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For products such as plastic sheets or films, cooling is achieved by pulling through a set of cooling rolls (also known as calender or chill rolls), usually 3 or 4 in number. In sheet extrusion, these rolls not only deliver the necessary cooling but also help determine sheet thickness and surface texture (in case of structured rolls; i.e ...
Shearing, also known as die cutting, [1] is a process that cuts stock without the formation of chips or the use of burning or melting. Strictly speaking, if the cutting blades are straight the process is called shearing; if the cutting blades are curved then they are shearing-type operations. [ 2 ]
A common post-extrusion process for plastic sheet stock is thermoforming, where the sheet is heated until soft (plastic), and formed via a mold into a new shape. When vacuum is used, this is often described as vacuum forming. Orientation (i.e. ability/ available density of the sheet to be drawn to the mold which can vary in depths from 1 to 36 ...
The selection criteria of all process parameters are governed by the sheet thickness and by the strength of the work-piece material being pierced. The punch/die clearance is a crucial parameter, which determines the load at the cutting edge of the tool, commonly known as point pressure. Excessive point pressure can accelerate tool wear.
extrusion with cylinders into sheets (0.5–20 mm (0.020–0.787 in)) and films (below 1 mm (0.039 in)), which can be used directly or manufactured into other shapes using thermoforming or secondary fabrication techniques, such as bending, drilling, or routing. Due to its chemical properties it is not conducive to laser-cutting.
Self-tapping screws can be divided into two classes: [3] those that displace material (especially plastic and thin metal sheets) without removing it, known as "thread-forming" self-tapping screws, and self-tappers with sharp cutting surfaces that remove the material as they are inserted, termed "thread-cutting" self-tapping screws.
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Colorforms are sheet-thin, die-cut vinyl pieces in colorful geometric "forms" and abstract shapes (figurative or object), often with over-printed images that are to be attached to a smooth plastic-laminated paperboard background, much like placing paper dolls against a paper backdrop.