PVC Formulation by Application: Pipe, Profile, Sheet, Cable and Foam

1. Question

Which additive roles does a PVC formulation actually depend on for pipe, window profile, rigid sheet, cable and foam — and which of those applications can Allzone supply against today?

2. Direct Answer

Every rigid PVC application uses the same four functional roles — thermal stabilizer, lubricant balance, processing aid and impact modifier — but weights them differently. Pipe is dominated by throughput, fusion consistency and long-term pressure integrity. Window profile is dominated by outdoor colour hold and corner-weld strength. Rigid sheet and board are dominated by surface quality and gauge control. Cable and foam are different systems entirely: cable is driven by the plasticiser and the fire performance written into the cable standard, and foam is driven by cell structure and density, which depend on a blowing system that must be confirmed grade by grade.

Allzone supplies verified system components for the three rigid extrusion applications: PVC resin, a calcium-zinc thermal stabilizer system (ST-CZ200), a lubricant system (LU), and an acrylic processing aid / impact modifier (PA-PVC Core). Cable compounds and foamed PVC are routed to formulation review, not to a product page. The rest of this article separates what we can supply from what is general engineering information.

3. The Four Roles, Restated Briefly

• Thermal stabilizer — intercepts the hydrogen chloride released by the PVC chain at processing temperature and protects colour and mechanical properties. Chemistry selection is covered in the stabilizer comparison article.
• Lubricant balance — external lubrication controls metal release and fusion timing; internal lubrication controls shear heat inside the melt. Balance, not quantity, is the decision. Covered in the internal-versus-external lubricants article.
• Processing aid — accelerates and homogenises fusion, and raises melt strength so the melt holds shape.
• Impact modifier — restores ductile failure behaviour in a rigid, notch-sensitive part.

4. Rigid PVC Pipe — supported

Pipe extrusion runs long, steady and fast. The formulation is judged on three things: does it fuse to a consistent degree at line speed, does it survive the thermal history of the run without colour drift, and does the pipe pass its pressure and impact requirements after it is cool.

• Stabilizer carries the thermal load of a long residence time and any hold-up in the die.
• Lubricant balance sets fusion timing and controls output; too much external lubrication moves fusion downstream and costs throughput.
• Processing aid is used where fusion is incomplete at the required speed, and where weld-line quality matters.
• Impact modifier is used where the pipe must survive handling and low-temperature impact.

Allzone coverage: PVC resin, ST-CZ200, LU and PA-PVC Core are all relevant components to review for pipe. Suitability for a specific pipe standard is confirmed at quotation against supplier documentation.

5. Window & Door Profiles — supported

Profile is the most demanding rigid application on the outdoor side. A profile is welded at the corner and then left in daylight for decades.

• Stabilizer must hold initial colour and support weatherability; calcium-zinc systems are specified where lead and cadmium chemistry is not acceptable.
• Lubricant balance governs surface finish through the calibrator and the tendency to plate out on the die.
• Processing aid raises melt strength so the profile holds its section through calibration.
• Impact modifier determines whether the corner weld survives installation impact and cold-weather handling.

Allzone coverage: the same four components are relevant to review. PA-PVC Core is the single record that carries both the processing-aid and the acrylic impact-modifier role; it is not two products.

6. Rigid PVC Sheet and Board — supported

Sheet and board are judged on surface and gauge before anything else. Defects that would be tolerated inside a pipe wall are visible on a sheet face.

• Lubricant balance is usually the first place to look for matte patches, die lines and melt fracture.
• Processing aid improves melt coherence and reduces surface defects that come from incomplete fusion.
• Stabilizer carries the thermal load of calendering or wide-die extrusion.
• Impact modifier is used where the board is handled, drilled or fabricated.

Allzone coverage: PVC resin, ST-CZ200, LU and PA-PVC Core are relevant components to review.

7. Cable Compounds — general information only

Cable is a plasticised system, not a rigid one. What the formulation must achieve is written into the cable standard the customer is building to: insulation resistance, temperature rating, flame behaviour, smoke and acid-gas limits where they apply. The plasticiser system, the filler and the fire-performance package dominate the formulation, and none of those can be inferred from a rigid PVC starting point.

Allzone does not publish a PVC cable system. Nothing in the Allzone additive range should be read as an approved cable compound component: our flame-retardant and cable-related records belong to other polymer systems and are not offered as PVC cable solutions. Cable enquiries are handled as a technical review against the standard you are working to.

8. Foamed PVC — general information only

Foam board, foam core pipe and free-foam profile are governed by cell structure and target density. That depends on the interaction between the blowing system, the fusion profile set by the processing aid, and the melt strength available to hold the cells open. Chemical blowing agents exist as a product class, but their suitability for a specific PVC foam system is a grade-level question — decomposition temperature has to sit inside the fusion window of the compound, and that has to be confirmed against supplier documentation rather than assumed.

Allzone does not publish a PVC foam system, foam density guidance or a blowing-agent dosage. Foam enquiries are routed to formulation review.

9. Injection-Moulded and Flexible PVC — review first

Injection moulding sets the formulation for flow and cycle time rather than for continuous extrusion, and flexible PVC is defined by the plasticiser system and the target hardness. Both are handled as a technical review rather than from a shelf.

10. What This Article Deliberately Does Not Say

• No dosage, phr range, processing temperature or fusion figure is published here. Those values belong to the supplier technical data sheet for the specific grade.
• No claim is made that any Allzone grade is approved for a specific pipe, profile, sheet, cable or foam standard.
• No non-PVC product is presented as a PVC system component.

11. How to Take This Forward

Describe the application, the machine, the current formulation and the defect you are seeing. A formulation review is the right first step for every application on this page — including the three supported ones, because the component that needs to change is often not the one the symptom points at.

12. Related Reading

• PVC Additives Explained — how the four families act as one system
• Calcium-Zinc versus Lead and Tin Stabilizers
• Internal versus External Lubricants in PVC
• Processing Aids and Acrylic Impact Modifiers