What are Composites?

What are Composites?

Composites are materials made by combining two or more natural or artificial elements that are stronger as a team than as individual players.

Are typically designed with a particular use in mind, such as added strength, efficiency or durability.

Fiber

Provides strength and stiffness (glass, carbon, aramid, basalt, natural fibers)

Matrix

Protects and transfers load between fibers(polyester, epoxy, vinyl ester…)

Fiber Composite

Material with attributes superior to either comp. alone.

Fuente:

RESINS

The primary functions of the resin are to transfer stress between the reinforcing fibers, act as a glue to hold the fibers together, and protect the fibers from mechanical and environmental damage.

There are two major groups: thermosets and thermoplastics

THERMOSET RESINS: Used to make the most composites. They’re converted from a liquid to a solid through a process called polymerization, or cross-linking. Thermosetting resins are “cured” by the use of a catalyst, heat or a combination of the two.

· POLYESTER: Unsaturated polyester resins (UPR) represent approximately 75% of the total resin used in the industry. Polyesters are versatile because of their capacity to be modified or tailored during the building of the polymer chains. Their principle advantages is a balance of properties (mechanical, chemical and electrical) dimensional stability, cost and ease of handling or processing.

REINFORCEMENTS

Many materials are capable of reinforcing polymers. Some materials, such as cellulose in wood, are naturally occurring products. Many forms of fiber are used as reinforcement in composites laminates, glass fibers account for more than 90 percent of the fibers used in reinforced composites because they are inexpensive to produce and have relatively good strength-to weight characteristics.

FIBERS

Glass Fibers: glass produced fibers are considered the predominant reinforcements for polymer matrix composites, glass is generally a good impact resistant fiber, Have excellent mechanical characteristics, stronger than steel in certain forms.

Carbon Fibers: Carbon fibers offers the highest strength and stiffness of all the reinforcement fibers. High temperature performance is particularly outstanding. The major drawback to PAN-based fibers is their high relative cost.

New Fibers: Polyester and nylon thermoplastic fibers have recently been introduced both as primary reinforcement and in a hybrid arrangement with fiberglass. Low density, reasonable cost, good impact and fatigue resistance.

SURFACE FINISHES

Used mostly for UV protection, corrosion resistance and aesthetics, can be molded un process or secondarily applied coatings

FRP composites can accept a wide range of surface finishes, gel coat, adhesives, polyurethanes, polyesters, acrylics, epoxies and in some cases with fine sand for additional protection.

BENEFITS OF COMPOSITES

Strong

Per pound, composites are stronger than other materials such as steel. Fibers carry the load, while resin distributes the weight through the composites part as required.

When considering the density of the materials are on the strongest materials around, it’s no surprise they are the material choice for everything from airplanes to automobiles.

By combining specific resins and reinforcements – and there a lot of them – you can customize the formulation to meet specific strength requirements. You can alter the ration of the resin and reinforcement or orient the fibers in one or various directions.

Composites are anisotropic, meaning the material properties change depending on placement and number of layers of reinforcement.

Lightweight

Fiber-reinforced composites offer excellent strength-to-weight ratios. Producing parts that are light weight is critical to industries such as transportation, infrastructure and aerospace. Lightweight reduces costs on shipping and carry.

Easy to install, simple to handle. Concrete structure can be 80 percent heavier than one in FRP, this reduces the time and costs of installation in same percentage.

Corrosion resistance

Products made from composites provide long-term resistance to severe chemical and temperature environments. Often choice for outdoor exposure, chemical handling applications and other severe environments.

Composites do not rust or corrode. There are many examples of glass fiber reinforced polymer ductwork being in service in chemical manufacturing plants for more than 25 years, operating 24 hours a day.

Composites offer corrosion-resistant solutions for many industries also for many when combined with water as pipes or tanks.

Corrosion resistance is determined by the choice of resin and reinforcement used. Properly applied and designed composites have a long service life and minimum maintenance.

Design Flexibility

Because composites are a blend of reinforcing fibers, resin and additives, they can be manufactured to meet an array of requirements.

One of the biggest benefits of composites is the ability to mold them into complicated shapes more easily that most other materials.

Contours are possible without the need for high-pressure tools because composites are formed when the resin cures – or solidifies – during production.

Recreational boats have long been built with FRP because improves boat design while lowering costs.

Composites surfaces can be molded to simulate any finish or texture, from smooth to coarse.

Durability

Composites structures have an exceedingly long life span. Combine this with their low-maintenance requirements and composites become the material of choice for a host of applications.

How long do composites last? There is no answer. That’s because many of the original composites structures put in place more than 50 years ago have not yet come to the end of their lives. Composites hold up well against fatigue and are resistant to environmental factors such as U.V. damage, temperature fluctuations, moisture and chemical exposure.

COMPOSITES VS STEEL

Composites are lighter than steel: Depending on formulation can be 70% lighter than steel.

Composites are incredible strong: Can be custom-tailored to add strength. In steel if greater strength is needed then more metal must be added, which it turns in more weight.

Composites are corrosion resistant:  Composites stands up in severe weather, steel rusts easily unless is protected or coated with zinc.

Composites are nonconductive: Steel conducts electricity. Composites are superior insulators, do not respond to an electric field.

COMPOSITES VS GRANITE

Composites are non-porous: This make them more sanitary than granite, it also can withstand disinfectant products without damaging the material, unlike granite

Composites are easy to maintain: Do not require sealants or special cleaning products. Because granite is porous, it must be sealed annually to prevent staining.

Composites are inexpensive: Granite sinks routinely cost more than 10 times that of composites sinks. They require professional installation, composite can be do-it-yourself.

Composites offer endless appearance options: They can be easily formed into any shape and customized to any color. Granite must be carefully selected, matched and cut and is available in a limited colors.

Composites are heat resistant: Composites retain their integrity when exposed to high temperatures. Granite surfaces can’t absorb heat.

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