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 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:
Paper sheets useful for tissues, paper towels, napkins, disposable absorbent products and the like can be made to exhibit a high degree of wet resiliency. This property is achieved by using a combination of high yield pulp fibers (such as bleached chemithermomechanical pulp fibers) and a wet strength agent in an uncreped throughdrying process. The resulting product, when wetted, can spring back after being crumpled in one's hand.
摘要:
Cellulosic webs, such as tissue webs, can be dewatered to consistencies of about 70 percent or greater in a high intensity extended nip press while retaining a substantial amount of bulk. While webs intended for use as tissues containing conventional furnishes become overly densified when passed through a high intensity extended nip press, furnishes containing certain types of fibers, such as chemically cross-linked or heat-treated fibers, resist compression and allow the compressed web to retain a high level of bulk after a high degree of dewatering.
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:
Tissue webs, such as are useful for making bath tissue, can be surface-treated in a pattern with selected papermaking chemicals, such as debonders and strength agents, to selectively improve the directional properties of the resulting tissue product, particularly the cross-machine direction strength properties. The pattern can be applied to the tissue sheet by spraying the selected chemical outwardly through a pattern of open areas in the shell of a rotating hollow roll, where the pattern of open areas corresponds to the desired pattern of chemical deposited on the surface of the tissue web.
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 method of making an environmentally-friendly tissue sheet for conversion into a single-ply roll product, such as bath tissue or paper towels, is disclosed. The method utilizes numerous process aspects that are determined to minimize energy consumption, which is about 100 grams CO2 equivalent emissions or less per 38 square feet of tissue, while at the same time producing a tissue roll product having desirable roll bulk, firmness and absorbency.
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 system and process for producing tissue webs is disclosed. The tissue webs are formed from an aqueous suspension of fibers and dried using a through-air dryer. During formation of the web, the web is transferred from a transfer fabric to a throughdrying fabric and then conveyed around a drying cylinder of a through-air dryer. In accordance with the present invention, a pressurized roll emits a gaseous stream through a pressurized zone that pushes and transfers a wet web from a transfer fabric to the throughdrying fabric. The amount of pressure used during the transfer can vary depending upon the particular application and may be used to control the bulk of the web. By using a pressurized transfer roll, the amount the throughdrying fabric is wrapped around the drying cylinder of the through-air dryer can be maximized for increasing the efficiency of the system and the process.