JP2004501676A - Common perforated system for hygiene products - Google Patents

Abstract

A system is provided for a sanitary product having a cover layer, an intake / distribution layer, and an absorbent core, wherein at least the cover layer and the intake / distribution layer are co-perforated. By combining these improvements with an integrated absorption system, variable flow management can be successfully achieved and a good balance between intake and cover removal properties. The result is improved multi-intake performance and a clean and dry cover surface during use.

Description

【００５１】
上記の表１に見られるように、不織布の界面活性剤の含有量を増加させると、吸収システムの取入れ時間が短くなる。更に、層を共通穿孔することにより、取入れ時間を更に短くする。高レベルの界面活性剤と共通穿孔された層との組合せを有することは、この効果を高める。
【００５２】
実施例５
これらの吸収材見本は、２〜３ｇｓｍの添加レベルでカバー接着剤を用いて組立てられ、米国市場で現在販売されているような「Ｓａｆｅｔｙ　Ｚｏｎｅ（登録商標）」を有する「Ｋｏｔｅｘ（登録商標）Ｕｌｔｒａｔｈｉｎ　Ｍａｘｉ」製品を形成した。
カバー層：２０．３ｇｓｍ（０．６ｏｓｙ）のＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布、３．５ｄｐｆ。局所的に塗付された０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤で処理。カバー層は、８センチメートル×２４．２センチメートルであった。
取入れ／分配層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ　Ｔ−２５５バインダー繊維。２５０ｇｓｍで、密度は０．１４グラム／立方センチメートル。この層は、１０．２センチメートル×１９センチメートルであった。
移送遅延層：２７．１ｇｓｍ（０．８ｏｓｙ）、０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤を有する２．８ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布。この層は、５センチメートル×２０．５センチメートルであった。
吸収層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ　Ｔ−２５５バインダー繊維。１７５ｇｓｍ、及び、０．１０グラム／立方センチメートル。この層は、幅６．４センチメートル×長さ２１．５センチメートルであった。
【００５３】
実施例６
これらの吸収材見本は、２〜３ｇｓｍの添加レベルでカバー接着剤を用いて組立てられ、米国市場で現在販売されているように「Ｓａｆｅｔｙ　Ｚｏｎｅ（登録商標）」を有する「Ｋｏｔｅｘ（登録商標）Ｕｌｔｒａｔｈｉｎ　Ｍａｘｉ」製品を形成した。ピン・ローラ及び別の（雌）ローラを使用するピン穿孔処理を用いて、カバー層及び取入れ／分配層のみが共通穿孔され、８穴／平方センチメートルを有する１４％の開口面積をもたらした。使用された温度は、４０フィート／分の速度で、ピン・ロール上で２８０゜Ｆ（１３８℃）、及び、雌ロール上で１７０゜Ｆ（７７℃）であった。
カバー層：２０．３ｇｓｍ（０．６ｏｓｙ）のＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布、３．５ｄｐｆ。局所的に塗付された０．５体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤で処理。カバー層は、８センチメートル×２４．２センチメートルであった。
取入れ／分配層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ Ｔ−２５５バインダー繊維。２５０ｇｓｍで、密度は０．１４グラム／立方センチメートル。この層は、１０．２センチメートル×１９センチメートルであった。
移送遅延層：２７．１ｇｓｍ（０．８ｏｓｙ）、０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤を有する２．８ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布。この層は、５センチメートル×２０．５センチメートルであった。
吸収層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ Ｔ−２５５バインダー繊維。１７５ｇｓｍ、及び、０．１０グラム／立方センチメートル。この層は、６．４センチメートル×２１．５センチメートルであった。
製品の裏打ちは、流体封じ込め装置として使用される０．６ミルのポリエチレンフィルム層であった。この層は、２０ｇｓｍのホットメルト接着剤を使用して吸収層に接着された。裏打ち層は、幅８センチメートル×長さ２４．２センチメートルであった。
【００５４】
実施例７
これらの吸収材見本は、２〜３ｇｓｍの添加レベルでカバー接着剤を用いて組立てられ、キンバリー・クラーク・コーポレーションにより米国市場で現在販売されているような「ＳＡＦＴＹ　ＺＯＮＥ（登録商標）」を有する「ＫＯＴＥＸ（登録商標）ＭＡＸＩ（登録商標）」製品を形成した。
カバー層：２０．３ｇｓｍ（０．６ｏｓｙ）のＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布、３．５ｄｐｆ。局所的に塗付された０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤で処理。カバーは、ターゲット領域で８センチメートル、及び、ローブ上で９センチメートルの幅を有し、長さが２２．０センチメートルであった。
取入れ／分配層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ　Ｔ−２５５バインダー繊維。２５０ｇｓｍで、密度は０．１４グラム／立方センチメートル。この層は、９．４センチメートル×１５．６センチメートルであった。
移送遅延層：２７．１ｇｓｍ（０．８ｏｓｙ）、０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤を有する２．８ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布。この層は、幅が４．８センチメートルで、長さが２０．０センチメートルであった。
吸収層：空気形成されたＮＢ４１６パルプフラフ。４３０ｇｓｍ、及び、０．０７グラム／立方センチメートル。幅がターゲット領域で６．０センチメートル、製品のローブ上で７．０センチメートル、長さが２０．０センチメートルである。
第２の吸収材：空気形成されたＮＢ４１６パルプフラフ。４００ｇｓｍで密度が０．０９グラム／立方センチメートル。幅４．５センチメートル及び長さ１６．０センチメートルを有する。
製品の裏打ちは、流体封じ込め装置として使用される１．１ミルのポリエチレンフィルム層であった。この層は、４０ｇｓｍのホットメルト接着剤を使用して吸収層に接着される。裏打ち層は、幅がターゲット領域で８センチメートル、ローブで９センチメートル、長さが２２．０センチメートルであった。
【００５５】
実施例８
これらの吸収材見本は、２〜３ｇｓｍの添加レベルでカバー接着剤を用いて組立てられ、キンバリー・クラーク・コーポレーションにより米国市場で現在販売されているような「ＳＡＦＴＹ　ＺＯＮＥ（登録商標）」を有する「ＫＯＴＥＸ（登録商標）ＭＡＸＩ（登録商標）」製品を形成した。
ピン・ローラ及び別の（雌）ローラを使用するピン穿孔処理を用いて、カバー層及び取入れ／分配層のみが共通穿孔され、８穴／平方センチメートルを有する１４％の開口面積をもたらした。使用された温度は、４０フィート／分の速度で、ピン・ロール上で２８０゜Ｆ（１３８℃）、及び、雌ロール上で１７０゜Ｆ（７７℃）であった。
カバー層：２０．３ｇｓｍ（０．６ｏｓｙ）のＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布、３．５ｄｐｆ。局所的に塗付された０．５体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤で処理。
取入れ／分配層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ Ｔ−２５５バインダー繊維。２５０ｇｓｍで、密度は０．１４グラム／立方センチメートル。この層は、９．４センチメートル×１５．６センチメートルであった。
移送遅延層：２７．１ｇｓｍ（０．８ｏｓｙ）、０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤を有する２．８ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布。この層は、９．４センチメートル×１５．６センチメートルであった。
吸収層：空気形成されたＮＢ４１６パルプフラフ。４３０ｇｓｍ、及び、０．０７グラム／立方センチメートル。幅がターゲット領域で６．０センチメートル、製品のローブ上で７．０センチメートル、長さが２０．０センチメートルである。
第２の吸収材：空気形成されたＮＢ４１６パルプフラフ。４００ｇｓｍで密度が０．０９グラム／立方センチメートル。幅４．５センチメートル及び長さ１６．０センチメートルを有する。
製品の裏打ちは、流体封じ込め装置として使用される１．１ミルのポリエチレンフィルム層であった。この層は、４０ｇｓｍのホットメルト接着剤を使用して吸収層に接着された。裏打ち層は、幅がターゲット領域で８センチメートル、ローブで９センチメートル、長さが２２．０センチメートルであった。
上記で示した取入れ及び再濡れ試験による上述の材料の試験結果は表２の通りである。
【００５６】
【表２】
（表２）

【００５７】
これらの結果から分かるように、材料の共通穿孔処理は、最濡れ値に影響を及ぼすことなく、１回の流体放出の吸収時間にかなりの減少を示した。本発明者の考えでは、より速い取入れ時間を与えることになるシステムを設けることにより、カバーからの流体の流出が減少し、それが、流体がライナ及び使用者の身体を通って運ばれて流体の漏れを生じる危険も低減させる。
異なる製品層を共通穿孔することは、どの層がどの程度まで流体を分配又は吸収すべきかを製品開発者が制御することを可能にする。表３は、実施例５〜８の「流体分配試験」データを提供し、各層に保持される流体の百分率比を示す。（実施例６及び８は、共通穿孔された。）
【００５８】
【表３】
（表３）

【００５９】
表３のデータから分かるように、共通穿孔されたシステムは、下層の吸収層へのより良い流体分配を可能にして流体をカバーから遠く離れて留まらせ、それによって着用者により乾いた表面を作り出し、製品の全吸収容量をより効果的に使用する。全吸収層に対する取入れ／分配層の流体量は、比で表してもよく、この場合は流体分割比である。本発明による材料に対する流体分割比は、７０／３０と２０／８０との間にあることが必要であり、より好ましくは、６０／４０と２０／８０との間である。
【００６０】
