1. this ppt presentation has 187 slides, some with notes. It is much more than my short presentation. It includes sections on identification, degradation, conservation and storage and display. It is meant as an aide memoire as many of the slides are to support discussions. Should you need any help or further explanation please email me on cjw@smile-plastics.co.uk Please accept that this ppt presentation is my copyright. I am normally happy to visit collections which may include plastics materials and to give advice on identification and associated guidance. Please understand that I do not have any organisation to fund these visits so I shall have to make a charge for this service. Compared to the risks associated with degrading collections, this charge should be considered an investment! Colin Williamson, Mansion House, Ford, Shrewsbury, SY5 9LZ cjw@smile-plastics.co.uk

2. Plastics Colin Williamson

3. materials Plastics Colin Williamson

4. materials production techniques Plastics Colin Williamson

5. materials production techniques identification Plastics Colin Williamson

6. all you ever wanted to know about plastics

7. all you ever wanted to know about plastics in 3 x 20 minutes

8. all you ever wanted to know about plastics in 3 x 20 minutes + questions +discussion

9. only 2 types of plastic thermosetting

10. only 2 types of plastic thermosetting thermoplastic

11. thermosets moulded whilst soft and hot ‘set’ demoulded hot once heated and ‘cured’ won’t melt again generally compression moulded

12. thermosets Bois Durci rubber & vulcanite phenol formaldehyde - Bakelite urea formaldehyde - Bandalasta GRP – glass fibre reinforced polyester epoxies – adhesives polyurethane

13. compression moulding - thermosets

14. Phenol formaldehyde – Bakelite thermoset

15. thermoplastics melted to form shape cooled to set in mould can be re-melted

16. thermoplastics injection mould film blow bottle blow extrude calendar rotomould compression mould combination

17. injection moulding thermoplastics

18. extrusion - thermoplastics

19. calendar – sheet

20. thermoforming thermoplastics sheet

21. thermoplastic materials cellulose esters – Celluloid, CA polyethylene - polythene polypropylene polystyrene – also expanded, HIPS & ABS pvc – flexible or rigid PMMA – acrylic (Perspex)- sheet polycarbonate polyamide – nylon etc., etc., etc.

22. Identification

23. Identification education thirst for knowledge

24. Identification education thirst for knowledge conservation

25. Identification non-destructive non-invasive

26. Identification appearance dating - style & design

30. Identification appearance dating – trade marks, patents

36. British Patents prior to 1916 – annually 1916100,0011950634,001 1920136,8521955721,191 1925226,5711960826.321 1930323,1711965978,901 1935421,82719701,175,851 1940516,33819751,378,941 1945566,45119802,023,381

37. 1842 – 18671868 - 1883

38. A letter occupying the top of the diamond indicates the year A1845J1854S1849 B1858K1857T1867 C1844L1856U1848 D1852M1859V1850 E1855N1864W1865 F1847O1862X1842 G1863P1851Y1853 H1843Q1866Z1860 I1846R1861

39. If a number occupies the top of the diamond, the right field indicates the year A1871I1872U1874 C1870J1880V1876 D1878K1883X1868 E1881L1882Y1879 F1873P1877 H1869S1875

40. Bandalasta – urea/thiourea f

41. Xylonite – cellulose nitrate

42. Identification appearance colour and transparency

43. Transparent (i.e. glass clear) as thick solids (>2mm) PMMA – acrylic, Perspex, Plexiglas polystyrene polycarbonate cast phenolic – normally tinted polyester cellulose esters silicones, polyurethane

44. transparent solids polystyrene polycarbonate

45. Transparent (i.e. glass clear) as thin film or sheet as solid + PVC both rigid and flexible polypropylene regenerated cellulose (Cellophane) polyethylene PET (polyethylene terephthalate)

46. Only opaque (at best, translucent) phenol + urea formaldehyde – moulded gutta percha vulcanite Bois Durci + most compositions bitumen + cold moulded compositions composites, including GRP ABS foams

47. Colour phenol formaldehyde – Bakelite – dark cast pf – shades of amber pigment or compound wood or cloth fillers

48. phenol formaldehyde – Bakelite dark colours

49. Cast phenol formaldehyde – amber shades

51. pf – colour in blotches

52. thiourea formaldehyde colour pigment particles

53. wood flour filled shellac

54. cloth filled pf

55. cloth filled pf - Tufnol

56. Identification appearance surface finish

57. knife marks in CN sheet

58. ‘orange peel’ on urea formaldehyde

59. ‘sink marks’ modern inj. mld

60. Identification appearance degradation

61. cellulose nitrate – acidic, wet

62. cellulose nitrate, acidic, wet

63. cellulose acetate, plasticiser, dry

64. CA – distortion due to shrinkage after plasticiser migration

65. CA, plasticiser migration, constrained shrinkage

66. Casein, moisture

67. Identification appearance function

68. Identification appearance production method

69. Thermoformed sheet cellulose nitrate – very common pre 1950 casein – very limited bending polystyrene – very common post 1950 uPVC – very common post 1950 PMMA – Perspex, common post 1950 many other modern materials can be post formed from sheet

