- Email: [email protected]
Laminated thread
VACUUM Classified A b s t r a c t s
II I - -
Vacuum
Processing Techniques Contd.
--
II I
Improvements i.o.r.t. The Metallisation of Plastic Materials United Kingdom. V a c u u m m e t a l l i s a t i o n of flexible plastics h a s p r o v e d difficult because of t h e h i g h volatility of t h e plasticisers c o n t a i n e d in t h e plastic r e s u l t i n g in poor adhesion b e t w e e n t h e plastic a n d t h e m e t a l film. To o v e r c o m e t h i s difficulty it is proposed to coat t h e flexible plastic (such as cellulose nitrate, cellulose esters a n d v i n y l polymers) w i t h a non-metallic m a t e r i a l i m p e r v i o u s to t h e volatile s u b s t a n c e s in t h e plastic. T h i s barrier layer, on to w h i c h t h e e v a p o r a t i o n of m e t a l t a k e s place, h a s good a d h e s i o n to b o t h t h e plastic a n d t h e m e t a l film. Suitable m a t e r i a l s are nylon, zein a n d gelatine. T h e l a t t e r works m o s t efficiently if a 0.001 inch t h i c k film of unplasticised cellulose n i t r a t e is applied to its surface before metallisation. Details are given of a t e s t to e v a l u a t e t h e a d h e s i o n of t h e m e t a l film. A p p l y i n g this t e s t it was f o u n d t h a t a l u m i n i u m films deposited on cellulose n i t r a t e m a t e r i a l plasticised w i t h 4 0 % b y weight castor oil, after a barrier film of n y l o n a p p r o x i m a t e l y 0.3 oz./sq.yd, h a d been applied u s i n g a solution of n y l o n in alcohol a n d h o t water, gave c o n s i s t e n t r e a d i n g of 100% adhesion.
Abstract No. and References
17/III
R. D. Brace, R. W. Maxwell & Imperial Chemical Industries Ltd. Brit..Pat. 370. 745,819
Improved Method of Coating Polytetrafluoroethylene See A b s t r a c t s No.: 84/II
lS/III
Method for the Manufacture of Plastic Articles Having Reflecting Surfaces Thereon See A b s t r a c t No.: 76/I
19/III
Laminated Thread United States. I n t h e past, t h r e a d s of metallic a p p e a r a n c e as e m p l o y e d in embroidering, braiding, knitting, etc. h a v e been p r o v i d e d in t h e form of a m e t a l foil strip l a m i n a t e d on b o t h sides with t r a n s p a r e n t strips of cellulosic material. T h e m i n i m u m t h i c k n e s s of t h e foil available for t h e p u r p o s e is of t h e order of 10 -3 m m . W h e n s u c h t h r e a d is twisted, its a p p e a r a n c e is dull. F u r t h e r , l a m i n a t e d foil t h r e a d of t h i s kind h a s a low shock s t r e n g t h a n d u n s a t i s f a c t o r y elongation properties. It is p r o p o s e d to p r o d u c e t h r e a d of metallic a p p e a r a n c e b y a m e t h o d w h i c h e m p l o y s v a c u u m deposition w h e r e b y a s h e e t of cellulose a c e t a t e b u t y r a t e of a n a p p r o x i m a t e t h i c k n e s s of 0.0016 inch is coated w i t h a l u m i n i u m b y v a c u u m e v a p o r a t i o n to a t h i c k n e s s s u b s t a n t i a l l y below 10 .3 m m . A f t e r deposition, a second s h e e t of t h e plastics m a t e r i a l is pressed on to t h e coated side of t h e first sheet, giving a t o t a l t h i c k n e s s of 0.0032 inch, suitable a d h e s i v e being used to effect firm bonding. S u b s e q u e n t l y t h e s h e e t is c u t in w i d t h s of 1/80th of a n inch. D u e to t h e good flexibility a n d i m p r o v e d elongation properties o b t a i n e d f r o m a p p l y i n g t h e n e w process, a t h r e a d of s u b s t a n t i a l l y lower w i d t h c a n be processed f r o m t h e strip c u t to t h e d i m e n s i o n s j u s t m e n t i o n e d . In addition, s u b s e q u e n t processing of t h e strip leaves t h e b r i g h t n e s s of t h e strip unimpaired.
