safety with acrylic

59 Pages·2010·4.93 MB·English

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Acknowledgments
This document was produced in collaboration with the Education Liaison Group and
other leI staff onTeeside, who assisted with the technical details and provided support.
for printing and the teachers involved. Out ofprint Ifll and ESPI booklets provided a
framework ofinformation which was built upon by the working party. The cover
photographs were supplied by leI.
Members of the Working Party
Don Raspin - Education Liaison, ICI
Keith Waugh - Development Officer, Design and Technology, Cleveland L.E.A.
Polly Brettle - Advisory Teacher, Design and Technology, Cleveland L.E.A.
Paul Bennington -Head of Technology, Ormesby School, Cleveland
David Barrass - Head ofTechnology, Hartlepool Sixth Form College, Cleveland
Editor
Alan Stan cliffe
Polymer Industry Education Centre
Department ofChemistry
University of York
Heslington
York
Y015DD
Telephone [phone]
© Jointly held by ICI and the University ofYork
Published 1994
ISBN:185342700 4
The copyright holders waive the copyright onthe material which follows to the extent
that teachers may reproduce this material for use with their pupils in the establishment
for which the material was purchased, but for all other purposes permission to reproduce
any ofthis material in any form must be obtained from leI orthe University ofYork.
The material may not be duplicated for lending, hire or sale.
CONTENTS
Page
Introduction
SECTION1 SCHOOLBASEDPROCESSES
1.1WORKSHOPPRACTICE 1
1.1.1 Storage 1
1.1.2 Protective masking 1
1.1.3 Static electricity 1
1.2SAFETYWITHACRYLIC 2
1.2.1 Handling and machining 2
1.2.2 Flammability 2
1.2.3 Pressure shaping 2
1.3FABRICATIONPROCESSES 3
1.3.1 Safety 3
1.3.2 Perspex acrylic sheet 3
1.3.3 Marking out 3
1.3.4 Edge treatment 3
1.3.5 Cutting straight lines 4
1.3.6 Cementing 5
1.3.7 Machining 7
1.4SIMPLETHERMOFORMINGTECHNIQUES 8
1.4.1 Effect of moisture 8
1.4.2 Oven heating 8
1.4.3 Single curvature forming 9
1.4.4 Double curvature forming 11
1.5VACUUM FORMING 13
1.5.1 Equipment 13
1.5.2 Moulds 14
1.5.3 Heating times 15
1.5.4 Cooling times 16
1.6FLUIDBEDCOATING 17
SECTION2 INDUSTRIALBASEDPROCESSES
2.1PROCESSINGMETHODS 18
2.1.1 Extrusion 18
2.1.2 Balloon blowing 19
2.1.3 Calendering 20
2.1.4 Injection moulding 2 1
2.1.5 Thermoforming by pressure 22
2.1.6 Thermoforming by vacuum 23
2.1.7 Biaxial stretching of film 24
2.1.8 Glass Reinforced Plastics Lay-up and Moulding 25
2.1.9 Plastic laminates 27
2.1.10 Compression moulding 28
2.1.11 Rotational moulding 29
2.1.12 Extrusion blow moulding 30
2.1.13 Injection stretch blow moulding 3 1
2.1.14 Dip moulding 33
2.1.15 Structural foam moulding 34
1
APPENDICES
Appendix 1 Properties and applications - Thermoplastics 35
Appendix 2 Properties and applications - Thermosets 36
Appendix 3 Physical properties of some thermoplastics 37
Appendix 4 Chemical resistance of some thermoplastics 3 8
Appendix 5 Summary of main industrial processes 39
Appendix 6 Equipment and materials suppliers 40
Appendix 7 Other resources 4 1
Trade names and abbreviations associated with different materials are
included in the tables listed above.
11
Introduction
This booklet has been produced in response to enquiries from teachers of
Design and Technology seeking information on working practices in industry
and schools relating to thermoplastics. It is not an exhaustive reference guide
but does provide an introduction to basic techniques suitable for schools and the
more common processes found in industry.
The booklet is intended as a resource for the teacher but could also be used as a
source of information for students engaged in Design and Technology project
work for National Curriculum Key Stage 4 and for 16+ courses. Some ofthe
practical working methods outlined will also be relevant to Design and
Technology projects at Key Stage 3 ofthe National Curriculum. Teachers
involved with the Scottish Curriculum for Technical Education, particularly
with the 11-18yrs age group, will find the information relevant.
Section one considers storage and safety procedures to be observed in schools
and colleges in respect of plastics materials. It then goes on to outline some
practical processes which can be undertaken using equipment normally found
in school/college Design and Technology departments.
Practical workshop processes have been outlined using acrylic as a sample
material since this is one of the most commonly used in schools. However,
most ofthe techniques described will be suitable for other thermoplastic sheet
materials (e.g. polystyrene, PVC, ABS) providing consideration is given to
differences in softening temperatures and appropriate categories of adhesives.
Some techniques previously used in schools are now restricted as a result of
regulations relating to Control of Substances Hazardous to Health (COSHH)
and are not included in this document.
It is common for all acrylic materials to be incorrectly described as Perspex.
In fact Perspex is an ICI trade name for their own acrylic products. When
referring to the material in general terms the correct title is Acrylic.
.~ection two describes some of the more common industrial processes currently
In use.
Appendices 1 to 5 provide extensive tables ofproperties, applications and
processes which will be useful for both teachers and older students studying at
sixth form and FE levels. Appendix 6 lists equipment and material suppliers;
appendix 7 lists locations of other resources.
iii

SECTION 1
SCHOOL BASED PROCESSES