| 摘要 |
An eye bath (470) has a thin wall (471) and a hollow annular rim (472). This was formed in an injection mould too] with a tear drop cross-sectional shape (473) - shown at one side - around the wall as a pre-form of polypropylene material mixed with blowing agent. On mould opening before the material has solidified in the tear drop, this expands to circular cross section with a circumferential length (474) equal to that of the tear drop (475). This results in a slight fore- shortening of the height (476) of the eye bath from the height of the pre-form (477).
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