明らかに、原材料の選択と共通穿孔される層の選択とは、製品がどの位良好に機能することになるかを決める。本発明が利点を示す１つの領域は、カバーに近づくにつれて吸収材の密度が高くなるシステムに見出せる。このようなシステムは、製品に弾力性を与えて使用中に束になったり捻れたりすることを低減し、流体を優先的にＸ−Ｙ平面に分配する傾向がある。これにより、複数の流体放出のより効果的な吸収が準備される。
【００６１】
当業者は、選択された層を共通穿孔して製品の好ましい区域での素早い吸収及び流体保持を可能にすることから恩恵を受けることができる、異なる材料密度及び吸収特性を有する製品を容易に想起するであろう。穿孔の配列は、製品全体に亘って流体の移動を改善するために、異なる層に対して設計することができる。　カバーが取入れ層と共に共通穿孔された他の更なる実施例は、以下の例に見ることができる。
【００６２】
実施例９
カバー層：２０．３ｇｓｍ（０．６ｏｓｙ）のポリプロピレン・スパンボンド不織布、３．５ｄｐｆ。局所的に塗付された０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤で処理。
取入れ／分配層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ　Ｔ−２５５バインダー繊維。１７５ｇｓｍで、密度は０．１４グラム／立方センチメートル。この層は、幅１９．０センチメートル及び長さ３７センチメートルであった。
移送遅延層：２７．１ｇｓｍ（０．８ｏｓｙ）、０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤を有する２．８ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布。この層は、長さ２０．６センチメートル及び幅４．８センチメートルであった。
吸収層：空気形成されたＮＢ４１６パルプフラフ。５００ｇｓｍ、及び、０．０９グラム／立方センチメートルで、長さが２０．６センチメートル、幅が４．８センチメートルである。下層のフラフは、坪量６００ｇｓｍ、及び、密度０．０９グラム／立方センチメートルで、長さが２９．５センチメートル、幅が中央で６．５センチメートル、ローブで７．５センチメートルである。
製品の裏打ちは、流体封じ込め装置として使用される１．１ミルのポリエチレンフィルム層であった。この層は、４０ｇｓｍのホットメルト接着剤を使用して吸収層に接着される。裏打ち層は、幅がターゲット領域で８．５センチメートル、ローブで９．５センチメートル、長さが３１．５センチメートルであった。
【００６３】
実施例１０
ピン・ローラ及び別の（雌）ローラを使用するピン穿孔処理を用いて、カバー層及び取入れ／分配層のみが共通穿孔され、８穴／平方センチメートルを有する１４％の開口面積をもたらした。使用された温度は、４０フィート／分の速度で、ピン・ロール上で２８０゜Ｆ（１３８℃）、及び、雌ロール上で１７０゜Ｆ（７７℃）であった。
カバー層：２０．３ｇｓｍ（０．６ｏｓｙ）のポリプロピレン・スパンボンド不織布、３．５ｄｐｆ。局所的に塗付された０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤で処理。
取入れ／分配層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ Ｔ−２５５バインダー繊維。１７５ｇｓｍで、密度は０．１４グラム／立方センチメートル。この層は、幅１９．０センチメートル及び長さ３７センチメートルであった。
移送遅延層：２７．１ｇｓｍ（０．８ｏｓｙ）、０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤を有する２．８ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布。この層は、長さ２０．６センチメートル及び幅４．８センチメートルであった。
吸収層：空気形成されたＮＢ４１６パルプフラフ。５００ｇｓｍ、及び、０．０９グラム／立方センチメートルで、長さが２０．６センチメートル、幅が４．８センチメートルであり、下層のフラフ層は、坪量６００ｇｓｍ、及び、密度０．０９グラム／立方センチメートルで、長さが２９．５センチメートル、幅が中央で６．５センチメートル、ローブ上で７．５センチメートルである。
製品の裏打ちは、流体封じ込め装置として使用される１．１ミルのポリエチレンフィルム層であった。この層は、４０ｇｓｍのホットメルト接着剤を使用して吸収層に接着される。裏打ち層は、幅がターゲット領域で８．５センチメートル、ローブで９．５センチメートル、長さが３１．５センチメートルであった。
【００６４】
実施例１１
ピン・ローラ及び別の（雌）ローラを使用するピン穿孔処理を用いて、カバー層及び取入れ／分配層のみが共通穿孔され、８穴／平方センチメートルを有する１４％の開口面積をもたらした。使用された温度は、４０フィート／分の速度で、ピン・ロール上で２８０゜Ｆ（１３８℃）、及び、雌ロール上で１７０゜Ｆ（７７℃）であった。
カバー層：２０．３ｇｓｍ（０．６ｏｓｙ）のＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布、３．５ｄｐｆ。局所的に塗付された０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤で処理。
サージ層：２３．７ｇｓｍ（０．７ｏｓｙ）で、ＨＲ６仕上げを有する６ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布ポリプロピレン繊維ウェブ。仕上げを有する繊維は、チッソ・コーポレーションから入手できる。この層は、幅１９．０センチメートル及び長さ３７センチメートルで、厚さが１．３ミリメートルであった。
取入れ／分配層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ Ｔ−２５５バインダー繊維。１７５ｇｓｍで、密度は０．１４グラム／立方センチメートル。この層は、幅１９．０センチメートル及び長さ３７センチメートルであった。
移送遅延層：２７．１ｇｓｍ（０．８ｏｓｙ）、０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤を有する２．８ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布。この層は、長さ２０．６センチメートル及び幅４．８センチメートルであった。
吸収層：空気形成されたＮＢ４１６パルプフラフ。５００ｇｓｍ、及び、０．０９グラム／立方センチメートルで、長さが２０．６センチメートル、幅が４．８センチメートルであり、下層のフラフ層は、坪量６００ｇｓｍ、及び、０．０９グラム／立方センチメートルで、長さが２９．５センチメートル、幅が中央で６．５センチメートル、ローブ上で７．５センチメートルである。
製品の裏打ちは、流体封じ込め装置として使用される１．１ミルのポリエチレンフィルム層であった。この層は、４０ｇｓｍのホットメルト接着剤を使用して吸収層に接着される。裏打ち層は、幅がターゲット領域で８．５センチメートル、ローブで９．５センチメートル、長さが３１．５センチメートルであった。
【００６５】
実施例１２
取入れ／分配層及び移送遅延層は、ピン・ローラ及び別の（雌）ローラを使用するピン穿孔処理を用いて共通穿孔され、８穴／平方センチメートルを有する１４％の開口面積をもたらす。使用された温度は、５０フィート／分の速度で、ピン・ロール上で２８０゜Ｆ（１３８℃）及び雌ロール上で１７０゜Ｆ（７７℃）であった。
カバー層：１７％の開口面積、１００穴／平方センチメートル、及び、１９ｇｓｍを有する真空穿孔されたポリエチレンフィルム。
取入れ／分配層：９０重量％のＮＢ４１６パルプ、及び、１０重量％のＫｏＳａ Ｔ−２５５バインダー繊維。１７５ｇｓｍで、密度は０．１４グラム／立方センチメートル。この層は、幅１９．０センチメートル及び長さ３７センチメートルであった。
移送遅延層：２７．１ｇｓｍ（０．８ｏｓｙ）、０．３体積％のＡＨＣＯＶＥＬ（登録商標）界面活性剤を有する２．８ｄｐｆのＥＳＣＯＲＥＮＥ（登録商標）ＰＤ−３４４５ポリプロピレン・スパンボンド不織布。この層は、長さ２０．６センチメートル及び幅４．８センチメートルであった。
吸収層：空気形成されたＮＢ４１６パルプフラフ。５００ｇｓｍ、及び、０．０９グラム／立方センチメートルで、長さが２０．６センチメートル、幅が４．８センチメートルであり、下層のフラフ層は、坪量６００ｇｓｍ、及び、密度０．０９グラム／立方センチメートルで、長さが２９．５センチメートル、幅がターゲット領域で６．５センチメートル、ローブ上で７．５センチメートルである。
製品の裏打ちは、流体封じ込め装置として使用される１．１ミルのポリエチレンフィルム層であった。この層は、４０ｇｓｍのホットメルト接着剤を使用して吸収層に接着される。裏打ち層は、幅がターゲット領域で８．５センチメートル、ローブで９．５センチメートル、長さが３１．５センチメートルであった。
上記の実施例は、上述の３回取入れ及び再濡れ試験に従って試験を受け、その結果が表４に示されている。
【００６６】
【表４】
（表４）

【００６７】
これらの実施例から分かるように、複数の流体放出の状況においては、種々の吸収層と共にカバーを共通穿孔することは、材料の取入れ時間を低減するのに有利であることが示された。例えば、実施例１０では、システムの取入れ時間を更に少なくするために、利用可能な開口面積及び処理の更なる最適化を行うことができるであろう。同じくこのデータから分かることは、カバーの空隙容積が大きい材料ほど一般に複数の流体放出に対する取入れ時間が速く、穿孔されていない吸収システムと比較してかなりの減少を示すことである。
当業者が理解するように、本発明に対する変更及び修正は当業者の能力の範囲内で行われると考えられる。本発明者は、そのような変更及び修正が本発明の範囲に包含されることを意図している。
【図面の簡単な説明】
【図１】流量容積をグラム／時間（ｇ／ｈｒ）でｙ軸上に示し、時間を時間（ｈｒ）でｘ軸上に示した、単一の製品の耐用期間に亘る変動流（菱形）及び連続流（正方形）のグラフである。
【図２】直径２．０６ミリメートルのピンを使用した、７．４孔／平方センチメートルのピン穿孔パターンを示す図である。
【図３】図２と同じピン直径を用いた、２．５孔／平方センチメートルのピン穿孔パターンを示す図である。
【図４】材料又は材料システムの流体取入れ時間を測定するのに使用する適切なレートブロック装置の概略図である。
【図５】カバー及び取入れ／分配層に亘って孔を有する吸収システムの概略図である。
【図６】カバーと取入れ／分配層との間に追加の材料層が組み込まれた、図５と類似の共通穿孔された吸収システムの概略図である。
【図７】本発明の実施において使用し得る区画化された共通穿孔パターンの実施例を示す図である。
【図８】本発明の実施において使用し得る区画化された共通穿孔パターンの実施例を示す図である。
【図９】本発明の実施において使用し得る区画化された共通穿孔パターンの実施例を示す図である。
【図１０】本発明の実施において使用し得る区画化された共通穿孔パターンの実施例を示す図である。
【図１１】本発明の実施において使用し得る区画化された共通穿孔パターンの実施例を示す図である。
【図１２】本発明の実施において使用し得る区画化された共通穿孔パターンの実施例を示す図である。
【図１３】本発明の実施において使用し得る区画化された共通穿孔パターンの実施例を示す図である。[0001]
(Technical field)
The present invention is a system for an absorbent sanitary personal care article, especially a feminine hygiene product. Such products need to quickly receive the viscous fluid and retain it so that the viscous fluid does not spread outside the product, which can soil the wearer's clothing.
