slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
A bone... PowerPoint Presentation
Download Presentation
A bone...

Loading in 2 Seconds...

play fullscreen
1 / 32

A bone... - PowerPoint PPT Presentation


  • 126 Views
  • Uploaded on

A bone. P. T. E. M. L. A. T. E. 3.082 FINAL PRESENTATION May 17, 2001. Bao-Yi Chang Elissa Robbins Elizabeth Immen Lisa Scoppettuolo. Thank you to Speed of Light for the Casting photograph. Injection Molding. www.biomet.com. Iron or Stainless Steel. Polymers: PLLA or PCL.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'A bone...' - chavi


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide3

P

T

E

M

L

A

T

E

3.082

FINAL PRESENTATION

May 17, 2001

Bao-Yi Chang Elissa Robbins

Elizabeth Immen Lisa Scoppettuolo

slide6

Iron or Stainless Steel

Polymers:

PLLA or PCL

mission goals
Mission/Goals
  • To fabricate a bioresorbable bone plate
  • To fabricate a bone plate with a modulus close to that of bone through selection of materials and processing conditions
injection molding1
Injection Molding
  • Used to fabricate plastic objects
    • -CD cases, water bottles, toys
  • Easy one step process
  • Ideal for mass production
injection molding machine

Hopper

Mold Chamber

Injection Molding Machine

Plasticating Unit

Control System

Equipment Specifications

Battenfeld 250

injection mold process

1. Begin Plastication

2. End Plastication

screw

nozzle

4. Begin Injection Mold

3. Close Mold

5. Eject Part

Injection Mold Process
slide11
Mold

-Obtaining Mold Blank

-Design Process

-Machining

-Adjustments

Plate Dimensions(in)

experimental runs
Experimental Runs

Varying Parameters

Establishing Ideal IM Conditions

Product Testing….

im parameters mechanics
IM Parameters  Mechanics

IM3: high screw speed, low pressure

IM1: low screw speed, low pressure

Bone plate, not shaped for tensile testing

IM4: high screw speed, high pressure

IM2: low screw speed, high pressure

g el p ermeation c hromatography
Gel Permeation Chromatography

• PCL degrades by hydrolysis

• PCL was placed in water to simulate the body’s aqueous environment

• Hydrolytic cleavage of PCL chains  Decrease in molecular weight

d ifferential s canning c alorimetry
Differential Scanning Calorimetry

Melting point of PCL = 63.245 oC

Polymers with low melting points are typically:

• low molecular weight

Tma Mw

slide19

Fabricate bone plate from a completely bioresorbable COMPOSITE

Bioglass Fibers

Ceramic Particles:

- Hydroxyapatite

- b-tricalcium phosphate

Possible Reinforcers

b-tricalcium phosphate (Ca3(PO4)2, b -TCP) is a bioresorbable ceramic

Future Plans

... Further Work and Study

- Satisfy the mechanical requirements of bone plates

- Mechanically superior to many bioresorbable homopolymers

slide20

FTIR patterns of PDLLA, TCP, and a PDDLA/TCP composite (50 wt. % TCP)

Possible Problems :

Poor adhesion between polymer matrix and ceramic reinforcer Poor mechanical properties

slide21

Methods of fabricating a PCL/b-TCP bone plate:

-Melting and Hot Pressing - Twin Screw Extrusion

- Pelletize Composite Mixture

- Injection Molding:

Viscosity (h) is an important parameter

slide22

“To fabricate a bone plate with a modulus of 3 GPa, the composite would have to be 90 % TCP by volume!”

Feasibility of a

PCL/b-TCP Composite

Ecomposite = XTCPETCP + (1-XTCP)EPCL (upper bound)

Ecomposite = 1 / [(XTCP / ETCP) + (1-XTCP)/ EPCL] (lower bound)

Source: Ashby, M.

Engineering Materials I.

template s composite bone plate
TemPlate’s Composite Bone Plate

By hot pressing a composite material of volume fraction 90% PCL / 10% -TCP, the modulus was increased by 60%.

cost analysis1
Cost Analysis

Polymer Injection Molding

  • Purchase Mold: (Master Unit Die) = $400
  • Design ($60/hr * 30hr) = $1800
  • Machining ($52/hr * 35hr) = $1820

----------

Total for Mold $4060

cost analysis3
Cost Analysis

Processing

  • Battenfeld Machine Repair = $250
  • Optimizing Initial Processing Conditions ($60/hr * 6hr) =$360
  • Injection Molding 1000 plates ($60/hr * 40hr) = $2400

----------

Total for IM $3010

cost analysis5
Cost Analysis

Material

  • Polycaprolactone (Polysciences, Inc. ($200/kg*20kg) = $4000
cost analysis6
Cost Analysis
  • Mechanical testing (Instron) ($60/hr*10hr) = $600

Product Analysis

cost analysis7
Cost Analysis

Summary

  • Overhead ~ $7000
  • Mold = $4060
  • Injection Molding = $3010
  • Materials = $4000
  • Product Analysis = $ 600
  • = $18,670

---------------

Total Cost of 1000 bone plates

cost analysis8
Cost Analysis

competition *

$168/bone plate

$20/bone plate

*Biomet.com