US 4,290,988 AGranted

Method for the manufacture of cellulosic fibrous material which can be pressed into moulded parts

AssigneeCasimir Kast GmbH & Co. KG

InventorsHerbert Nopper, Wolfgang Knoch

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Abstract

Cellulosic fibrous material which can be pressed into moulded parts is manufactured from cellulose-containing material which is separated into a fibrous material, the separated fibrous material then being mixed with a binding agent (particularly a combination of thermoplastic and thermosetting substances) and formed into a fleece which is compressed under heat action. The cellulose-containing starting material is derived from waste cellulosic fibrous material and such waste material is cut up and ground in a dry state and the bonding agent is added in particulate form also in the dry state. An apparatus is described which has a pre-pulverizing apparatus, a mixing chamber, a grinder, an endless fleece conveyor, a forming head, a heating apparatus and a pressing apparatus. The resulting cellulosic fibrous material can be pressed into moulded parts between pressing tolls in the dry state and with a single pressing stroke.

Claims22

Dependent claims

A method of manufacturing a dry shaped cellulosic fibrous transportable mat suitable for future compressing into a molded article, comprising:

(a) passing a dry celulosic fibrous waste material composed predominantly of paper, cardboard and/or textiles through a mill to pre-pulverize said material,
(b) mixing said pre-pulverized material with a dry thermoplastic bonding agent and a dry thermosetting bonding agent,
(c) grinding, and blending said mixture,
(d) feeding said mixture to a forming head, and depositing said mixture therefrom as a layer upon a moving endless conveyor having a suction chamber therebeneath,
(e) setting the thickness of said layer on the upper surface of said moving layer,
(f) passing said layer on said moving conveyor through a heater to plasticize the thermoplastic bonding agent while avoiding setting of the thermosetting bonding agent,
(g) passing said heated layer beneath a pressing roll to compact said layer to a transportable mat,
(h) cooling said compacted mat, and
(i) cutting said mat to desired lengths.

6 more elements

Dependencies are inferred from the claim text.