[0002]
(Background technology)
Personal care articles include items having diapers, training pants, feminine hygiene products such as sanitary napkins, panty liners, and tampons, incontinence clothing and equipment, bandages, and the like. Including. The most basic design of all such articles usually includes a bodyside liner (cover material), an outer cover (also called a baffle), and an absorbent core disposed between the bodyside liner and the outer cover. Is included.
[0003]
Personal care products must quickly receive and retain fluid to reduce the likelihood of fluid leaking out of the product. The product must be flexible and feel comfortable on the skin and, even after the release of the liquid, may become bunched, twisted, or wrapped around the user and remain liquid to the wearer. The release must not be unpleasant. Unfortunately, conventional products have met many of these criteria to varying degrees, while many did not.
[0004]
In particular, feminine hygiene products for long-term (ie, overnight) use experience more and more variable flow rates and fluid loads than products intended for normal or short-term use. Thus, a product for overnight use must have the ability to absorb and contain large bursts and sudden large flows as well as small continuous flows throughout the life of the product. The continuous flow fluid discharge in feminine hygiene products averages 1 milliliter / hour, but may be higher and is not literally continuous or constant, but rather varies in flow rate and pauses between cycles. It has been found that even it can happen. "Ejection flow" is defined as a sudden, high flow state, occurring at a flow rate of up to 1 milliliter / second. During the squirt, 1-5 milliliters of fluid is released from the body onto the product. The term "continuous flow" is used to define any flow that does not fall into the definition of effluent.
[0005]
Combining the conditions of continuous flow and jet flow results in a fluctuating flow. In essence, a "fluctuating flow" is defined as a continuous flow having an intermittent burst flow occurrence. FIG. 1 is a graph showing the difference between a fluctuating flow (diamond) and a continuous flow (square) over the life of one product, where flow is in grams / hour on the y-axis and time is time on the x-axis. Indicated by This problem of dealing with jets and continuous streams is called variable flow management and involves multiple jets or sudden large fluid discharges (1-2 milliliters / hour) as well as continuous small streams (1-2 ml / hr) throughout the life of the product. (1 ml / sec for a total volume of 1-5 ml).
[0006]
The ultimate challenge for the product is that it can handle the squirt (sudden flow) even after the product has undergone a fluid discharge and the absorption system has been partially or completely saturated.
Many of the feminine care cover materials have low z-direction conductivity, low surface energy, and low void volume, and provide little separation between the absorbent core and the user due to their two-dimensional structure. Do not form. As a result, these covers result in slow and incomplete uptake, high rewet, and large surface contamination. In addition, conventional uptake or acquisition layers are low density, high void volume structures that are ideal for fast fluid uptake, but these structures generally have low capillary attraction and generally have a high fiber Due to the nature of the quality, fluids do not desorb properly from the cover material, resulting in dirt and surface wetting. Materials that increase desorption from the cover are typically dense, high-capillary materials, but these materials have inherently low fluid volume and low z-permeability, thereby essentially introducing fluid uptake. Delay.
[0007]
There remains a need for a system that accepts fluid at a suitable rate, designed to encourage quick uptake and keep it clean and dry. There also remains a need for a system that further absorbs fluid into a particular absorbent layer.
It is therefore an object of the present invention to provide such a system. It is a further object of the present invention to provide a design of a feminine hygiene product incorporating such a system, especially for moderate to high fluid loads.
[0008]
(Disclosure of the Invention)
The object of the invention is achieved by a system having a cover layer, an intake / distribution layer and an absorbent core, wherein at least the cover layer and the intake / distribution layer are co-perforated. Other layers, including surge layers and transport delay layers, may also be present. The cover may be a film or nonwoven made from a thermoplastic polymer. The uptake / distribution layer is preferably a nonwoven, more preferably made by an air deposition process. The surge layer and the transport delay layer are generally nonwoven fabrics that vary in wettability, pore size, permeability, and fiber denier. The absorbent core may be made from pulp, superabsorbent, or various other absorbent materials. The system of the present invention improves the absorption of multiple fluid emissions, allows for the storage of fluid in specific layers, and provides a clean, dry cover surface during use. These functional properties are provided through improved material technology and product construction.
[0009]
(Best Mode for Carrying Out the Invention)
Definition
As used herein, the term "nonwoven or nonwoven web" means a matrix of individual fibers or threads interposed without resorting to an identifiable method such as a knitted fabric. Nonwovens or webs have been formed by a number of processes, such as, for example, meltblowing, spunbonding, and bonded carded web processes. The basis weight of a nonwoven is usually expressed in ounces per square yard (osy) of the material, or grams per square meter (gsm), and useful fiber diameters are usually expressed in microns. (Note that to convert osy to gsm, multiply osy by 33.91.)
[0010]
By "spunbond fibers" is meant small diameter fibers formed by extruding molten thermoplastic material as filaments from a plurality of fine capillaries of a spinneret. Such a method is disclosed, for example, in US Pat. No. 4,340,563 to Appel et al. The fibers may also have a shape as described, for example, in US Pat. No. 5,277,976 to Hogle et al., Which describes fibers having a non-conventional shape. .
"Bonded carded web" means a web made from staple length fibers sent through a combing or carding device, which separates or breaks the staple length fibers and aligns them in the machine direction. Forming a fibrous nonwoven web oriented substantially in the machine direction. Such materials will be joined together in a manner that includes point bonding, through-air bonding, and the like.
[0011]
"Air deposition" is a well-known process that can form a fibrous nonwoven layer. In an air deposition process, bundles of fibrils having a typical length in the range of about 3 to about 19 millimeters (mm) are separated and entrained in the supply air, and then usually with the aid of a supplied vacuum. Deposited on the forming screen. The randomly deposited fibers are then bonded together using, for example, hot air or a spray adhesive. Air deposition methods are taught, for example, in US Pat. No. 4,640,810 to Laursen et al.
[0012]
As used herein, the term "coform" refers to a process in which at least one meltblown die head is positioned near a chute that adds other materials to the web while the web is being formed. means. Such other materials may be, for example, pulp, superabsorbent or other particles, natural polymers (eg, rayon or cotton fibers), and / or synthetic polymer (eg, polypropylene or polyester) fibers, The fibers can be staple length. Coform processing is shown in commonly assigned U.S. Patent Nos. 4,818,464 to Lau and 4,100,324 to Anderson et al. The web produced by the coform process is commonly referred to as a coform material.
[0013]
"Common perforation" refers to the perforated material and the process of perforating, where two or more materials are perforated together. These holes extend from the top to the bottom of the material and are substantially aligned with one another. Common perforation methods can join materials either temporarily or permanently by confounding, physical bonding, or chemical bonding. Common perforation of the layers may be performed at ambient or elevated temperatures. High temperatures help bond the material and create smoother holes. One step of the common perforation process is to push the pins through the layers by feeding the various layers together through a nip formed by two counter-rotating rollers having pins that create holes on one side. It is a process. These holes have dimensions of, for example, 0.5 millimeters to 5 millimeters using a pin density of 1 to 15 holes per square centimeter, an area of less than 19.6 square millimeters, and about 2 to about 25%. It will result in a hole with a wide open area. Common drilling may be performed as a separate "off-line" operation or as part of a larger conversion operation (in-line), depending on the economics of the process and the availability of equipment. Examples of some common perforation patterns for feminine hygiene pads can be seen in FIGS.
[0014]
"Transport delay layer" refers to a material that slows fluid transfer between other adjacent layers, but does not itself retain a sufficient amount of fluid.
"Personal care product" means diapers, training pants, disposable swimwear, absorbent pants, adult incontinence products, feminine hygiene products, wound care products such as bandages, and other articles.
"Women's hygiene products" means sanitary napkins or pads and panty liners.
"Target area" means the area of a personal care product where the wearer normally emits a fluid release while the product is being worn.
[0015]
Test method
Material caliper ( thickness): Caliper of material is a measure of thickness, measured in millimeters using a STARRET® type bulk tester under 0.05 pounds per square inch (3.5 grams per square centimeter). The samples were cut into 4 inch x 4 inch (10.2 cm x 10.2 cm) squares, 5 samples were tested, and the results averaged.
[0016]
density: The density of the material is the weight per unit area of the sample, expressed in grams per square meter (gsm), with the material caliper in millimeters (mm) at 0.05 pounds per square inch (3.5 grams per square centimeter). Divide and convert the result to 0.001 to convert to a value in grams / cubic centimeter (g / cc). A total of three samples will be evaluated and averaged to determine a density value.
