Interfolding method of sheet material not or not enough permeable to air and machine for carrying out such method

• US 6,213,927 B1
• Filed: 08/19/1999
• Issued: 04/10/2001
• Est. Priority Date: 08/21/1998
• Status: Expired due to Term

• Current Assignee: Mtc-Macchine Trasformazione Carta SRL, M.T.C. - Macchine Trasformazione Carta, Srl
• Original Assignee: Mtc-Macchine Trasformazione Carta SRL
• Inventors: Landucci, Sergio, De Matteis, Alessandro
• Primary Examiner(s): Gerrity, Stephen F.
• Assistant Examiner(s): TAWFIK, SAMEH
• Application Number:
  US09/378,015
• Time in Patent Office: 600 Days
• Field of Search: 493/360, 493/359, 493/357, 493/356, 493/430, 493/429, 493/363, 493/370, 493/428
• US Class Current: 493/360
• CPC Class Codes: B65H 45/24 Interfolding sheets, e.g. cigarette or toilet papers

Abstract

A method and a machine for the production of interfolded stacks (17) formed by a plurality of sheets (4a,4b) comprising the steps of: transversally cutting or tearing sheets obtained from at least one web (3a,3b) and offset with respect to one another so that a sequence of offset sheets is created; passage of the sheets on folding rollers (7a,7b) which comprise sucking means for the alternate holding of the sheets (4a,4b) in order to obtain an interfolded disposition; formation of a continuous interfolded stack downstream of the folding rollers. Upstream of the folding a step of treatment of the sheets is provided in order to make them, at least in certain zones (14), enough permeable to air, in particular through perforating means. These perforating means can be provided on rollers (10a,10b) having sharpened points (11a,11b).

Claims

1. A method for production of interfolded stacks formed by a plurality of sheets comprising the steps of:

transversally separating said plurality of sheets, obtained from at least one web, offset with respect to one another so that a sequence of offset sheets is created, where each of said separated sheets has a first end and a second end;

puncturing each of said separated sheets with puncturing means at a location between said first and second ends to render said separated sheets permeable to air;

passing said separated sheets onto folding rollers which comprise sucking means for the alternate holding of said sheets in order to obtain an interfolded disposition;

formation of a continuous interfolded stack downstream of said folding rollers.

2. A method as recited in claim 1 wherein said puncturing comprises perforating.

3. A method as recited in claim 2 wherein said puncturing means comprises a roller having outwardly extending needles that engage corresponding apertures in said folding rollers.

4. A method as recited in claim 2 wherein said perforating is arranged to have a speed of perforation which corresponds to a speed of operation of said sucking means.

5. A method as recited in claim 2 wherein a surface speed of said perforating corresponds with a surface speed of said sucking means.

6. An interfolding machine for the formation of stacks of interfolded sheets, comprising:

separating means for separating sheets from a web;

perforating means operatively arranged to perforate each of said separated sheets between first and second ends of said separated sheets;

folding rollers counter-rotating with respect to each other, said folding rollers supplied with separated sheets from at least one web;

sucking means located within each of said folding rollers and in communication with a periphery of each of said folding rollers, operatively arranged to hold said separated sheets in an alternating arrangement on said folding rollers; and

,

interfolding means operatively arranged to form a stack of interfolded sheets.

7. An interfolding machine as recited in claim 6 wherein said perforation means and said sucking means are operatively arranged to operate at the same time.

8. An interfolding machine as recited in claim 6 wherein said perforating means comprises rollers having perforation tools.

9. An interfolding machine as recited in claim 8 wherein said perforation tools comprise outwardly extending needles.