Report 6 from a series of 5 Prosyma Research Ltd reports to Ametex AG, 15th February 1989 to 14th January 1990.

Report 6 dated 31st May 1989, Report 7 dated 11th July 1989, Report 8 dated 24th July 1989.
S F Bush

Summary: Part 1

1. During the period under review, SAFIRE project A has followed up the breakthrough in finishing technology achieved in the previous six-month period.
2. On the process itself follow-up has concentrated on establishing the design and operating parameters which determine acceptable and indeed exceptional finish with the new technology, at the same time making many metres of pipe for burst and creep testing.
3. Both polypropylene (PP) and HDPE SAFIRE pipe can be made with fine finishes on a routine basis. While not of direct benefit to the project, the finishing technology gives quite remarkable mirror finishes to virgin pipe.
4. In the period under review, SAFIRE project C has concentrated on producing SAFIRE granules in a wide range of combinations of fibre and polymer, and evaluating these for use in pipes.
5. The signs are that the evaluations made for this purpose will also give a good indication of the commercial potential for SAFIRE granules in combination with Fibre Separating Devices (FSD) sold in their own right. The significance of this potential has become clear from recent information on present commercial products.

Report 3 from a series of 4 Prosyma Research Ltd reports to Ametex AG, 29th November, 1987 to 1st December 1988.

Report 2 dated 24th February 1988 and Report 3 dated 16th May 1988.
S F Bush

Summary: Progress on pipe surface finish quality with SAFIRE material

The project has concentrated on developing the process technology needed to achieve an acceptable finish on both the internal and external pipe surfaces simultaneously. This report reviews the developments from the beginning of the work in December 1986, i.e. before the SAFIRE ‘A’ project commenced on 1st October 1987 up to the end of April 1988.

This overview enables the essential continuity in the work to be seen so that we can converge on the solution as rapidly as possible.

In the period up to the start of the Ametex project, calibration was carried out either on the outside or on the inside of the pipe, but not both sides together. To carry out both together has required a major design changed followed by a sequence of mechanical and operational changes in the light of the experience gained. These changes are recorded in the body of the report and summarised in Tables 1-5 of the Appendix. The progress towards achieving the required finish is summarised immediately overleaf.

The indications are now that the solution is in sight using a heated mandrel followed by a cooled extension, together with a cooled outer calibration die placed in specific relation to it. This system is then followed by intense cooling by means of a water spray and trough combination.

It should be noted that reaching this point has generated fundamental information on the behaviour of SAFIRE material in the melt state vital to the scale-up stage.

Presentation to Ametex AG

S F Bush, Prosyma Research Ltd

Introduction: Basis of the SAFIRE Idea

1. To use Polymer flow to assemble the filaments into a coherent reinforcing structure upstream of the extrusion die or mould.
2. To protect filaments from breakage by separating them from their strands only after they have passed through the extruder of injection moulding machine.
3. To make the long fibre compound in granule form so that fibre length can be readily adjusted to applications and so that the granule matches the fibre management units.

Proposal made to Ametex AG

S F Bush

Summary

The project is split into three programmes, A, B, C. Programmes A and B are designed to carry the present technology to the point of commercial production using bought-in fibre granules. Programme C is designed to provide the technology for in-house fibre granule production.

Reinforcement of polymers: the general position

It has long been appreciated that the addition of glass or other stiff fibres to a thermoplastic or thermoset in a suitable fashion usually brings increased strength and stiffness to the processed materials. Fibre reinforcement is readily incorporated in both thermosetting and thermoplastic materials. However, in the case of thermoplastics the glass fibres have until recently been comparatively short – in the range 0.3 to 1.00 mm, while in the case of thermosets, the fibres have usually either been long discrete fibres woven into a loose mat (e.g. chopped strand mat) or actually continuous through a considerable portion of the structure.

If, for thermoset materials, long discrete fibres are used, they are either constructed into a loose woven mat and then impregnated with resin (as in conventional polyester GRP) or scattered in a random overlapping fashion on to a layer of resin with further resin poured on top as in Sheet Moulding Compounds. In either case a form of semi-coherent structure is obtained within the polymer liquid, this structure being maintained after the composite sets solid. This coherent structure is one of the two main reasons (the other being the cross-linked nature of a thermoset polymer) why fibre reinforced thermoset composites show much greater strength and stiffness than do the thermoplastic varieties based on short fibres which do not usually form such structures.

All three programmes were carried out at the Polymer Engineering labs at UMIST from 1987 to 1990, when the project moved to South Africa.