syringe

To be honest, it sounds like English is your second language & something is lost in the translation.

I am not quite sure what you are trying to do.

1. Just measuring a stock syringe and modeling it is one hour's work in solidworks. I've done that on disposable syringes, so I know it is easy. It is a good practice project.

1. Analysis: That is vague. There is stress analysis, mold flow , mold fill, shrink, failure analysis, materials compatibility analysis & others like human engineering analysis/design which might be considered analysis.

Can you define better what you are tryingto do?

Bo

Perhaps the green card needs to be attained along with a certification in the English language.

I think Chinese people selling English goods should also have some form of English - tried reading any owner's manuals imported from China lately ?

Maybe the UN wwould regulate that language translation to an applicable standard. No, they are more concerned with fighting a war peacefully and getting some more AID's dollars to Africa. Also they would like to do away with private property so you can be their slave under their control.

Danny,

Can you explain further please?. We need to know if you are asking about how to model the syringe or how to do FEA analysis.

OK I sorry about my English. I would like to know how much oversize take in the plunger, And how to put the restraints on the part. Danny

1. The amount of "oversize" (interference fit) of the rubber plunger tip will depend on the exact grade and hardness of elastomer used, and its thickness over the solid support, and the pressure that the seal must withstand (pounds per square inch). There is no easy answer here. In addition to everything else, some neoprene or similar rubber compounds that are used on disposable syringes are not inert with some of the chemicals used, and those reactions can cause swelling of the rubber which makes for an even tighter fit as exposure time increases.

1. If by "restraints" you mean the undercut in the rubber tip or undercut inside the ID of the barrel to keep the plunger/piston from easily becoming separated from the barrel, again it depends on the materials used. Polycarbonate will require less undercut than a softer disposable Polypropylene.

Both of these things you ask about require either a "follow the leader" approach where you use the same basics as the major competitor, or you start doing your own experiments if that is necessary to optimize for your usage.

Myself, I have just copied what exist in disposables for my models, as I am not trying to do an improved design or produce syringes myself.

Bo