Manual Trimming vs. Automated Trimming for Rotomolded Parts

automated trimming | CNC Routing
automated trimming | CNC Routing

Plastic trimming for rotomolded parts is a finishing operation that removes excess material so that your parts fit correctly and work properly. Traditionally, rotational molders trimmed plastic parts by hand; however, manual trimming can result in inconsistent cuts and higher scrap rates. Hand trimming is also time-consuming and adds labor costs.

Automated trimming improves consistency and efficiency while reducing labor costs and scrap rates. When you choose Gregstrom for rotational molding, you have a choice of automated trimming methods.

  • CNC routing uses five-axis equipment and provides fast, accurate cutting.
  • Robotic routing adds a sixth axis for greater freedom of movement along with other benefits.

Both automated trimming methods have advantages, so what’s the right choice for your plastics project?

CNC Routing for Rotomolded Parts

CNC routing uses computer numerical control (CNC) to follow programmed instructions without a manual operator. Computer-aided manufacturing (CAM) software turns a computer-aided design (CAD) files into G-code and generates a tool path. There’s support  for complex shapes that would be difficult to produce by hand. Plus, production runs are cost-efficient even with one-off parts like large plastic tanks.

With five-axis CNC routing, computer-numerically controlled tools remove unwanted or excess material from rotomolded parts and products. By moving the CNC tool tangentially to the part’s surface, this multi-axis machine supports complex designs and smooth surface finishes. Five-axis CNC routing also produces compound radii on plastic surfaces.

Robotic Routing for Rotomolded Parts

Six-axis robots for plastics trimming have a large working environment and are equipped with rotary joints that provide greater freedom of movement. Robotic routing cuts thick sheets cleanly, is suitable for a wide range of rotomolding materials, and can handle three-dimensional (3D) parts. Robotic routers can also process more parts per hour than CNC equipment.

With six-axis robotic routing, an industrial robot is equipped with a rotating router bit that’s attached with a collet. The tool rotates at a high speed along a defined path. Depending on the application, the robot can be programmed to cut through the plastic part completely, or to trim excess material. Rapid tool changes on the fly are another benefit of robotic routing.

Ask Gregstrom About Automated Trimming

Gregstrom Corporation of Woburn, Massachusetts (USA) is an experienced rotational molder with a wide range of value-added services. We offer both five-axis CNC machining and six-axis robotic routing and can help you to choose the best automated trimming method for your application.  To learn more, contact us.