• What are Low Temperature Thermoplastic Materials (LTTPs)?

    The splinting materials we use to fabricate orthoses today are referred to as low temperature thermoplastics (LTTPs) because we activate them using relatively low heat (water between 60-70°C or 140°-170°F) as compared to other high temperature thermoplastics which require higher activation temperatures ( greater than 100°C or 210°F). We can also place these LTTPs directly on our patients while we are molding the orthoses, unlike the previous generations of therapists who used higher temperature products and had to create molds of their patient’s arms.

    There are so many types and varieties of LTTP splinting materials available today.  It is just as important to know and understand the correct orthotic design for your patient’s needs as it is to select a proper LTTP for the orthosis. This ensures that your custom made fabricated orthosis is not only procedurally correct, but also supportive, durable, and comfortable as well.  Patients will tend to be more compliant with a comfortable and proper fitting orthosis.

  • How did we get so many types of LTTPs?

    LTTPs became available in the 1960’s. The first LTTPs were made from rubber products and therapists working with these had good control of the material as they formed splints.  But the material itself had minimal stretch and very little conformability. It was hard to mold around bony prominences. Plastic LTTPs were introduced in the 1970’s. Plastic LTTPs are highly conforming materials, but challenging to control. So, the manufacturers of these products tried combinations of plastic and rubber together. These LTTPs created well molded orthoses and offered a good amount of control.  Newer concepts in polymer production and design greatly improved the strength and rigidity as well as the elasticity of the LTTPs. As technology improves, we will continue to see improvements in our LTTPs.

  • What're some of the basic characteristics of thermoplastics?

    1. Rigidity refers to the strength of the material. High rigidity is necessary for large splints, specific diagnoses such as spasticity, and splints projecting large forces.
    2. Memory is the ability of the material to return to its original size and shape after being stretched. This is an important concept when frequent remolding of the splint will be necessary, as in serial splinting to increase extension or flexion over time. Memory makes the material more cost efficient. When working with materials possessing excellent memory, remember to let the splint harden sufficiently before removing or it will lose its shape rapidly. Also LTTPs with excellent memory tend to take longer to harden, so be patient!
    3. Coating is applied to certain LTTPs to make them easier to work with and less likely to adhere together where no adherence is desired. Bonding is the ability of the material to stick to itself or to other materials. Non-Stick coated materials do not bond without having the coating removed. Non coated materials have very good bonding to themselves and other attachments.
    4. Conformability or drapability refers to the way the material conforms to the shape of the hand. Materials with high drapability work best with gentle handling as they conform easily to the arches or bony prominences by just placing the material on the patient. These materials work with gravity. Materials with low drapability require firm handling and are recommended for larger splints where this moldability is less important.
    5. Resistance to stretch refers to the amount of resistance the material gives to being stretched when heated. High resistance means you must work slowly, firmly and steadily to stretch the material. Low resistance to stretch means you need to carefully control the material as it stretches. Too much pulling will make the material stretch out of control.
    6. Activation temperature is the temperature at which the splinting material becomes pliable for molding. If the water is too cool, the material will not become pliable. If it is too hot, the material will get overheated and sticky and become difficult to work with.  The ideal temperature for most LTTPs is between 60-70°C or 140°-160°F.  Please read the manufacturer’s instructions for use for each individual LTTP.
    7. Perforations in the splinting material allow for ventilation of the skin and make the material lighter in weight. Today we have choices ranging from percentages of perforations to various names of perforation patterns. Catalogs usually feature pictures which demonstrate the different perforation patterns. Always check to make sure the perforation style is suitable for the splint you are making.
    8. Thickness of an LTTP must be taken into consideration as well. Thinner materials such as 1.6 mm (1/16”) and 2.0 mm (1/12”) are better for smaller splints while larger splints may need thicker materials such as 2.4 mm (1/8”) or 3.2 mm (3/32”).  Thinner LTTPs are activated more quickly and also harden more quickly than thicker materials, meaning they have a shorter working time. Thicker materials take longer to become soft and pliable, but have a longer working time as well.  Thicker materials can retain a lot of heat and must be cooled slightly before placing on the patient’s skin.
    9. Working time describes the amount of time from when the material is fully heated to when it is cooled off.  Novice splint makers may want to choose materials that have a longer working time while advanced splinters can usually work quickly and accurately with LTTPs that cool and harden quickly.
    10. Pre-cuts or precut splints are ready to be heated and molded to your patient’s extremity. They are splint designs cut out of specific LTTPs and ordered by size (and/or Right and Left hand). Make sure you measure your patient correctly for each design.
    11. Prefabricated and /or preformed splints have already been molded into a specific shape.  These must be carefully fit to your patient’s extremity and some adjustments may be necessary.  The advantage in these is that the fabrication is complete and you may save time and effort.  However, you may not get as good a fit as when you custom make your own orthoses on your patients.
    12. Klarity’s LTTPs are biocompatible and biodegradable. They are being tested by an external firm for biocompatibility to make sure no skin irritations will be caused. Biodegradability means that the material will degrade in nature and is therefore environmentally friendly.
  • What is the shelf life of the splinting material I purchased

    LTTPs do have a limited shelf life as these materials are made from organic components that are vulnerable to environmental factors. UV rays, heat and humidity, bacteria and germs can all have a negative effect on the thermoplastic material causing breakdown. Always store your splinting materials flat in a dry, dark place for maximum benefit. Each product will have a label declaring the expiration date which is typically three years. If your product has been sitting on the shelf for longer than 3 years, it may not perform as expected. It may become brittle, discolored and overly stretchy.