The second of three Prosyma Research Ltd reports to Santar on SAFIRE projects

“Santar Pipe and Forward Programme” 30th August 1991 and “Design of Fibre Lacing Device” 22 January 1993.
S F Bush

Introduction

1. Commissioning the vacuum-forming pipe mandrel (at Santar).
2. Commissioning the Mark VI granulation die (at UMIST).
3. Modifications to Mark VI: manufacture with Polybond coupling agent.
4. Results from AFI fibre.
5. Precoating:
   1. UMIST
   2. Santar
6. Commercial potential for SAFIRE granules: examination of competitor products.

The third of three Prosyma Research Ltd reports to Santar on Granex, 6th December 1990, 5th June 1991 and 15th August 1991.

S F Bush

Summary

The SAFIRE long fibre reinforced pipe and sheet-making processes depend on the production of suitable long-fibre granules. The granules are used either in conjunction with virgin granules or on their own depending on the concentration of fibre required in the final product. Recently the granules have been applied to injection moulding.

For good final product it is apparent that each fibre should (a) be well-wetted by the polymer and (b) should retain a high proportion of its original length. The Granex process is designed to produce granules with these characteristics. This report concentrates on measuring characteristic (a) for a variety of Granex head designs. The last design in the series (Mk Va – March 1991) shows about 65% wetting which is a great improvement on the earliest results (10% – October 1988) though these low levels were not recognised at the time. Further improvements are in hand to raise the wetting level to 95% without increasing fibre breakage.

Prosyma Research Ltd report “Glass Rovings Delivery System” to Santar

S F Bush

Summary

This is a brief report on a system which has been designed to improve steady running in the granule making process at UMIST and Santar.

The system reduces glass roving breakage and therefore increases production run-times. As it stands the system can be further improved, but even as it stands it is a marked improvement on simply drawing roving from a cheese.

Extracts from three Prosyma Research Ltd reports to the Everite Group, 6th April 1990 to 19th November 1990.

S F Bush

(The focus of the SAFIRE work moved to Santar situated in South Africa.)

SAFIRE A – Pipe extrusion (6th April 1990)

The work in the period under review (the S-runs) was taken up with extending the work of the R-runs (reported in Report 7) to a wide range of SAFIRE materials.

Altogether we have demonstrated pipe making capability in the SAFIRE polypropylene granules typical of the Santar materials as well as the Santar specified HDPE Hostalen GM5010. Note that this HDPE grade is black and this adds a dimension of potential difficulty because of the tendency for carbon black to cling to upstream discontinuities.

SAFIRE A – Pipe extrusion (1st May 1990)

The last report highlighted the likely effects of temperature on the presence or absence of weld lines. Consequently the work in the period under review (T-runs) has concentrated on repeating, where possible, the S-runs but at higher temperatures.

The results so far show that a significant decrease in polymer MFI requires a substantial increase in temperature in the mixing zone. This is particularly evident with Hostalen 5010, the HDPE grade proposed by Everite. Its MFI is about 0.3 at 230 ^oC compared with 0.4 for the PP Profax used up to now. Runs at 240 ^oC insread of 220 ^oC used in the S-runs show an appreciable increase in burst strength which may tentatively be ascribed to more complete disappearance of the weld line.

Injection Moulding (19th November 1990)

Recent results at UMIST have shown that SAFIRE granules may be injection moulded with separation and average fibre length retentions comparable with the values found in extrusion. This is achieved with a minor adaptation of a standard injection moulding machine and a simple version of the Fibre Separating Unit.

Prosyma Research Ltd report to Nueva AG

S F Bush

The overall objectives of the projects over the six months to 30th June 1990 are:

1. Provide the process data for optimising the strength performance of the scale up pipe process, in particular for HD-Hostalen 5010. Part of this objective is to define, if possible, the conditions under which fibre loadings above 2.5 v/v do or do not give broadly proportionate increases in strength and stiffness (SAFIRE A).
2. Provide input to the scale-up design so that the results of objective 1 can be readily implemented (SAFIRE B).
3. Complete the development of the Mark IV granulation head so that the SAFIRE granules can be made in the relevant fibre concentrations (4 – 10% v/v) for the Olefine polymers of main interest (HD, PP, LD) (SAFIRE C).
4. Continue the testing programme to support objectives 1 and 3, in particular focussing on fracture behaviour. Carry out creep experiments for SAFIRE Hostalen at 2% and 3% v/v at 23 and 60 ^oC (SAFIRE D).