Weatherstripping is an extruded rubber product that is used to insulate structures, vehicles and objects from weather conditions. It is a type of rubber trim, though unlike rubber trim it functions almost exclusively as a form of insulation. In addition to functioning as a climate-control aid, weatherstripping protects buildings and vehicles against unwanted exposure to water.

While the scope of industrial and commercial applications for weatherstripping is limited, it is an essential product to many industries. Some manufacturing companies dedicate all of their extrusion lines to the production of different kinds of weatherstripping. Weatherstripping functions primarily as a door and window insulator. Specifically, it fills gaps between the moving parts of doors and windows and their fixtures.

In the automotive industry, weatherstripping for car doors, windows, trunks and hoods is indispensable. In the construction industry, particularly in geographical areas where cold weather is a consideration for residential builders and maintenance professionals, weatherstripping is becoming an increasingly important part of energy-efficient climate control. Weatherstripping products also have limited applications in industries that manufacture ice machines or storage refrigerators.

All weatherstripping products are processed with rubber extruders, which are machines that convert raw natural or synthetic rubber materials into strengthened, functional products. An extrusion line begins with a collection of rubber pellets in a hopper that directs the raw material, or stock, into a conveyor channel. The hopper is usually placed above an opening in the conveyor channel, and gravity sends the stock into the channel. In most rubber extruders, the conveyor channel is equipped with a long screw that moves and pressurizes the stock while it is heated. Near the end of the channel, the pressurized, heated stock reaches a near-liquefied state and is ready to be forced into the die.

A die is a tool that is used to create hardened shapes out of a given raw material. In the case of weatherstripping dies, the die will be a narrow hole through which the stock is forced. As this happens, the stock takes the shape of the die, which it keeps once it has hardened. The newly extruded rubber may at this point be cut and shipped, or it can continue to additional processing if necessary. For use in demanding applications, like in the automotive industry, weatherstripping may be cured with sulfur or other curatives in a process called vulcanization. This process improves the rubber’s strength and durability, making it more weather-resistant.

Weatherstripping Informational Video