摘要:
A sound masking system for generating background sound. The background sound is automatically adjusted to ambient noise levels by adjusting the amplitude of the frequency levels detected.
摘要:
A reinforced sheet product for selective sorption of an immiscible liquid from a liquid mixture is disclosed. The reinforced sheet product comprises a flexible net-like reinforcing structure secured between at least two sheets or layers of non-woven material predominately composed of cotton which are preferentially sorptive of one liquid over another liquid in the mixture. The product according to the invention finds particular application as a lightweight reinforced wiping cloth or towel especially useful for removing oil from an aqueous mixture.
摘要:
A carpet backing for tufted carpets comprising non-woven fiber material secured to plastic netting is disclosed. The non-woven fiber material is secured to the netting by needle punching. The carpet yarn may thereafter be tufted into the backing.
摘要:
In accordance with the present invention the aging period for low density polyethylene foam is substantially reduced by forming the foam from at least two different resins having different melt indexes which are blended together.
摘要:
An apparatus for the production of perforated tubular film i.e., net is disclosed. A tube of a thermosetting polymer is continuously extruded and the extrusion opening is alternately interrupted first from one side of the tube and then from the other thereby doubling the capacity of the machine.
摘要:
A method and apparatus for perforating and, if desired, eroding fibrous board surfaces in a non-repetitive pattern are disclosed. The boards perforated according to the present invention are especially useful as acoustical tiles and panels. The board is formed and dried with a surface pattern developed on the board surface if desired and thereafter the board surface is punched by a series of randomly arranged pins or tacks on a plurality of rolls whereby a non-repetitive pattern results.
摘要:
A seedling transplant container is disclosed. The container is a net-like tube preferably with an open bottom and having one set of strands which is of substantially greater strength (at least 25% and preferably 50%) than the other set of strands so that the container can be machine planted but yet easily ruptured by the growing plant.
摘要:
Fibrous web structures in which the individual fibers are uniformly felted in random orientation are produced by projecting a stream of solids suspended in air toward a moving porous collection surface. The fibers are maintained in a controlled condition uniformly dispersed in air during transit from the nozzle to the porous collecting surface and before the stream of air has spread to the point of disrupting the uniform fiber dispersion, the fibers are felted and collected on the porous support while air is continuously passed through the support to insure no gravity free fall of fibers. Liquid or dry adhesive binders may be incorporated into the structure at any convenient stage of the process but preferably before the web structure is formed on the moving support.
摘要:
The invention relates to a process and apparatus for making a thermoplastic polymer sheet and particularly a thermoplastic polymer netting structure. It further relates to a process and apparatus for splitting a thermoplastic polymer sheet or net structure so as to divide the sheet or net at the center thereof into two thin sheets. According to the invention, a previously formed plastic sheet or netting structure is reheated and then placed between two opposed heated smooth surfaces such as metal rolls. The sheet or net is heated to a temperature within the range of temperatures wherein the adhesion of the resin forming the sheet to the metal rolls is good and where its cohesion is poor. The opposed faces of the sheet or net structure adhere to the heated smooth surfaces. The opposed heated surfaces are separated; this causes the sheet or net to split in half to follow each surface. The split halves are quick-cooled to a temperature in the temperature range in which the resin's cohesion is increased and adhesion to the rolls is reduced so that the split sheet halves can be removed from the smooth roll surface.
摘要:
A remarkably superior plastic netting for use in palletized loads is disclosed. The plastic netting is composed of linear low density polyethylene. The netting is molecularly oriented by a minimum factor of 4 in the longitudinal direction. The resulting netting is highly desirable for use in the wrapping of palletized loads since it is relatively inexpensive, lightweight, strong, and has a low degree of permanent stretch coupled with a relatively high degree of elastic stretch.