abrasive 마모는 표면이 거칠고 경한 돌기의 작용이나 경한 분말이나 외부로부터 분진
등의 연마작용, abrasive paper 등에 의해 발생하는 마모이다. 주로 재료의 기계적 성질의
영향이 크다 할 수 있다. 이것은 전술한대로 요철설에 의한 마모의 확장으로 간주할 수
있다.
그림 18. abrasive 마모의 모식
amount, and the process is repeated. In order to build an object the controlling drawing for each layer changes very slightly.
Typical standard manufacturing methods are subtractive, that is material is removed from a base form by machining with a lathe, with a drill, by cutting, planing or broaching. By contrast 3D-printing is an additive process, because material is added, layer by layer.
rest from
the fat man and Bacon?
Fat man, Bacon and myself.
Looks like its time
to call Harry.
Whos this fat man, eh?
Sandwich, Bacon?
Its not easy to take
a seat at this card table.
The amount of money
has to be grand upwards
and theres no shortage
of punters.
This is the man who decides
whether you can play -
Harry, or as some,
including himself, like to say,
Hatchet Harry.
grand.
If you go
1.Tiltle
Synthesis of PVAc and PVA
2.Objective
PVA(poly vinyl alcohol) is prepared by hydrolysis of PVAc, which is synthesized by emulsion polymerization of vinyl acetate.
3.Theory
◇ Background
-PVA
Polyvinyl alcohol has excellent film forming, emulsifying, and adhesive properties. It is also resistant to oil, grease and solvent. It is odorless and nontoxic. It has high tensile
adhesion between photo-resist and silicon wafer. The smaller the pattern size is, the slimmer the thickness of resist coating on silicon wafer is. As a results, because of bad contact, photo-resist can be strip from silicon wafer after patterning(strip phenomenon). To improve this problem, there is resists that polyoxyethylene or polysiloxane is main chain of polymer. Synthesized resist like this