‘Designer piece’ Bohle UV-bonding technology and hardware

CASE STUDY: UV Bonding technology is being used by glass processors across a wide range of applications from furniture to retail display cases. What is notable is that there has been a definitive shift across sectors towards larger installations.

“This creates an immediate challenge”, says: Amanda Carr, Bohle UV Bonding Specialist. “The pressure applied through the sheer weight of the glass used can mean that adhesive is pushed out from the joint, something which can lead to failure."

“Bohle has created a specially developed range of UV bonding adhesives designed to support glass processors in achieving the optimum bondline, guaranteeing the structural integrity of the bond in display cases and larger glass furniture.” 

Bohle’s MV760 UV bonding adhesive system delivers a sheer strength load capacity of 25 newtons/mm2. It does this using pioneering spacer technology, which employs transparent 90 micron spacer granules, to achieve the optimum bondline gap by preventing the pressure exerted by glass weight in larger bonds from forcing adhesive from the joint.

This global leading technology, was employed by Halsall Glass in its fabrication of four specialist retail display cases for fashion outlet, the Design Retail Centre in York. Measuring 2m x 2.5m x 1.3m, the display cases were designed to accommodate full sized manikins, making them too large for offsite manufacture.

This meant that Halsall Glass had to develop a specialist solution involving on-site manufacture as Rob Halsall, founder and Managing Director of Halsall Glass, explained.

He said: “The display cases were simply too large to fit through the door which meant on-site assembly was a pre-requisite to the job. To UV bond in a site environment requires a lot of specialism. Lifting and handling large 10mm toughened glass was just one of a number of logistical challenges.

The other major challenge was the sheer weight of glass we were using and the pressure that that put on the joints. The use of Bohle’s MV760 spacer bonding adhesive was a critical element in delivery, allowing us to achieve a consistent bond-line along the joint.

We also used Bohle lifting and handling equipment, its suction holders and clamps, plus Bohle’s clamping and UV lamps to cure the bonds on site.”

This included use of Bohle’s Verifix Pro Angle Suction Holders, which bring scientific precision to bonding gaps, optimising the thickness of the adhesive layer to within a tenth of a millimetre.

Halsall Glass also used Bohle’s new UVA Star UV bonding tube lamps, which deliver higher quality cures while at the same time reducing energy consumption.

Part of Bohle’s leading-edge Verifix UV bonding range, the new UV lamp range is can be used to bond lengths of glass of up to 1410mm. The new ‘T8’ tube technology creates a high UVA output with a wave range of 315-400nm, operating from a power source of just 230 volts. 

This high ratio of output to power, is achieved using a new electrical transformer, which is integrated in the housing. This also reduces flickering, significantly improving the curing of acrylate adhesives. It’s also fitted with special filter disks to prevent damage to the eyes, skin and to avoid stresses in the bonding.

“Having vacuum clamped the unit, we bonded it a metre at a time, five metres per joint on the largest joint between the top of the case and the sides, to deliver a consistent cure and even set on both sides of the joint”, said Rob.

Another critical element of the design was an access door and opening. This was hinged using Bohle hardware and locking mechanisms.

“We used Bohle technology across the board from hinges and hardware to the preparation, handling an installation of glass”, said Rob. “We see this as an area of growth, although one which requires some area of specialism, as there are lots of handling and health and safety implications along the way."

With capabilities to work with glass from 4mm through to 19mm in both annealed and toughened glass, Halsall Glass works across a wide range of market sectors, including interior fit out, leisure, retail display, construction and supply of product to other glass companies.

It moved to a new 20,000sq ft facility in Easter last year, also investing in a laminating oven with 4 beds 3500mm x 1980mm and upgrading its in-house painting facility.

“It doesn’t matter if you’re manufacturing retail units, boardroom furniture or high end designer dining tables. You need precision. That’s what UV bonding delivers. Products are about clean sightlines and perfection. If you deliver it, particularly in premium sectors, the margin and returns are significant and that’s exactly what Bohle’s UV bonding range has been developed to support our customers in achieving”, said Amanda.