust the mold steel or the cooling cycle.
Focusing on the assembled state limits expensive tool modifications to those that truly affect product performance.