[0017]
Preparation of imitation menstrual secretions
The artificial menstrual fluid used in the test separates blood into plasma and red blood cells according to US Pat. No. 5,883,231 and has a “rich” of 150 seconds.^-1Separate the egg white into rich and lean portions, meaning that the fluid has a viscosity greater than about 20 centipoise after homogenization, and mix the rich egg white with the plasma thoroughly, and finally red blood cells. Was made from blood and egg white by adding again and mixing well. The more detailed procedure is as follows.
[0018]
In this example, the blood, which is pig blood without fibrin, is separated by centrifugation at 3000 rpm for 30 minutes, but other methods, speeds and times may be used if effective. it can. The plasma is separated and stored separately, the buffy coat is removed and discarded, and the compressed red blood cells are stored separately as well. Note that blood must be handled in some way so that it can be processed without clotting. Various methods are known to those skilled in the art, such as removing fibrin from blood to remove coagulating fibrous material, adding anticoagulant drugs, and others. Blood needs to not coagulate to be useful, and any method of achieving this without damaging plasma and red blood cells is acceptable.
[0019]
The oversized chicken eggs are sorted out, the yolk and egg band are discarded and the egg whites are retained. The egg white is separated into thick and lean portions by straining through a 1000 micron nylon mesh for about 3 minutes, and the thinner portions are discarded. The thick portion of egg white retained on the net is collected and aspirated into a 60 cubic centimeter syringe, and then the syringe is placed on a programmable syringe pump to release and replenish the contents five times. To homogenize the egg white. The amount of homogenization is controlled by a syringe pump flow rate of about 100 milliliters / minute and a tube inner diameter of about 0.12 inches. After homogenization, the thick egg white is 150 seconds^-1Has a viscosity of about 20 centipoise at, and is then placed in a centrifuge and spun at about 3000 rpm for about 10 minutes to remove debris and air bubbles.
[0020]
After centrifugation, the homogenized thick egg white containing ovomucin is added to a 300 cubic centimeter "FENWAL® Transfer" pack container using a syringe. Next, 60 cubic centimeters of porcine plasma is added to the “FENWAL® Transfer” pack container. This “FENWAL® Transfer” pack container is clamped, all air bubbles are removed, and the stomacher experiment is performed at normal (or medium) speed for about 2 minutes to mix the pack container. Put on the mixer. Thereafter, the “FENWAL® Transfer” pack container is removed from the mixer and 60 cubic centimeters of swine red blood cells are added and the contents are hand kneaded for about 2 minutes or until the contents appear uniform. Mixed. The hematocrit of the final mixture should show a red blood cell content of about 30% by weight, and should generally be in the range of at least 28-32% by weight for artificial menstruation made according to this example. The amount of egg white is about 40% by weight.
[0021]
The materials and equipment used to prepare the artificial menstruation are readily available. A list of manufacturers of the items used is as follows, but of course other manufacturers may be used as long as they are roughly equivalent.
Blood (pig): Cocalico Biologicals, Inc., 449 Stevens Road, Leamstown, Pennsylvania, USA, (tel) (717) 336-1990.
"FENWAL® Transfer" pack container, 300 ml, with coupler, code 4R2014: Fenwal Division, Baxter Healthcare Corporation, Deerfield, 60015, Illinois, USA.
Harvard Apparatus Programmable Syringe Pump, Model 55-4143, Harvard Apparatus, South Natick, 01760, Mass., USA.
"Stomacer 400" laboratory mixer, model number BA7021, serial number 31968: Seward Medical, London, England, UK.
1000 micron network, Item No. CMN-1000-B: Small Parts, Inc., Miami Lakes, 33014-0650, PO, PO Box 4650, (Tel) 1-800-220-4242.
"Hemata Stat-II" instrument for hemocrit measurement, serial number 1194Z03127: Separation Technology Inc., 1096 Reiner Drive, Altamont Springs, Florida 32714, USA.
[0022]
Rate block adoption test
This test is used to determine the uptake time of a known amount of fluid into a material and / or material system. The test apparatus comprises a transparent and preferably acrylic rate block 10 as shown in FIG. The rate block 10 is 3 inches (76.2 millimeters) wide, 2.87 inches (72.9 millimeters) deep (into the page), and has a total of 1.125 inches (28.6 millimeters). But has a height that protrudes far from the body of the rate block 10 and has a height of 0.125 inches (3.2 millimeters) and a width of 0.886 inches (22.5 millimeters). A central area 19 on the bottom of the block 10 is included. The rate block 10 has a 0.186 inch (4.7 mm) inside diameter capillary 12 extending diagonally downward from one side 15 to a centerline 16 at an angle of 21.8 degrees from the horizontal. Capillary tube 12 may also be made by drilling the right size hole at the right angle from side 15 of rate block 10, starting at a point 0.726 inches (18.4 millimeters) above the bottom of rate block 10. Good, but with the condition that the starting point of the drill hole on the side 15 must subsequently be plugged, so that the test fluid does not escape therefrom. The upper hole 17 has a diameter of 0.312 inches (7.9 millimeters) and a depth of 0.625 inches (15.9 millimeters) so that it intersects the capillary 12. Top hole 17 is perpendicular to the top of rate block 10 and is centered 0.28 inches (7.1 millimeters) from side surface 15. The upper hole 17 is an opening in which the funnel 11 is located. The central hole 18 is for observing the progress of the test fluid and is actually oval towards the plane of FIG. The central hole 18 is centrally located in the width direction of the rate block 10 and has a bottom hole width of 0.315 inches (8 millimeters) and a length of 1.50 inches (38.1 millimeters), which length is , The center-to-center length of a 0.315 inch (8 millimeter) diameter semicircle that forms the end of this ellipse. For ease of observation, the dimensions of the oval are 0.395 inches (10 mm) wide and 1.930 inches (49 mm) long 0.44 inches (11.2 mm) above the bottom of the rate block 10. Mm). The top hole 17 and the center hole 18 can also be made by drilling.
[0023]
A 10.2 cm x 10.2 cm (4 inch x 4 inch) piece of absorbent 14 and cover 13 is cut out in a die. Certain embodiments describe certain covers. The absorbent used in these tests was standard and, unless otherwise noted, 90 grams of 250 grams / gram made of CR-0054 (US Alliance Pulp Mills, Coosa, Alabama, USA). It consisted of square meters of air-laid material and 10% KoSa @ T-255 binder. The overall density of this system was 0.14 grams / cubic centimeter. The cover 13 was placed over the absorbent material 14, and the rate block 10 was placed over the two materials. Two milliliters of the imitation menstrual secretion was dispensed into the funnel 11 of the test device and the timer was started. Fluid moves from funnel 11 into conduit 12 where it is supplied to the material or material system. The timer was stopped when all fluid had been absorbed into the material or material system, as observed from the chamber of the test apparatus. The uptake time for a known quantity of a known fluid was recorded for a given material or material system. This value is a measure of the absorbency of the material or material system. Typically 5 to 10 repetitions were performed to determine the average uptake time.
[0024]
Rewetting test
This test is used to measure the amount of fluid that will return to the surface when a load is applied. The amount of fluid that returns through this surface is called the "rewetting" value. The more fluid that returns to the surface, the greater the "rewetting" value. Lower rewet values are associated with a drier material and therefore a drier product.
When considering rewet, the following three characteristics are important. That is, (1) the uptake rate, (2) the ability of the absorbent to retain the fluid (the absorbent retains the fluid, because the fluid may re-wet if the uptake rate of the material / system is poor) The greater the volume, the less that can be used for rewetting) and (3) the backflow, since the less the cover blocks more fluid returning through the cover, the less rewetting.
The cover system was evaluated when the absorbent was kept constant and the amount of variation (2) was excluded from consideration. As a result, only the fluctuation amounts (1) and (3), which are the intake and the backflow, respectively, remain to be considered.
[0025]
A 10.2 cm x 10.2 cm (4 inch x 4 inch) piece of absorbent and cover was die cut. The absorbent used in these tests was standard and was composed of 90% CR-0054 (US Alliance Pulp Mills, Coosa, Ala., USA) and 10% KoSa @ T-255 binder. Consisting of a 250 gsm air-laid material made. The overall density of this system is 0.14 grams / cubic centimeter unless otherwise specified. A cover was placed over the absorbent and a rate block was placed over the two materials. Two milliliters of the imitational menstrual secretion was fed to a rate block device and absorbed into a 4 inch x 4 inch sample of cover material placed on a 4 inch x 4 inch piece of absorbent material. The fluid was allowed to interact with the system for one minute with the rate block over the material. The cover and the absorbent of the material system are placed on a bag filled with fluid. One blotter is weighed and placed on the material system. The bag is moved vertically until it contacts the acrylic plate above it, thus pressing the entire material system against the blotter paper side first. The system was pressed against an acrylic plate until a total pressure of 1 psi was applied. The pressure is held constant for 3 minutes, after which the pressure is released and the blotter is weighed. The blotter holds any fluid transferred from the cover / absorbent system to the blotter. The difference in weight between the original blotter and the blotter after the experiment is known as the "rewet" value. Usually 5 to 10 repetitions of this test are performed to determine the average rewet.
