Lightweight rigid or flexible foamed boards made of Polyvinyl chloride. Most have sandwich-like structures of smooth outer skin and interior fine-cell foam.
Examples of some types of PVC boards are:
|Product name||company||Color||density||Shore hardness||max service temp (deg C)||Coefficient of linear expansion (mm/m-k)||water absorption (%)||min ; max thickness (mm)||Comments|
|FOREX® Classic||3A Composites||white||0.7||40-44||55||0.07||<1||2 ; 19||standard product; PE film on one side|
|FOREX® Print||3A Composites||white||0.5||>32||55||0.07||<1||2 ; 19||more economical; less rigid and resistant; PE film on one side|
|FOREX® Color||3A Composites||9 colors||0.6||37||55||0.05||<1||3 ; 8 (10, 19 black only)||cannot be used outdoors; PE film on one side|
|KomaCel®||Kommerling||0.55-0.7||55-77||56||<0.08||<0.2||4 ; 30||standard product|
|KomaTex®||Kommerling||w/b||~0.6||48-55||60||<0.08||<0.3 - 3.0||1 ; 25 (white), 2 ; 19(black)||free foamed sheet, (no outer skin)|
|KomaLite®||Kommerling||w/b||0.5||58||3 ; 6||more economical for of KoamTex|
|Sintra||3A Composites||9 colors||0.5-0.9||46||1 ; 12.7||standard product, low gloss; has two release liners - one on each side|
|Sintra Vers (formerly ePVC)||3A Composites||w/b||3 ; 6||more economical and versatile|
|Sintra Construct||3A Composites||w/b||6 ; 19||designed for fabrication|
Synonyms and Related Terms
foam sheet; foam board
Commercial products: [Kommerling, USA] KomaCel® Plus; KomaTex®; KomaLite® [3A Composites USA] Sintra; Sintra Vers (formerly ePVC); Sintra Construct [3A Composites, Airex AG, Switzerland] FOREX® Color; FOREX® Classic; FOREX® Print [Palram] Palight
- Graphic substrates (signs)
- Case interior elements: mount making (risers, fabric wrapped backers, decks), labels
- Storage: open shelves, trays (not in proximity to sensitive objects)
- Harmful to health when inhaling or ingesting dust and vapors during unpacking, sawing, grinding and thermoforming.
- Ensure good ventilation and dust extraction on processing machines and at other places where dust may develop.
- Hazardous thermal decomposition products: Hydrochloric acid (HCl), Carbon dioxide (CO2), Carbon monoxide (CO)
- Some PVC board products pass the Oddy test, while some fail.
- Some PVC boards pose risk to sulfide-sensitive materials and possibly to materials sensitive to acetic acid.
- Some rigid, unplasticized PVC construction boards give off a sulfur containing heat stabilizer (2-ethylhexyl thioglycolate [2-EHTG]) that can tarnish silver (publication forthcoming). Other specific brands of PVC construction board, namely Komacel (Kommerling) and e-PVC (3A Composites) are safe for use in exhibition casework as they do not contain 2-EHTG.
- KomaCel is more recently approved for permanent use (vs KomaTex).
- KomaTex has a heat stabilizing component which leaches out over time.
Physical and Chemical Properties
- PVCs are generally fire resistant.
- Not biodegradable but may be recycled in some locations.
- Properties of the same product can change over time and may depend on geography.
- All can be cut, machined, joined, and receive paint.
- mechanical fasteners (screws)
- Tetrahydrofuran (solvent weld): need proper extraction, PPE; quick and fast, not much clean up, perhaps more solid bond than 3M epoxy
- adhesive: 3M DP605 2 part epoxy - may need to score or rough up smooth surfaces to get good adhesion
Wood, acrylic, and fabric can be adhered to PVC boards:
- laminated acrylic to PVC with 3M Scotch-Weld DP605NS two-part epoxy - good for heavier, stronger decks because acrylic has tapping properties
- To adhere fabric to PVC: ATG 695, Instabond C (double-coated polyester film), 3M 465 Clear Tape
To prevent open-celled edges from showing:
- spackle edge before painting
- cut at 45 deg angle and miter join
- mechanically fasten L angle frame around it so the edge is covered
Fairly rigid, but will sag; not intended to be a weight-bearing substrate. Thus, need for supports like U channels or ribs.
Takes acrylic paint relatively well.
Takes DTS (direct to substrate) inks really well.
Presence and number of protective release liners may be used to quickly identify products (i.e. Sintra always has two liners).
Forms and Sizes
- Most come in full sheet sizes (4x8 feet), usually available in at least white and black.
- Check product brochures/table for specific info on colors, finishes, sizes available.
- Need a trusted supplier that does not fill orders with multiple products.
Resources and Citations
- Canosa et al. (Swedish National Heritage Board), Characterization of Emissions from Display Case Materials, 2019, https://www.diva-portal.org/smash/get/diva2:1324017/FULLTEXT01.pdf
- Samide and Smith, “Assessing the Suitability of Unplasticized Poly(Vinyl Chloride) for Museum Showcase Construction,” JAIC, 2020.
- Samide, Liggett, Mill and Smith, “Relating volatiles analysis by GC–MS to Oddy test performance for determining the suitability of museum construction materials,” Heritage Science 6 (47), 2018.
- Samide and Smith, “Analysis and quantitation of volatile organic compounds emitted from plastics used in museum construction by evolved gas analysis–gas chromatography–mass spectrometry,” Journal of Chromatography A, Sept. 2015.