Polystyrene foam blocks

Types of Polystyrene Foam Blocks

Polystyrene foam blocks, also known as polystyrene foam sheets or simply “blocks,” are versatile materials used in a variety of applications. They are categorized based on their manufacturing process, composition, and application. Below are the various types of polystyrene foam blocks:

• Expanded Polystyrene (EPS) Foam Blocks

  These are the most common types of polystyrene foam blocks. They are lightweight, inexpensive, and have good insulation properties. EPS foam blocks are made from polystyrene beads that are steamed to expand and form a foam with air pockets. The foam is then molded into blocks or sheets. Expanded polystyrene foam blocks have a wide range of applications, including packaging materials, insulation in construction, and floatation devices. They are often referred to as styrofoam, although styrofoam is a trademark name.

• Extruded Polystyrene (XPS) Foam Blocks

  XPS foam blocks are created through an extrusion process that involves melting and mixing polystyrene with a chemical agent. The mixture is then forced through a mold, cooled, and solidified to form a continuous foam board. The resulting blocks or sheets have a uniform density and structure without air pockets. XPS foam blocks are typically used for insulation applications in construction. They are moisture-resistant, have a higher compressive strength, and provide better thermal insulation compared to EPS blocks.

• Polyurethane Foam Blocks

  These blocks are made from a different chemical process. Polystyrene granules are mixed with a blowing agent, a catalyst, and a surfactant. The mixture is then poured into a mold, where it expands and hardens into foam blocks. Polyurethane foam blocks are not as common as the first two types. They are mostly used in furniture making and the automotive industry.

• Reinforced Polystyrene Foam Blocks

  These blocks have internal reinforcements, such as wooden or metal beams, that are embedded within the foam during the manufacturing process. This reinforcement adds strength and stability to the blocks while maintaining the lightweight properties of the foam. They are commonly used for architectural models and prototypes.

• High-Density Polystyrene Foam Blocks

  These blocks have a higher density than standard polystyrene foam. They are made from a polystyrene resin with a higher molecular weight or by adding fillers that increase density. Their applications include signage, machining, and modeling.

• Low-Density Polystyrene Foam Blocks

  These blocks are made from the standard polystyrene foam by incorporating air into the resin during the manufacturing process. They are lightweight and easy to handle. They are primarily used for insulation and packaging.

Function and Feature of Polystyrene Foam Blocks

Polystyrene foam blocks are used for insulation in construction. Their hollow nature and light weight make them ideal for insulation in construction. Here are their main features:

• Lightweight

  Polystyrene blocks are very light. This makes them easy to handle and transport. It also reduces the weight of the structure. Reduced weight means a building can be constructed on weak ground or with weak materials. Expanded polystyrene blocks have air pockets. These pockets make them light.

• Buoyant

  Polystyrene foam blocks float on water. They are used to make floats and rafts. Their buoyancy is also useful in the packaging industry. It prevents products from getting damaged during transport. Closed-cell blocks are more buoyant than open-cell blocks.

• Thermal insulation

  Polystyrene foam blocks are used in construction to make insulated walls, roofs, and foundations. Heat cannot pass through them easily. This keeps houses warm in winter and cool in summer. Houses with polystyrene walls have reduced energy costs. This is because they do not need heating or cooling. There are two types of polystyrene foam blocks: expanded and extruded. The latter has better insulation properties.

• Moisture resistance

  Polystyrene does not absorb water. The foam blocks will remain strong and stable when exposed to water. Their structural integrity will not be affected by water. The blocks are also used to make foundations. Water cannot damage them. This prevents rot and rust. Closed-cell blocks have better moisture resistance.

• Compressibility

  Polystyrene foam blocks can be compressed to a certain extent without breaking. This makes them ideal for packaging fragile items. They absorb shock and impact. This prevents items from breaking or getting damaged during transport. The compressibility of these blocks is also useful in construction. It distributes weight and pressure evenly. This reduces the risk of cracks forming in walls or structures.

• Ease of handling

  Polystyrene foam blocks are very light. This makes them easy to handle when building. Builders can cut, shape, and fit them with little effort. This speeds up the construction process. Their light weight reduces the risk of injuries. This is especially when lifting heavy materials.

• Cost-effective

  Polystyrene foam blocks are cheap to make. This makes them a cheap building material. Builders can pass the reduced costs to clients. This makes building affordable. The blocks are also durable. They do not succumb to rust, water, or pests. Builders spend less on repairs and maintenance.

Applications of Polystyrene Foam Blocks

• Construction and Insulation

  Polystyrene foam blocks are widely used in construction and insulation due to their lightweight, strong, and insulating properties. The blocks create insulated concrete forms (ICFs) that help build energy-efficient and long-lasting structures. In ICF construction, a hollow core is formed using foam blocks filled with reinforced concrete. This process creates walls with polystyrene insulation on both sides.