[0026]
Procedure for 3 times import test
The purpose of this test is to determine the difference in uptake between materials and / or composites or between composite systems when three sudden fluid bleeds (spouts) are applied, to determine the fluids between each fluid bleed. And the time it takes to distribute the material. The material to be tested is made in a manner similar to the "rate block incorporation" test described above. Two milliliters of the imitational menstrual secretion is supplied to the material through the rate block. After 9 minutes the rate block is removed, each layer weighed and its weight recorded. This step is repeated for a total of three fluid discharges, after which the rewet test described above is performed and its value recorded. The fluid load on each component is calculated as the post-fluid weight minus the pre-fluid weight. Fluid release time is a direct measurement of the time required for absorption. A smaller value of the uptake time means a sample with higher absorbency, and a larger value of the uptake time means a sample with lower absorbency. For each material, three samples need to be evaluated.
[0027]
Fluid distribution test
This test is aimed at measuring the fluid distribution of the various layers that make up a personal care product, especially a feminine hygiene product. Each layer of material of the sample to be tested must be weighed and its weight recorded before testing. The material to be tested is laid flat and an hourglass shaped plate is laid on the material. The plate is preferably acrylic and is 21.5 centimeters long, 8.7 centimeters wide, weighs 230 grams, and has a 3 millimeter wide hole in its center. The plate is loaded with an additional 800 grams of weight distributed as evenly as possible over its surface. With the sample ready for testing, 7 milliliters of the simulated menstrual discharge is delivered to the sample through the hole at a uniform rate over one hour. One method of providing a simulated menstrual secretion to a sample uses a "Harvard Appalatus Model 55-4143" pump and plastic tubing, but equivalent methods known to those skilled in the art may be used. After 1 hour, the board is removed and the layers weighed. The difference in weight between the dried and wet layers is the amount of imitation menstrual secretion absorbed in each layer. The percentage ratio of fluid retained in each layer may then be calculated. For each material, three samples need to be evaluated.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Overall, the present invention is a composite perforated cover and intake / distribution layer for use in feminine hygiene pads. These layers are a cover, an intake / distribution layer, an optional surge layer, an optional transport delay layer, and an absorbent core. The fabric used in the practice of the present invention may be made by a variety of processes, including air deposition, spunbonding, meltblowing, carding, coform, and foam molding processes. An air deposition method is preferable for the distribution layer, and a spun bond method is preferable for the transfer delay layer. These different layers may be made from synthetic polymers and natural fibers. Due to cost considerations, polyolefins such as polyethylene and polypropylene are particularly preferred.
[0029]
FIG. 5 shows an embodiment of the present invention. In FIG. 5, the outer cover 5 is the outermost part of the product. The absorbent core 4 is placed near the outer cover 5. Adjacent to the absorbent core 4 is an optional transport delay layer 3. The cover 1 and the intake / distribution layer 2 are co-perforated as indicated by the cone 6.
FIG. 6 shows another embodiment of the invention, similar to FIG. 5, in which another layer 7 is inserted between the cover 1 and the intake / distribution layer 2. The additional layer 7 may for example be a surge layer.
[0030]
It is important that the cover quickly absorb the fluid discharge into the product and have a soft surface. Some materials provide such uptake properties. These include films, nonwovens and film / nonwoven laminates, nonwoven / nonwoven laminates, composite fiber spunbond fabrics, creped spunbond fabrics, air-laid fabrics, bonded carded webs, spunlace fabrics, and embossing Nonwoven fabrics and the like are included. Some cover materials, which may be initially inadequate, may be made acceptable through the use of local chemical treatments and machining. Any material that, when combined with the absorbent core, allows for rapid uptake, low fouling, low re-wetting, and low fluid retention under all flow conditions is suitable for use in the practice of the present invention. There will be. Such materials could also include various additives that improve softness or that benefit skin health.
[0031]
The uptake / distribution layer is made of a variety of fibers and fibers, including synthetic and natural fibers, including mechanically and chemically softened pulp, staple filaments, slivers, meltblown and spunbond fibers, and superabsorbents. Can be made from a mixture. The fibers in such webs can be made from fibers of the same or different diameters and may be of different shapes, such as pentalobe, trefoil, oval, and circular. The uptake / distribution layer may be made in a number of ways, including air deposition, hydraulic entanglement, bond carding, and coform methods, with air deposition being preferred. The uptake / distribution layer will have a density of about 0.06 to 0.19 grams / cubic centimeter and a basis weight of about 100 to 300 gsm.
[0032]
The optional surge layer serves to absorb large and sudden liquid flows. Surge control materials are designed to quickly accept incoming fluid discharges and either absorb, hold, carry, or otherwise manage the liquid so that the liquid does not leak outside the article. Brought. Surge control is typically provided by fluff pulp in absorbent products or a highly permeable nonwoven layer such as spunbonded or bonded carded webs.
[0033]
The optional transport delay layer can also be made from various fibers of various shapes and sizes and may alternatively be a film. The transport delay layer may be made according to a number of methods, such as spunbonding, carding, meltblowing, and film forming, with spunbonding being preferred. The purpose of the transport delay layers is to slow the passage of fluid from the intake / distribution layers to the absorbent layers, these layers being adjacent on either side of the transport delay layers.
[0034]
The material of the absorbent core or retaining layer can be made from materials or substances known in the art that absorb liquids, and any other that may be created for this purpose. Examples include fast and slow superabsorbents, pulp, and mixtures thereof. The mixture of superabsorbent and pulp used as a retention material may be used in a weight ratio of about 100/0 to 0/100, and more specifically, between about 80/20 and 20/80. Absorbent cores suitable for use in the present invention typically have a density of about 0.05 to 0.20 grams / cubic centimeter and a basis weight of 150 to 500 gsm. The absorbent core may be composed of more than one layer. The absorbent core also usually has some sort of binder that holds the components together. Typical binders include bicomponent fibers, heat-activatable adhesive powders, and liquid binders.
[0035]
Synthetic fibers include those made from polyamide, polyester, rayon, acrylic, superabsorbent, and LYOCELL® regenerated cellulose, and any other suitable synthetic fibers known to those skilled in the art. Synthetic fibers may also include kosmotropes for product degradation.
Many of the polyolefins are available for fiber production, for example, polyethylene such as ASPN® 6811A linear low density polyethylene, 2553 LLDPE, and 25355 and 12350 high density polyethylene from Dow Chemical. Such a suitable polymer. These polyethylenes have melt flow indices of about 26, 40, 25, and 12, respectively. Fiber-forming polypropylenes include ESCORENE® PD3445 polypropylene from Exxon Chemical Company and PF-304 from Montell Chemical Company. Many other polyolefins are also commercially available.
[0036]
Natural fibers include wool, cotton, flax, hemp, and wood pulp. Wood pulp includes standard softwood fluff grades such as CR-1654 (US Alliance Pulp Mills, Coosa, Alabama, USA). Pulp may be modified to enhance the intrinsic properties and processability of the fiber. The crimp will be imparted to the fiber by methods involving chemical treatment or mechanical twisting. Crimp is generally applied before crosslinking or hardening. The pulp may be a formaldehyde or a derivative thereof, a glutaraldehyde, epichlorohydrin, a methylolated compound such as a derivative of urea or urea, a dialdehyde such as maleic anhydride, a non-methylolated urea derivative, citric acid, or other Hardening may be achieved by the use of a crosslinking agent such as polycarboxylic acid. Some of these drugs are less preferred than others due to environmental and health concerns. Pulp may also be stiffened by the use of heat or a caustic treatment such as mercerizing. An example of this type of fiber includes NHB 416, a chemically crosslinked southern softwood pulp fiber available from Weyerhauser Corporation, Tacoma, Washington, USA, which increases the wetting coefficient. Other useful pulps are debonded pulp (NF405) and non-debonded pulp (NB416), also available from Weyerhauser. HPZ3, available from Buckeye Technologies, Inc. of Memphis, Tennessee, United States, imparts additional dry and wet stiffness and elasticity to the fiber, as well as a chemical treatment that causes crimping and twisting. I have. Another suitable pulp is "Backeye HP2" pulp, and yet another pulp is "IP Super Soft" obtained from International Paper Corporation. A preferred rayon fiber is 1.5 denier "Merge 18453" fiber obtained from Accordis Cellulose Fibers, Inc., Axis, Alabama.
[0037]
Superabsorbents useful in the present invention can be selected from a class based on chemical structure as well as physical form. These include superabsorbents having low or high gel strength, surface crosslinked superabsorbents, uniform crosslinked superabsorbents, or superabsorbents having various crosslink densities throughout the structure. Superabsorbents can be based on chemistries including, but not limited to, acrylic acid, isobutylene / maleic anhydride, polyethylene oxide, carboxymethylcellulose, polyvinylpyrrolidone, and polyvinyl alcohol. Superabsorbents will range from slow to rapid. The superabsorbent may take the form of foam and macro- or micro-porous particles or fibers, and may have a fluffy or fibrous coating or form. The superabsorbent may be in the form of a ribbon, particle, fiber, sheet, or film. Superabsorbents will have sizes with different lengths and diameters, and different distributions. The superabsorbent may have various degrees of neutralization. Neutralization occurs through the use of counter ions such as Li, Na, K, and Ca.
[0038]
The material of the present invention will include a superabsorbent of the type described above. An example of these types of superabsorbents is available from the Stockhausen Company (Greensboro, NC, USA), referred to as FAVOR (R) 880. Examples of this type of superabsorbent obtained from Camelot Technologies Limited (Alberta, Canada) are designated FIBERDRI® 1241 and FIBERDRI® 1161. Examples of this type of superabsorbent obtained from Technical Absorbs Limited (Grimsby, UK) are referred to as OASIS® 101 and OASIS® 111. Another example of these types of superabsorbents is obtained from Chemdor International (Arlington Heights, Ill., USA) and is referred to as FLOSROB® 60LADY®. Yet another example included in these types of superabsorbents is obtained from Sumitomo Seika of Japan and is referred to as SA60N Type 2.
