CHANGE THE DIE改变口模
Coating die surfaces with fluoropolymers like PTFE has had only limited success in preventing buildup. More effective is application of metallic coatings that incorporate fluoropolymers to the inside of the die to reduce stress at the die exit.
在阻止积料方面,用氟聚合物(如PTFE)涂覆口模表面只有有限的成功。更有效的方法是将加有氟聚合物的金属涂层施予口模内部,以减少口模出口的应力。
Die-flow modeling has also been used successfully to study the stresses occurring at the die exit and to evaluate changes in die-exit geometry. Modifying the exit geometry to reduce stress is an area of ongoing development.
口模-流动模拟也被成功用于研究口模出口处出现的应力,以及评价口模-出口几何的变化。修改出口几何以减少应力是目前正在开发的一个领域。
Some exit geometries have been patented by processors and resin producers. Modified die exits that claim to decrease die buildup include a sharp square exit, sharp pointed exit, radiused exit, outward-stepped exit, inward-stepped exit, and outward-flared exit (see diagram).
一些(口模)出口几何结构被加工者和树脂生产者申请了专利。修改的口模出口据称可以减少口模积料,包括一种方形陡出口、尖形陡出口、弧形过渡形出口、外扩台阶出口、内扩台阶出口、外展形出口(见图)。
Increasing die land length can also help because it reduces swell. Or you can use a larger die opening to reduce die-exit stress, and then draw the extrudate down to the desired size.
增加口模流动长度也有帮助,因为它减少了出口膨胀。否则,你也可以使用一个较大的口模开口,以减少口模出口应力,然后把挤出物拉细到所需要的尺寸。(翻译完毕)