Harnessing the Power of Wind and Solar with CHR® Tapes and Norgard® Specialty Films

At which stage of the wind turbine lifecycle do our products make the biggest impact?

Is it true that composite molding tapes are preferred over silicone coatings?

Yes, composite molding tapes are often a preferred alternative to silicone coatings. This is because silicone release products could potentially obstruct bond formation, creating defects on the surface such as spots, cracks, pinholes or other surface irregularities. Since composite molding tapes have a lower coefficient of friction than silicone, they remove more easily and cleanly from the mold.

Composite molding tapes, unlike silicone-based coatings, do not have to be sprayed, painted or dipped onto the mold surface prior to the lay-up of each part. Therefore, a major advantage includes reduced labor costs as well as time saved. Composite molding tapes could be reused multiple times, have better part quality, allow for longer tool life and greater production throughput.

Could you elaborate more on these common applications?

Yes. Let’s take a look at each of the three applications separately.

1. When utilized as mold release liners, tapes are applied to the inside of the molds to make the removal of composite parts easier. Mold release liners are comprised of a substrate made of PTFE which is known for its non-stick properties, temperature resistance and smooth surface finish. This is essential to ensure finished blades with surfaces that are defect-free. Within this application, products such as PTFE glass laminate tape, PTFE glass cloth tape and PTFE film are often a go-to for proven durability, performance, chemical resistance and overall durability.
    
2. For tool protection and seaming, the go-to tapes should consist of extruded, high modulus and skived PTFE tapes and FEP tapes. These products generally have better conformability than PTFE glass cloth tapes and can allow for easier application to complex geometries. Products such as CHR 2275-2, 2285-2 AND 2296-2 are extruded PTFE tapes. They are coated with high-temperature, pressure-sensitive adhesive and can come in bright colors, making them easy to find on composite parts and tooling, especially on large wind turbine blades. In high temperature curing applications, 2275 (dark orange), 2285 (bright orange) and 2296 (bright yellow) have been used for flash masking. Perhaps the most common product used in composite molding is CHR 2250-2. It is used at the edges of molds and to cover the seams between the release layers. This helps allow for a longer lifespan of the mold release tape. FEP and ETFE tapes, CHR 2355 & CHR 2455 are conformable, stretchy tapes that are used with 2255-2 for masking the corners of the tool.
    
3. When it comes to flash masking and hold down, tapes such as polyimide or polyester (PET) tapes are commonly utilized. They help to mask the bond lines and remove flash. With features like temperature resistance and no residue (provided by non-silicone options), these tapes help to protect the outside of the composite build-up on the mold (commonly referred to as the tool). Flash masking and hold down tapes can help protect the expensive tool from resin. If resin leaks out during the process,  removal of the tape is recommended. This also removes the overage (also called “flash”). Some examples of products that are appropriate for these applications include: CHR M824, M832, M887, M895, M851, M783, M852 & M855.

Can you provide more detail about the custom-engineering of these tapes to help customers meet their specific performance, cost and manufacturing requirements?

Yes. We have some of the highest temperature masking tapes for composite molding applications. These tapes can certainly be custom-engineered for specific performance and application requirements. For example, our film-based tapes can come in widths as large as 1219 mm and our glass cloth tapes can come in widths up to 1524 mm. Additionally, when it comes to non-silicone masking tapes, products such as CHR M851, M852, M783 and M855 can perform at curing temperatures of 200°C, which is comparable to a silicone alternative.

Could you elaborate on the main benefits of using these products in wind turbine manufacturing?

Of course. Let’s focus on three areas: efficiency, cost-savings and quality improvement.

1. In terms of efficiency, the non-stick properties of these products helps reduce both the time and effort required to clean and prepare molds between production cycles, leading to higher throughput in the manufacturing process and increased efficiency.
    
2. In terms of cost-savings, these products can be used and reused. They also protect the molds by withstanding harsh conditions such as high temperatures, exposure to aggressive chemicals and general wear and tear, ensuring long-lasting performance and significant cost savings due to reduced frequency of maintenance and replacement.
    
3. Finally, in terms of quality improvement, these materials can allow for superior surface finish of the wind blades. This surface finish needs to be perfect to allow for optimal aerodynamic performance of the blade. When this happens, the quality of the blade is where it needs to be, leading to more efficient wind energy capture and better overall turbine performance.

Now that we’ve explored how our materials can help to better harness the power of the wind by aiding in the composite molding process, let’s turn our attention to how our products and solutions can help harness the energy of the sun in some photovoltaic applications.

Watch this Q&A video to discover how Norgard products can benefit the solar infrastructure.

Our teams are dedicated to helping advance the quest for sustainable energy sources. As we push to reduce our carbon footprint by increasing the use of solar, wind and other energy sources, it is essential to understand how small parts like tapes can protect the longevity, durability and performance of these new renewable energy solutions today and well into the future. For questions regarding a specific project or application, connect with our team today.