PVB Interlayer
Definition
Polyvinyl butyral film bonding the two glass layers in a laminated automotive windshield; retains broken glass in place after fracture, preserving the fracture pattern as forensic evidence.
- Material
- Polyvinyl butyral film
- Primary use
- Bonding layer in laminated glass, especially windshields
- Forensic value
- Preserves fracture patterns for evidence analysis
Common questions
Why does PVB interlayer matter in forensics?+
The PVB layer holds broken glass together after impact, keeping the fracture pattern intact. This pattern is critical evidence for reconstructing how, when, and from what direction the glass broke. Without the interlayer, the glass would shatter into loose pieces and the evidence would be destroyed.
Where is PVB interlayer used?+
PVB is bonded between glass plies in laminated glass, most commonly in automotive windshields. It's also found in other safety glass applications where the glass needs to stay in place after breaking.
What does PVB do to broken glass?+
The polyvinyl butyral film acts as an adhesive between the two glass layers. When the windshield breaks, the PVB keeps the pieces held together instead of letting them separate, which preserves the fracture pattern and other forensic features.
Related terms
- ASTM E2927
- Standard test method for the determination of trace elements in glass samples using LA-ICP-MS; specifies the element suite, calibration standards (NIST SRM...
- LA-ICP-MS
- Laser ablation inductively coupled plasma mass spectrometry; a technique that fires a laser pulse at a sample surface, vaporises a tiny amount,...
- BNS 2023 § 106
- Bharatiya Nyaya Sanhita 2023 provision criminalising causing death by negligence; the primary charging provision for fatal hit-and-run cases in India, with enhanced...
- Cold Filament Failure
- Fracture of a tungsten bulb filament below operational temperature; characterised by a clean, brittle transverse fracture with no deformation and no oxide...
- ENFSI ENG3-2013
- The ENFSI Glass Expert Working Group guideline for glass comparison casework; specifies the examination sequence, within-source variation requirements, statistical comparison framework, and...
- EUCAP
- European Collection of Automotive Paints, maintained at the Bundeskriminalamt (BKA) in Wiesbaden; the European counterpart to PDQ for automotive hit-and-run paint comparison.
- FCIN
- Forensic Collision Investigation Network (UK); provides standardised protocols for fatal and serious-injury collision forensic examination, including paint, glass, tyre and filament examination.
- Float Process
- The Pilkington 1959 manufacturing method in which molten glass is poured onto a bath of molten tin, producing a ribbon with two...
- Glass-Transition Temperature (Tg)
- The temperature below which a glass behaves as a rigid solid rather than a viscous liquid; a fundamental thermal property that varies...
- Hot Filament Failure
- Fracture of a tungsten bulb filament while at operational temperature (2,500-3,000 K); characterised by ductile deformation at the break, coiling, and tungsten...
- Network Former
- Oxide (SiO2, B2O3, Al2O3) that forms the tetrahedral backbone of a glass network by sharing bridging oxygen atoms between units.
- Network Modifier
- Metal oxide (Na2O, CaO, K2O, PbO, MgO) that introduces cations into the glass network, breaks Si-O-Si bridging bonds, and lowers the melt...
Explained in these topics
- Glass: Types, Properties and ManufacturePolyvinyl butyral film bonded between glass plies in laminated glass; prevents shard separation on impact and retains the fracture pattern for forensic analysi...
- Vehicle Examination: Paint, Glass, Tyre, Headlight FilamentPolyvinyl butyral film bonding the two glass layers in a laminated automotive windshield; retains broken glass in place after fracture, preserving the fracture...