Penetration resistance testing involves the insertion of a probe into a material with thickness.
This can determine the change of state of a material that cures or sets, or the texture of a material (e.g. food, pharmaceutical preparations, or cosmetics) whose firmness is a measure of a quality.
Cone probes are used for gels or viscous materials, needle probes for silicone pharmaceutical stoppers, and broader probes for penetrometers as used in cements and concretes.
Puncture resistance is a function of controlled stretch and tear at a point.
There are two sides to puncture resistance: it can be used to measure the sharpness of a point in penetrating a known membrane, or the resistance of a membrane to a known point.
Testing is therefore as important for medical devices such as hypodermic and suturing needles, as for silicone-stopped vials, and sharps containers.
High-force puncture testing is used for sharps, and for protective clothing such as gloves, stab vests, and fabrics for inflation.
Slow puncture testing employs a radiused probe under load, applied more slowly, and is important for materials such as foils and films, construction membranes or geotextiles.