Akra Plastic Products, Inc. 1504 E. Cedar Street Ontario, CA. 91761
	Phone: 909.930.1999 Fax: 909.930.1948

Drape and Oven Forming

Drape and Oven Forming

Akra uses drape forming (also called oven forming) when a plastic part requires a more general, or gradual, bend than heat bending processes can provide. It works well on both large and small parts. We usually produce a mold or form with the desired shape or curve for the part. . After the sheet is softened by thermal processing, it sags and conforms to the shape of the mold under its own weight or by slight pressure applied by an operator. Once cooled, the formed part is removed from the mold and any secondary operations can proceed. Drape forming is perfect when a gradual bend is required for the part.

Akra has used drape forming in such applications as:
Lighting Fixtures
Motorcycle Windshields

Heat Bending
When heated to specific temperatures, thermoplastic sheet can be re-molded or formed. Akra can heat bend plastic sheet, also referred to as strip heating or line bending, to give it a well-defined line bend. After bending, the material is normally put onto a fixture and then cooled. After cooling, the material holds its basic form (i.e. sheet) but also holds the bend(s) put into the material during the forming process.
This heat bending process is used with a variety of types of plastics, particularly acrylic, where it is often used to manufacture point-of-purchase displays.

Heat Bended Parts
Depending on the requirement specified by the customer, Akra uses a variety of methods to heat bend thermoplastic material such as hot wire, radiant heat and convection ovens. The type of resulting bend depends on the width of the heat source and the thickness of the material.

This process is in contrast to Drape Forming (Oven Forming), which puts larger radii or curves into entire parts. When heated to specific temperatures, thermoplastic sheet can be re-molded or formed. Midland can heat bend plastic sheet, also referred to as strip heating or line bending, to give it a well-defined line bend. After bending, the material is normally put onto a fixture and then cooled. After cooling, the material holds its basic form (i.e. sheet) but also holds the bend(s) put into the material during the forming process.

Cold Bending
In addition to heat bending, some thermoplastic materials can be cold bent.
Depending on the thickness of the material, most plastics can be bent in a gradual radius without negatively affecting the integrity of the material. This is often seen in architectural applications for use in skylights or transparent walkway ceilings.

Cold Bended Parts
A few plastics can actually be bent using a press brake, which is the same equipment used for bending metal. The thickness of the material helps determine the ability of the material to be bent in this manner.
Materials 3/16” thick or less are typically easier to bend. Polycarbonate and acrylic/PVC alloys (e.g. Kydex®) are the primary materials that lend themselves to this process.

Thicker material can sometimes be bent on a press brake, but the material may need to be heated along the bend line, prior to bending, to reduce the potential for stress fractures at the point of the bend.