August 12, 2020


Wind Mill Blades | Saint-Gobain Tape Solutions
Figure 1: Large-scale composite lay-up. Source: Shutterstock.

Molds are used extensively to lay-up large scale composite structures, such as wings, fuselages, propellers, antennas, wind turbine blades, boat hulls and vehicles (Figure 1). These molds are then placed into autoclaves, which subject the composite lay-ups to elevated temperatures and pressures until they are cured, after which the molds are taken apart and the finished composite parts are removed.

In the past, these applications would have needed to be assembled using screws, clips or other fasteners, which caused other problems. For example, the use of mechanical fasteners increases part count and assembly time, increasing material, labor and tooling costs. It is also difficult for mechanical fasteners to make assemblies water-tight, leading to premature rusting and failure of the fasteners or connecting parts. Mechanical fasteners can also increase forces and stresses in the vicinity of the fastener, causing unsightly waviness and compromising aesthetic appearance.

In order to facilitate the removal of the parts from the molds, silicone-based coatings have typically been sprayed, painted or dipped onto the surface of the mold prior to the lay-up of each part.

This process could be labor-intensive and prone to error if the mold surface is not properly coated, leading to undesirable surface defects in the composite parts. Furthermore, certain materials in the composite lay-up may not be compatible with silicone, leading to undesirable chemical reactions, poor surface finish or sticking of the part to the mold.

An alternative to silicone coatings, composite molding tapes may offer certain advantages, such as reduced labor costs, longer tool life, greater production throughput and better part quality. Discover some of the important properties and characteristics of composite molding tapes and the products and services we offer for composite manufacturers and OEM suppliers.

Composite Molding Tape Applications and Advantages
Mold Release Liners

Applied to the inside of molds to facilitate the removal of the composite parts (Figure 2)

Protection and Seaming Tapes

Used to protect mold or tool surfaces, which may extend their life or increase time between preventive maintenance intervals

Flash Masking and Hold Down Tapes

Applied to mold surfaces to ensure smooth bond lines and to remove or minimize flash


Painting a wind turbine blade inside an industrial setting.
Improve Composite Molding Efficiency with Tapes

Specialty adhesive tapes that protect tooling, create smooth surfaces in composite molding applications and extend the life of your composite molding tools.