Binder(redirected from obstetrical binder)
Also found in: Dictionary, Thesaurus, Medical, Legal, Financial.
, agricultural machine that performs both harvesting and threshing operations. Although it was not widely used until the 1930s, the combine was in existence as early as 1830.
..... Click the link for more information. .
a machine for cutting the stalks of grain crops and tying them into sheaves.
any of a group of materials that cause cohesion of grains of silica sand or other fillers used in making foundry molds or cores. The binder ensures the necessary strength of the core or mold. The film of binder applied to the surface of the filler grains is hardened either by heating the mixture or by the action of external agents.
Binders fall into three classes: anhydrous organic binders (linseed oil, drying oil), hydrous organic binders (synthetic resins, sulfite residues [liquor], molasses), and hydrous inorganic binders (molten glass, cement, foundry clay). Binders can also be classified according to the type of hardening as those with irreversible hardening (drying oil, ethyl silicate, synthetic resins), intermediate hardening (sulfite residues [liquor], dextrin), and reversible hardening (rosin, foundry clay).
Binders with irreversible hardening produce mixtures that exhibit a tensile strength when dry of more than 0.5 meganewton per sq m (MN/m2), or 5 kilograms-force per sq cm, assuming 1 percent binder in the mixture. Binders with intermediate hardening produce mixtures with tensile strengths in the range 0.3–0.5 MN/m2, and mixtures made from binders with reversible hardening have strengths up to 0.3 MN/m2.
REFERENCESKumanin, I. B., and A. M. Liass. Sviazuiushchie materialy dlia sterzhnei. Moscow, 1949.
Berg, P. P. Formovochnye materialy. Moscow, 1963.
G. V. PROSIANIK