Knowledge Base

Discover how to cut your formulation development time in half with the Caleva Multi Lab and its wide range of variable density dies.

At Caleva, we offer a variety of extruders to meet your needs, from laboratory scale extruders for research and development purposes, to pilot scale extruders and larger models for batch production environments.

The Caleva Multi-Lab (CML) can Mix/Granulate, Extrude and Spheronize all in one base unit.

This article is about the Extruder attachment that comes with the CML.

The Multi-lab is capable of working with a variety of materials from catalysts and pharmaceuticals, to agricultural products.

The Extruder

The extrusion attachment on the CML is in the form of a single screw extruder.  A variety of dies...

It is not possible to extrude and spheronize everything.  Extrusion and spheronization can be used on a wide range of products and formulations.  However, if you are having trouble extruding your formulations with the Caleva Multi Lab (CML) then please read this article.

Caleva offers extruder screws of different designs for use with the CML.  If you are having issues with the CML then the first...

In the process of extrusion, having different dies available to process your product is key to increasing your chances of development success.  This is why we offer a large range of dies to help you find the best options for your formulation.

We offer die plates that are excellent for most uses, like our 1 x 1 mm die, however sometimes a more specialist die may be needed.  Our trilobe and...

An opportunity in laboratory extrusion with catalyst material.  We have recently had some considerable success with one of our customers working with the extrusion of small quantities of catalytic material.

In collaboration with some of its users, Caleva have recently been successful in extruding of small quantities of catalytic material using the Caleva Multi Lab (the first steps of blending and mixing can also be completed in the same multilevel base machine) whilst increasing the surface area/volume ratio of the extrudate produced.

Is there a guide to the optimum Length to Diameter ratio of the extrudate fragments?

In the calculations used to demonstrate the data it is assumed that the extrudate is an infinitely long strand. In this case the length of the extrudate has no influence on the data shown. In reality, extrudate is not infinitely long and as the individual strands of the extrudate produced become shorter, the...

All extrusion processes require the generation of pressure within the material to be extruded. When materials are put under pressure heat is generated. This cannot be avoided but different extrusion types generate different amounts of heat. There are basically three different types of extruder and the one chosen may have far reaching implications on production operations. It is important that the...

This range of Variable Density extruders is designed to allow scale up starting from the initial development with the product saving, time saving and flexible Caleva Multi Lab (CML). Moving forward to the manufacture of larger trial batches (kilos rather than grams) the bench top VDE™ would be the preferred equipment.

Can the equipment design help to increase the Surface Area to Volume ratio (SA/V) in the extruded material (extrudate)?

Caleva offers a range of dies that have the standard round holes with different diameters. With the CML extruder, die-hole diameters can range from 0.5 mm to 3.0 mm. Die holes larger that this will require a larger bench top system such as the Caleva bench top Variable...

The Caleva CML extruder attachment is the smallest in the family of screw driven extruders that can offer the operator the ability to extrude the material at high, medium high, medium low, or low density. By management of the extrudate density physical properties of the extruded material can be influenced. The most important of these are likely to be:

During the formulation development process, challenges related to final product performance have to be examined, exposed and overcome.

This is not always easy or straight-forward. However, if you have more options that you can investigate then there is likely to be an increased probability of a successful result.   Different factors are considered as part of any formulation development and these...

There is no simple answer to this question as it depends on the characteristics of your formulation and the size of the pellets you require.

One of the key factors (but not the only factor) that determines the diameter of the final dry pellet is the diameter of the hole in the extruder die. For example, if you are trying to make a pellet of 1.0 mm diameter then you should use a hole of the same...