20/III
K. E. PrindIe, G. Lacy & Dobeekmum Co. U.S. Pat. 2,714,569
Vaporised Metal on Synthetic Fibres Germany. Brief reference is m a d e to a process developed b y t h e Textile Chemical R e s e a r c h I n s t i t u t e , B a d e n weiler, w h e r e b y gold, silver, c h r o m i u m a n d a l u m i n i u m h a v e been successfully e v a p o r a t e d in a h i g h v a c u u m on to s y n t h e t i c fibres, f o r m i n g s t r o n g l y a d h e r i n g layers, 1 ~t thick. R e s e a r c h is proceeding on r e n d e r i n g t h e fibres durable a n d washable. Electrically-conductive metallised Perlon tissues are also being i n v e s t i g a t e d .
21/III Note by Anon. Prod. Engng. March 1956 8529-151
Coatings for Vacuum Metallised Plastics United States. V a c u u m metallising processes are used to give a mirror-like, p l a t e d a p p e a r a n c e on plastics. V e r y few plastic m a t e r i a l s can be metallised directly because of t h e presence of m o u l d flaws a n d surface b l e m i s h e s a n d t h e a b s e n c e of lustre. N o r m a l l y a l a c q u e r base coat is required to provide t h e requisite s m o o t h base for t h e metallic film. T h e base coat m u s t h a v e perfect adhesion. O n l y certain solvents c a n be u s e d in t h e m a t e r i a l for t h e base coat to avoid 'crazing' of t h e specific plastic. T h e base coat m u s t be capable of being 'cured' so as n o t to be affected b y a s u b s e q u e n t t o p coat, t h e ' s a n d w i c h coat' of m e t a l being too t h i n to form a n y barrier a g a i n s t solvents. 'Curing' is delicate for v a r i o u s reasons, e.g. m a n y of t h e cellulose plastics, a n d s o m e other, like polystyrene, c a n n o t w i t h s t a n d h i g h t e m p e r a t u r e s . Finally, t h e base coat m u s t p r e v e n t o u t g a s s i u g of t h e volatiles in t h e plastic as this increases t h e p u m p - d o w n t i m e in t h e v a c u u m c h a m b e r . T h e m a t e r i a l for t h e t o p c o a t (applied for p r o t e c t i v e purposes) should h a v e v e r y good clarity a n d flow-out in order to preserve t h e gloss a n d brilliance p r o d u c e d b y t h e metallic film, a n d should also t a k e dyes. Variables s u c h as differences in t h e plastics t h e m s e l v e s , m e t h o d s of application, m e t h o d s of production, colours desired a n d d u r a b i l i t y r e q u i r e m e n t s h a v e m a d e it i m p r a c t i c a b l e to f o r m u l a t e a ' u n i v e r s a l ' base a n d t o p c o a t i n g s a t i s f a c t o r y u n d e r all conditions a n d c o a t i n g s are still devised to m e e t t h e specific conditions of t h e job in every case.
22/III
Method of Applying Protective Layers to Reflecting Metal Surfaces
Article by C. C. Barbera Induatr. Finish. February 1956 53-54
23/III
Holland. T h e provision of reflecting m e t a l surfaces b y t h e deposition in vacuo of a t h i n l a y e r of a l u m i n i u m or silver on to a base coat of h a r d e n e d t h e r m o - s e t t i n g l a c q u e r is well known. I n order to e n s u r e d u r a b i l i t y of t h e reflecting surfaces v a r i o u s t y p e s of protective l a y e r are used. A p a r t i c u l a r l y i n e x p e n s i v e m e t h o d is described
October, 1956
Vacuum Vol. VI
;265
II I - -
Vacuum
Processing Techniques Contd.
