BLOW MOLDING

Blow
molding is the most popular method to produce hollow products out of thermal
plastic material. It is the leading plastic manufacturing process because of
wide range of plastic resin that can be blow molded. Blow molding parts vary in
sizes, from very small to very large parts. The most common example of blow
molding is plastic bottles and containers but other items for instance
automotive components, medical equipment and toys etc.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

PRODUCTION OF THERMOPLASTIC RESIN:

Blow molding
products are formed from thermoplastic resin. Names are mentioned below. 

1.    
 High density polyethylene

2.    
Medium and low density polyethylene

3.    
Polyethylene terephthalate

4.    
Polypropylene

5.    
 Polyvinyl chloride

6.    
 Thermoplastic Elastomers

7.    
 Polystyrene

8.    
 Polycarbonate

9.    
 Fluoropolymers

10.                       
 Polyimide

 

 

 

TYPES
OF BLOW MOLDING:

It is basically classified into three
main types that are  extrusion blow
molding, injection blow molding and injection stretch blow molding, each of
three shares four common points of manufacturing.

1.    
Melting of resin.

2.    
Formation of preform.

3.    
Preform inflation and cooling in blow
molding

4.    
Ejection from the blow mold.

EXTRUSION
BLOW MOLDING:

Extrusion blow molding can either be
continuous or intermittent. In former the preform is subjected into mold and
each form will be cut off as the formation is done, while in later blow molding
process, while in former it expels each new plastic from the metal mold when it
is cooled and parison is fed into mold only after the preceding parison is
expelled out.

INJECTION
BLOW MOLDING:

In this process basically blow is
used. Parison is feed into a split mold cavity around the rod. The core rod
shifts the praison to blow mold machine where final shape is formed through
air. Final product is then extrude from machine. It is more economical than
extrusion blow molding.

INJECTION
STRECH BLOW MOLDING:

It is the combination of above two
types. The plastic is molded first to create bottle neck, as I cools down it is
dump into stretch blow molding machine, here it is reheated and the it is
forced into a plastic bottle.

ADVANTAGES
OF BLOW MOLDING:

v It brings variation in the product.

v It is economical.

v There are many alternative methods of
production.

v Productivity rate is increased.

                        DISADVANTAGE
OF BLOW MOLDING:

v It has bad effects on environment.

v It is largely based on petroleum.

v It has limited uses.

v It requires process and material precision
that creates waste.

x

Hi!
I'm Mack!

Would you like to get a custom essay? How about receiving a customized one?

Check it out