70. Blow moulded polyethylene – eg detergent bottles PET – eg fizzy drink bottles also uPVC, polypropylene, polycarbonate

71. Rotation Moulded polyethylene, e.g. canoes, road cones plasticised pvc, e.g. footballs, dolls also nylon and polycarbonate

72. Injection moulded most thermoplastics except casein and cellulose nitrate thermosets after 1960

73. Compression moulded almost all plastics materials but commercially not viable for modern thermoplastics. typical of thermosets

74. Casting polyester (especially embedding resins) PMMA (especially embedding resins) cast Phenolic polyurethane foam, e.g. shoes

75. ‘old vulcanite plaque’

76. ‘old vulcanite plaque’ - bubbles

77. ‘old vulcanite plaque’ – reverse raised rim

78. ‘old vulcanite plaque’ – reverse raised rim, crack, sawdust

79. ‘old vulcanite plaque’ raised rim, crack, sawdust  modern polyester

80. extrusion most thermoplastics parallel marks along the long axis film and sheet rod and profile fibres

81. Identification physical properties

82. hardness some plastics are softer than a finger nail polyethylene polypropylene gutta percha (except very old) plasticised pvc polyurethane rubber

83. smell phenol cast phenolic sulphur vulcanite camphorcellulose nitrate vinegarcellulose acetate (degrading) waxypolyethylene

84. Identification physical properties specific gravity solvents heat & fumes odours melting point analytical methods e.g. FTIR

85. Identification - Dating Pre 1840 Compositionswax, resins, shellac, gums, glue, drying oils Papier Maché Hoof and Horn Tortoiseshell Amber 1840 – 1880 More compositions, especially shellac based Gutta percha Bois Durci Vulcanite

86. Identification - Dating 1880 – 1900 Cellulose nitrate Compositions decrease 1900 – 1920 Cellulose nitrate increases Cellulose acetate Casein Bitumen

87. Identification - Dating 1920 – 1939 Phenol formaldehyde (cast phenolic, Bakelite) Thio-urea/urea formaldehyde Cellulose acetate injection moulded Melamine formaldehyde (polystyrene, polyethylene, pvc, pmma etc. ) 1945 – 1960 Thermosets decline Semi-synthetics decline Thermoplastics increase Composites introduced Foams, thermoplastic and thermosetting

88. why identify ?

89. to identify potential problems

90. why identify ? to identify potential problems to identify problem materials

91. problem materials cellulose nitrate – Celluloid cellulose acetate pvc polyurethane foams

92. questions

93. there’s no such thing as a stupid question

94. questions there’s no such thing as a stupid question only stupid answers

96. Degradation surface bloom distortion splitting colour change embrittlement crazing

97. Degradation surface bloom distortion splitting colour change embrittlement crazing

98. cellulose nitrate – acidic, wet

99. cellulose nitrate, acidic, wet

100. cellulose acetate, plasticiser, dry

101. Degradation surface bloom distortion splitting colour change embrittlement crazing

102. CA – distortion due to shrinkage after plasticiser migration

103. CA, plasticiser migration, constrained shrinkage

105. Degradation surface bloom distortion splitting colour change embrittlement crazing

106. Horn brooch front

107. Horn brooch back

108. CN billiard ball, zinc oxide

109. CA negative film

110. CN delamination

111. Degradation surface bloom distortion splitting colour change embrittlement crazing

112. CA, UV colour fade

113. CN, iron stain

114. CN

115. Polypropylene, UV, phototenderised

116. Rubber, oxygen + UV

117. Vulcanite, UV + water

119. Vulcanite, UV + moisture

120. pf (Bakelite) UV

121. pf (Bakelite) UV on pigment

122. Degradation surface bloom distortion splitting colour change embrittlement crazing

123. cn – stage 1

124. cn – stage 2

127. cn stage 3

128. cn movie film – stage 1

129. gutta percha sheet, oxygen

130. Irradiated polyethylene

131. uPVC, UV

132. Degradation surface bloom distortion splitting colour change embrittlement crazing

133. Casein, moisture

135. Degradation surface bloom distortion splitting colour change embrittlement crazing weeping

136. Degradation Weeping – typically CA plasticiser loss

137. Stability of Plastics

138. Cellulose Nitrate (Celluloid) hydrolysis Nitrogen oxides off gas Nitrous and nitric acids

139. Cellulose Nitrate (Celluloid) off gassing - corrosion moist haze acidic surface cuboid cracking movie film dry deepfreeze