[0039]
Binders commonly used in these structures help provide mechanical integrity and stabilization. The binder includes fibers, liquids, or other bonding means that can be thermally activated. Preferred fibers include fibers having a relative melting point, such as polyolefin fibers. The low melting polymer, upon application of heat, provides the ability to bond fabrics together at the points where fibers intersect. Furthermore, fibers having a low melting point polymer, such as bicomponent fibers and bicomponent fibers, are suitable for practicing the present invention. Fibers having a low melting polymer are commonly referred to as "soluble fibers." By "low melting polymer" is meant a polymer having a glass transition temperature of less than about 175 ° C. It should be noted that the fabric of the absorbent web can vary from soft to stiff through the selection of the glass transition temperature of the polymer. Exemplary bonding fibers include polyolefin, polyamide, and polyester composite fibers. Three preferred binding fibers are sheath-core bicomponent fibers available from KoSa, Inc. (Charlotte, NC) under the designations T-255 and T-256, or "copolyesters". However, many suitable bonding fibers are known to those skilled in the art and are available from many manufacturers, such as Chisso and Fibervisions LLC of Wilmington, Del., USA. Kosa has developed a suitable copolyester binding fiber for sheath-core applications and is known by the name T254 (low melting point CoPET). A suitable liquid binder is KYMENE® 557LX available from Fibervisions LLC. Other suitable liquid binders are available from the National Starch and Chemical Company (Bridgewater, NJ, USA) in the Dur-O-Set® ELITE® series (ELITE® 33 and ELITE® (Registered trademark) 22) under the trade name of Ethylene Vinyl Acetate Emulsion Polymer. Air Products Polymers and Chemicals markets another suitable binding fiber under the name AIRRFLEX®.
As manufactured, the web must be properly stabilized and solidified to retain its shape. Inclusion of a sufficient amount of soluble fiber and subsequent thermal bonding is a preferred method to obtain adequate stabilization. This method is believed to allow for proper bonding on the center and surface of thick materials.
[0040]
As described above, at least the cover and the intake / distribution layer of the system are co-perforated, thus creating a structure that allows for rapid uptake of fluid and absorption of fluid at the intended absorbent layer. The other layers may optionally be co-perforated with each other, co-perforated with the cover and the intake / distribution layer, or not perforated at all. By co-perforating the cover with the absorption system, the permeability of the material is increased, thereby reducing the fluid uptake. Creating holes through all layers also creates the necessary passages for the fluid so that the fluid is absorbed into the preferred layer under conditions of high or ejecting flow. This results in a balance of fluid absorption in the XY and Z directions, where the Y direction is toward the back of the product and the Z direction is perpendicular to the Y direction and into the product. , X direction is a direction perpendicular to both the Y and Z directions. Simultaneous co-perforation of the layers also provides a higher degree of structural integrity to the system.
[0041]
The various layer shapes are not considered important for the success of the present invention. However, the air-deposited intake / distribution layer and the absorbent core layer or retaining layer have reduced dimensions that prevent fluid from being pumped to the pad edges when used, for example, in feminine hygiene products. It should be noted that a rectangular strip shape may be employed. The shape of the retaining layer may be the same or different from the shape of the other layers, and may have a rectangular, hourglass, oval, or other shape. In addition, embossing may be applied to the retaining layer and / or other layers to enhance the integrity of the layer. The common perforation process may be performed only at the center of the product to enhance the functionality of the product in the target area and to give the user a visual cue about the remaining life of the product. Alternatively, the product could be co-pierced throughout its dimensions or in other localized areas.
[0042]
The cover may be treated with a surfactant to improve its wettability. The surfactant can be placed in specific areas or compartments throughout the pad, or mixed internally into the fibers. For this last embodiment, if the material is pin-punched with a hot pin, sufficient heat may be applied so that the surfactant creates "bloom", i.e., on the outer surface of the fiber Moving towards it, creating a wettable area surrounding the holes, thereby improving the uptake properties of the material. Examples of chemicals that may be used for this material include, but are not limited to, AHCOVEL® (from ICI Surfactants, Wilmington, Del., USA), GLUCOPON® (Ohio, USA) PLURONICS® (manufactured by BASF, Germany); TRITON® X-102 (manufactured by Union Carbide Corporation, Danbury, Connecticut, USA); , MASIL @ SF-19® (manufactured by PPG Industries, Inc., Gurney, Illinois, USA), or combinations thereof.
[0043]
The optional fluid transfer delay layer according to the present invention is intended to enhance distribution in the xy plane by delaying the transfer of fluid from the intake / distribution layer to the retention layer. The transfer delay layer transfers fluid to the retention layer when high pressure, high flow, or saturation levels occur. This controlled transfer mechanism results in a pattern of stretched dirt in the retaining layer, helps prevent supersaturation in the fluid discharge area, and provides a visual indication to the wearer that the remaining life of the product has been reduced. Will provide a signal.
[0044]
The transfer delay layer creates a permeability and wetting gradient between the uptake / distribution layer and the underlying retention layer by preventing close contact between the two layers. The transfer delay layer thus promotes lateral fluid distribution within the intake / distribution layer under conditions of continuous flow and controls the fluid movement in the Z-direction so that it has relatively low permeability and wetting. It is necessary to have nature. However, under jet flow conditions, the holes in the transfer delay layer allow fluid to immediately pass to the underlying reservoir. The wettability of the transport delay layer may be altered by local chemical treatment, as described above for the cover layer.
[0045]
Another embodiment of the present invention can include multiple layers of common perforation that can comprise an absorbent core, thereby transferring and absorbing fluid to a preferred product layer to improve fluid absorption. This increases the utilization efficiency of the absorbent material and creates a different absorption pattern.
The following examples have been developed and tested to determine the amount of improvement provided by the exemplary system according to the present invention.
[0046]
Example 1
The layers described below were cut into 4 inch x 4 inch pieces, and each piece was stacked on top of each other without the use of adhesive in the order described.
Cover layer: 20.3 gsm (0.6 osy) ESCORENE® PD-3445 polypropylene spunbond nonwoven with 3.5 dpf fibers. Treated with topically applied 0.3% by volume AHCOVEL® surfactant.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa @ T-255 binder fiber. At 250 gsm, the density is 0.14 grams / cubic centimeter.
Transport delay layer: 27.1 gsm (0.8 osy). 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume AHCOVEL® surfactant.
Absorbing layer: 90% by weight of NB416 pulp and 10% by weight of KoSa @ T-255 binder fiber. 175 gsm and 0.10 grams / cubic centimeter.
[0047]
Example 2
The layers described below were cut into 4 inch x 4 inch pieces, and each piece was stacked on top of each other without the use of adhesive in the order described.
Cover layer: 20.3 gsm (0.6 osy) ESCORENE® PD-3445 polypropylene spunbond nonwoven with 3.5 dpf fibers. Treated with topically applied 0.5% by volume AHCOVEL® surfactant.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa @ T-255 binder fiber. At 250 gsm, the density is 0.14 grams / cubic centimeter.
Transport delay layer: 27.1 gsm (0.8 osy). 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume AHCOVEL® surfactant.
Absorbing layer: 90% by weight of NB416 pulp and 10% by weight of KoSa @ T-255 binder fiber. 175 gsm and 0.10 grams / cubic centimeter.
[0048]
Example 3
The layers described below were cut into 4 inch x 4 inch pieces, and each piece was stacked on top of each other without the use of adhesive in the order described. Using a pin perforation process using a pin roller and another (female) roller, only the cover layer and the intake / distribution layer were co-perforated, resulting in a 14% open area with 8 holes / cm 2. The temperatures used were 280 ° F (138 ° C) on the pin roll and 170 ° F (77 ° C) on the female roll at a rate of 40 feet / minute.
Cover layer: 20.3 gsm (0.6 osy) ESCORENE® PD-3445 polypropylene spunbond nonwoven with 3.5 dpf fibers. Treated with topically applied 0.3% by volume AHCOVEL® surfactant.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa T-255 binder fiber. At 250 gsm, the density is 0.14 grams / cubic centimeter.
Transport delay layer: 27.1 gsm (0.8 osy). 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume AHCOVEL® surfactant.
Absorbing layer: 90% by weight of NB416 pulp and 10% by weight of KoSa T-255 binder fiber. 175 gsm and 0.10 grams / cubic centimeter.
[0049]
Example 4
The layers described below were cut into 4 inch x 4 inch pieces, and each piece was stacked on top of each other without the use of adhesive in the order described. Using a pin perforation process using a pin roller and another (female) roller, only the cover layer and the intake / distribution layer were co-perforated, resulting in a 14% open area with 8 holes / cm 2. The temperatures used were 280 ° F (138 ° C) on the pin roll and 170 ° F (77 ° C) on the female roll at a rate of 40 feet / minute.
Cover layer: 20.3 gsm (0.6 osy) ESCORENE® PD-3445 polypropylene spunbond nonwoven with 3.5 dpf fibers. Treated with topically applied 0.5% by volume AHCOVEL® surfactant.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa T-255 binder fiber. At 250 gsm, the density is 0.14 grams / cubic centimeter.
Transport delay layer: 27.1 gsm (0.8 osy). 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume AHCOVEL® surfactant.
Absorbing layer: 90% by weight of NB416 pulp and 10% by weight of KoSa T-255 binder fiber. 175 gsm and 0.10 grams / cubic centimeter.
[0050]
[Table 1]
(Table 1)

[0051]
As can be seen in Table 1 above, increasing the surfactant content of the nonwoven reduces the uptake time of the absorption system. In addition, co-perforation of the layers further reduces the uptake time. Having a combination of high levels of surfactant and a co-perforated layer enhances this effect.
