Channel: Autoglass
Safety Glass Experts International: bending perfect shapes part II

2012-02-15 | Autoglass

The second part of this two-part article “Bending perfect shapes” will review the challenge of bending smooth and progressive sagging (cross curvature). Smooth and progressive sagging profile is an important quality feature of a windshield and is a fundamental requirement. The importance of this characteristic has been acknowledged by vehicle manufacturers, but the interesting fact is that a trained eye can spot some recent vehicle models featuring poor sagging profiles.

Example of points of deformation in centre sagging profile
As explained in the first part of this article, published in Glass-Technology International issue 5/2011, modern windshield design features cross curvatures over 30 millimetres in car windshields and well over 70 millimetres in bus and special vehicle windshields. Although the trend of increasing height of the windshields naturally compensates challenges related to sagging depth to a degree, centre line sagging in modern extent still creates a real challenge. Of course any modern bending furnace, serial or single chamber, features enough IR-heating power to bend even deeper sagging than required, and, in fact, it is not really a question of total IR-power either, since simply increasing the bending time over glass transition temperature will result in more sagging.
One can continue to bend the glass pair up to the physical limitations created by the glass and mould size – there is no difficulty in executing this. However, bending deep cross curvature, which potentially includes a number of points that have to remain within a narrow frame of repetition still maintaining smooth progressive sagging profile and correct cycle time, is an objective that not all manufacturers can reach.
What really creates the challenge in bending modern centre sagging is the equation of the following points:
1.    controlling deep sagging shape->bending smooth and progressive shape;
2.    repeating the sag within narrow tolerance from specified points (value adding devices in modern windshields);
3....




expand

Article taken from Glass-Technology International bi-monthly magazine (6 issues per year)
Year: 2011 number: 6
Check out Glass-Technology International magazine

Autoglass
8 Total results
Page  1 of 1 
latestOrder by:

GlassOnline Articles by Channel

Safetyglass

2013-08-09
Industries are developing fast and competitiveness goes hand in hand with this development. Being competitive no longer...

Safetyglass

2013-01-09
Lamination defects typically represent no more than 1-2 per cent waste from the production of laminated windshields....

Safetyglassexperts

2012-03-09
Large windshields for buses and special vehicles are manufactured using the gravity bending method. Producing this...

Safetyglassexperts

2012-02-15
The second part of this two-part article “Bending perfect shapes” will review the challenge of bending smooth and pro...

Immagine

2011-09-01
Modern vehicle windshield design is introducing many challenges to the manufacturers. In this two-part article, I will...

8 Total results
Page  1 of 1 
Other channels: A.T.I.V. Articles - Adhesives and sealants - Advanced electronics - Annealing - Annealing & decorating - Annealing & tempering - Anniversary - Autoglass - Automation and it - Automotive glass - Ball Gathering - Batch plants - Building applications - Case history - Coatings - Cold-end - Company financial news - Company news - Conditioning - Containers - Conveyors - Cooperation - Country outlook - Crystal - Cullet treatment - Cutting technology - Decoration - Design - Detection systems - Directives - Double glazing - Drilling - Drying - Ecology - Edging - Energy saving - Events - Fibre treatment - Finishing lines - Forming - Furnace technology - Fusing - Glazing / Insulating Glass - Grinding and bevelling - Handling - Hot-end equipment - Ig equipment - Industry update - Innovation - Inspection - Institutes - Laminating - Lehrs - Load moving - Lubrication systems - Machinery developments - Manufacturing technology - Markets & trends - Mathematical recreations - Mergers, acquisitions & disposals - Mirror technology - Mould technology - Neutralisation plants - Numerical control - Old issues - Optoelectronics - Other news - Palletising/depalletising - Personnel & industrial relations - Photovoltaic glass - Plant technology - Pressing - Printing and tempering - Processing - Product news - Production costs - Purification plants - Refractories - Representative organizations - Research and development - Resin technology - Safety glass - Science & technology - Screen printing equipment - Sealants - Sector trends - Shaping - Sheet processing - Software - Specialist applications - Statistics - Storage and handling - Surface treatment - Surveys - Tableware - Tempering technology - Testing - Thermal imaging - Thermal insulation - Transitions - Treatment plants - Tube production - Turnkey plants - Viewpoint - Worker safety -

Our Glass Magazines & Annual Guides Read online free of charge

Glass-Technology International
 
Glass Machinery Plants & Accessories
 
World Glass Directory
 
Flat Glass World Directory
 
Return to top

Powered by GlassOnline Logo

Copyright © Smartenergy S.r.l. 1996-2016 - All rights reserved

Smartenergy S.r.l. - publications@glassonline.com - Cookie policy
Registered office: Via Antonio Gramsci, 57 - 20032 Cormano (MI), Italy
Company registry - Milan, REA No.: MI-2022277 | Share capital: € 10,000 | P.IVA/VAT No.: IT 08386450962