140. Cellulose Acetate hydrolysis acetic acid - vinegar plasticiser migration

141. Cellulose Acetate smell of vinegar weeping dry plasticiser on surface distortion blisters

142. PVC originally unstable but UV and ΔH stabilisers added plasticiser migration rigid – darkens & embrittles flexible – stiffens/liquefies

143. Polyurethanes unstable as foam as high surface area and O 2 exposure darken, powder, crumbling

144. Other polymers all UV sensitive transparent worse than opaque amorphous (e.g. PMMA, P’s, Polycarb) – solvent sensitivity

146. Caring basic considerations storage inc. passive cons. cleaning handling degradation indicators display

148. Basic considerations identify the material before acquisition

149. Basic considerations identify the material before acquisition only acquire non-degrading items

150. Basic considerations identify the material before acquisition only acquire non-degrading items physical damage better than chemical

151. Basic considerations identify the material before acquisition only acquire non-degrading items physical damage better than chemical exposure stress, labels, paint, adhesive

152. Caring basic considerations storage inc. passive cons. cleaning handling degradation indicators display

153. storage no sunlight, heat, & damp no lights in stores 30-50% RH <5 o C < 30% slows degradation

154. storage no sunlight, heat, & damp no enclosed wrappings allow off gassing except for passive conservation

155. storage no sunlight, heat, & damp no enclosed wrappings acid free tissue

156. storage no sunlight, heat, & damp no enclosed wrappings acid free tissue not touching other items

157. storage not touching other items plasticiser migration degradation bi-products colour bleed

158. storage no sunlight, heat, & damp no enclosed wrappings acid free tissue not touching other items supported

159. storage supported stress sculpted bed cushion strongest points open framework check materials (cf display)

160. storage no sunlight, heat, & damp no enclosed wrappings acid free tissue not touching other items supported indicators

161. storage indicators cresol paper cresol string

162. storage no sunlight, heat, & damp no enclosed wrappings acid free tissue not touching other items supported indicators passive conservation

163. storage passive conservation scavengers activated charcoal – poss CN CA Zeolites – ok CA film long term Ageless – ok for rubber NOT CN CA

164. storage no sunlight, heat, & damp no enclosed wrappings acid free tissue not touching other items supported indicators passive conservation gloves

165. storage gloves lint free - snagging non-absorbent (acids)

166. Caring basic considerations storage inc. passive cons. cleaning

167. Caring cleaning advisable for conservation but curatorial ?

168. Caring cleaning water (sparingly) generally safe BUT

169. water generally safe BUT not immersion ? surface dyed casein not vulcanite not foam not degrading CN

170. Caring cleaning olive oil ok for sticky labels BUT beware ESC

171. Caring cleaning wax polish ?

172. Caring basic considerations storage inc. passive cons. cleaning handling degradation indicators display

173. Caring display 50 lux max 30-50% RH constant 20 0 C clean(ed) air acid fumes, organic vapours

174. Caring display suitable plastics for direct contact polyolefines (check stability and creep) polyethylene foam PET – polyester eg, Melinex, Mylar nylons

175. Caring display un- suitable plastics for display/support cellulose esters e.g.celluloid plasticised PVC polyurethane foam paint – esp solvent

176. So, you’ve got plastics in the collection ???

177. So, you’ve got plastics in the collection ??? What to do

178. Survey identify materials

179. Survey identify materials identify degradation

180. Survey identify materials identify degradation determine risk

181. Category A – High Risk Degradation started Likely to affect other materials

182. Category A – High Risk Degradation started Likely to affect other materials Cellulose Nitrate – ‘celluloid disease’ Attacked metals, wrapping

183. Category A – High Risk Actively degrading –record and discard -active conservation -isolate No active degradation –storage -6 monthly inspection -indicators -active conservation -cleaning

184. Category B – Medium Risk Likely to degrade but products of degradation inoffensive

185. Polyurethane Foam Store in reduced O 2 environment Ageless no light

186. PVC Unplasticised – UV sensitive Plasticised (flexible) Plasticiser loss -embrittlement Eventually liquifies