[0052]
Example 5
These absorbent swatches are assembled with cover adhesives at an addition level of 2-3 gsm and have a "Kotex (R) Ultrathin" with "Safety @ Zone (R)" as currently sold in the US market. Maxi "product was formed.
Cover layer: 20.3 gsm (0.6 osy) of ESCORENE® PD-3445 polypropylene spunbond nonwoven, 3.5 dpf. Treated with topically applied 0.3% by volume of AHCOVEL® surfactant. The cover layer was 8 cm × 24.2 cm.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa @ T-255 binder fiber. At 250 gsm, the density is 0.14 grams / cubic centimeter. This layer was 10.2 cm x 19 cm.
Transfer delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume of AHCOVEL® surfactant. This layer was 5 centimeters x 20.5 centimeters.
Absorbing layer: 90% by weight of NB416 pulp and 10% by weight of KoSa @ T-255 binder fiber. 175 gsm and 0.10 grams / cubic centimeter. This layer was 6.4 centimeters wide by 21.5 centimeters long.
[0053]
Example 6
These absorbent swatches are assembled using cover adhesives at an addition level of 2-3 gsm and have a "Kotex (R) Ultrathin" with "Safety @ Zone (R)" as currently sold in the US market. Maxi "product was formed. Using a pin perforation process using a pin roller and another (female) roller, only the cover layer and the intake / distribution layer were co-perforated, resulting in a 14% open area with 8 holes / cm 2. The temperatures used were 280 ° F (138 ° C) on the pin roll and 170 ° F (77 ° C) on the female roll at a rate of 40 feet / minute.
Cover layer: 20.3 gsm (0.6 osy) of ESCORENE® PD-3445 polypropylene spunbond nonwoven, 3.5 dpf. Treated with topically applied 0.5% by volume of AHCOVEL® surfactant. The cover layer was 8 cm × 24.2 cm.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa T-255 binder fiber. At 250 gsm, the density is 0.14 grams / cubic centimeter. This layer was 10.2 cm x 19 cm.
Transfer delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume of AHCOVEL® surfactant. This layer was 5 centimeters x 20.5 centimeters.
Absorbing layer: 90% by weight of NB416 pulp and 10% by weight of KoSa T-255 binder fiber. 175 gsm and 0.10 grams / cubic centimeter. This layer was 6.4 centimeters x 21.5 centimeters.
The product backing was a 0.6 mil polyethylene film layer used as a fluid containment device. This layer was adhered to the absorbent layer using a 20 gsm hot melt adhesive. The backing layer was 8 cm wide by 24.2 cm long.
[0054]
Example 7
These absorbent swatches are assembled using cover adhesives at an addition level of 2-3 gsm and have "SAFTY @ ZONE (R)" as currently sold in the United States market by Kimberly-Clark Corporation. The KOTEX® MAXI® product was formed.
Cover layer: 20.3 gsm (0.6 osy) of ESCORENE® PD-3445 polypropylene spunbond nonwoven, 3.5 dpf. Treated with topically applied 0.3% by volume of AHCOVEL® surfactant. The cover had a width of 8 cm in the target area and 9 cm on the lobe and was 22.0 cm in length.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa @ T-255 binder fiber. At 250 gsm, the density is 0.14 grams / cubic centimeter. This layer was 9.4 centimeters x 15.6 centimeters.
Transfer delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume of AHCOVEL® surfactant. This layer was 4.8 centimeters wide and 20.0 centimeters long.
Absorbing layer: NB416 pulp fluff formed with air. 430 gsm and 0.07 grams / cubic centimeter. The width is 6.0 cm in the target area, 7.0 cm on the product lobe, and 20.0 cm in length.
Second absorbent: air formed NB416 pulp fluff. 400 gsm and density 0.09 grams / cubic centimeter. It has a width of 4.5 centimeters and a length of 16.0 centimeters.
The product backing was a 1.1 mil layer of polyethylene film used as a fluid containment device. This layer is adhered to the absorbent layer using a 40 gsm hot melt adhesive. The backing layer was 8 centimeters wide in the target area, 9 centimeters in the lobe, and 22.0 centimeters in length.
[0055]
Example 8
These absorbent swatches are assembled using cover adhesives at an addition level of 2-3 gsm and have "SAFTY @ ZONE (R)" as currently sold in the United States market by Kimberly-Clark Corporation. The KOTEX® MAXI® product was formed.
Using a pin perforation process using a pin roller and another (female) roller, only the cover layer and the intake / distribution layer were co-perforated, resulting in a 14% open area with 8 holes / cm 2. The temperatures used were 280 ° F (138 ° C) on the pin roll and 170 ° F (77 ° C) on the female roll at a rate of 40 feet / minute.
Cover layer: 20.3 gsm (0.6 osy) of ESCORENE® PD-3445 polypropylene spunbond nonwoven, 3.5 dpf. Treated with topically applied 0.5% by volume of AHCOVEL® surfactant.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa T-255 binder fiber. At 250 gsm, the density is 0.14 grams / cubic centimeter. This layer was 9.4 centimeters x 15.6 centimeters.
Transfer delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume of AHCOVEL® surfactant. This layer was 9.4 centimeters x 15.6 centimeters.
Absorbing layer: NB416 pulp fluff formed with air. 430 gsm and 0.07 grams / cubic centimeter. The width is 6.0 cm in the target area, 7.0 cm on the product lobe, and 20.0 cm in length.
Second absorbent: air formed NB416 pulp fluff. 400 gsm and density 0.09 grams / cubic centimeter. It has a width of 4.5 centimeters and a length of 16.0 centimeters.
The product backing was a 1.1 mil layer of polyethylene film used as a fluid containment device. This layer was bonded to the absorbent layer using a 40 gsm hot melt adhesive. The backing layer was 8 centimeters wide in the target area, 9 centimeters in the lobe, and 22.0 centimeters in length.
Table 2 shows the test results of the above-mentioned materials by the above-described incorporation and rewetting test.
[0056]
[Table 2]
(Table 2)

[0057]
As can be seen from these results, the common perforation treatment of the material showed a significant reduction in the absorption time of a single fluid release without affecting the wetting value. In the inventor's view, by providing a system that would provide a faster uptake time, the outflow of fluid from the cover would be reduced, as the fluid would be transported through the liner and the user's body Also reduces the risk of leaks.
Co-perforating different product layers allows product developers to control which layers should distribute or absorb fluid and to what extent. Table 3 provides the "Fluid Distribution Test" data for Examples 5-8 and shows the percentage of fluid retained in each layer. (Examples 6 and 8 were co-drilled.)
[0058]
[Table 3]
(Table 3)

[0059]
As can be seen from the data in Table 3, the co-perforated system allows for better fluid distribution to the underlying absorbent layer, allowing fluid to stay far from the cover, thereby creating a more dry surface for the wearer. To use the full absorption capacity of the product more effectively. The fluid volume of the intake / distribution layer relative to the total absorption layer may be expressed as a ratio, in this case the fluid split ratio. The fluid splitting ratio for the material according to the invention needs to be between 70/30 and 20/80, and more preferably between 60/40 and 20/80.
[0060]
Clearly, the choice of raw materials and the choice of co-perforated layers will determine how well the product will perform. One area where the present invention has advantages is found in systems where the density of the absorbent material increases as one approaches the cover. Such systems tend to impart elasticity to the product to reduce clumping and twisting during use and to preferentially distribute the fluid in the XY plane. This provides for more effective absorption of multiple fluid discharges.
[0061]
One skilled in the art readily recalls products having different material densities and absorption properties that can benefit from co-perforating selected layers to allow for quick absorption and fluid retention in the preferred areas of the product. Will do. The arrangement of perforations can be designed for different layers to improve fluid movement throughout the product. Other further embodiments where the cover is co-perforated with the intake layer can be found in the examples below.
[0062]
Example 9
Cover layer: 20.3 gsm (0.6 osy) polypropylene spunbond nonwoven fabric, 3.5 dpf. Treated with topically applied 0.3% by volume of AHCOVEL® surfactant.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa @ T-255 binder fiber. At 175 gsm, the density is 0.14 grams / cubic centimeter. This layer was 19.0 centimeters wide and 37 centimeters long.
Transfer delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume of AHCOVEL® surfactant. This layer was 20.6 centimeters in length and 4.8 centimeters in width.
Absorbing layer: NB416 pulp fluff formed with air. It is 500 gsm and 0.09 grams / cubic centimeter, 20.6 centimeters in length and 4.8 centimeters in width. The lower layer fluff has a basis weight of 600 gsm, a density of 0.09 grams / cubic centimeter, a length of 29.5 centimeters, a width of 6.5 centimeters in the center, and 7.5 centimeters in the lobe.
The product backing was a 1.1 mil layer of polyethylene film used as a fluid containment device. This layer is adhered to the absorbent layer using a 40 gsm hot melt adhesive. The backing layer was 8.5 centimeters wide in the target area, 9.5 centimeters in lobe, and 31.5 centimeters in length.
[0063]
Example 10
Using a pin perforation process using a pin roller and another (female) roller, only the cover layer and the intake / distribution layer were co-perforated, resulting in a 14% open area with 8 holes / cm 2. The temperatures used were 280 ° F (138 ° C) on the pin roll and 170 ° F (77 ° C) on the female roll at a rate of 40 feet / minute.
