Printed German Application No. 1,753,695, U.S. Pat. No. 3,399,425, and British Patent No. 1,072,236 disclose processes and apparatus for manufacturing products which have a tufted surface from non-fibrous polymers. In these known processes at least one thermoplastic layer is pressed to the extent of at least part of its thickness against a heatable surface, which is provided with projections or depressions and the layer is subsequently stripped from the surface. In one of the processes, the surface of the polymer layer which has been shaped by the pressing operation is heated to a moderately elevated temperature as it is stripped.
German Patent Specification No. 1,266,441, corresponding to U.S. Pat. No. 3,708,565 describes another process in which a polymer is brought between two smooth drawing surfaces and in a molten state is torn apart at right angles to its direction of movement and is cooled at the same time so that fibers are formed. In that case the coolant stream acts on the fiber-forming region in a direction which is opposite to the direction of movement of the polymer. In a more recent process, which is a development of the one just outlined and has been disclosed in the Opened German Application No. 2,053,408, the molten polymer is forced through a porous carrier and against a smooth drawing surface, from which the layer is then pulled and simultaneously cooled so that fibers are formed.
Opened German Specification No. 2,157,510 describes a process of manufacturing a product which has a plush surface. That process is characterized in that, inter alia, the polymer is forced with the aid of a carrier against a heatable drawing surface and, as the formation of the fibers begins, is pulled away from said drawing surface with simultaneous cooling and subsequent deflection of the carrier. The coolant stream acts also into the fiber-forming region in a direction which is opposite to the direction of travel of the carrier. Besides, a contact cooling is effected on the rear of the carrier. Processes of this kind have the disadvantage that the fibers which are forming are contacted by the coolant throughout their length at the same time, so that the action of the coolant on fibers behind those which are being formed is highly reduced; this is not altered by the contact cooling on the rear.
A development of that proposal in consideration of its disadvantages has led to a process which is disclosed in Opened German Specification No. 2,057,149, corresponding to U.S. Pat. No. 3,701,621 and in which a flowing coolant acts on the rear of the carrier approximately in the direction of travel of the carrier and flows along and in part through the carrier. In that case the carrier layer is not deflected in the fiber-forming region and fibers which are forming remain subjected to the temperature of the heated drawing surface.
In these known processes, cooling is accomplished by a stream of gas or liquid, which produces a cooling action which is either too slow or too abrupt. In connection with such processes, it is generally stated that the polymer must be completely removed from the drawing surface to avoid interference with subsequent fiber formation.
The recognition of the shortcomings have led to providing means which control the action of the flowing fluid in the very area in which the fibers originate or are in "statu nascendi" and also control of the shape of the fibers throughout the fiber-forming region so that production can be carried out at a high, economical rate and the quality of the product can be uniformly controlled.
USPTO Backgrounds
USPTO Backgrounds