What Chemicals are in Vinyl Flooring?

Polyvinyl chloride resins, also sometimes just called vinyl resins, are the primary ingredient in vinyl flooring. Polyvinyl chloride, or PVC, is a thermoplastic resin made of 5 7 percent chloride and 43 percent carbon, and is manufactured via a polymerization process of Vinyl Chloride Monomer (VCM). The VCM is derived from industrial grade salt (chloride source), and the vinyl mainly comes from ethylene, a petroleum or natural gas product. PVC is less dependent on petroleum than many other polymers. As a thermoplastic resin, PVC becomes pliable at high temperatures and solidifies once cooled.

PVC may be supplied in the form of a powder that is resistant to degradation and oxidation, allowing for long-term storage. PVC has inherent block resistance, and typically does not require flow aids when processed further. Before using PVC as resins for flooring or other products, processers mix in various additives (plasticizers, lubricants, heat stabilizers) to enhance or alter specific properties. After additives are mixed in, the result is a vinyl compound, often in the form of pellets.

In flooring, there may be several layers of PVC compounds. Typically, there is a core layer, a decorative layer and then a clear, durable wear layer on top that protects the other layers.

Without the addition of plasticizers, PVC is a rigid, brittle material. Rigid PVC is used to make piping and building elements such as siding. Adding plasticizers to PVC makes it flexible, enabling its use in flooring as well as other applications such as insulation for electrical cables, wire rope, and clothing. In addition to flexibility, plasticizers can improve the durability, temperature resistance, and weather resistance of PVC.

Plasticizers are ester compounds produced via reaction of an alcohol and an acid. Using different combinations of alcohols and acids creates different kinds of ester plasticizers, of which there are many. Most plasticizers used for vinyl flooring are phthalates, derivatives of phthalic acid. Phthalates are colorless, odorless ester liquids, and compatibilize well with PVC. Phthalates are non-volatile, and do not readily evaporate from PVC. Types of phthalates include diisodecyl phthalate (DIDP), diisononyl phthalate (DINP), and di-2-ethylhexyl phthalate (DEHP or DOP). These three plasticizers make up approximately 75 percent of what is used for PVC.

Other kinds of plasticizers that may be used include adipates, which are ideal for low-temperature resistance, and trimellitates, which are impart heat resistance. Benzoates are high solvating plasticizers for PVC, available as either monobenzoates or dibenzoates. Dibenzoates are environmentally friendly plasticizers. They are mainly used in PVC plastisol applications including flooring and film, but also in adhesives and sealants.

Pigments are another type of additive used in making vinyl flooring. Pigments give flooring its color and enable manufacturers to make flooring in a variety of designs, including those that mimic other materials such as wood or marble.

Pigments differ from dyes. Pigments are typically insoluble and come in the form of a powder, while dyes generally are liquids or soluble substances suspended in liquids.

There is a massive variety of pigments for flooring available that may be made from a myriad of natural materials or petrochemical derivatives. The right pigment depends on the desired colors as well as other factors such as availability and cost. Like plasticizers, the chosen pigments are mixed with the vinyl resin.

Vinyl flooring may also contain small amounts of stabilizers, which help to increase durability and reduce fading due to exposure to heat and sunlight. These stabilizers are mixed directly and thoroughly into the vinyl compound.

Vinyl stabilizers are typically metal compounds and may consist of a variety of substances derived from heavy metals. The primary heat stabilizers in a vinyl product may also be combined with other stabilizers made of organic materials such as epoxidized esters and polyols. Different stabilizer mixtures provide different qualities. Proper stabilization depends on their performance requirements, cost, and regulatory status.

Lead was once the leading stabilizer used, but due to health concerns, it is being phased out in some areas. Other substances that may be used include cadmium, calcium zinc, barium zinc, and tin.

Installing vinyl flooring often involves the use of adhesives. Flooring may come with adhesive already applied, or the installer may need to purchase an adhesive separately.

