Choosing Male or Female Tooling in Thermoforming

When designing tooling for vacuum-formed plastic parts, components, or products, one of the first decisions is whether to fabricate a male or female tool. Whether the tooling is male or female affects every aspect of the project from cost and time to fabricate to the clarity of design and material usage. If you’re unsure what goes into choosing what type of tooling is used or how to know which your best option is, our thermoforming company is breaking down the difference between the two, as well as the benefits and drawbacks of each.

What Is Vacuum Forming?

Primarily, male and female tooling is a factor when vacuum forming plastics. This is a method of thermoforming in which the plastic is heated until pliable and then fitted to a custom tool or mold. Vents are strategically placed in the tooling, and after the plastic is strategically placed and clamped down to the tool, a high-powered vacuum is switched on, suctioning out all the air and drawing the plastic tightly against the tool to create the desired shape.

Male Tooling in Vacuum Forming

Male tooling, also called “positive tooling,” is convex, meaning the shape protrudes up. The plastic is draped over it and clamped into place, so the dimensions of the tooling are inside the plastic. When the vacuum is turned on, the plastic draws against the protrusion, leaving the finished plastic shape above the clamps. The plastic at the corners and bottom of the finished part may be thicker as the plastic isn’t stretched as significantly as the material toward the top of the mold - this may be a benefit or downside, depending on the desired end result.

Benefits to Using Male Tooling

The two main benefits to using a male, or positive, tool are cost and exterior appearance. Male tooling is the least expensive type of tooling used in custom plastic manufacturing and can be quickly fabricated, keeping manufacturing costs low. When considering the final appearance, because the mold is forming the plastic from the inside, the end result often has a glossy exterior with few to no molding marks on the surface.

Drawbacks to Using Male Tooling

Male tooling is often used when a less precise, more rounded shape is needed. A male tool requires draft angles to allow for removal of the plastic from the tooling to prevent webbing and wrinkling, and it’s impossible to get crisp details, sharp angles, and intricate surface details.

Female Tooling in Vacuum Forming

Female, or negative molds, are concave. The pliable plastic is laid inside the tool rather than over it, and the design or shape is formed below the clamps, so the dimensions of the mold are outside of the plastic. When the vacuum is turned on, the plastic is pulled down and against the tooling to get the finished result.

Benefits to Female Tooling

The main benefit of using female tooling in vacuum forming is the amount of detail possible. The tooling can be textured to impart a textured design on the plastic, and by pulling the plastic into the tool, parts have crisp, intricate detail and sharper corners without the need for draft. The overall result are parts that look like they were formed through injection molding, rather than thermoforming.

Downside of Female Tooling

The main concern with using female tooling is the cost. Because they are more complex of a shape than male molds, the cost and time to fabricate them may be more. However, it’s important to consider that these are still a fraction of the cost of tooling used in injection molding. Also, while the occurrence of webbing and other flaws are reduced, there may still be mold marks left behind on the outer surface.

Contact Us for Custom Thermoformed Plastics

At Advanced Plastiform, Inc., we work with a wide variety of industries to create the high-quality, durable custom plastics they need. With decades of experience in design, engineering, and manufacturing, we can help you determine the right type of tooling that will be cost-effective while getting the design and features you need.  To learn more about how we can help you reduce your costs and improve your quality, schedule a quote with our team today. We work with all types of industries in  North Carolina, South Carolina,  Pennsylvania,  Maryland, Tennessee, Georgia, and Virginia.