PVC hose formulation
1. Non-toxic transparent hose [1]
PVC 100 DOP 45 ESBO 5 lauryl cinnamic 2
Calcium – zinc composite stabilizer 1
The plasticizer can also be used in BPBG and tributyl citrate.
2. Transparent hose [2]
PVC 100 epoxy plasticizer 5 DOP 30 organic tin 1.5
DBP 10 stearate and cadmium 1 DOA 5
3. Transparent hose [2]
PVC 100 ESBO 5 DOP 45 barium – cadmium liquid stabilizer 2
4. Transparent hose [2]
PVC 100 stearate zinc 0.05 stearate 1 DOP 28
Barium stearate 0.4 DBP 18 stearic acid lead 1
5. Transparent hose [3]
PVC 100 MBS 5~10 DOP 30 c-102 3
15 HSt 0.3 DBP
6. Non-toxic blood transfusion tube [3]
PVC 100 ESBO 5 DOP 45 HSt 0.5 AlSt 0.5 ZnSt 0.5 paraffin 0.2
7. Transparent courtyard water pipe [4]
PVC 100 DOP 40 ED3 10 barium – cadmium liquid stabilizer 1
Chelating agent 0.3 stearate
8. Transparent tube for beverage [4]
PVC 100 DOP (or DOA) 50
Calcium – zinc liquid stabilizer 3 stearate 0.5
9. Blood transfusion tubes and plasma bags [4]
PVC 100 DOP 45
ESBO 5~10 calcium – zinc liquid stabilizer 1.5
PVC transparent hose is made from polyvinyl chloride resin with a large amount of plasticizer, a certain amount of stabilizer and other auxiliaries. Has a transparent, light quality, good appearance, smooth soft and coloring is good wait for a characteristic, is widely used in construction, chemical industry, household, used to transport corrosive medium, water infusion, casing pipe and wire insulation is also used as a wire.
The formula of PVC transparent hose includes PVC resin, thermal stabilizer, lubricant, plasticizer and colorant. According to the above technical indexes, the formula design should meet the requirements of transparent, moderate hardness and higher intensity. In order to improve the transparency, in selecting the processing auxiliary materials, the refractive index (1) with the same or close auxiliary agent is selected as far as possible. The refractive index is similar to the refractive index of raw materials because the same or similar material is processed into a homogeneous mixture. Thus, the scattering phenomenon in the direction of incident light will not increase, so the turbidity of the products will not increase, and the transparency of the products will not be affected too much.
PVC resin: due to the large amount of plasticizer in the formula, it is necessary to choose the loose type resin. The white and thermal stability of resin is also required. Fewer impurities and fewer fish eye counts. In order to meet the requirements of mechanical properties, PVC transparent hose should be produced with a slightly lower molecular weight resin. Because of the common plasticizers dop and DBP often contains low relative molecular mass of the components, when processing temperature higher than 105 ℃, often volatile and form bubbles, low temperature can only control. In this case, the plasticization of resin with low molecular weight is higher than that of relative molecular weight, which is beneficial to improve the transparency of products. In addition, relatively low molecular weight resin is easy to process. General PVC- SG3, SG4, SG5 resin can be selected according to the product requirements.
Plasticizer:Â mainly consider its plasticizing effect, cold tolerance, durability and impact on PVC transparency. DOP is a kind of plasticizer with better comprehensive performance, with a refractive index of 1.484 and close to PVC refractive index (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 the refractive index of PVC resin. It will not affect the transparency too much, but its growth rate is poor and volatile, usually as a DOP auxiliary plasticizer. In order to improve cold tolerance, DOS as auxiliary plasticizer. The dosage of plasticizer commonly is 40~ 55.
Thermal stabilizer: in addition to the basic performance such as heat resistance, weathering and processing, the transparency should be considered. Organic tin stabilizer is the most ideal and most commonly used thermal 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 as thermal stabilizers in PVC transparent tube. Its composite products Ca/Zn, Ba/Zn, Ba/Ca and Ba/Ca/Zn are ideal. In order to reduce the amount of organic tin, choose calcium stearate (calcium soap) and zinc stearate (zinc soap) as auxiliary stabilizer.
Antioxidant phosphite vinegar and plasticizing and thermal stability of epoxy soybean oil, good transparency, cheap, can reduce the dosage of organic tin, has good effect to reduce process middle shading, and calcium stearate and zinc stearate with synergy, to formula system stability has a positive contribution.
Lubricant: can be divided into internal and external lubricants two kinds. In the P V C transparent hose, due to the larger dosage of plasticizer, the material’s viscosity is relatively small and its liquidity is good. Therefore, the amount of lubricant is less, and the dosage is 0.1~ 1.0. General use of metal soap, such as CaSt, BaSt, ZnSt, PbSt (the amount of PbSt is controlled at about 0.1, for example, use of the general assembly to influence product transparency), etc. The practical use of transparent lubricant is also: paraffin, polyethylene wax, stearic acid, stearate etc.
Colorant: more objective should be complementary color agent, due to the particularity of PVC molecular structure, the effect of heat and mechanical friction in the process of machining, even joined the enough stabilizer, also to a certain extent, yellow. Add a little paint to hide the yellow and make the product look more beautiful. The commonly used colorants are group blue, phthalein blue and whitening agent.
