机电专业英语第2版7Unit7分解.ppt

The Injection Molding and Machine Many reciprocating-screw machines are capable of handing thermosetting plastic materials. Previously these materials were handled by compression or transfer molding. Thermosetting materials cure or polymerize in the mold and are ejected hot in the range of 375℃～410℃. Thermoplastic parts must be allowed to cool in the mold in order to remove them without distortion. Thus thermosetting cycles can be faster. Of course the mold must be heated rather than chilled, as with thermoplastics. thread [θred] n. 螺纹; 线；线状物；玻璃纤维；思路；路线 undercut [?nd?k?t] n. 侧向分型,牛腰部下侧嫩肉；砍口；切球 plasticize [pl?stisaiz] vt. 使成可塑体 shear [?i?] vt. 修剪，剪；剥夺 n. 切变；修剪；大剪刀 barrel [b?r?l] n. 料筒 chamber [t?eimb? ] n. 加料室, （身体或器官内的）室，膛；房间 trip [trip] vt. 使跳闸, 切断 switch [swit?] n. 开关, 转换；鞭子 vt. 转换；用鞭子等抽打 hydraulic [haidr?:lik] adj. 液压的, 水压的, 水力的；水力学的 cylinder [silind?] n. 汽缸；圆筒；圆柱状物；柱面 polymerize [p?lim?raiz] vt. (使)聚合 distortion [dist?:??n] n. 扭曲, 变形；曲解, 失真 2. The problem of injecting a melted plastic into a mold cavity from a reservoir of melted material has been extremely difficult to solve for thermosetting plastics which cure and harden under such conditions within a few minutes. 译文：热固性塑料熔体在很短的时间内就会固化和硬化, 在从料斗向模具型腔 注入热固性塑料熔体的过程中, 也会出现这种情况, 这个问题一直非常难以解决。 说明：句中of injecting a melted．．．of melted material是介词短语作后置定语 , 修饰the problem?；which cure and harden．．．是定语从句作后置定语, 修饰 thermosetting plastics。be difficult to do sth意为做某事有困难，e.g. 1）The little child cannot be made to do such a difficult thing. 不要让这个小孩子来做如此困难的事情。 2）Life may be difficult to achieve the goal, but I do not care. 也许一生也难达到目标，但我并不在乎。 7. It is based on two tons of clamp force per square inch of projected area. If the flow pattern is difficult and the parts are thin, this may have to go to three or four tons. 译文：一般在塑件投影面积上每平方英寸需要作用两吨锁模力。如果 熔体流动困难或塑件较薄, 锁模力应提高到3～4吨。 说明：“is based on” 意为“根据，以…为基础；建立在…基础上”， e.g. 1）His argument is based o