Gerteis Maschinen + Processengineering AG

GERTEIS MASCHINEN + PROCESSENGINEERING AG had its beginnings in 1986 as a one-man enterprise in Jona, Switzerland where the corporate headquarters is located to this day. Throughout the years the company grew exponentially and established itself as the market leader for premium dry granulation equipment. With our focus on roller compactors for the pharmaceutical industry, we possess an in-depth knowledge in this field which is much to the benefit of our customers.

Introduction

Granulation is a process in which powder particles are made to adhere to each other, resulting in larger, multi-particle entities, so called granules. If such a process is performed without adding liquids, this is called dry granulation.

In dry granulation, the powder blend is compacted by applying a force onto the powder, which in general causes a considerable size enlargement.

The compacts obtained are called ribbons, flakes or briquettes. In order to obtain the desired granules, the compaction process is followed by a milling step.

Process Basics

Principally there are two methods to obtain the compacts when using dry granulation: slugging and roller compaction.

Slugging

If a tablet press is used for the compaction process, the term slugging is used. But since particles with a small particle size do not flow well into the die of a tablet press, resulting in weight differences from one tablet (slug) to another. This in turn causes large fluctuations in the forces applied onto the individual slugs, and variability in the mechanical strength of the slug. Therefore, the properties of these granulates obtained by milling the slugs cannot be controlled.This is one of the main reasons why slugging is rarely used as a dry granulation method.

Roller Compaction

A GERTEIS® Roller compactor generally consists of three major units:

• A feeding system, which conveys the powder to the compaction area between the rollers
• A compaction unit, where the powder is compacted between two counter rotating rolls by applying a force, to form ribbons or flakes
• A size reduction unit, for milling the ribbons into granules of the desired particle size