US 5,350,548 AGranted

Method and apparatus for making two-layer tablets in a twin rotor pressing machine

AssigneeWilhelm Fette GmbH

InventorsJurgen Hinzpeter, Ingo Schmidt, Helmut Brommrowitz

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Abstract

A method of making two-layer tablets or pellets in a twin rotor pressing machine, in which method during a normal manufacturing period powdery or particulate material is fed into die bores of a die rotor so as to form first layers, said first layers are compressed in a first step by plungers synchronously rotating with the die rotor so as to form first layer pressed articles, the two layers within the die bores are compressed in a second step by said plungers so as to obtain two-layer tablets or pellets, and said two-layer tablets or pellets are removed at a main discharge station, and in which method during an inspection period first layer pressed articles removed at an intermediate discharge station or two-layer tablets or pellets removed at said main discharge station are fed to an inspection station, characterized in that during the inspection period said first layers are compressed more than in said first step during the normal manufacturing period before samples thereof are withdrawn at said intermediate discharge station, and in that the second layers are compressed and the resulting second layer pressed articles are fed either to a scrap path or to said inspection station at least after removal of said samples of the first layer pressed articles.

Claims8

Dependent claims

A method of making two-layer tablets or pellets in a twin rotor pressing machine, the method comprising the steps of:

a) feeding into die bores of a die rotor a first powdery or a first particulate material so as to form first layers;
b) compressing said first layers with a first compression force in a first step by plungers synchronously rotating with said die rotor so as to form first layer pressed articles;
c) feeding into said die bores including said first layer pressed articles a second powdery or second particulate material so as to form a second layer;
d) compressing commonly said first and said second layer in a second step with a second compression force by said plungers so as to form two-layer tablets or pellets;
e) removing said two-layer tablets or pellets from said bores at a main discharge station;
f) periodically subjecting the machine to an inspection period and during said inspection period:
(i) compressing said first layers with a third compression force larger than said first compression force so as to form said first article with increased compression;
ii) rejecting said first articles with increased compression through a rejection channel at an intermediate discharge station after said third compression force has been fully reached;
iii) removing said first layer pressed articles from said bores at said intermediate discharge station for inspection of said articles for one or more predetermined parameters;
iv) feeding into said die bores said second powdery or particulate material and compressing said second layer with a fourth compression force larger than said second compression force;
and
v) removing said compressed second layer articles from said die bores at said main discharge station for inspection of said second layer articles for one or more predetermined parameters, or rejecting said second layer articles, respectively, through a second rejection channel.

9 more elements

Dependencies are inferred from the claim text.