Difference Between Opened & Unopened Fiberglass Cloth

As a source manufacturer of Teflon high-temperature cloth, Jiangsu Aokai New Materials mainly uses fiberglass cloth as the base material. Fiberglass cloth is divided into opened fiber cloth and unopened fiber cloth (traditional process), with the key differences as follows:

1. Production Process

· Opened Fiber Cloth: An additional fiber opening process is applied after weaving. The fiber bundles are split and flattened by physical methods such as high-pressure water jetting or roller pressing.

· Unopened Fiber Cloth: Glass fibers are directly twisted into yarns and then woven into cloth. The fiber bundles are cylindrical, with obvious mesh gaps between the yarns.

2. Microstructure

· Opened Fiber Cloth: The fiber bundles are split and flattened, filling the gaps between warp and weft yarns. The protrusions at the intersections are greatly reduced, resulting in a smoother and denser surface.

· Unopened Fiber Cloth: There are obvious protrusions at the intersections of warp and weft yarns, with square "windows" (gaps) of varying sizes between yarns—this is the core issue solved by the fiber opening process.

3. Core Advantages

· Opened Fiber Cloth:

o Excellent Moisture Resistance: Filled gaps prevent moisture penetration, effectively avoiding PCB short circuits caused by dampness.

o Better Resin Impregnation: Flattened fibers have a larger contact area with resin, ensuring a tighter bond and reducing bubbles and voids.

o More Stable Signal Transmission: A uniform structure minimizes the "fiberglass effect" on high-speed signals, ensuring consistent signal transmission.

· Unopened Fiber Cloth: Lower material cost due to the absence of the fiber opening process. It is a cost-effective choice for general electronic products with low performance requirements.

4. Pros, Cons & Applications

Opened Fiber Cloth: Higher production cost due to the extra process. Since the cloth is thinner, more layers are required to achieve the same PCB thickness, further increasing costs.Application: High-end PCBs (e.g., computer motherboards, servers, high-speed network equipment, smartphones) requiring high signal integrity and reliability.

Unopened Fiber Cloth: Poor moisture resistance—gaps between yarns act as channels for moisture, posing a short-circuit risk in humid environments.Application: General PCBs (e.g., household appliances, toys, simple electronic devices) that are cost-sensitive and have moderate performance demands.

The above information is provided by Jiangsu Aokai New Materials Technology Co., Ltd..

If you want to learn more about the detailed parameters, application scenarios and customized solutions of our full product range, including Teflon high-temperature cloth, Teflon high-temperature tape, Teflon high-temperature mesh belt, seamless belt for bonding machines, single-sided PTFE cloth, high-temperature resistant conveyor belt, high-temperature resistant fiberglass cloth, please contact us:

· Service Hotline: Mr. Guo 18944819998

· Mr. Liu 13705266308

Adhering to the philosophy of high quality, competitive price, professionalism and integrity, we are dedicated to providing you with one-stop solutions and attentive service!