Glass fiber adhesion

Adhesion promoters were first used to treat glass fibers and other fdlers before they are incorporated into liquid resin to make composite materials. In the fiber industry, adhesion promoters are also known as finishes. Certain finishes have been specially developed to match a fiber with a resin matrix. Without adhesion promoters, the interfacial resin-glass fiber adhesion is weak, and water can diffuse along the interface with catastrophic results on the end properties of the composite. 

Mix of PP-PP- -MAH with glass fibers. Adhesion between the fibers and matrix... 

Uses Binder for fabrics, glass fibers adhesive for wood, plastic, paper, pkg. textile auxiliary and coaling... 

Figure 6.17 Stress vs. strain for dry EMS Grivory Grilon BG-50 HM 50% glass fiber (adhesion modified) PA6 resin [1],...

A Diwanji. Next Generation Coupling Agents for Glass Fibers. Adhesion and Coupling Agent Technology 97, Boston, 1997. 

Glass fiber adhesives Dimethallyl ether United States 2,611,718 1952 Owens-Corning Fiberglass... 

Starch pyrodextrins and British gums have the abiUty, in aqueous dispersion, to form films capable of bonding like or unlike materials. Thus, they have uses as adhesives for envelopes, postage stamps, and other products. These dextrins are used in glass-fiber siting to protect the extmded fiber from abrasion, and as binders for metal core castings, water color paints, briquettes, and many other composite materials (qv). 

Introduced successfully for tires in 1967, glass fibers had properties that made them very attractive for use in tires (5,8). The britdeness of glass fibers, however, imposed some limitations on the final tine cord properties because of the requirement that each fiber be individually coated with a mbbery adhesive to avoid interfilament damage during fabrication and use. This additional treatment step is introduced at the fiber manufacturing stage. For several years fiber glass was used extensively in bias-belted and radial tires, but was ultimately replaced by steel belts in radial tires. 

Fig. 19. Inlerfacial shear strengths of various fiber/matrix composites as a function of the work of adhesion as determined by IGC. 1, glass fiber-poly (ethylene) 2, carbon fiber-epoxy B 3, carbon fiber-epoxy A and 4, carbon fiber-PEEK. Redrawn from ref. [102].

In this examination, glass fibers were replaced by coir fibers. A proper treatment of the fibers improved adhesion and, therefore, tensile strength was increased (Fig. 18). 

The mechanical properties of composites are mainly influenced by the adhesion between matrix and fibers of the composite. As it is known from glass fibers, the adhesion properties could be changed by pretreatments of fibers. So special process, chemical and physical modification methods were developed. Moisture repel-lency, resistance to environmental effects, and, not at least, the mechanical properties are improved by these treatments. Various applications for natural fibers as reinforcement in plastics are encouraged. 

SCRIMP process This Seeman Composites Resin Infusion Process (SCRIMP) is described as a gas-assist resin transfer molding process. As an example glass fiber fabrics/ thermoset vinyl ester polyester plastic and polyurethane foam panels (for insulation) are placed in a segmented tool. A vacuum is pulled with a bag so that a huge amount of plastic can be drawn into the mold (Marco process approach). Its curved roof is made separately and bonded to the box with mechanical and adhesive fastening. It is similar to various reinforced plastics molding processes. 

About 8,000 metric tons of peroxides were consumed in 1972. This consumption was strongly stimulated by the rapid growth in reinforced plastics (Ref 23). The largest volume product is benzoyl peroxide which is used in polystyrene and polyester markets for such items as toys, automobiles, furniture, marine, transportation and mil requirements. Also, methyl ethyl ketone peroxide is used in large volumes to cure (as a catalyst) styrene-unsatur-ated polyester adhesive resins used in mil ammo adhesive applications, as well as in glass fiber reinforced plastic products such as boats, shower stalls, tub components, automobile bodies, sports equipment, etc. The monoperesters are growing slowly because of some substitution of the peroxydicarbonates and azo compds (Refs 8,9 23)... 

As soon as the Ar s were determined and the values of r s are found, the values of the adhesion coefficient A may be readily defined by using relation (27). The values of A s for the different fiber-volume contents studied are given in Table II for E-glass fiber-epoxy resin composites with different amounts of fillers, up to 70 percent 22 >. 

Again, Eqs. (28) and (48) form a system of two equations and two unknowns, which can be solved and yield the values of the exponents q, and q2. Their difference A=r 1— q2, which expresses the quality of adhesion, is called the adhesion coefficient. The values of the exponents q, and q2> as well as of their difference A were given in Table 2 and plotted in Fig. 15 for the glass-fiber composites given in Ref. 22). 

Liquid rubbers In order to improve the flexibihty of short glass fiber-reinforced epoxy composites, Kaynak et al. [53] modified the epoxy resin matrix with hydroxyl-terminated polybutadiene (HTPB) liquid mbber. A silane coupling agent was also used to improve the interfacial adhesion between glass fibers and epoxy matrix. However, Humpidge et al. [54] reported some unique processing problems for the resulting pasty mixmres when short textile fibers were incorporated in a hquid mbber medium. 

Heat-bonding process Glass fiber mat is embedded into the exterior surface of the pipe liner. This serves as an adhesion key for the reinforcement resin. This is an expensive process owing to the necessity for strict control over the surface fusion process. 

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