| 摘要 |
Melt is injected into the closed mold using injection sills positioned with respect to mold cavities, permitting molding of ridges. These are covered by the foam, to locations limiting loss of melt charge at the cavity entrances. Injection pressure suffices to cause shear in zones where deformation and expansion can take place into cavities. Preferred features: Sills are positioned no closer than 10 mm from the cavity molding the ridge. Pressures acceptable for shearing the material are equal to those used to mold the same object without ridges. Flow rates are controlled in the case of a ridge, such that the material joins together between zones. Such control is effected by adjusting the diameters of holes passing the material.
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