Manila Hemp or Abaca

MANILA HEMP or ABACA, the most valuable of all fibres for cordage, the produce of the leaf-stalks of Musa tex tilis (family Musaceae), a native of the Philippine islands. The plant, called abaci by the islanders, throws up a spurious stem from its underground rootstocks, consisting of a cluster of sheath ing leaf-stalks, which rise to a height of from 15 ft. to 25 f t., and spread out into a crown of huge undivided leaves character istic of the various species of Musa (plantain, banana, etc.). From 12 to 20 clusters are developed on each rhizome. In its native regions the plant is rudely cultivated solely as a source of fibre; it requires little attention, and when about three years old develops flowers on a central stem, at which stage it is in the most favourable condition for yielding fibre. The stalk is then cut down, and the outer fibre-bearing layer of each succes sive leaf-stalk is torn into ribbons 1 in. to 2 in. wide and less than * in. thick. These strips in their fresh succulent condition are drawn between a knife-edged instrument and a hard wooden block to which it is fixed. The knife is kept in contact with the block except when lifted to introduce the ribbons. By means of a bamboo spring pole sufficient pressure is exerted on the knife to keep back all pith when the operator is drawing forward the ribbon between the block and knife. By once scraping in this way the soft cellular matter which surrounds the fibre is removed, and the fibre so cleaned has only to be hung up to dry in the open air, when, without further treatment, it is ready to be graded and baled for shipment. Each stock yields, on an average, a little under 1 lb. of fibre; and two natives cutting down plants and separating fibre will prepare not more than 25 lb. per day. The fibre yielded by the outer layer of leaf-stalks is hard, fully developed and strong, and used for cordage, particularly for binder twine, but the produce of the inner stalks is increasingly thin, fine and weak. The finer fibre is used by the natives, with out spinning or twisting (the ends of the single fibres being knotted or gummed together), for making exceedingly fine, light and transparent yet comparatively strong textures, which they use as articles of dress and ornament. Women's "hemp" hats

are made from knotted abaci braided. It is also used for matting and twines. It is of a light colour, very lustrous, and possesses great strength, being thus exceptionally suitable for the best class of ropes. It is extensively used for marine and other cord age. The abaci exported for cordage purposes is a somewhat woody fibre, of a bright brownish-white colour, and possessing great durability and strain-resisting power. Nearly all marine cordage, well drilling cables, hoisting ropes, and generally ropes requiring strength and durability are made of abaci.

Strength of Manila Hemp.

The strength of Manila hemp compared with English hemp is indicated by the fact that a Manila rope 31 in. in circumference and two fathoms long stood a strain of 4,669 lb. before giving way, while a similar rope of English hemp broke with 3,885 lb. The fibre contains a very considerable amount of adherent pectinous matter, and in its so-called dry condition an unusually large proportion, as much a:, 12%, of water. In a damp atmosphere the fibre absorbs mois ture so freely that it has been found to contain not less than 4o% of water, a circumstance which dealers in the raw fibre should bear in mind. From the old and disintegrated ropes is made the well-known manila paper. The plant has been introduced into tropical lands (the West Indies, India, Java and Sumatra, Borneo, etc.), but only in the Philippines has the fibre been successfully produced as an article of commerce. It is distributed throughout the greater part of the Philippine archipelago from southern Luzon southward. The area of successful cultivation lies ap proximately between 6° and 12° N. and 121° and 126° E. ; it may be successfully cultivated up to about 3,00o ft. above sea level. The provinces, or islands, where cultivation is most suc cessful are those with a heavy and evenly distributed rainfall.

Large power machines for cleaning abaci were first used com mercially in the Philippines and Sumatra in 192 7.

See T. Woodhouse and P. Kilgour, Cordage and Cordage Hemp and Fibres (1919). (T. W.)