摘要:
A tissue sheet is made using a modified wet pressing machine in a modified wet pressing process employing an integrally sealed air press. After initial formation and conventional vacuum dewatering, the wet web is conformed to the surface contour of a relatively coarse fabric to give the web a textured surface. By creating a pressure differential across the web of at least 30 inches of mercury and an air stream through the web of at least 500 SCFM/in2, the air press noncompressively dewaters the wet web to a consistency of about 30 to about 40 percent prior to a heated drying cylinder. The web is dried to substantially preserve its three-dimensional, throughdried-like texture. The process provides a web having an exceptionally high degree of bulk and absorbency not expected in wet-pressed products.
摘要:
A fabric dewatering apparatus for use after a fabric cleansing apparatus in a paper machine including: an endless wicking substrate disposed for rotation about a dryer roll; the endless wicking substrate and the fabric brought into surface contact as the fabric traverses at least a portion of the dryer roll's circumference; and a wicking substrate dewatering apparatus disposed along the wicking substrate's travel path after the dryer roll.
摘要:
A method of making soft, strong, high bulk tissue is disclosed. The method includes pre-conditioning a wet web by straining the wet web in the cross-machine direction prior to transferring the wet web to a throughdrying fabric. The pre-conditioned web provides improved sheet softness and conforms more readily to the surface contour of the throughdrying fabric, thereby creating greater caliper (bulk) in the resulting dried sheet. The bulk is maintained during a subsequent creping step by maintaining the dried sheet in registration with the throughdrying fabric when the dried sheet is applied to the surface of the creping cylinder.
摘要:
A tissue product having a combination of substantially equal tensile energy absorbed (TEA) in the machine direction and the cross-machine direction of the tissue sheet and a significant level of stretch in both directions provides improved perception of strength and resistance to “poke through” in use.
摘要:
Pressurized web treatment systems include a moving web that passes through a pressurized treatment chamber having a sealing assembly with a leakage control system. Leakage control is achieved by the cooperative effect of localized leak detectors and leak reduction means that applies a local sealing force on the seal assembly responsive to a signal from the leak detectors such that increased sealing occurs in the vicinity of the leak. In particular, an air press for paper web dewatering has improved efficiency by virtue of the leakage control system, which features local leak detectors and local force generation means associated with a flexible seal assembly to reduce leakage at the edges of the stationary plenum of the air press. Local leak detection can be based on sonic measurement with microphones, detection of escaping tracer gas, optical signals, and other means. Other embodiments of web treatment systems include those for continuous production of activated carbon fabrics and steam and chemical treatment of textiles and other fibrous webs.
摘要:
A tissue sheet is made using a modified wet pressing process employing an integrally sealed air press. After initial formation and conventional vacuum dewatering, the wet web may be conformed to the surface contour of a relatively coarse fabric to give the web a textured surface. By creating a pressure differential across the web, the air press noncompressively dewaters the wet web to a consistency of about 30 to about 40 percent prior to a heated drying cylinder. The web may be dried to substantially preserve its three-dimensional, throughdried-like texture. The process provides a web having an exceptionally high degree of bulk and absorbency not expected in wet-pressed products.
摘要:
An uncreped tissue sheet having improved softness results from supplementally dewatering a wet web to a consistency of greater than about 30 percent using noncompressive dewatering techniques prior to a differential speed transfer and subsequent throughdrying. An air press particularly well suited for providing the supplemental noncompressive dewatering incorporates side and/or end seals to minimize escape of pressurized fluid. A creped tissue sheet can be produced with a variety of manufacturing benefits using the air press.
摘要:
A tissue sheet is made using a modified wet pressed tissue machine employing an integrally sealed air press. The apparatus includes: a forming roll; a drying cylinder positioned downstream of the forming roll; an air press positioned between the forming roll and the drying cylinder; a molding fabric adjacent a first fabric such that both fabrics travel through the air press, and wherein the air press is installed to direct a pressurized fluid through the molding fabric first and then through the first fabric; and a pressure roll adjacent the drying cylinder for pressing the molding fabric against the drying cylinder.