The MuscleMate™ is manufactured in Australia using polyurethane integral skin foams. These comprise a low density foamed core surrounded by a high density skin of the same material, and are made in a single molding operation. The materials used are TGA approved.
Polyurethane integral skin foams find wide application as structural materials, and the mechanical properties of such foams are significantly affected by the foam structure, which in turn is determined by the foaming process. By using organically inspired flow mould designs and optimal mold wall temperature we have developed an ideal skin thickness and smoothness giving a hard wearing and easily cleaned massage tool.
The new MuscleMate™ is a development of an earlier design which although effective could not achieve consistency of hardness and finish, particularly accounting for the air bubbles dispersed during mixing. The new MuscleMate™ gives an improved “hand feel” and an even more consistent treatment action for fascial release and trigger point stimulation.
Fatigue resistance and durability of MuscleMate™
It is vital that the MuscleMate™ endure for a considerable length of time, even under intensive use. When researching fatigue, we looked at two test methods:
- the static fatigue test, in which the foam is subjected to a fixed stress for a long period of time, and
- the dynamic fatigue test, in which the foam is subjected to rhythmically changing stress.
By using optimal volumetric (density) loads both fatigue performance and durability have improved.
Optimal Hardness of MuscleMate™
Hardness is a measure of the comfort of plastics in therapeutic applications and is most commonly measured by the Shore A (Durometer) test which measures the resistance of plastics to indentation and provide an empirical hardness value. This is the preferred method for polyurethane integral skin foams used in the NEW Muscle Mate.
The Shore hardness is measured with an apparatus known as a Durometer and consequently is also known as ‘Durometer hardness’. The hardness value is determined by the penetration of the Durometer indenter foot into the sample. Because of the resilience of rubbers and plastics, the indentation reading my change over time – so the indentation time is sometimes reported along with the hardness number.
The ASTM test method designation is ASTM D2240 00 and is generally used in North America. The results obtained from this test are a useful measure of relative resistance to indentation of various grades of polymers.
However, the Shore Durometer hardness test does not serve well as a predictor of other properties such as strength or resistance to scratches, abrasion, or wear, and should not be used alone for product design specifications. Shore hardness is often used as a proxy for flexibility (flexural modulus) is specifying elastomers.
The correlation between Shore hardness and flexibility holds for similar materials, especially within a series of grades from the same product line, but this is an empirical and not a fundamental relationship.
The NEW Muscle Mates have a hardness of 30-50 Durometer A, in accordance with Standard Test Method for Rubber-Property Durometer Hardness, ASTM D2240.