The Invention of…
Download
1 / 12

LOW TEMPERATURE THERMOPLASTICS (LTT) - PowerPoint PPT Presentation


  • 101 Views
  • Uploaded on

The Invention of…. LOW TEMPERATURE THERMOPLASTICS (LTT). The story of Lester Larson and Dorothy Kester. Most Common Uses…. Splints - removable, comfortable casts for almost any part of the body. Foot Orthotics – custom-made shoe inserts to relieve back and knee pain. HISTORY.

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 ' LOW TEMPERATURE THERMOPLASTICS (LTT)' - gino


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

The Invention of…

LOW TEMPERATURE THERMOPLASTICS (LTT)

The story of Lester Larson and Dorothy Kester


Most Common Uses…

Splints - removable, comfortable casts for almost any part of the body

Foot Orthotics – custom-made shoe inserts to relieve back and knee pain


HISTORY

3000 BC - bark and palm ribs held together with egg whites or clay

860 AD - predecessor to plaster: lime/egg white mixture

Early 19th century - leather and straw treated with wine, acetate, spirits and egg whites - hardened quickly, but cast was very heavy

1835 - lighter-weight, removable bandage made of cardboard and starch - took several days to harden


HISTORY Cont…

Plaster of Paris - natural plaster deposits found near Paris, France - plaster powder rubbed into cotton, soaked in water and applied - cast had to be kept dry - very cumbersome

1970’s – fiberglass: light, durable and waterproof, still used today


HISTORY Cont…

  • Casts are not suitable for all injuries—such as tendon damage, soft tissue tears or post healing protection

  • LUCITE – High-temperature thermoplastic

  • Rigid and clear

  • Could not be molded directly on skin

  • Time-consuming process involving a negative cast and a positive mold



THE INVENTORS:

  • Lester Larson

  • DuPont Chemist

  • Broken wrist

  • Lucite Splint from

  • Dorothy Kester

  • Occupational Therapist

1963-1966

Invented Low Temperature Thermoplastics (LTT)


Eureka!!

The Metaphor


The Science of Thermoplastics

  • Plastic

  • Must meet three conditions:

  • Main ingredient must be a polymer

  • It must be fluid at some point of processing

  • It must be “solid” in its final form

Transpolyisoprene

Polymers


Lester Larson & Perkins' Model

Long Search/Little Apparent Progress:

Short process. Aware there was a problem, but no documentation of if there was other experimentation or ideas.

Precipitating Event:

Visit with OT and receives uncomfortable Lucite splint

Eureka!

Seeing the warm, moldable golf ball covers – that could be a splint

Transformation:

Acceptance by the OT community

Supplying the product to Orthopedic Shoe Company in NY


One 18” x 24” sheet of LTT sells for ~$60.00

HOW LTT IS USED:

  • Swan Neck Deformity - caused by finger injury or rheumatoid arthritis

  • Non-extending fingers – caused by injury or arthritis

  • Re-attached fingers – comfortable support and protection

  • Also used in radiation and burn treatment


QUESTIONS

Question 1: What was the metaphor used by Lester Larson?

Question 2: True plastic must meet three conditions. What are they?


ad