Multi-ply paper and paperboard having a wet-laid ply and a dry-laid ply
AssigneeKarl Kroyer St. Anne's Limited
InventorsHarold George Curry, Brian William Attwood, Derek Graham Walter White
Life of this patent
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Abstract
A method and apparatus for making a multi-ply paper sheet wherein a first web is formed by wet-laying fibres and a second web is formed by dry-laying fibres, the two webs being combined to form a multi-ply sheet and wherein the dry-laid web is produced by depositing dry fibres on a supporting band and consolidating the web by hot moist pressing before transferring to the first wet-laid web.
Claims10
In a process for making a multi-ply paper sheet or board comprising the steps of, forming a first web by wet-laying fibres, forming a second dry-laid web at a location away from the first web by depositing dry fibres on a supporting band and applying adhesive or binder to the dry fibres, and subsequently transferring the dry-laid web onto the first wet-laid web, including utilizing moisture in the first wet-laid web to adhere the two webs together, the improvement wherein said step of forming the second dry-laid web includes passing the dry-laid web through a press nip formed between a press roll and a heated cylinder to consolidate the dry-laid web before it is transferred onto the first wet-laid web.
In an apparatus for forming a multi-ply paper sheet or board comprising:
- means for wet-laying fibres to form a first web,
- means for dry-laying fibres to form a second web at a location away from the first web, and
- means for applying adhesive or binder to the dry fibres,
- the improvement comprising means including two rolls defining a press nip for consolidating the second web after the adhesive or binder has been applied thereto,
- heating means connected to one of said rolls for heating the second web as it passes through the nip, and,
- means for combining the first web with the consolidated second web to provide a multi-ply paper sheet or board.
Dependencies are inferred from the claim text.