--
II I
Improvements i.o.r.t. The Metallisation of Plastic Materials United Kingdom. V a c u u m m e t a l l i s a t i o n of flexible plastics h a s p r o v e d difficult because of t h e h i g h volatility of t h e plasticisers c o n t a i n e d in t h e plastic r e s u l t i n g in poor adhesion b e t w e e n t h e plastic a n d t h e m e t a l film. To o v e r c o m e t h i s difficulty it is proposed to coat t h e flexible plastic (such as cellulose nitrate, cellulose esters a n d v i n y l polymers) w i t h a non-metallic m a t e r i a l i m p e r v i o u s to t h e volatile s u b s t a n c e s in t h e plastic. T h i s barrier layer, on to w h i c h t h e e v a p o r a t i o n of m e t a l t a k e s place, h a s good a d h e s i o n to b o t h t h e plastic a n d t h e m e t a l film. Suitable m a t e r i a l s are nylon, zein a n d gelatine. T h e l a t t e r works m o s t efficiently if a 0.001 inch t h i c k film of unplasticised cellulose n i t r a t e is applied to its surface before metallisation. Details are given of a t e s t to e v a l u a t e t h e a d h e s i o n of t h e m e t a l film. A p p l y i n g this t e s t it was f o u n d t h a t a l u m i n i u m films deposited on cellulose n i t r a t e m a t e r i a l plasticised w i t h 4 0 % b y weight castor oil, after a barrier film of n y l o n a p p r o x i m a t e l y 0.3 oz./sq.yd, h a d been applied u s i n g a solution of n y l o n in alcohol a n d h o t water, gave c o n s i s t e n t r e a d i n g of 100% adhesion.
Abstract No. and References
17/III
R. D. Brace, R. W. Maxwell & Imperial Chemical Industries Ltd. Brit..Pat. 370. 745,819
Improved Method of Coating Polytetrafluoroethylene See A b s t r a c t s No.: 84/II
lS/III
Method for the Manufacture of Plastic Articles Having Reflecting Surfaces Thereon See A b s t r a c t No.: 76/I
19/III
Laminated Thread United States. I n t h e past, t h r e a d s of metallic a p p e a r a n c e as e m p l o y e d in embroidering, braiding, knitting, etc. h a v e been p r o v i d e d in t h e form of a m e t a l foil strip l a m i n a t e d on b o t h sides with t r a n s p a r e n t strips of cellulosic material. T h e m i n i m u m t h i c k n e s s of t h e foil available for t h e p u r p o s e is of t h e order of 10 -3 m m . W h e n s u c h t h r e a d is twisted, its a p p e a r a n c e is dull. F u r t h e r , l a m i n a t e d foil t h r e a d of t h i s kind h a s a low shock s t r e n g t h a n d u n s a t i s f a c t o r y elongation properties. It is p r o p o s e d to p r o d u c e t h r e a d of metallic a p p e a r a n c e b y a m e t h o d w h i c h e m p l o y s v a c u u m deposition w h e r e b y a s h e e t of cellulose a c e t a t e b u t y r a t e of a n a p p r o x i m a t e t h i c k n e s s of 0.0016 inch is coated w i t h a l u m i n i u m b y v a c u u m e v a p o r a t i o n to a t h i c k n e s s s u b s t a n t i a l l y below 10 .3 m m . A f t e r deposition, a second s h e e t of t h e plastics m a t e r i a l is pressed on to t h e coated side of t h e first sheet, giving a t o t a l t h i c k n e s s of 0.0032 inch, suitable a d h e s i v e being used to effect firm bonding. S u b s e q u e n t l y t h e s h e e t is c u t in w i d t h s of 1/80th of a n inch. D u e to t h e good flexibility a n d i m p r o v e d elongation properties o b t a i n e d f r o m a p p l y i n g t h e n e w process, a t h r e a d of s u b s t a n t i a l l y lower w i d t h c a n be processed f r o m t h e strip c u t to t h e d i m e n s i o n s j u s t m e n t i o n e d . In addition, s u b s e q u e n t processing of t h e strip leaves t h e b r i g h t n e s s of t h e strip unimpaired.
