Closed-cell PVC foamboard

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Closed-cell PVC foamboard is a lightweight rigid material used primarily in the manufacture of signs and displays. It is considered robust for outdoor use, being immune to rain and resistant to wind and sunlight.

Contents

History

In 1912, the first patents for polyvinyl chloride (PVC) were founded in Britain and Germany. It was not until the early 1930s that PVC was able to be produced cheaply, limiting its marketable applications for the time. World War II helped make the substance popular, as manufacturers used it to make an assortment of items for soldiers. It was here that PVC's water resistance was shown to be an important property, and tools made from PVC were used in many marine applications. After the war, PVC was not a popular choice of materials in the marine industry due to its density. In the 1970s, the need for a strong, moisture-resistant material led to plastic manufactures working with PVC to make it lighter. This led to the creation of PVC foamboard, by combining PVC with polyurea at the molecular level. [1]

Processing

PVC foamboard is made up of an interpenetrating polymer network between PVC and polyurea. Now, the manufacturing process has become much more involved. First, polyvinyl chloride and polyurea are mixed together under controlled conditions. The mixture is then dispensed into a mold (commonly square as to make the foamboards). The filled mold is sealed by clamping the sides shut and then put into a large press where it is heated. After, a slab of solid material emerges from the mold. The material then undergoes a hot bath in order to expand it to a final density and is cured. The material is then ready to be cut into sheets of varying sizes and thickness, depending on purchaser requirements. [2]

Properties

PVC foamboard is distinct from the extra-lightweight foamcore board, laminated of foam and card surfaces, used for indoor signage and modelling. Like PVC, closed-cell PVC foamboard is solid and has a very rigid structure. Where it differs is in its closed-cell foam structure, which makes it very light (as little as half the weight of solid PVC), highly resistant to moisture and some chemicals, and very easy to cut and shape. It also has thermoplastic properties, and begins to soften at around 65 °C (149 °F). Typically, closed-cell PVC foamboard can be cut as easily as wood, softened and shaped by immersing in boiling water or with a standard heat gun, and painted with standard automobile paints. In addition, Closed-cell PVC foamboard is made up of polarized molecules otherwise known as dipoles.

It has a very low moisture absorption. The mixture of polyvinyl chloride and polyurea has a good bond strength. Closed-cell PVC foam takes solid shape due to its linear structure. However, due to this structure, it is more brittle than open-celled PVC foam. It is available in densities varying from 3 to 25 pounds per cubic foot (0.048 to 0.400 g/cm3). [3] It has a low flammability rate. [4] A universal cross-linked closed-cell PVC that was used in a comparison with three heat-resistant cross-linked had a glass temperature of 83.2 °C. However, there are issues using PVC that can affect one's health and safety when in use. [5]

Common uses

Closed-cell PVC foamboard is mainly used for industrial and manufacturing purposes. The material is primarily used in the manufacturing of signs and displays which are used for promotion ads, as well as road signs. [6] Its appealing material properties have made it popular among the makers of scale models and theatrical props. Builders who create yachts and composites used for experimental aircraft are typically found using PVC foamboard. This type of PVC foamboard is well resistant to weather and sunlight, and can thus be used to protect other, more damage-prone products. [7]

Issues

One drawback to PVC materials is that hot working them produces noxious fumes containing hydrochloric acid and potentially even dioxins. These are a respiratory hazard in a workshop, and the acid fumes are so serious that they may damage equipment. Some heat-based processes, notably laser cutting, are generally considered impossible, owing to the equipment risk. [8] Where PVC materials are cut by laser, this is a highly specialized process requiring adapted machines and acid-specific fume extraction and filtering. [9]

Related Research Articles

Polyvinyl chloride Synthetic plastic polymer

Polyvinyl chloride is the world's third-most widely produced synthetic polymer of plastic. About 40 million tons of PVC are produced each year.

Polyurethane Polymer composed of a chain of organic units joined by carbamate (urethane) links

Polyurethane refers to a class of polymers composed of organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from a wide range of starting materials. This chemical variety produces polyurethanes with different chemical structures leading to many different applications. These include rigid and flexible foams, varnishes and coatings, adhesives, electrical potting compounds, and fibers such as spandex and PUL. Foams are the largest application accounting for 67% of all polyurethane produced in 2016.

Thermoplastic Plastic that becomes soft when heated and hard when cooled

A thermoplastic, or thermosoft plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.

Foam Form of matter

Foams are materials formed by trapping pockets of gas in a liquid or solid.

Thermosetting polymer Polymer obtained by irreversibly hardening (curing) a resin

In materials science, a thermosetting polymer, often called a thermoset, is a polymer that is obtained by irreversibly hardening ("curing") a soft solid or viscous liquid prepolymer (resin). Curing is induced by heat or suitable radiation and may be promoted by high pressure, or mixing with a catalyst. Heat is not necessarily applied externally, but is often generated by the reaction of the resin with a curing agent. Curing results in chemical reactions that create extensive cross-linking between polymer chains to produce an infusible and insoluble polymer network.

Wood-plastic composite Composite materials made of wood fiber and thermoplastics

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Ethylene-vinyl acetate Chemical compound

Ethylene-vinyl acetate (EVA), also known as poly (PEVA), is the copolymer of ethylene and vinyl acetate. The weight percent of vinyl acetate usually varies from 10 to 40%, with the remainder being ethylene. There are three different types of EVA copolymer, which differ in the vinyl acetate (VA) content and the way the materials are used.

Vinyl composition tile Flooring material

Vinyl composition tile (VCT) is a finished flooring material used primarily in commercial and institutional applications. Modern vinyl floor tiles and sheet flooring and versions of those products sold since the early 1980s are composed of colored polyvinyl chloride (PVC) chips formed into solid sheets of varying thicknesses by heat and pressure. Floor tiles are cut into modular shapes such 12-by-12-inch squares or 12-by-24-inch rectangles. In installation the floor tiles or sheet flooring are applied to a smooth, leveled sub-floor using a specially formulated vinyl adhesive or tile mastic that remains pliable. In commercial applications some tiles are typically waxed and buffed using special materials and equipment.

Waterproofing Process of making an object or structure waterproof or water-resistant

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Building insulation materials

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Spray foam

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Rigid panel

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Butyltin trichloride Chemical compound

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A thermoset polymer matrix is a synthetic polymer reinforcement where polymers act as binder or matrix to secure in place incorporated particulates, fibres or other reinforcements. They were first developed for structural applications, such as glass-reinforced plastic radar domes on aircraft and graphite-epoxy payload bay doors on the Space Shuttle.

Polymeric foam

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References

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  2. "PVC Foam". NetComposites. Retrieved 2018-10-01.
  3. "PVC Foam". netcomposites.
  4. "Komatex". Kommerling USA, inc.
  5. PVC#Health and safety
  6. "Spandex".
  7. "AD Know More About PVC Foam Board". Pontetech: Cellular PVC Manufacture. Archived from the original on 2013-09-16. Retrieved 2013-11-30.
  8. "Plastic cutting & engraving". Cut Laser Cut. 21 October 2020.
  9. "AD PVC – Advantage Range of Laser Fume Extractors". BOFA.