Choose HDPE, PP-H or PVC-U for the service conditions, not the polymer name alone. For a tank, liner, guard, duct or machined part, chemical exposure, temperature, load and joining method can point to different materials.
The comparison below covers common unfilled industrial sheet grades. Density figures are approximate material examples, not specifications for the products we quote. Use the offered grade's technical data and chemical-resistance information to check the final choice.
HDPE vs PP-H vs PVC-U: useful differences
| Selection factor | HDPE (PE-HD) sheet | PP-H sheet | Rigid PVC (PVC-U) sheet |
|---|---|---|---|
| Illustrative density of unfilled grades* | About 0.95 g/cm³ | About 0.91 g/cm³ | About 1.4 g/cm³ |
| Temperature under continuous load | Check creep, support spacing and chemical exposure | Often considered for warmer chemical service; check the grade and design | Check the grade's lower service-temperature range before selecting |
| Stiffness at comparable dimensions | More flexible; may need a thicker section or closer supports | Commonly stiffer than HDPE; compare the specified grades | High stiffness; check impact and thermal requirements as well |
| Low-temperature impact | Often shortlisted for impact at low temperatures | PP-H impact performance can fall in cold service | Depends on grade; impact-modified PVC-U is not equivalent to standard PVC-U |
| Common fabrication | CNC machining, thermoforming, extrusion welding and hot-gas welding | CNC machining, thermoforming, extrusion welding and hot-gas welding | Machining, hot-gas welding, warm bending and compatible adhesive bonding |
| Typical reasons to shortlist | Impact resistance, low water absorption and outdoor service with UV stabilisation | Chemical equipment requiring stiffness and warmer service conditions | Rigid panels, ducts and equipment with grade-specific fire requirements |
1. Compare chemical resistance at the actual concentration and temperature
Check the chemical name and concentration, normal and cleaning temperatures, contact duration and applied stress. Mixtures and cleaning agents matter too. A room-temperature compatibility rating does not establish suitability for a loaded tank at a higher temperature.
When PP-H is worth evaluating
For chemical tanks, pickling equipment, scrubbers and ventilation components, PP-H sheets are commonly used. Many grades resist aqueous acids and alkalis, and PP-H is often evaluated for warmer service than conventional HDPE or PVC-U. Oxidising media and solvents still need a grade-specific check.
If the design needs more stiffness, glass-fibre-reinforced polypropylene sheets (FRPP) are another option to evaluate. Reinforcement changes the mechanical behaviour, but does not establish chemical suitability. Check the proposed grade, chemical exposure and joining method.
When HDPE is worth evaluating
HDPE combines low water absorption with useful impact performance, including in cold service. It is often considered for water-handling parts, liners and outdoor panels. UV stabilisation is needed where the application requires it; strong oxidisers, hydrocarbons and surfactants can raise compatibility, permeation or stress-cracking concerns.
For cut-to-size or machined industrial HDPE sheets, send us the finished dimensions or drawing and state whether UV stabilisation is required. We confirm the available grade and fabrication scope with the quotation.
When PVC-U is worth evaluating
PVC-U offers high rigidity and resistance to many aqueous chemicals, making it a candidate for chemical-equipment panels, laboratory installations and ducts. Some solvents are unsuitable, and temperature limits can rule it out. Fire behaviour depends on formulation, thickness and the test used; request the required classification for the offered grade.
2. Match temperature to load and support
Plastics creep under sustained load, and their stiffness changes with temperature. A catalogue's short-term maximum does not define a tank's continuous design temperature. Compare wall thickness, support spacing, liquid density and welded joints together, rather than choosing a material from a temperature figure alone.
- Include the normal operating temperature and any hotter cleaning cycle.
- Describe continuous loads, fixings and whether the sheet is fully supported.
- Allow for thermal expansion in long panels, ducts and tank walls.
- For outdoor use, specify UV exposure and the lowest service temperature.
3. Check joints and machining before fixing the material
HDPE and PP can be extrusion- or hot-gas-welded using compatible sheet and filler materials with an appropriate procedure. PVC-U can also be welded or bonded with a suitable adhesive system. Conventional adhesive bonding is not the default for HDPE or PP. For machined parts, assess tolerance, flatness, clamping, heat generation and loads around holes.
Compare designs, not equal thickness alone. A thicker HDPE part with closer supports may serve a different purpose from a thinner PP-H or PVC-U part. Send the drawing so the machining scope and achievable dimensions can be reviewed before quotation.
4. Compare the cost of the finished installation
No fixed price ranking applies to HDPE, PP-H and PVC-U. Grade, thickness, colour, additives, documentation, quantity and freight affect sheet cost. Compare that with machining waste, welding, supports, assembly and replacement: a cheaper sheet is not necessarily a cheaper installation.
Ask for comparable quotations using the same finished dimensions, tolerances, fabrication scope, packing and delivery destination.
Material shortlist by project condition
| Project condition | Material to evaluate | Key selection check |
|---|---|---|
| Outdoor panels with impact or cold-service requirements | UV-stabilised HDPE | UV grade, minimum temperature, stiffness, expansion and fixings |
| Chemical tank or scrubber operating above ambient temperature | PP-H; assess FRPP separately if more stiffness is needed | Exact media, concentration, continuous temperature, structural design and joints |
| Rigid panels or ducts for chemical equipment | PVC-U | Chemical compatibility, service temperature, impact grade and required fire classification |
| Food-contact component | An HDPE or PP grade with suitable supporting documents | Target-market food-contact requirements, additives and cleaning conditions |
| CNC-machined component | HDPE, PP-H or PVC-U according to the duty | Tolerance, sustained load, temperature, chemicals and fastening method |
Send the service conditions with the quotation request
Include enough information to compare a material and a finished-part option, rather than asking only for a price per sheet:
- Specified material and grade, or the application if the material is not yet selected.
- Chemical names and concentrations, including mixtures and cleaning agents.
- Normal, minimum and maximum temperatures, with the duration of hot exposure.
- Sheet thickness, width and length, or a dimensioned PDF/DWG drawing.
- Quantity and expected repeat-order requirements.
- Colour, surface finish and any UV, fire or food-contact requirements.
- Required machining, welding, cutting and finishing operations.
- Delivery country, city or port and packing requirements.
Send us your project details for a quotation. We check the requested material and fabrication scope before confirming the offer, minimum order quantity and lead time.
Frequently asked questions
Is PP-H always better than HDPE for a chemical tank?
No. PP-H may suit a design needing more stiffness or warmer service; HDPE may suit impact or cold-service requirements. The exact medium, concentration, temperature, tank geometry and joint design decide the shortlist.
Can HDPE, PP-H and PVC-U use the same welding procedure?
No. All three can be welded with suitable methods, but compatible filler material, preparation and process settings differ. A procedure qualified for one polymer should not be assumed valid for another.
Which material gives the lowest finished cost?
Compare the actual grade and design, including finished thickness, material waste, machining, joints, supports, packing and freight. There is no universal cheapest polymer for every installation.
Can a published maximum temperature be used as a design limit?
Not on its own. Check whether the value describes short-term or continuous exposure and under what load. Chemical compatibility, creep, support and joint design must also be assessed for the offered grade.
