Bulk density is a property of powders and granules and other substances. It is defined as the mass of many particles of the material divided by the total volume they occupy. The total volume includes particle volume, inter-particle void volume, and internal pore volume.
Bulk density is very important when using volumetric dosing systems, same pigments concentration can do different result if bulk density is different.
The science of colour measurement.
Tendency of the colour to remain constant in time when applying the same masterbatch dosage under the same conditions along the production process.
Measure of the colouring ability of a masterbatch. A degree of the colour intensity given by the masterbatch.
It is the general term for the process of forming covalent bonds or relatively short sequences of chemical bonds to join two polymer chains together.
The cross-linking can be done by different ways in the cable industry. They are Peroxid Crosslinking, Silane Crosslinking and irradiation Crosslinking.
Dilution is the property according to which a masterbatch is integrated in the polymeric compound. A problem of dilution appears when the Masterbatch doesn’t evenly incorporate into the polymeric compound.
It can observe lines of colour more intense or masterbatch lumps in the final product. It can solve this problem modifying process conditions, raw materials or masterbatch formulation.
Dispersion is the property according to which a pigment contained in masterbatch is evenly distributed in the polymeric compound. A problem of dispersion can be when you observe pigment spots in the final product.
You can solve this problem improving quality of masterbatch.
Dosage o LDR (Let Down Ratio) is the amount of additive/masterbatch that needs to be added into the polymeric compound to reach the active material/color target. Technicians express this value in several different ways, being the more common to express % LDR on weight (3% of masterbatch into 97% polymer).
The heat stability of a masterbatch is the temperature until the masterbatch keeps its defined properties (do not confuse with polymer heat stability). This characteristic is defined by the polymers, additives and pigments. The most restricted heat stability of those components define the masterbatch heat stability.
It is the degree at which the color resists to fade because of light exposure, and it is commonly measured by the wool blue scale (1 minimum to 8 maximum). The type of pigments and the total amount of them in the masterbatch defines how resistant the color will be under light exposure.
It’s a concentrated mixture of dispersed pigments and/or additives encapsulated during a heat process into a carrier, via extrusion or high speed mixing, and presented on a granular shape.
UV stabilizers are a class of chemical additives added to polymeric materials to inhibit or retard their degradation produced by the photo-oxidation which is the combined result of light and oxygen.
UV stabilizers usually act by absorbing the UV radiation preferentially, and dissipating the energy as low-level heat.
Different UV stabilizers are utilized depending upon the substrate: benzotriazoles and benzophenones, work by absorbing the UV radiation and preventing the formation of free radicals, and HALS (Hindered amine light stabilizers) work to scavenge radicals produced by weathering.
It is the degree at which the color resists to fade because of outdoor conditions (light, temperature and humidity), and it is commonly measured by the grey scale (1 minimum to 5 maximum). The type of pigments, the total amount of them, and the polymeric compound recipe define how resistant the final product will be under outdoor conditions.
Technician can carry out experimentation leaving the material outdoors during months or years; or they can use specific equipment to carry out accelerated simulation tests (QUV test or Xenon Lamps) that can reduce the amount of time needed by 10 times approximately.
