Solventless Extruded Double-Base (EDB) propellant charges. A review of the properties, technology, and applications

Extruded double-base (EDB) charges are used mainly due to their efflux having minimum smoke, attractive oxygen balance, and low corrosivity. The propellant class also has desirable burn-rate characteristics since it exhibits plateau burning and has a low temperature sensitivity to burning rate (πk). External ballistic modeling results are...

Solventless Extruded Double Base (EDB) propellant charges. A review of the properties, technology, and applications

EDB propellant may be manufactured by solvent or solventless processes. Generally, the former is used for small diameter gun propellants (

The origin of weld seam defects related to metal flow in the hot extrusion of aluminium alloys en AW-6060 and en AW-6082

Longitudinal weld seams are an intrinsic feature in hollow extrusions produced with porthole dies. As these joins occur along the entire extruded length, it is desirable that these weld seams have a minimal impact on the structural integrity of the extrudate. In particular, defects associated with weld seam formation should be avoided. In this...

Definition of a JA-2 equivalent propellant to be produced by continuous solventless extrusion

In order to eliminate residual solvents in ammunition and to reduce the emissions of volatile organic compounds to the atmosphere, the U.S. Army ARDEC has teamed with TNO in developing a new process for the production of solventless propellant for tank ammunition. To reduce the costs of solventless propellants production, shear roll mill and...

Definition of a JA2 equivalent propellant to be produced by continuous solvent-less extrusion

The aim of this work is to demonstrate the manufacturing of a propellant by solvent-less continuous twin screw extrusion processing while maintaining gun performance characteristics of conventional JA-2 propellant. This is elucidated by explicitly researching the relationship between interior ballistic properties of the gun propellant and...

Hydrostatic extrusion of magnesium alloys

This chapter deals with the capabilities and limitations of the hydrostatic extrusion process for the manufacturing of magnesium alloy sections. Firstly, the process basics for the hydrostatic extrusion of materials in general and of magnesium in particular are introduced. Next, some recent research and development issues are discussed,...

Processing aspects of magnesium alloy stent tube

Biomedical applications are an emerging field of interest for magnesium technology, envisioning biodegradable implants that resorb in the human body after having cured a particular medical condition (such as artery clogging or bone fractures). This challenges research in a sense that the materials to be used need to dissolve in vivo in a...

Surface quality prediction in aluminum extrusion

The surface quality of aluminium extrusion products can be hampered by undesired surface features like die lines and pickups. In particular the presence of pickups is considered as undesirable. Surface pickups appear as intermittent torn marks on the aluminium extrusion products, often terminated with a protruding lump rising above the surface...

The effect of extrusion on the nutritional value of canine diets as assessed by in vitro indicators

A 3 × 2 × 2 factorial trial was designed to investigate the effect of different extrusion conditions and product parameters on the nutritional quality as determined by a number of in vitro measurements (e.g. reactive lysine, and starch gelatinization degree) as well as physical quality of the kibble (durability and hardness) of a canine diet....

Design of an aluminium bicycle path integrated in a steel bridge

This paper describes the design of the aluminium structure of a bicycle path which is mounted on an existing steel brige. The benefits of aluminium, being low self weight, freedom in design obtained by extrusion and good corrosion resistance were maximal utilized. One of the main drawbacks of aluminium, being the low modulus of elasticity,...

Recycling of a TPE based gun propellant (Poster presentation)

At TNO- PML we started to work with thermoplastic elastomers (TPEs) because of an international trend towards the development and application of propellants using TPEs as a binder matrix. The most important reasons for this trend are: less or no solvent needed in the production process, recycling of waste into the process and filler recovery at...

An effective split of flow and die deformation calculations of aluminium extrusion

The purpose of the research project of which this paper is a result is to gain insight in design and control parameters of aluminium extrusion by FE simulations. This is done by means of a thermal FE code based on an ALE algorithm (Dieka). A short overview is given of the material models as well as the FE methods that are used. It is shown that...

Aluminium building and civil engineering structures

The design of aluminium structures in building and civil engineering applications is different from designing in traditional materials. This difference is based on the physical and mechanical properties of the material and the freedom of cross-sectional shape provided by the extrusion manufacturing process. This freedom of shape is a key to...

Extrusion trials with a TSK045 twin screw extruder (Poster presentation)

In 1994 a 45mm twin screw extruder was introduced at the Prins Maurits Laboratory of TNO for the processing of energetic materials. Initial safety experiments were carried out by using inert compositions with small amounts of different energetic components and micro encapsulated chemical sensors to simulate solventless extrusion processing.

Foam stability related to polymer permeability. 1: Low molecular weight additives

In the production of polyethylene foams by extrusion with alkanes as a blowing agent, significant changes in the dimensions of extruded products are encountered. The dimensional stability of a foam with a structure of closed cells is improved by blending the polymer with small amounts of a low molecular weight additive. It is believed that the...