  Besides ICFs, polystyrene foam blocks can also build non-load bearing walls in construction. The blocks provide excellent insulation for walls, reducing heat loss or gain. Additionally, these blocks are used as infill panels in steel or wooden frame construction. The blocks offer good insulation when filled in a framed structure.

• Packaging

  Polystyrene foam blocks are also popular in packaging due to their shock-absorbing characteristics. They create protective packaging for fragile items, electronics, and perishable goods during shipment and storage. The blocks form custom molds that hold fragile items securely, preventing movement and impact during transit.

  Additionally, the blocks create inserts for boxes and cartons used to pack fragile items like glassware, ceramics, and electronics. The inserts provide cushioning and support, preventing breakage. Also, the blocks create insulated containers for perishable goods such as pharmaceuticals and food products. The insulation keeps the products at the required temperatures.

• Arts, Crafts, and Education

  Polystyrene foam blocks are also popular in arts, crafts, and education. The blocks are readily available, lightweight, and easy to modify, making them a popular option for DIY projects. They can be used in educational projects to construct models of buildings, bridges, and other structures.

  Besides, they are popular in the construction of sculptures and architectural models. The blocks are easy to shape, enabling the creation of detailed models and sculptures. Also, the blocks can be painted due to their smooth surface.

How to choose polystyrene foam blocks

• Application:

  How the foam block will be used has to be considered carefully. Load-bearing or non-load bearing? Insulation requirements? Structural integrity? Design flexibility?

  The application will determine the type of block chosen. Load-bearing needs a denser block. Insulation needs a thicker block. Non-structural uses can allow for lighter densities.

• Shape and Size:

  Shapes and sizes differ between block types. Slabs come in large flat sizes for walls/roofs. Pipes have pre-cut openings for plumbing. Sheets are versatile flat sizes for many uses. Beams and columns have the shapes named. Choosing the right shape/size matches the application needs.

• Density and R-value:

  Polystyrene's density affects its insulation ability (R-value). A denser block will have a higher R-value. Higher R-values mean better insulating from heat transfer. For insulation applications, density and R-value need to be considered. Thicker blocks of denser foam provide better insulation values.

• Moisture Resistance:

  Expanded polystyrene (EPS) is usually less costly but not as moisture-resistant as extruded polystyrene (XPS). If the block will be used where water is present, XPS may be the better choice because of its higher moisture resistance.

• Thermal Performance:

  Foam's thermal performance is measured by R-value insulation. Higher R-values mean better insulating from heat transfer. For insulation applications, density and R-value need to be considered. Thicker blocks of denser foam provide better insulation values.

• Cost:

  EPS is usually less costly but not as moisture-resistant as extruded polystyrene (XPS). If the block will be used where water is present, XPS may be the better choice because of its higher moisture resistance.

Polystyrene Foam Blocks Q & A

Q1: What are the main applications of polystyrene foam blocks in construction?

A1: PS foam blocks are mainly used as insulation in construction. Expanded polystyrene (EPS) is commonly referred to as 'insulation foam.' Due to its lightweight and strong characteristics, it is also used as a fill in the beam and slab foundation. Additionally, it is used in the construction of inexpensive shelters, retaining walls, and insulated concrete forms.

Q2: Are polystyrene foam blocks environmentally friendly?

A2: The short answer is no. Expanded polystyrene foam blocks are not environmentally friendly. They are made from petrochemical materials, which are non-renewable. Additionally, EPS foam takes hundreds of years to decompose. However, foam blocks can be recycled, and about 95% of the recycled material is usable in making other products.

Q3: How are EPS foam blocks manufactured?

A3: Manufacturing foam blocks consists of three main processes: pre-expansion, molding, and cutting. In the pre-expansion process, a small quantity of pentane is added to the polystyrene beads. The beads are then subjected to steam, which causes them to expand. In the molding process, the pre-expanded beads are expanded again using a mold. Steam is used once more to solidify the beads into blocks. The last process is cutting, where the resultant foam blocks are cut into specific sizes and shapes.

Q4: How does the insulation performance of polystyrene foam compare to other materials?

A4: Foam's insulation performance is solid. Its R-value, which measures insulation, is higher than that of most insulation materials. Its R-value per inch is 4.0 to 4.5, depending on whether it is an R4 or R4.5 foam block. The only insulation material with a higher R-value is polyurethane foam, which has an R-value of between 5.0 and 6.0. The good thing about its R-value is that it remains constant over time, unlike other insulation materials.