20/III
K. E. PrindIe, G. Lacy & Dobeekmum Co. U.S. Pat. 2,714,569
Vaporised Metal on Synthetic Fibres Germany. Brief reference is m a d e to a process developed b y t h e Textile Chemical R e s e a r c h I n s t i t u t e , B a d e n weiler, w h e r e b y gold, silver, c h r o m i u m a n d a l u m i n i u m h a v e been successfully e v a p o r a t e d in a h i g h v a c u u m on to s y n t h e t i c fibres, f o r m i n g s t r o n g l y a d h e r i n g layers, 1 ~t thick. R e s e a r c h is proceeding on r e n d e r i n g t h e fibres durable a n d washable. Electrically-conductive metallised Perlon tissues are also being i n v e s t i g a t e d .
21/III Note by Anon. Prod. Engng. March 1956 8529-151
Coatings for Vacuum Metallised Plastics United States. V a c u u m metallising processes are used to give a mirror-like, p l a t e d a p p e a r a n c e on plastics. V e r y few plastic m a t e r i a l s can be metallised directly because of t h e presence of m o u l d flaws a n d surface b l e m i s h e s a n d t h e a b s e n c e of lustre. N o r m a l l y a l a c q u e r base coat is required to provide t h e requisite s m o o t h base for t h e metallic film. T h e base coat m u s t h a v e perfect adhesion. O n l y certain solvents c a n be u s e d in t h e m a t e r i a l for t h e base coat to avoid 'crazing' of t h e specific plastic. T h e base coat m u s t be capable of being 'cured' so as n o t to be affected b y a s u b s e q u e n t t o p coat, t h e ' s a n d w i c h coat' of m e t a l being too t h i n to form a n y barrier a g a i n s t solvents. 'Curing' is delicate for v a r i o u s reasons, e.g. m a n y of t h e cellulose plastics, a n d s o m e other, like polystyrene, c a n n o t w i t h s t a n d h i g h t e m p e r a t u r e s . Finally, t h e base coat m u s t p r e v e n t o u t g a s s i u g of t h e volatiles in t h e plastic as this increases t h e p u m p - d o w n t i m e in t h e v a c u u m c h a m b e r . T h e m a t e r i a l for t h e t o p c o a t (applied for p r o t e c t i v e purposes) should h a v e v e r y good clarity a n d flow-out in order to preserve t h e gloss a n d brilliance p r o d u c e d b y t h e metallic film, a n d should also t a k e dyes. Variables s u c h as differences in t h e plastics t h e m s e l v e s , m e t h o d s of application, m e t h o d s of production, colours desired a n d d u r a b i l i t y r e q u i r e m e n t s h a v e m a d e it i m p r a c t i c a b l e to f o r m u l a t e a ' u n i v e r s a l ' base a n d t o p c o a t i n g s a t i s f a c t o r y u n d e r all conditions a n d c o a t i n g s are still devised to m e e t t h e specific conditions of t h e job in every case.
22/III
Method of Applying Protective Layers to Reflecting Metal Surfaces
Article by C. C. Barbera Induatr. Finish. February 1956 53-54
23/III
Holland. T h e provision of reflecting m e t a l surfaces b y t h e deposition in vacuo of a t h i n l a y e r of a l u m i n i u m or silver on to a base coat of h a r d e n e d t h e r m o - s e t t i n g l a c q u e r is well known. I n order to e n s u r e d u r a b i l i t y of t h e reflecting surfaces v a r i o u s t y p e s of protective l a y e r are used. A p a r t i c u l a r l y i n e x p e n s i v e m e t h o d is described
October, 1956
Vacuum Vol. VI
;265