Laboratory Tests

Ash test

Our “Ash Test” method is used to determine the ash residual in molded plastics or the resin. The direct calcination method involves taking a known amount of sample into a pre-conditioned and pre-weighed crucible, burning the organic matter in an air atmosphere at temperatures around 600ºF (pre-burn), heating the remaining residue at 800ºF, and weighing the crucible after it has been cooled to room temperature in a desiccator. The procedure is repeated until a constant mass is reached.

The ash test result is expressed as % ash, calculated from the mass of the ash (Mash) and the initial mass of the sample (Msample). We can report the net ash in parts per million (ppm) or equivalently mg/kg.
% 𝑛𝑒𝑡 𝑎𝑠ℎ = M𝑎𝑠ℎ/M𝑠𝑎𝑚𝑝𝑙𝑒 × 100

Coordinate Measuring Machine

A coordinate measuring machine (CMM) is a device for measuring the physical geometrical characteristics of an object. This machine may be manually controlled by an operator or it may be computer controlled. Direct Computer Control (DCC). DCC CMMs can be programmed to repeatedly measure identical parts.

Measurements are defined by a probe attached to the third moving axis of this machine. Probes may be mechanical, optical, laser, or white light, among others. A CMM takes readings in six degrees of freedom and displays these readings in mathematical form.

Our CMM capabilities are repeatability of ± 2.4µm and linear accuracy of (1.74 + 4.6-L)µm and our part capacity in X & Y axis is 47” and Z axis is 29”. Table Load: 3000 LBS

Melt flow indexing

Melt flow indexing is the most popular, but least accurate way to determine material viscosity. The melt flow index (MFI) is the measure of how many grams of polymer pass through a standardized capillary under a standard load over 10 minutes. The value obtained through the melt flow index test is a single data point. The melt flow index only tests the material at one shear stress and temperature.
In general, a higher melt flow index indicates a lower material viscosity. This means that a material with a melt flow index of 20 flows easier than a material with a melt flow index of 5. Melt flow index information from different materials and material grades may be used for a rough comparison of flow characteristics for different materials.

We use this data to quality control inbound lots of material to help prevent and anticipate changes in the process. For example, if the lot of material you are processing has a MFI of 10, and a new lot has an MFI of 15. You can anticipate issues such as flash, over packing, or overweight product and make the necessary changes to provide continual process optimization.

Specific Gravity

Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water at its densest (4°C) for liquids; for gases it is air at room temperature (21°C) Being a ratio of densities, specific gravity is a dimensionless quantity.

Specific gravity varies with temperature and pressure. Substances with a specific gravity of 1 are neutrally buoyant in water. Those with SG greater than 1 are denser than water and will sink in it. Those with an SG less than 1 are less dense than water and will float on it. The apparent specific gravity is simply the ratio of the weights of equal volumes of sample and water in air. With regards to polymers, each plastic has its own SG and therefore can be measured to ensure its density properties are correct.

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