How to Compare and Choose Composite Materials

How to Comparing and Choosing Composite Materials

Various composite material are on the market, and they have various characteristics.How to comparing and choosing composite materials? Here we take a look at the pros and cons of the components: the resins and the fibers used to strengthen them.

There are three main recipes: polyester, vinylester and epoxy. Various flavours of each are available, depending on whether they are strengthened with glass, carbon or aramid fibers, and the particular application. For example, high UV (sunlight) tolerance may be chemically engineered using additives.

There are three main families in use at present: glass fiber, carbon fiber and aramid fiber (more commonly known as Kevlar, a trademark of the DuPont Corporation).

Glass fiber is by far the cheapest and most widely used, and works well with all three resin types, but it is relatively heavy. Carbon fiber is much lighter, as are aramid fibers.

Glass fibers (either in chopped strand or woven cloth form) are most commonly used with a polyester resin, whereas carbon fiber, as a relatively high cost strengthener, is most usually combined with epoxy resins.

A resin has to 'stick' to the fiber strengthener, and it is important to select a resin/fiber combination (particularly with carbon and aramid fibers) so that there is good adhesion and the fibers are properly bonded within the resin.

Composite Comparisons

In general terms, Kevlar mechanical properties are good in strength (double that of glass fibers) but very poor in stiffness, whilst the glass composite is ten times as stiff and half the strength.

Kevlar is very expensive compared to glass, so it is used where higher strength and elongation is needed.

Both aramid composites and GRP are good at handling repeated flexing cycles (such as in a boat hull), but carbon fiber has an unpredictable life when subject to repeated flexing.

GRP requires a considerably 'heavier' construction to achieve the strength of carbon fiber. Aramid fibers offer equivalent strength to fiberglass at a much lower weight, although abrasion resistance is lower.

Sichuan Sincere&Long-term Complex Material Co., Ltd is a professional manufacturer of fiberglass chopped strand mat. Welcome to inquiry! Email: fred@chinaweibo.com.cn