How to Choose the Core Material for Cleanroom Panels

In industries such as biopharmaceuticals, semiconductor manufacturing, and food processing, cleanroom panels are the foundation for building controlled environments. The performance of cleanroom panels, such as fire resistance, strength, insulation, and corrosion resistance, depends entirely on their internal core material. Faced with a dazzling array of core material options on the market, which one is the optimal solution for your project? In this article, Glostar Manufacturer will introduce the basic knowledge of six mainstream cleanroom panel core materials.

What is a Cleanroom Panel Core Material?

Cleanroom panels (also known as cleanroom boards) are building materials composed of a panel made of materials such as color-coated steel or stainless steel, and an inner core material. The core material not only supports the structure but also determines the cleanroom's insulation, sound insulation, fire resistance, and pressure resistance. In-depth Comparison of Six Mainstream Cleanroom Panel Core Materials

1. Rock Wool Core Material

 – A classic fire-resistant pioneer, rock wool is currently the most widely used material in cleanroom engineering.

a. Definition: Rock wool products are made from high-quality basalt, dolomite and other raw materials. After being melted at a high temperature of over 1450℃, they are centrifuged into fibers using an internationally advanced four-axis centrifuge. At the same time, a certain amount of binder, dust-proofing oil and water-repellent agent are sprayed in. The fibers are then collected by a cotton collecting machine, and after being laid in a three-dimensional manner using a pendulum method, they are cured and cut to form rock wool products of different specifications and uses.

b. Production process flow: Feeding — Melting (1450℃) — Fiber formation — Sizing — Cotton collection — Pendulum — Pleating — Curing — Cooling — Cutting — Packaging

c. Performance Indicators:

Density Deviation: The permissible deviation of rock wool density refers to the range of density deviation for rock wool products. Rock wool is a common building sound insulation and thermal insulation material, and its density directly affects its sound insulation and thermal insulation effects. According to national standards, the permissible deviation range for rock wool density is ±10%.

Hydrophobic rock wool achieves its non-absorbent effect by altering the surface tension of traditional rock wool to reduce the interaction force between it and water.

1. Excellent water resistance: Hydrophobic rock wool does not absorb water, ensuring long-term water resistance.

2. Enhanced corrosion resistance: After modification, hydrophobic rock wool is more uniform and dense, exhibiting stronger corrosion resistance and a longer service life.

Fire resistance rating:

Class A: Non-combustible building materials;

Class B1: Flame-retardant building materials, self-extinguishing after being removed from the heat source, or extinguishing within 10 seconds;

Class B2: Combustible building materials, the fire does not grow larger after ignition, and dripping materials will not ignite filter paper;

Class B3: Flammable building materials, ignites easily and the fire grows larger and larger. The ease of combustion varies depending on the class.

Strength properties:

d. Advantages:

High Strength: Structural wool itself has excellent structural performance. Combined with special joints that only require fixing at both ends, single-span panels can reach 12m, significantly reducing structural material usage and lowering overall costs.

High Fire Resistance: Non-combustible structural wool, combined with a dense joint design, can create panels with a fire resistance limit of up to 4 hours and can block the spread of heat and flames.

High Ignition Point: Structural rock wool is a non-combustible material with a melting point of 1000℃ and has excellent fire resistance.

e. Applications: Ceilings and partitions in pharmaceutical factories, laboratories, and other places with extremely strict fire resistance requirements.

2. Glass Wool

– Lightweight Insulation Expert: Made of glass fiber, it is lighter than rock wool.

Definition: Glass wool boards are board-shaped materials made of ultra-fine glass fibers with added resin binders, cured under pressure and heat. Aluminum foil can be adhered to the surface. Used for roof insulation and sound absorption materials, and building insulation.

Production process: Various minerals including crushed glass, borax, silica sand, feldspar, limestone, dolomite, and soda ash.

Glass wool properties:Sound absorption and noise reduction effectively block sound propagation. 

