Engineer Insight

Ask Ian - Manufacturing Artificial Plants and Trees

by Ian Renwick

Love them or hate them, artificial plants and trees have come a long way since their early years of production. The process of manufacturing garland, branches, and needles seemingly more and more realistic has grown into a very large manufacturing sector. Millions of artificial plants and trees are produced yearly for seasonal use, hotels, trade shows, homes, offices, and temporary landscaping projects. Seasonal production of pine, fir, and balsam products are sought after in large volumes during the Christmas holiday season. Let’s look at the production process and identify some of the areas where heating elements are used to help in the manufacturing processes.

The PVC materials commonly used in these applications require heat to be shaped, cut, and welded. Hot knives and heated cutting wheels cleanly shear PVC into strips that will eventually create the illusion of needles and branches. PVC is easier to work with when it is kept at a pliable temperature.

Construction begins with inexpensive metal wire cut to different lengths. These raw metal lengths will eventually become the branches. The metal pipe for the trunk of the tree is typically coated and placed into a large oven to dry and cure the powder coating. At the same time, the process of cutting the PVC into needles is being produced in specified lengths of garland. The garland can be produced in many colors, lengths, and shapes to simulate different tree needles.

Once the flexible wire rod is cut to length, the next step is to spin the garland around metal wire branches. Each of the rods is coated and the garland is wound tightly around the rod and later added to a larger branch with a threaded winding process. The thread is often wound tightly and adhered to the newly created branch using tacky adhesive. This process often uses a low temperature heated air to make the PVC more compliant and help the needles adhere to the rod.

The final product starts to take shape by attaching the branches to the sections of pipe that make up the tree trunk. The pipes used to simulate the main trunk of the tree are also spun with garland to hide the pipe. Other faux bark treatments are also produced and applied. Again, often using a spinning technique, tied off, a dab of adhesive and heated air.

In some cases, with more expensive or different leafy plants, compression moulding processes are used to create the needles, leaves, and details of each tree. Heat is applied to the mould with a release agent to produce the desired finished product. Air heat is used in the deflashing process to remove any fringe or burrs. The product is hit with high-temperature air for a short burst that essentially melts the thin frayed or unwanted material that squeezes around the mould. The thicker areas are not affected due to the limited time exposure to the high temperatures.

Each plant or tree may have special details that require more processes. The more realistic thefinished products are the more expensive it becomes. A good example would be the tips of pine tree branches, pine cones, the application of the trunk of the tree, and other built-in features like LED lights. Using a painting process called flocking, frosted tips and other mossy looks can be applied to the branches. The latex paint that is used dries quickly with heated air as the garland continues passing through the process lines.

We are here and happy to help with any technical questions related to our heaters and your application. We look forward to working with you.