Extrusion Basics

At Formtech, we believe it is important for our customers to understand the plastic extrusion manufacturing process and how your products will be produced.

Obtaining the Materials

In order to produce a plastic extruded profile, Formtech first obtains raw material compounds from trusted suppliers.  These raw materials are typically sold in pellet or powder form, depending on the material itself and the type of extrusion machine on which the profile will be produced.  Materials often used in plastic extrusion include PVC, ABS, Polycarbonate, Polyethylene, Polypropylene, and others.  Each extrusion manufacturer has specific materials that they will extrude, largely based on their equipment and knowledge of the materials.

Depending on the profile, Formtech may also obtain additives that will be added to the raw material compound.  These add-ons may include color concentrate (to color the profile), UV stabilizer (to enhance the product’s performance under UV rays), or some other modifier that affects the extrudability or performance of the material in its end product.

Preparing for Production

When Formtech is ready to extrude the profile, an extrusion operator (or person responsible for operating the extrusion equipment while the product is produced) must prepare the extrusion line and gather materials to produce the profile needed.  This process is repeated each time a profile is produced.  To complete this process, the extrusion technician will obtain the necessary materials and packaging from our warehouse and will set up the tool on the extrusion line.  This process requires the extrusion technician to follow specific instructions (or a process control book), which are provided to them for each profile produced.  The instructions may include the placement of the tooling pieces, the heats necessary for the extruder, specific instructions for preparing the cut-off equipment, as well as any other information to ensure the profile will be produced within tolerances.

Production

Next, the plastic material and necessary additives are fed into the machine.  The materials make contact with one or more rotating screws, which help to mix the material and melt it using frictional heat.  The screw pushes the material through the barrel.  This barrel is heated and cooled to maintain tight control over the melt temperature of the material.  This same process is followed for multiple-material extrusions, where two or more materials are extruded into a single profile.  In this case, multiple extruders are used so that the materials can each melt at the proper temperature and can be combined with their respective additives.

After the material melts, it is pushed into a die to form the desired shape of the profile.  The final shape of the profile is determined as it passes through calibrators (or sizing), which, with the help of water or air, also cools the profile.  The product continuously is produced until it reaches a saw, cutter, punch, or other cutting device at the end of the line.  These devices will cut the profile into the length specified.

Throughout the production process, the extrusion technician evaluates the profile per a quality control plan and records key dimensions and characteristics of the product on a regular basis.  In addition, the technician keeps retains for further evaluation by our quality staff.

Packaging and Warehousing

The extrusion technician packages the products per our customers’ specifications and labels the product for identification at Formtech and at our customers’ locations.  As the order is completed, full pallets of product are moved to our warehouse for safekeeping and storage until delivery is made.