Ultrasonic sound in membrane manufacture

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Patents

Ultrasonic s o u n d in membrane manufacture P o r o u s m e m b r a n e s a r e often manufactured by irradiating a non-porous material with an e l e c t r o n b e a m or w i t h h e a v i e r ions, t h e n e t c h i n g t h e m a t e r i a l to enhance the minute holes made by the irradiation. The etching p r o c e s s is h e r e s p e e d e d u p b y subjecting the membrane and e t c h i n g b a t h to u l t r a s o n i c s o u n d a t f r e q u e n c i e s b e t w e e n 103 a n d 106 Hz. T h e m e m b r a n e i s p u l e d through a 1-100 micron gap b e t w e e n t h e two u l t r a s o n i c radiators.

cross-sectlon bundle can contain a g r e a t e r n u m b e r of f i b r e s t h a n a c y l i n d r i c a l b u n d l e of t h e s a m e width: this allows improved p e r f o r m a n c e w h e r e s p a c e is a t a premium. Patent number: J P 6 0 3 1 1 4 3 Date: 8 F e b r u a r y 1994 Inventor: T. Y a m a m o t o AppllcanL" UI~ I n d u s t r i e s Ltd

In t h i s i n v e n t i o n , t h e h o l l o w f i b r e s a r e p r e p a r e d i n t h e f o r m of a continuous woven sheet in which the hollow fibres are arranged across the sheet and other, n o n - p o r o u s , f i b r e s r u n a l o n g t h e s h e e t a n d give it i t s s t r u c t u r a l integrity. C o n t i n u o u s b a n d s of t h e r m o p l a s t i c a d h e s i v e a r e l a m i n a t e d to t h e e d g e s of t h e sheet. The sheet can then be f o l d e d to f o r m a s t a c k , or it c a n be cut and the individual sheets stacked. T h e r e c t a n g u l a r s t a c k of s h e e t s is t h e n h e a t e d s o t h a t t h e adhesive melts and secures the f i b r e s firmly, The b u n d l e - m a k i n g process then becomes a continuous operation. A square

Chilled water jug R e v e r s e o s m o s i s u n i t s for t r e a t i n g t a p w a t e r to p r o d u c e d r i n k i n g water can be plumbed into the w a t e r s u p p l y s y s t e m of a h o u s e ,

Patent number: SU 1 7 8 7 4 8 4 Date: 15 J a n u a r y 1993 Inventors: S.V. E l k i n , V.V. K u s h i n , V.K. L y a p i d e v s k i i

Applicant: M o s c o w E n g i n e e r i n g Physics Institute

Hollow fibre bundle manufacture B u n d l e s of f i b r e s a r e u s u a l l y produced by gathering individual fibres together, then applying t h e r m o p l a s t i c a d h e s i v e to o n e e n d of t h e b u n d l e , c o o l i n g t h e a d h e s i v e a n d t h e n c u t t i n g a slice off t h e a s s e m b l y s o t h a t t h e l u m e n s of t h e f i b r e s a r e c l e a r of glue. T h e p r o c e s s i s t h e n r e p e a t e d a t t h e o t h e r e n d of t h e b u n d l e to m a k e a b u n d l e of k n o w n l e n g t h which can be secured inside a container.

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Hollow flbre bundle manufacture

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Chilled water Jug

M e m b r a n e T e c h n o l o g y No. 53