Knife handles

In a 24-h water soaking test, compreg has an ASE value of 95%. The rate of water pickup is so slow that complete swelling equiHbrium of a 1.27-cm specimen is not achieved in a year at room temperature. Compreg is brown and acquires a high poHsh on buffing. It is made commercially in small quantities and is used for knife handles, gears, and certain musical instmments and decorative objects. 

Today the principal outlets are knife handles, table-tennis balls and spectacle frames. The continued use in knife handles is due to the pleasant appearance and the ability of the material to after-shrink around the extension of the blade. Table-tennis balls continue to be made from celluloid since it has been difficult to match the bounce and handle of the celluloid ball, the type originally used, with balls fabricated from newer polymers. Even here celluloid is now meeting the challenge of synthetic polymers. Spectacle frames are still of interest because of the attractive colour. There are, however, restrictions to their use for this application in certain countries and cellulose acetate is often preferred. 

The development of furfurylation began with the research by Alfred J. Stamm at the Forest Products Laboratory in Madison, Wisconsin, in the 1950s. This led on to an industrialization of the process, with production in the USA of furfurylated wood in the mid-1960s. Products included laboratory bench tops, pulp mixer rotorblades and knife handles. However, commercial production had ceased by the early 1970s. 

More recent uses have been for forming dies and jigs, weaving shuttles, knife handles, glass door pulls and railroad track connectors where electrical resistance is needed for automatic signaling systems. 

A knife handle made of Kraton which is a block copolymer of styrene and butadiene that is made by living anionic polymerization (Source www.knifeoutlet.com). 

Later ivory became much more readily available to the general public, and by the start of the twentieth century was immensely popular in Europe. It was used for such items as dressing table sets, writing sets, card cases, games and knife handles - all useful objects but with ivory giving them the added touch of luxury. 

Bone can be stained to alter its colour. This was fi quently done in the manu cture of knife handles. 

The most enduring use for antler over the centuries has probably been as knife handles, where the end of the antler tine is used in its entirety and simply polished. Knives such as these have been popular in all sizes, from small pocket knives to hunting knives. The material sits well in the hand and the ridged surfiice gives a good grip (Fig. 5.4). 

The horn industry produced countless items such as knife handles, pocket knives, buttons, boxes, shoehorns, glove stretchers, hair combs, backs for hair brushes, fans and jewellery. Some of it displayed very simple workmanship (Fig. 7.4), while some was intricate and involved skilled craftsmanship. 

Although there are no illustrations in the tombs of ancient Egypt of tortoiseshell in use, there are pictures of marine turtles, and it is thought that the material was used for decorative purposes, for example knife handles or bracelets. Like horn, tortoiseshell does not survive the passage of time. 

The handle can be made from any traditional knife handle material or it can. be machined from aluminum or brass bar stock. When completed, a hole Is drilled in the center of the handle and the blade is epoxyed In place. Use a quality brand of epoxy and allow 24 hours curing time before using the knife. A good way to determine the optimum handle shape is to first carve it from soft pine or balsa wood. When the right shape is found, it Is copied In the final material. 

Place knife on board. Drive 2 nails into board on each side of knife handle so knife is held in place. 

At the International Exhibition of 1862, Alexander Parkes [2] first introduced an organic derivative of cellulose that could be moulded when heated and retain that shape when cooled. He invented the treatment of cellulose fibres with nitric acid forming cellulose nitrate that was the first semi-synthetic plastic material. He used this to make decorative brooches, trinkets and knife handles. He claimed that it could do anything that rubber could do but could be produced at a lower price. He formed a company making a... 

FIGURE 25.9 A comparison of (a) a mixed DNA profile (two females and one male contributor) followed by (b) the Y-STR profile of the same sample. The sample was collected with a single surface swab (moistened with DI water) from a knife handle (homicide case). Amplification was performed using PowerPlex Y with 1.2 ng and Profiler Plus with 0.8 ng of template DNA. The male component DNA obtained from the knife handle and the suspect has the same Y-haplotype therefore, the suspect could not be eliminated as the source of the male DNA in the mixture. The results also indicate the presence of only one male contributor in the DNA extract. It should be noted that all of the suspect s male relatives from his paternal lineage would also have the same Y-haplotype. (Courtesy of DNA Unit—Orange County Sheriff-Coroner Department, CA.)... 

