Cold Forming Plastic Sheet

Uk educational supply center centre mindsets online sells variously sized 3mm thick sample sheets of eastman s spectar copolyester at not completely outlandish prices.

Cold forming plastic sheet.

Spectar supposedly looks and handles much like acrylic but with the surprising property that it can be cold formed without breaking or whitening and exhibits a memory effect holding a cold bend until reheated. A vacuum is created to enhance the sheet s conformity to the mold. In this procedure after heating the polycarbonate sheet to its forming temperature the sheet is lowered to the mold followed by the plug. Thermoforming is useful for clamshell packaging.

The recommended radius of curvature should be a value greater than 180 times the thickness of the sheet for plexiglas g sheet and 300 times the thickness for plexiglas mc sheet see table below recommended minimum radii of curvature for cold formed plexiglas sheetnominal sheet thickness recommended. It sandwiches the sheet between the mold and the plug. It is also a shape memory polymer which will return to its original flat form on application of moderate heat such as immersion in very hot water. This is a type of vacuum forming where thin or thick gauge plastic sheet is placed over a die heated to a temperature that allows the material to become pliable then is stretched over the surface of the die while vacuum pressure pulls the sheet down and into its final shape.

Cold forming plexiglas sheet can be cold formed bent at room temperature in a smooth arc and held to a radius by forcing the material into a curved channel support. The only major variable that can affect the forming process is the thickness of the plastic sheet. Any of the amorphous sheet plastics can be heated and formed. This article uses a sheet about 1 4 thick so all times are about 10 to 15 minutes per step.

Cold formed plastic cfp looks like acrylic but has a toughness approaching polycarbonate. Many plastic sheet materials can be shaped by thermoforming. Styrene thermoform plastic sheets high impact styrene is an inexpensive thermoform plastic that is easy to work with and produces excellent vacuum forming results making styrene the perfect beginner plastic for folks who are new to vacuum forming. It can be formed into a permanent shape without heating avoiding the use of ovens or strip heaters.

Amorphous plastics like abs and polycarbonate generally have wide processing windows and good melt strength making them easy to thermoform. Clamping and unclamping sheets preparatory to forming. For thicker sheets it will take longer and for thinner sheets it will take less time. Modify the timing as necessary.