Core Concept
Thermoforming is a manufacturing process where a plastic sheet is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product.
The simplest analogy is "vacuum forming"—imagine stretching a warm, soft plastic sheet over a shape and using a vacuum to suck out the air, making the plastic conform perfectly to that shape.
Detailed Process Breakdown
The thermoforming process consists of several key steps:
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Clamping: A flat plastic sheet is securely clamped into a frame.
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Heating: The sheet is heated using an oven or ceramic heaters until it becomes soft and flexible (reaches its "glass transition temperature").
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Forming: The softened sheet is shaped. This is done primarily in three ways:
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Vacuum Forming (Most Common): The mold is raised into the sheet, and a powerful vacuum sucks the air out from between the sheet and the mold, forcing the plastic to take the mold's shape.
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Pressure Forming: Compressed air is applied from above the sheet, "pushing" it down onto the mold with greater force. This allows for sharper details and more complex shapes.
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Mechanical Forming: A "plug" or "mate" mold is pressed into the softened sheet from the opposite side, similar to a waffle iron. This is less common.
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Cooling: The plastic, now formed, is allowed to cool and solidify in the mold, often with the help of fans or water cooling.
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Demolding: The formed part is released from the mold.
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Trimming: The finished product is removed from the surrounding sheet, and excess material (trim waste) is cut away.