There is a wide range of adhesives that you can use to install flooring. Adhesives for flooring are often made of resins and may be pressure-sensitive. The best adhesive depends on various factors including the type of sub-floor, the layer of flooring that will be underneath the vinyl. The adhesive must be alkaline resistance and non-staining, fast drying allowing for easier traffic and less slippage.

Depending on the desired aesthetics, a coating of polyurethane may be applied over vinyl flooring composite. This coating provides a glossy finish, abrasion resistance and durability, and some UV stability. This finish typically lasts for many years, but if it becomes dull, the homeowner might apply a new coat of vinyl floor finish.

Polyurethane coating is a type of durable organic coating. It is a polymer in liquid form and may be either oil-based or water-based.

Polyurethane is also used in a variety of other products including footwear, automobile seats, and pillows in many different forms including hard plastic and foam.

Vinyl flooring may also contain various types of fillers, which can add texture, durability, and color as well as decrease costs. The vinyl core of a piece of flooring may be attached to a felt backing made of substances such as paper, wood pulp, clay, and calcium carbonate, which is a compound that appears naturally in the form of chalk, limestone, or marble and, in its pure form, contributes to various industrial processes.

• To produce sheet flooring, vinyl resin, plasticizer and additives are mixed in a vat to form what is called a plastisol. An azo compound is added to this mix. The whole mixture is then heated, causing the azo compound to decompose and form nitrogen gas bubbles. This process produces a vinyl foam that has a semiliquid consistency.
• A reverse roll coater is then used to apply this substance to a backing, which may be made of wood pulp or felt. The mixture is poured on and then smoothed out.The backing and plastisol head into an oven. The heat causes the plastisol substance to gel, the vinyl resin to absorb the plasticizer, and the resin to set.
• Next, the gel goes through a printing press where metal intaglio plates with patterns carved onto them impress the desired decorative panel into the gel.
• Another plastisol of vinyl and additives is then applied on top of the printed gel. This will form the wear layer, the transparent layer that protects the decorative pattern beneath it.
• The backing, gel, and new layer of plastisol are again sent into an oven, which is heated to a higher temperature than before. The heat causes the vinyl resin to absorb the plasticizer and melt, which creates a clear vinyl layer.
• If the flooring requires a high-gloss finish, rollers will then be used to apply a polyurethane coating. After applying a coating and ensuring consistent thickness, ultraviolet radiation lamps are used to photochemically cure the polyurethane coating. If no high-gloss coating is needed, this step is skipped, or special matting agents are used in the coating to ensure a matte finish.
• The sheet can then be rolled and cut to standard roll sizes.

If manufacturing tile flooring, some of the steps above will be different. Steps one through three are often quite similar, except for the use of plasticizer (little or none incorporated). During phase four, in which the design will be imprinted on the tiles, the plates will stamp designs that are the same as the size of the tiles.

Steps five through seven again will be quite similar. Instead of rolling the vinyl sheets, however, a die cutting machine will cut the sheet into individual tiles.

If the tiles will not have an adhesive backing, they are ready once they have cooled.

If they will have an adhesive, a roll coater will apply it to the backings of the tiles. A peelable paper cover will then be placed over the adhesive to protect it until installation.

The above process involves multiple layers of vinyl and backing. This is a common method of producing vinyl flooring, but there is also a similar method that is sometimes used that creates one homogenous piece of flooring. The design options for this type of flooring are more limited than with layered flooring, but it can be more cost-effective.

To produce a piece of homogeneous flooring, the manufacturer creates the plastisol as they would in the layered process by combining vinyl resin and additives. They then roll this mixture out into a thin layer. Applying heat and air, the plastisol dries into a durable sheet of vinyl.

If any decorative patterns are desired, the manufacturer can press them into the sheet before it finishes drying. Decorative elements and colors extend all the way through the sheet, so they will not wear away. The design needs to be one that can continue through the whole tile without compromising quality. This type of solid tile often has a satin finish and requires regular waxing or buffing to maintain a new look.