Formulation of pvc transparent hose

PVC transparent hose is made of PVC resin by adding a large amount of plasticizer, a certain amount of stabilizer and other additives, through extrusion molding.  It has the characteristics of transparent and smooth, light weight, beautiful appearance, softness and good coloring, etc. It is widely used in construction, chemical industry and family, used for water infusion, conveying corrosive medium, and also used as wire casing and wire insulation layer.

PVC transparent hose formula mainly includes PVC resin, heat stabilizer, lubricant, plasticizer and colorant.  The formula design should meet the requirements of transparency, moderate hardness and higher strength.  In order to improve transparency, in the selection of processing accessories, as far as possible to choose the refractive index and PVC resin refractive index (1) the same or similar additives.  Because the same or similar refractive index of the raw material processed into a uniform mixture, the refractive index and the refractive index of the raw material is similar.  In this way, the scattering phenomenon in the direction of incident light will not increase, so the turbidity of the product will not increase, and the transparency of the product will not be affected too much.

PVC resin: because of the large amount of plasticizer in the formula, PVC resin is required to absorb oil well, and loose resin should be selected.  At the same time, high whiteness and good thermal stability of resin are required.  Batch with low impurity count and fisheye count.  In the premise of meeting the requirements of mechanical properties, the production of PVC transparent hose should be used as far as possible with lower molecular weight resin.  Because commonly used plasticizer DOP and DBP often contain the component with relatively low molecular mass, when processing temperature is higher than 105℃, often can volatilize and form bubble, temperature can control on the low side only.  In this case, the degree of plasticization and melting of resin with low relative molecular weight is higher than that of resin with large relative molecular weight, which is conducive to improving the transparency of products.  In addition, lower molecular weight resins are also easier to process. General PVC-SG3, SG4, SG5 resin can be selected according to product requirements.

Plasticizer: mainly consider its plasticizing effect, cold resistance, durability and the influence of PVC transparency.  DOP is a plasticizer with good comprehensive performance, and its refractive index is 1.484, which is close to PVC (1.52~1.55).  Commonly used as the main plasticizer for PVC transparent hose.  The refractive index of DBP is 1.492, which is also close to that of PVC resin. It will not affect the transparency too much, but its growth efficiency is poor, and it is volatile, and it is generally used as DOP auxiliary plasticizer.  In order to improve cold resistance, DOS can be added as a supplementary plasticizer.  The dosage of plasticizer is 40~55 commonly.

Heat stabilizer: in addition to the requirements of heat resistance, weather resistance and easy processing and other basic properties, should also focus on its transparency.  Organotin stabilizer is the most ideal and most commonly used heat stabilizer for PVC transparent products, but the price is higher.  Metal soap stabilizers, such as calcium stearate, barium stearate, zinc stearate, etc., are commonly used heat stabilizers for TRANSPARENT tubes of P V C.  The compound products Ca/ Zn, Ba/ Zn, Ba/ Ca and Ba/ Ca/ Zn are more ideal.  In order to reduce the amount of organotin, calcium stearate (calcium soap) and zinc stearate (zinc soap) with good transparency and lubrication were used as auxiliary stabilizers.

Post time: Jul-07-2022