FAQ and Solutions for PVC Production

PVC formulation performance heavily relies on precise additive dosage. Either insufficient or excessive addition of stabilizers, foaming agents, lubricants, impact modifiers and processing aids will trigger visible surface flaws, mechanical‑property loss and processing difficulties. This technical brief summarizes typical defects caused by improper additive loading during PVC manufacturing.

FAQ:

Q1: What is the MOQ?

A1: MOQ. is about 500kgs.Exact minimum order quantity varies for different product types, please confirm with us for specific items.

Q2: What if your payment term?

A2: Payment terms: 100% by T/T ,30% by T/T and 70% by L/C.

Q3:What about the delivery ?

A3: Delivery date:5-7 days.Subject to order quantity.

Q4: Can you supply free samples?

A4: Of course, we can supply you 200g~500g per product.

PVC Production Defects & Additive Dosage Troubleshooting:

Q1: What are the effects of insufficient calcium-zinc stabilizer on PVC products?

A1: When the dosage of calcium-zinc stabilizer is insufficient, the product may turn yellow or become discolored, with reduced toughness and increased brittleness. Plasticization becomes slower, resulting in a longer plasticization time. During processing, insufficient stabilization may cause corrosion of the screw and barrel and may produce an acidic odor. The surface gloss of the product may also deteriorate.

Q2: What are the effects of excessive calcium-zinc stabilizer on PVC products?

A2: When the dosage of calcium-zinc stabilizer is excessive, the product surface may become whitish, with surface precipitation or blooming. Scorch particles, black spots, and thermal degradation may occur. Material slippage may also occur, resulting in incomplete plasticization. Surface haze may increase, causing the product to lose its gloss.

Q3: What are the effects of insufficient foaming regulator on PVC products?

A3: When the dosage of foaming regulator is insufficient, foaming performance is weak and the ability to control cell structure is inadequate. The surface texture is poor and lacks the desired three-dimensional appearance of a foamed product. The product may have low strength and be prone to foam collapse due to insufficient melt strength and inadequate structural support.

Q4: What are the effects of excessive foaming regulator on PVC products?

A4: When the dosage of foaming regulator is excessive, the cells may become too large and uneven. Excessively high melt viscosity and melt strength may make demolding difficult and cause the material to stick to the mold. After cooling, the product may experience excessive shrinkage, resulting in warpage and deformation. The processing temperature window becomes narrower, and even slight deviations in processing conditions may result in scorching and thermal degradation.

Q5: What are the effects of insufficient white foaming agent on PVC products?

A5: When the dosage of white foaming agent is insufficient, the foaming expansion ratio is low and the product density is relatively high. Although the surface may be smooth, it lacks the characteristic texture and depth of a foamed product. The product may become relatively hard, with insufficient toughness and poor impact resistance.

Q6: What are the effects of excessive white foaming agent on PVC products?

A6: When the dosage of white foaming agent is excessive, the cells may become coarse and uneven. The foam structure may become unstable, resulting in collapse, deformation, warpage, and other dimensional defects. The product surface may become rough, with holes and other appearance defects. Excessive foaming may also severely deteriorate the overall mechanical properties of the product, including strength, rigidity, and toughness.

Q7: What are the effects of insufficient yellow foaming agent on PVC products?

A7: When the dosage of yellow foaming agent is insufficient, the foaming expansion ratio is inadequate, and the cells may be coarse and sparse. The product density is relatively high and the product may feel hard, lacking the lightweight feel of a foamed product. The surface may remain smooth but lack the characteristic foamed texture and three-dimensional appearance. The foam structure may also lack sufficient support, resulting in inadequate overall product strength.

Q8: What are the effects of excessive yellow foaming agent on PVC products?

A8: When the dosage of yellow foaming agent is excessive, the cells may become too large and uneven, with cell coalescence occurring. The foam structure may become unstable, resulting in foam collapse and cracking in the ribs. Pits and dents may appear on the product surface, accompanied by significant shrinkage and deformation. The product may also become prone to fracture. In addition, excessive foaming agent may decompose too rapidly, releasing a large amount of gas and producing a pungent odor, while narrowing the processing window.

Q9: What are the effects of insufficient external lubricant on PVC products?

A9: When the dosage of external lubricant is insufficient, excessive friction between the material and the mold may cause mold sticking and make demolding difficult, while the product surface may be scratched. Localized overheating may generate scorch particles and black spots, resulting in color streaks and color variation on the product surface. Equipment load may increase, accelerating wear of the screw and barrel and shortening equipment service life.

Q10: What are the effects of excessive external lubricant on PVC products?

A10: When the dosage of external lubricant is excessive, the excess lubricant may migrate to the surface, causing whitening, delamination, and surface precipitation or blooming. Excessive external lubricant may also delay plasticization, resulting in poor plasticization and reduced product strength. In foamed products, excessive external lubricant may interfere with cell structure, leading to uneven cell formation and surface appearance.

Q11: What are the effects of insufficient internal lubricant on PVC products?

A11: When the dosage of internal lubricant is insufficient, excessive friction between the material and the metal surfaces of the processing equipment may cause roller sticking and material buildup, while also increasing the risk of scorch formation. Plasticization becomes slower, resulting in a rough and uneven product surface. Processing current and torque may increase, placing a greater load on the equipment and accelerating wear. Scratches, pits, and other surface defects may also appear.

Q12: What are the effects of excessive internal lubricant on PVC products?

A12: When the dosage of internal lubricant is excessive, excess lubricant may cause material slippage inside the barrel, preventing effective forward conveying and resulting in a starving condition and incomplete plasticization. The product surface may develop an unnatural oily appearance, while lubricant migration and surface precipitation may result in blooming. Product strength may decrease and brittleness may increase. Surface deposits may also adversely affect the adhesion of secondary processes such as printing and lamination.

Q13: What are the effects of insufficient CPE on PVC products?

A13: When the dosage of CPE is insufficient, the product may have inadequate toughness and become highly prone to brittle cracking at low temperatures. The product may feel relatively hard, with insufficient flexibility and elasticity. Its resistance to environmental aging may also be reduced, potentially resulting in discoloration and performance degradation during long-term outdoor exposure. Overall impact strength and elongation at break may be lower.

Q14: What are the effects of excessive CPE on PVC products?

A14: When the dosage of CPE is excessive, the melt may become sticky, making mixing and extrusion more difficult and increasing the tendency for roller sticking. The product surface may feel tacky, affecting its use and subsequent processing. Product rigidity may decrease. Once the dosage exceeds the effective range, further addition may provide little or no performance benefit while increasing raw material costs.

Q15: What are the effects of insufficient ACR on PVC products?

A15: When the dosage of ACR is insufficient, plasticization becomes slower and melt strength may be inadequate. Uneven plasticization may occur during processing. An increased number of fish eyes may appear on the product surface, resulting in an overall rough surface with reduced gloss. Product strength may be lower and brittleness may increase, making the product more prone to cracking under stress or at low temperatures. During extrusion, motor current and equipment torque may increase, placing a greater load on the equipment.

Q16: What are the effects of excessive ACR on PVC products?

A16: When the dosage of ACR is excessive, the material may plasticize too rapidly inside the barrel, resulting in excessively high melt viscosity and melt strength and making processing control more difficult. The melt may easily adhere to roller or mold surfaces, causing roller sticking. Scorch particles, black spots, and other thermal degradation products may also occur. Increased residual internal stress in the product may lead to stress cracking during subsequent use or storage. Melt flowability may deteriorate, and the product surface may become rough or hairy, resulting in a less smooth appearance.