The high inflammability and relatively poor chemical resistance of celluloid severely restrict its use in industrial applications. Consequently the material is used because of its desirable characteristics, which include rigidity, dimensional stability, low water absorption, reasonable toughness, after-shrinkage around inserts, and ability of forming highly attractive colored sheeting. Today the principal outlets of celluloid are knife handles, table-tennis balls, and spectacle frames. Celluloid is marketed as Xylonite (BX Plastics Ltd.) in UK. 

Acetic acid produced by degrading knife handles from the 1950s has attacked the paper in which the knives have been wrapped during storage. The knife blades have also undergone corrosion on contact with acetic acid. 

Today table-tennis balls, knife handles, guitar picks, carrier in topical medicines, filters for biological materials, nail polish, vehicle repair coatings. 

Major applications Phenolics can be cast into rod, tubes and sheet and foamed. They can be impregnated into paper and cloth. Electrical insulation, plugs and switches, radio and television housings, telephones, cameras (e.g. Kodak s Brownie 127), fuse box covers, bushings, gears, beads, knife handles, paperweights, billiard balls, saucepan handles and knobs, panelling (as foam). 

For many years, modified woods have been prepared by impregnation with prepolymers such as phenolic resins, followed by curing under heat and pressure. By this means considerable improvement in dimensional stability and mechanical properties may be obtained (Tarkow et a/., 1970), and products of this type are often encountered in articles of commerce, such as knife handles. In general, densely crosslinked thermosetting resins have been used in these applications. The structure of wood itself is briefly considered in Section 9.9. 

Soft-touch overmolding applications in kitchen appliances and tools (e.g., knife handles), handheld power tools, consumer electronics, etc. 

Braconnet in 1833, is the oldest of the synthetic plastics. It is made by treating fibrous cellulose with a mbcture of nitric and sulfuric acids, and was first used in the form of a lacquer (See collodion). In 1870, John Wesley Hyatt and his brother patented the use of plasticized cellulose nitrate as a solid, moldable material, the first commercial thermoplastic (celluloid). Camphor was the first (and is still the best) plasticizer for CN, although many camphor substitutes have been developed. Alcohol is normally used as a volatile solvent to assist in plasticization, after which it is removed. Molded products of CN are extremely tough, but highly flammable and subject to discoloration in sunlight. CN is amendable to many decorative variations. Its principal uses today are in knife handles, table-teimis balls, and eyeglass frames. A mixture of nitric and sulfuric acids converts cellulose into cellulose nitrate pyroxylin is a less nitrated material and it has been useful for photographic film, collodion, and celluloid plastics. 

Cocobolo derives from Central America it is strong, hard, compact, fairly heavy, easy to work with and of extreme durability. It holds a supreme position in the cutlery trade, especially in knife handles, but also serves for brush backs, chessmen, scientific instruments, bulbs of billard cues, wooden bracelets, wooden jewellery and interior turnery. Cocobolo is especially used for musical instruments 90% of all recorders manufactured before World War II were made from... 

As a hard and heavy blue-black coloured wood, Grenadil or African blackwood is mainly imported from Mozambique, Zimbabwe, Togo and Senegal. Its use comprises knife handles, brush backs, chessmen, truncheons, flutes, clarinets, oboes, chanters of bagpipes and some types of recorders. 

Cases of dermatitis have been described since 1934 and have been observed in clarinet makers and in knife-handle turners (Meister 1934 Woods and Calnan 1976 Hausen et al. 1984). The responsible allergens are (S) -4-methoxydalbergion, (S) -4 -hydroxy-4-methoxy-dalbergion and (S)-3 -hydroxy-4,4 -dimethoxydalber-gione (Schulz et al. 1979). 

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