Glass wool has tiny pores and voids. When sound waves strike the glass wool, they can enter through these pores, causing air molecules to vibrate. The viscous resistance of the air and the collision between the air molecules and the pore walls convert sound energy into heat energy, which is then dissipated. When there is an air layer behind the glass wool, the sound absorption effect is similar to that without the same thickness. Especially for glass wool boards with an air layer, the sound absorption performance at mid-to-low frequencies is significantly improved compared to a hard surface. The sound absorption coefficient increases with the increase of the air layer thickness. Glass wool boards are used in various sound-absorbing materials, including spatial sound absorbers and composite perforated sound-absorbing panels. The slag-free process does not damage the fiber structure and continuity. It has excellent sound absorption and noise reduction properties.

As can be seen from the table, its products have low density, low thermal conductivity, high sound absorption coefficient, wide operating temperature range, and also have the advantages of being non-flammable, frost-resistant, insect-resistant, and chemically stable.

Application: Large-span cleanrooms with high load-bearing requirements.

3. Magnesium Oxide Board

 –  A representative of extremely high strength, magnesium oxide cleanroom panel is often seen as "magnesium oxide mesh" or "double-layer magnesium oxide handmade board."

Definition: Magnesium oxide board (commonly known as magnesium oxide board) is a stable magnesium cementitious material made from a ternary system of magnesium oxide, magnesium chloride, and water, through formulation and the addition of modifiers. It is a new type of non-combustible decorative material composited with medium-alkaline fiberglass mesh as reinforcement and lightweight materials as fillers.

Features: High Mohs hardness, excellent flatness.

Advantages: Extremely strong load-bearing capacity, does not deform under foot pressure, completely non-combustible.

Applications: Walkway ceilings in electronic cleanrooms.

4. Silica Rock Board

 –  A Balance of Fire Resistance and Water Repellency: Silica rock cleanroom panel is a new type of environmentally friendly material that has emerged in recent years.

Definition: Rock wool is a rigid, environmentally friendly, and energy-saving foam plastic board made by extruding a continuous closed-cell foam through a process involving heating and mixing polystyrene resin with polymers and injecting a catalyst. Its internal structure consists of independent, closed-cell air bubbles. It is a thermal insulation material with excellent properties such as high compressive strength, low water absorption, moisture resistance, air tightness, lightweight, corrosion resistance, aging resistance, and low thermal conductivity. It is a commonly used and high-quality thermal insulation material in the construction industry. Its main raw materials are silica, magnesium oxysulfate, and polystyrene particles. Advanced technology is used to create closed pores within the slurry, followed by curing to produce a fire-resistant and thermal insulation board.

Features: Primarily made of inorganic minerals, closed-cell structure.

Advantages: Class A fire resistance and non-absorbent, solving the problem of performance degradation after moisture absorption in rock wool.

Applications: Purification projects in high-humidity environments.

Common specifications: 80K-3000*565*50

5. Honeycomb Paper

 –  Honeycomb paper is made by processing kraft paper into a regular hexagonal structure, based on the principle of the honeycomb structure in nature. It is a new type of sandwich structure environmentally friendly and energy-saving material made by bonding corrugated base paper into countless hollow three-dimensional regular hexagons to form a whole load-bearing component—the paper core, and then bonding face paper to both sides of it. It is inexpensive and has good flatness, but its fire resistance rating is usually only B1.

6. Aluminum Honeycomb

 –  Made entirely of aluminum, Class A fire retardant.

Features: Lightweight, high strength, moisture-proof, fireproof, sound-insulating, high flatness, high shock resistance, corrosion resistant;

Applications: High-precision electronics, aerospace cleanrooms, construction industry, furniture industry, transportation industry, etc.

Common Specifications: Aluminum foil thickness 0.04mm, aperture 20mm, side length 12mm, height 18.5/43.5/38.5/48.5mm

Manufacturing Process: The raw material for aluminum honeycomb is aluminum foil. Aluminum foil --- coating machine printing --- cutting --- stacking into blocks --- aluminum foil hot pressing --- honeycomb blocks. Honeycomb blocks can be cut into strips, the thickness of each strip depending on customer requirements. If needed, the strips can also be stretched into unfolded blocks.

Cleanroom Panel Core Material Selection List

When selecting cleanroom panels, these three technical parameters should be considered: density, bonding strength, and edge sealing technology. There is no "best" core material for cleanroom panels, only the "most suitable." For pharmaceutical factories, fireproof rock wool is standard; for precision electronics factories, aluminum honeycomb or magnesium oxide boards are more advantageous.