Principle selection of anti-blocking masterbatch

The use of plastic is different, the choice of anti-blocking masterbatch is not the same, in addition to the selection of anti-blocking masterbatch to meet its chemical properties are stable; Water resistance, chemical resistance, weather resistance, heat resistance and so on; Do not reduce the physical properties of plastic products; Large filling amount, small density; Besides the basic requirements such as cheap and easy to obtain, the following points should also be paid attention to.

The oil absorption of the anti-blocking masterbatch refers to the absorbability of the anti-blocking masterbatch itself to the liquid additive (such as plasticizer, etc.) in the formulation. Its size is determined by the amount of oil absorption. The amount of oil absorption is defined as the maximum number (mL) of the liquid additive absorbed by the opening agent. The oil absorption of the anti-blocking masterbatch mainly affects the amount of liquid additives added in the formula system. The larger the oil absorption is, the amount of liquid additives added should be increased accordingly to make up for the liquid additives absorbed by the filler and can not play a role.

The resin absorption of the opening agent refers to the absorption of the opening agent to the liquid resin (such as unsaturated polyester, etc.), and its size is expressed by the maximum volume (mL) of the opening agent absorption resin of 100g. The resin absorbency of the anti-blocking masterbatch depends on its property, particle size, shape, adsorbability and surface treatment.

Because the opening agent has oil absorption and resin absorption, the following two points should be paid attention to when choosing the opening agent:

1) When the formula system contains liquid auxiliaries, the filler with small oil absorption should be selected.

2) When the formula system contains liquid resin, the filler with small resin absorption should be selected.

The shape of the anti-blocking masterbatch can be divided into ball, granular, flake, fibrous, columnar and hollow microspheres. Except spherical and hollow microspheres, other shapes showed anisotropy, and the larger the aspect ratio of these anisotropy opener, the more beneficial to the improvement of mechanical and thermal properties.

Fibrous, columnar, sheet and other large aspect ratio of the anti-blocking masterbatch to improve mechanical properties, so sometimes called reinforcement, but this kind of filler is not good for molding processing.

Spherical and granular fillers with small aspect ratio are favorable to molding processing, but unfavorable to the mechanical properties of materials.

The particle size of the anti-blocking masterbatch has a great influence on the properties of the filled composites.

The smaller the particle size is, the tensile strength, impact strength, light scattering, light transmittance and rheological behavior of the materials have positive effects. Especially for tensile strength and impact strength, when the particle size of the opener is larger, both of them decrease.

When the particle size is small to a certain value, both of them rise, but with the increase of the filling amount reaches a limit value, they start to decline. The size of the limit value, that is, the maximum filling amount, is related to the particle size. The smaller the particle size, the higher the limit value.

Ultrafine fillers provide a very effective method for material modification, which can improve the rigidity and toughness of materials at the same time. At present, the particle size of the conventional opener is 0. 1 ~ 15μm, and for the ultrafine filler, such as nanometer material, the particle size can reach about 10nm.

While reducing the cost of composite materials, the anti-blocking masterbatch can also improve its rigidity and heat resistance. Some fillers can also give the material some special properties. Therefore, in the specific selection of the anti-blocking masterbatch, in addition to considering the cost, but also consider its modification function.

When there are many different auxiliaries in the filling compound system, it should be noted that the anti-blocking masterbatch cannot affect the role of other auxiliaries.

For example, the anti-blocking masterbatch often affects the curing effect of the curing agent. Because the anti-blocking masterbatch can adsorb the curing agent and accelerator, so the curing system containing the anti-blocking masterbatch, the addition of curing agent should be appropriately increased. In addition, when the PVC formula contains anti-blocking masterbatch, the amount of plasticizer should be increased appropriately.

The addition of the anti-blocking masterbatch reduces the processing fluidity of the resin, and increases the friction between the molten material, the molten material and the barrel or the screw, so it is necessary to add lubricant or increase the use of the original lubricant. But some fillers, such as talcum powder, graphite and so on have lubricating properties, can not add or add less lubricant.

The addition of the anti-blocking masterbatch increases the processing temperature of the resin, often reduces the thermal stability of the resin, so it is necessary to add the heat stabilizer or increase the amount of the original heat stabilizer.

The addition of anti-blocking masterbatch mostly reduces the surface gloss of products. In order to ensure the surface brightness of products, some substances that can improve the gloss are often added, such as white oil and so on.

The addition of anti-blocking masterbatch will affect the processing properties of resin, which can be improved by adding 3% ~ 5% processing additives.

The effect of adding different anti-blocking masterbatch into the filling system is better than that of adding the same amount separately. For example, when CaCO3 and talc are added together, they have synergistic effect in the range of 10% to 45% of the added amount.