The Ultimate Guide of XPS Foam Board

Table of Contents

What is XPS foam board?

XPS is extruded polystyrene, a type of foamed polystyrene board that is intended for insulation purposes. Conventionally, foamed polystyrene boards are known as EPS. So, how do we distinguish them? Hence, the letter X was chosen to emphasize the extrusion process that is required for production. Other examples include XEPS (extruded expandable PS beads), XPET (extruded foam PET) etc.

XPS is undergoes a continuous extrusion process, during which the physical blowing agents are injected into the molten PS. The mixed PS, blowing agents, and other additives are subsequently cooled by the cooling extruder. As the result, the pressurized and viscous molten material are extruded through the slot die. When the material exudes from the slot die, pressure is released, and the foaming process initiates. The foamed material will pass through the calibration system to embody shapes and models.

What are the features of XPS foam boards?

  • Completely closed cell structure
  • High resistance to moisture and water absorption
  • Low thermal conductivity
  • Excellent compressive strength
  • Excellent shock absorption
  • Dimensionally stable
  • Fire Retardant (by adding flame retardants)
  • recyclable for scrap and foam board
  • Lightweight and durable
  • Easy to cut, handle, and install

Requirements for raw materials

  • GPPS (virgin or recycled)
  • Color masterbatch
  • Flame retardant
  • Nucleating agent (talc, etc.)
  • Blowing agent (CO2, etc.)

The basic recipe for XPS

1PS pellets (Virgin or recycled)MFI between 3-15 are preferable90-95%
2CO2Industry use, purity 99%0-4%
3EthanolIndustry use, purity 99%0-4%
5Master batchCarrier: GPPS is preferable0-1%
6Nucleation agentTalc finer than 1000 meshes0-5%
7Flame retardant0-5%

The dosage of each material varies from different product categories.

Options for the blowing agents

  • CO2
  • Ethanol
  • Butane
  • Propane
  • DME
  • HFC
  • HFO

The utility of blowing agents is dependent on local availability, cost, and technical requirements. We are more than happy to provide know-how transfer service.

What are the applications of XPS foam boards?

XPS foam boards are the ideal heat insulation materials in “green” buildings. They can also meet the demands of high-performance insulation in different civil engineering branches, industrial floors (cold stores, chilled storage facilities, etc.), and withstanding heavy loads.

General applications

  • Thermal insulation of basements
  • Thermal insulation of foundations
  • Thermal insulation of floors
  • Thermal insulation of walls
  • Thermal insulation of roofs
  • Thermal insulation of utilities and in pools
  • Parking decks
  • Cold storage floors
  • And more…

Extended applications

- Graphite XPS

Graphite is added along with other raw materials to produce graphite XPS foam boards, whose conductivity factor is less prominent than conventional XPS foam boards.

Graphite XPS Foam Boards

- Integrated decoration and insulation boards

It includes a coating layer, carrier layer, and insulation layer, which are integrated and prefabricated in the workshop.

- Integrated XPS foam board in walls

Instead of applying insulation boards to exterior walls of the building, XPS foam boards are located between the wall and the outer concrete layer.

XPS foam board vs EPS board

ComparisonsExpanded Polystyrene (EPS)Extruded Polystyrene (XPS)
Raw materialsPolystyrene resinPolystyrene resin
Manufacturing processPolystyrene (PS) initially expands, and then it is molded to form a close cell material.PS and other ingredients are mixed and fed into the extruder with blowing agents injected. The rigid foam board is extruded and expands through the slot die.
Thermal conductivity (W/m·K) ≤0.042≤0.030
Compressive strengthUp to 400KpaUp to 1200Kpa
Water absorption % (v/v)≤4≤2
SizeWidths: up to 1200mm
Lengths: up to 400mm
Thicknesses: up to 90mm
Widths: 600mm, 900mm, 1200mm
Lengths: 2400mm
Thicknesses: 20 to 150mm

The biggest difference between EPS and XPS is cell structure, that results in EPS having worse (higher) water absorption and worse (lower) R-value per inch.

Extruded Polystyrene (XPS) rigid foam insulation has very well defined, uniform closed cells with continuous walls. The combination of hydrophobic (water-resistant) polystyrene polymer and closed cell walls results in a very low water absorption rate for XPS rigid foam insulation.

Well-known Brands of XPS Boards

There are hundreds of XPS brands all over the world.

Below we list some global brands or brands that have a higher reputation in certain regions. For your reference when choosing XPS board.

DuPont™ Styrofoam™

Styrofoam was created by Dupont (formerly Dow Chemical). It’s typically referred to as “blue board”. It is maybe the best known XPS insulation in the world.

Owens Corning FOAMULAR®

Owens Corning is a global building and industrial materials leader.

FOAMULAR® XPS Rigid Foam Insulation is one of their main products. Its production, sales and research network covers more than 30 countries around the world.


The company «PENOPLEX SPb» LLC is a large Russian manufacturer of thermal insulating, water-proofing, decorative and finishing materials on polymers basis.

PENOPLEX® XPS boards are of excellent quality. It is a brand worth choosing.

Kingspan GreenGuard®

The Kingspan Group was formed in the mid 1960s in Ireland and today is one of the world’s leading construction product manufacturers.

Kingspan GreenGuard® XPS insulation board offers an R–value of 5.0 per inch of thickness and is ideal for a variety of applications including below slab, below grade along the foundation, inside basement walls, exterior insulation over wood sheathing and residing.

PolyfoamTM XPS

PolyfoamTM XPS Ltd is a leading manufacturer of closed cell extruded polystyrene insulation in the UK.

PolyfoamTM XPS products are manufactured using blowing agents with low global warming potential (GWP) and zero ozone depletion potential (ODP), and are CFC and HCFC free.

北鹏 (Beipeng)

Beijing Beipeng specializes in R&D and production of thermal insulation materials. Beipeng has more than 7 XPS production lines. It is one of the most influential companies in energy-saving thermal insulation industry in China.

Its headquarter is located in Beijing, the capital of China, with production bases and subsidiaries in Beijing, Tianjin, Hebei, and overseas.

绿羽 Earthmother®

Earthmother is the premium brand of floor heating insulation XPS manufacturer in China.

After 16 years of hard work, the company has 6 manufacturing bases, 1,000 authorized HVAC dealers across the country, and 15 million square meters of floor heating and thermal insulation materials pavement every year.

How to Produce XPS Foam Boards

Step1: Feeding System and Main Extrusion System
Step2: Calibration
Step3: Conveyor and Printing
Step4: Cut-off and Rotary Cooling Tower
Step5: Ends Ship-lap Edge Trimming
Step6: Cross-over
Step7: Sides Ship-lap Edge Trimming
Step8: Stacker
Step9: Packaging
Step10: Transport

Where to Buy XPS Foam Boards

If you want to buy a large amount of XPS foam board, you can directly contact us.

We understand both the equipment and the production process, and can provide you with high-quality XPS boards in various specifications.

XPS Boards Specifications We Can Provide:

Contact Our Experts