Glass breakage during in-plant transfer is more than a material loss; it's a disruption to your entire production flow. A single cracked pane can halt a tempering furnace or an IGU assembly line, creating costly bottlenecks. Our Harp Racks are engineered specifically to transform this high-risk process into a secure, efficient part of your workflow, protecting your materials and your schedule.
For any custom glass fabricator, the journey a piece of glass takes from the CNC cutting table to the tempering furnace or laminating line is fraught with peril. Breakage during this phase is rarely due to a single catastrophic event. Instead, it's often the result of cumulative stress from three primary sources: vibration, inadequate support, and uncontrolled movement. Standard A-frame racks, designed for bulk storage, and simple dollies are not equipped to mitigate these subtle but destructive forces. High-frequency vibrations from the shop floor can induce micro-cracks along the edges of the glass. These invisible flaws become catastrophic failure points when the glass undergoes thermal stress in a glass tempering furnace. This is the core challenge that a specialized harp rack for glass is designed to solve.
A Harp Rack is not merely a holder for glass; it is an engineered system where each component directly counteracts a specific cause of damage. By addressing the physics of failure at the design level, it provides a stable and secure environment for glass in motion.
A primary failure point for traditional racks is their reliance on rollers or narrow support points. This design is sufficient for large, standard sheets but becomes a significant liability when handling the diverse outputs of a modern fabrication shop, such as long, narrow strips or irregularly shaped architectural glass. These pieces make minimal contact with the rollers, leading to instability, tipping, and stress concentration at the contact points.
The solution is a full base harp rack. This design replaces intermittent rollers with a solid, slotted steel base that provides continuous, edge-to-edge support along the entire bottom of the glass pane, regardless of its length. This uniform support distributes the load evenly, prevents sagging, and completely eliminates the risk of tipping associated with non-standard geometries. The slot width can be customized to snugly fit specific glass thicknesses, providing lateral support that is crucial when handling thin 6mm sheets for insulated glass units (IGU).
High-value products like Low-E glass or custom shower glass doors have sensitive surfaces that cannot tolerate scratches. During transport, vibrations cause the glass to shift and rub against hard steel dividers, leading to surface damage and rejection. Furthermore, these same vibrations travel up through the rack and into the glass itself, creating the dangerous micro-cracks mentioned earlier.
The dividers on a Harp Rack use a composite structure: a rigid steel core provides the necessary strength to separate heavy glass plates, while a thick, soft PVC casing envelops it. This PVC sleeve serves two functions. First, it creates a non-abrasive, cushioned contact surface that prevents scratches and scuffs. Second, its flexible properties act as a damper, absorbing and dissipating high-frequency vibrations before they can damage the glass edge. This protects not only the surface finish but also the structural integrity of the glass itself.
A standard caster brake merely stops the wheels from turning. It does not prevent the rack from shifting or sliding on a slick or uneven floor, especially when pushed by the inertia of a 1500kg load. This uncontrolled movement is a major safety hazard and a source of shock damage to the glass.
An advanced harp rack glass trolley features a foot-actuated lifting mechanism. When engaged, this system uses a mechanical lever to lift the entire load slightly, transferring the weight from the mobile casters to fixed rubber feet. This action physically anchors the rack to the ground, creating a completely stationary platform. It provides absolute stability during loading and unloading, ensuring the glass does not shift, slide, or vibrate, thereby protecting both the product and the personnel operating it.
Reducing breakage is a direct cost saving, but the true value of a Harp Rack lies in its ability to optimize your production workflow. It acts as a mobile Work-in-Progress (WIP) buffer station that facilitates sorting and kitting, turning a chaotic post-cutting stage into an organized pre-production process.
| Function | Harp Rack Application | Operational Improvement |
|---|---|---|
| Sorting Glass Units | Each slot on the rack can be assigned to a specific job or order. Glass coming off the cutting table is immediately placed in its designated slot. | Eliminates the time-consuming and error-prone process of manual sorting on a stationary table. Reduces the risk of mixing up orders. |
| Kitting for IGU Production | Operators can "pre-pair" the glass lites for an insulated glass unit, placing the inner and outer panes in adjacent slots. The entire "kit" is then moved to the assembly line. | Ensures all components for a unit arrive together, preventing line stoppages caused by missing or damaged panes. Streamlines the assembly process. |
| Creating a Lean Workflow | The mobile rack acts as a buffer between processes with different cycle times, such as cutting and edging, ensuring a continuous flow of materials. | Minimizes WIP congestion, improves overall plant throughput, and makes the production schedule more predictable and efficient. |
By integrating Harp Racks into your in-plant transfer process, you move beyond simple damage prevention. You implement a system that introduces order, enhances safety, and increases the overall velocity of your production line, directly impacting your bottom line by reducing waste and improving output.
The primary cause is not major impacts, but cumulative stress from constant, low-level vibration, combined with inadequate or improper support for the glass pane. This creates micro-cracks that can lead to failure later in the production process, especially under thermal stress.
Harp racks offer superior protection for thin glass through customizable, narrow slot widths. This provides tight lateral support that prevents the glass from flexing or rattling during movement, a common problem in racks with wider, universal spacing that leads to breakage.
Yes, specifically models with a full, slotted base. Unlike racks with rollers, the full base provides continuous support along the entire bottom edge of the glass, making it exceptionally stable for long, narrow strips, triangles, or other irregular shapes common in architectural glass fabrication.
The PVC coating serves two critical functions: it provides a soft, non-abrasive surface to prevent scratches on sensitive coatings like Low-E, and it acts as a vibration damper, absorbing energy from the floor and frame before it can be transferred to the fragile edges of the glass.
A harp rack is fundamentally a tool for transport and process flow. While it does store glass, its primary role is to act as a mobile Work-in-Progress (WIP) station, safely and efficiently moving sorted or kitted glass between different stages of the production line, such as from cutting to tempering or assembly.
