Abstract
Electrical shavers have been around for more than 50 years, and various hair cutting mechanisms have been invented and implemented in real products. From user feedbacks, hair-pulling sometimes occurs during shaving, which has an adverse impact on user satisfaction. Due to the demands of having an objective measurement tool with well-controlled experiment parameters, a novel measurement system for characterizing hair cutting quality is proposed in this report.
From the CTQ (Critical to Quality) flow-down, the design parameters of a hair-pulling event can be categorized into four parts: cutter, lamella, and target hair. Starting from the analysis, the concepts for cutting quality measurement are developed accordingly.
According to previous studies, unfortunately, there is a large variation in the tests which resulted from the conditions of hair, e.g. supply and skew angles, cut-off length, and mechanical properties of hair. Moreover, from the videos of high speed camera, we can find hair has an abnormal movement if it is a bad quality cut. Hence, it is also important to simulate hair anchorage on a human skin in order to re-create the abnormal movement during cutting process and to have a well-controlled positioning.
Based on the demands and the requirements fo control the hair feeding conditions, four concepts have been developed, and the concept of hair pulling force measurement with controlled hair feeding system is chosen due to its high score in the concept selection process.
With respect to the winning concept, a novel hair feeding system has been developed, in which:
1. The hair feeding angles can be controlled by using a gimbal
2. The location to feed a hair can be adjusted by using linear stages
3. The cutter leg position can be detected
4. Within 2 ms, a hair of 870um can be fed
5. The spring constant of the a real human hair anchorage can be simulated
6. Hair pulling force can be measured during shaving test
The results of the system quality check shows that under the some condtion of hair feeding angle and position, repeatable measurement results can be expected.
From the CTQ (Critical to Quality) flow-down, the design parameters of a hair-pulling event can be categorized into four parts: cutter, lamella, and target hair. Starting from the analysis, the concepts for cutting quality measurement are developed accordingly.
According to previous studies, unfortunately, there is a large variation in the tests which resulted from the conditions of hair, e.g. supply and skew angles, cut-off length, and mechanical properties of hair. Moreover, from the videos of high speed camera, we can find hair has an abnormal movement if it is a bad quality cut. Hence, it is also important to simulate hair anchorage on a human skin in order to re-create the abnormal movement during cutting process and to have a well-controlled positioning.
Based on the demands and the requirements fo control the hair feeding conditions, four concepts have been developed, and the concept of hair pulling force measurement with controlled hair feeding system is chosen due to its high score in the concept selection process.
With respect to the winning concept, a novel hair feeding system has been developed, in which:
1. The hair feeding angles can be controlled by using a gimbal
2. The location to feed a hair can be adjusted by using linear stages
3. The cutter leg position can be detected
4. Within 2 ms, a hair of 870um can be fed
5. The spring constant of the a real human hair anchorage can be simulated
6. Hair pulling force can be measured during shaving test
The results of the system quality check shows that under the some condtion of hair feeding angle and position, repeatable measurement results can be expected.
| Original language | English |
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| Award date | 30 Mar 2016 |
| Place of Publication | Eindhoven |
| Publisher | |
| Publication status | Published - 2016 |