Cover layer: 20.3 gsm (0.6 osy) polypropylene spunbond nonwoven fabric, 3.5 dpf. Treated with topically applied 0.3% by volume of AHCOVEL® surfactant.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa T-255 binder fiber. At 175 gsm, the density is 0.14 grams / cubic centimeter. This layer was 19.0 centimeters wide and 37 centimeters long.
Transfer delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume of AHCOVEL® surfactant. This layer was 20.6 centimeters in length and 4.8 centimeters in width.
Absorbing layer: NB416 pulp fluff formed with air. 500 gsm and 0.09 grams / cubic centimeter, 20.6 centimeters in length and 4.8 centimeters in width, the lower fluff layer has a basis weight of 600 gsm and a density of 0.09 grams / cubic centimeter With a length of 29.5 cm, a width of 6.5 cm in the center and 7.5 cm on the lobe.
The product backing was a 1.1 mil layer of polyethylene film used as a fluid containment device. This layer is adhered to the absorbent layer using a 40 gsm hot melt adhesive. The backing layer was 8.5 centimeters wide in the target area, 9.5 centimeters in lobe, and 31.5 centimeters in length.
[0064]
Example 11
Using a pin perforation process using a pin roller and another (female) roller, only the cover layer and the intake / distribution layer were co-perforated, resulting in a 14% open area with 8 holes / cm 2. The temperatures used were 280 ° F (138 ° C) on the pin roll and 170 ° F (77 ° C) on the female roll at a rate of 40 feet / minute.
Cover layer: 20.3 gsm (0.6 osy) of ESCORENE® PD-3445 polypropylene spunbond nonwoven, 3.5 dpf. Treated with topically applied 0.3% by volume of AHCOVEL® surfactant.
Surge layer: 23.7 gsm (0.7 osy), 6 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven polypropylene fiber web with HR6 finish. Fibers with a finish are available from Chisso Corporation. This layer was 19.0 centimeters wide and 37 centimeters long and 1.3 millimeters thick.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa T-255 binder fiber. At 175 gsm, the density is 0.14 grams / cubic centimeter. This layer was 19.0 centimeters wide and 37 centimeters long.
Transfer delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume of AHCOVEL® surfactant. This layer was 20.6 centimeters in length and 4.8 centimeters in width.
Absorbing layer: NB416 pulp fluff formed with air. 500 gsm and 0.09 grams / cubic centimeter, 20.6 centimeters in length and 4.8 centimeters in width, and the underlying fluff layer has a basis weight of 600 gsm and 0.09 grams / cubic centimeter. , 29.5 cm in length, 6.5 cm in center and 7.5 cm on the lobe.
The product backing was a 1.1 mil layer of polyethylene film used as a fluid containment device. This layer is adhered to the absorbent layer using a 40 gsm hot melt adhesive. The backing layer was 8.5 centimeters wide in the target area, 9.5 centimeters in lobe, and 31.5 centimeters in length.
[0065]
Example 12
The intake / distribution layer and the transport delay layer are co-perforated using a pin perforation process using a pin roller and another (female) roller, resulting in a 14% open area with 8 holes / cm 2. The temperatures used were 280 ° F. (138 ° C.) on the pin roll and 170 ° F. (77 ° C.) on the female roll at a rate of 50 feet / minute.
Cover layer: vacuum-perforated polyethylene film with 17% open area, 100 holes / square centimeter, and 19 gsm.
Intake / distribution layer: 90% by weight NB416 pulp and 10% by weight KoSa T-255 binder fiber. At 175 gsm, the density is 0.14 grams / cubic centimeter. This layer was 19.0 centimeters wide and 37 centimeters long.
Transfer delay layer: 27.1 gsm (0.8 osy), 2.8 dpf ESCORENE® PD-3445 polypropylene spunbond nonwoven with 0.3% by volume of AHCOVEL® surfactant. This layer was 20.6 centimeters in length and 4.8 centimeters in width.
Absorbing layer: NB416 pulp fluff formed with air. 500 gsm and 0.09 grams / cubic centimeter, 20.6 centimeters in length and 4.8 centimeters in width, the lower fluff layer has a basis weight of 600 gsm and a density of 0.09 grams / cubic centimeter With a length of 29.5 cm, a width of 6.5 cm in the target area and 7.5 cm on the lobe.
The product backing was a 1.1 mil layer of polyethylene film used as a fluid containment device. This layer is adhered to the absorbent layer using a 40 gsm hot melt adhesive. The backing layer was 8.5 centimeters wide in the target area, 9.5 centimeters in lobe, and 31.5 centimeters in length.
The above examples were tested according to the three take-in and rewet tests described above, and the results are shown in Table 4.
[0066]
[Table 4]
(Table 4)

[0067]
As can be seen from these examples, in multiple fluid discharge situations, co-perforating the cover with various absorbent layers has been shown to be advantageous in reducing material uptake time. For example, in Example 10, further optimization of available aperture area and processing could be made to further reduce system uptake time. It can also be seen from this data that materials with a larger void volume of the cover generally have faster uptake times for multiple fluid discharges, showing a significant reduction as compared to non-perforated absorption systems.
As those skilled in the art will appreciate, changes and modifications to the invention are deemed to be within the capabilities of those skilled in the art. The inventor intends that such changes and modifications fall within the scope of the present invention.
[Brief description of the drawings]
FIG. 1: Variable flow over the lifetime of a single product (diamonds), with flow volume indicated on the y-axis in grams / hour (g / hr) and time on the x-axis in hours (hr) And a continuous flow (square) graph.
FIG. 2 shows a 7.4 hole / square centimeter pin drilling pattern using a 2.06 millimeter diameter pin.
FIG. 3 shows a 2.5 hole / square centimeter pin drilling pattern using the same pin diameter as in FIG. 2;
FIG. 4 is a schematic diagram of a suitable rate block device used to measure the fluid uptake time of a material or material system.
FIG. 5 is a schematic view of an absorption system having holes across the cover and the intake / distribution layer.
6 is a schematic view of a common perforated absorption system similar to FIG. 5, incorporating an additional layer of material between the cover and the intake / distribution layer.
FIG. 7 illustrates an example of a partitioned common perforation pattern that may be used in the practice of the present invention.
FIG. 8 illustrates an example of a partitioned common perforation pattern that may be used in the practice of the present invention.
FIG. 9 illustrates an example of a partitioned common perforation pattern that can be used in the practice of the present invention.
FIG. 10 illustrates an example of a partitioned common perforation pattern that may be used in the practice of the present invention.
FIG. 11 illustrates an example of a partitioned common perforation pattern that may be used in the practice of the present invention.
FIG. 12 illustrates an example of a partitioned common perforation pattern that can be used in the practice of the present invention.
FIG. 13 illustrates an example of a partitioned common perforation pattern that may be used in the practice of the present invention.

Claims (20)

A cover layer adjacent to the uptake / distribution layer, wherein a side of the uptake / distribution layer opposite the cover layer is adjacent to the absorbent core;
Including
The cover layer and the intake / distribution layer are co-perforated;
A system for hygiene products, characterized in that: The system of claim 1, further comprising a transport delay layer between the intake / distribution layer and the absorbent core. The system of claim 1 having an open area of 2 to 25% and having holes less than 19.6 square millimeters in area. The system of claim 3, having a third fluid release intake time of less than 35 seconds. The system of claim 3, having a rewetting value of less than 0.3 grams. The system of claim 1, wherein the uptake / distribution layer has a basis weight of 50 to 500 gsm. The system of claim 1, wherein the cover material is treated with a hydratable surfactant. The system of claim 1, wherein the cover material is treated with a skin-friendly additive. The system of claim 1, wherein the cover material is an embossed nonwoven. The system of claim 1, wherein the system has a fluid split ratio of 60/40 to 20/80. A non-woven cover layer,
An uptake / distribution layer;
An absorbing layer,
Including
The cover layer and the intake / distribution layer are co-perforated;
A feminine hygiene pad characterized by the following. The pad of claim 11, further comprising a transport delay layer adjacent to the absorbent core. The pad of claim 12, wherein the transfer delay layer is a material selected from the group consisting of a spunbond fabric, a meltblown fabric, a carded fabric, and a film. The pad of claim 11, wherein the transfer delay layer is a spunbond fabric having a basis weight of about 15 to 50 gsm. The method of claim 11, wherein the intake / distribution layer is a material selected from the group consisting of an air-laid fabric, a bonded carded web, a coform material, a hydraulic entangled pulp fabric, and a meltblown fabric. Pad. The pad of claim 11, wherein the uptake / distribution layer is an air-laid fabric having a basis weight of about 100 to 300 gsm and a density of about 0.06 to 0.18 grams / cubic centimeter. The pad of claim 11, wherein the cover layer, the uptake / distribution layer, and the transport delay layer are co-perforated at a density of about 1 to 15 holes / square centimeter. The pad of claim 11, further comprising a surge layer between the cover layer and the intake / distribution layer. 19. The pad of claim 18, wherein the cover layer, the surge layer, and the intake / distribution layer are co-perforated at a density of about 1 to 15 holes / square centimeter. A polypropylene fiber nonwoven cover layer,
A pulp and binder fiber uptake / distribution layer having a density of about 0.09 to 0.19 grams / cubic centimeter and a basis weight of about 100 to 300 gsm;
A non-woven fabric transfer delay layer,
A first absorbent layer comprising pulp fluff having a density of about 0.05 to 0.10 grams / cubic centimeter and a basis weight of about 150 to 500 gsm;
A secondary absorbent layer comprising pulp fluff and having a lower density than the first absorbent layer;
Including
Said layer is co-perforated with a density of 1 to 15 holes / square centimeter;
A feminine hygiene pad characterized by the following.

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