Is your company in the process of looking for a simple, inexpensive way to create plastic pieces for items that you either sell or use on a regular basis? At Piper Plastics, we specialize in utilizing a process called dip molding to make these plastic pieces.

More specifically, we use plastisol dip molding to create customized plastic components that can be used in a variety of different applications. From creating everyday items to advanced medical equipment, we can assist you through every step of the design and production process.

Check out the videos below for an up-close look at the dip molding process that takes place here at Piper Plastics. 

An Introduction to Dip Molding with Piper Plastics

Dip molding is defined as a process where a dipping mandrel is dipped into a liquid polymer, typically plastisol, to eventually create a solid form on the external surface of the mandrel. The cost of molding by dipping is always low. Most molds are very simple and inexpensive. Dip molding, if automated is competitive with most other molding process.

What is Dip Molding?

Dip molding is a process where a heated metallic mandrel is carefully submersed and withdrawn from a tank of liquid PVC, which is called plastisol

After a post heat and a cooling, the molded vinyl can be removed from the mandrel. Advantages of plastisol dip molding include low tooling cost; competitive piece price; parts that have no parting lines, external marks or blemishes; and the ability to use materials of different durometers, colors, textures, and thicknesses.

Medical Dip Molding

This short video introduces you to the three main components needed in order to process plastisol, either by dip molding or dip coating. Those components are the ovens, the dipping axis system and the plastisol tank.

The ovens serve two purposes in plastisol dip molding and dip coating.

  • During preheat, the ovens put thermal energy into the mandrels so that it can be released into the plastisol during the dip.
  • During post heat, the oven adds energy to the gelled plastisol and enables it to fuse and become a solid when the molded or coated part is cooled.

The ovens in a plastisol dipping process are either batch type or continuous conveyor, depending upon the application. Oven consistency and repeatability are very important considerations for a plastisol dipping system, and these factors directly contribute to ultimate quality of the parts produced. It is for these reasons that well balanced convection ovens, with accurate PID control, must be specified and utilized in any high quality dipping system.

The next component is the dipping axis system. This is the component that actually dips the mandrel, or part to be dip coated, into the plastisol.

  • In some instances, it can be as simple as an operator manually dipping the mandrel into a tank of plastisol, and withdrawing it carefully. However, this simple method isn’t very accurate or repeatable.
  • Most quality plastisol dipping systems contain a robotic or computer controlled z-axis to accomplish the dip. The very best systems utilize position and velocity feedback, ensuring consistency and repeatability from dip to dip. This translates to high quality and low reject rates in production.


The dipping tank is the component that holds the plastisol. It needs to be made of materials that are compatible with the products to be produced. For instance, medical products should probably be dipped in a tank made of stainless steel, avoiding materials such as copper and aluminum, which could contaminate them. Since every dip removes material from the dip tank, there needs to be a method of refilling the tank, either manually or automatically. Another consideration in a dip tank is maintaining the level of the plastisol, as variations in this will lead to variations in part lengths. Finally, keeping the plastisol in the tank clean and free of contamination goes a long way to improving ultimate product quality.

Components of a Plastisol Dip Molding System

Piper really shines when it comes to dip moldings for the medical device industry. Using accurate PID controls for temperature, position, and velocity; your stainless steel mandrels are expertly dipped into a tank of medical grade plastisol. Once cool, your parts are carefully removed.

Quality is of the utmost importance. Our professionals perform rigorous inspections, and we utilize special clean areas for production and inspection.

Our medical components include comfortable nasal cannula, ultra-clear spring-reinforced endotracheal tubing, colorful stethoscope tubing, urodynamic balloons, and pilot balloons.