How much does the labour for handling glass sheets on trestles cost?

All these products share one common feature: “they have been developed and produced specifically to solve Glass Sector companies’ problems in the best possible way”.

Optimization to the last
This has been the starting point for the development of Perfect Rack, a module that has been studied for solving all problems of medium-large companies concerning the placement of glass sheets on trestles and perfectly integrated with the series of Perfect Cut products.
In all processes of glass working, from cut to subsequent processing (grinding, beveling, drilling, assembling of double glazing, etc.) trestles are widely used, since they are means for handling glass sheets, shipping them in manufacturing account and for the delivery of the product to the final customer.
Minimizing glass sheets handling on trestles, it is possible to save hours of work (with the subsequent lowering of production costs and a more effective use of resources) and to reduce the risk of scratching and breaking the sheets.
Keeping these considerations in mind, R.O., thanks to the interaction with some major customers, has integrated the optimization software with a management tool that takes also into account the trestle loading sequence.
A specific interface allows defining a Trestle Stock containing the description of the different Types of Trestles with their features (single or double, width, height, depth, capacity, etc.). For each defined type, the user can enter all specific data of each available trestle.

Some fundamentals have been taken for granted, among which it is worth reminding: On the same trestle / position measurements belonging to same job order should be placed. For job order we mean the production for one single customer / order / glass composition;
- On the same trestle glass sheets of different job orders can be placed if they belong to the same shipment area;
- For double-glazing, pieces should be placed on the trestle with the greatest size, generally, vertically (to reduce volume and maximize the number of pieces) from the smallest to the biggest one, so that after assembling they can be put on shipment trestles from the biggest to the smallest, eliminating the need for a following handling;
- All pieces of the same size, if there is enough place on the platform, are overlaid in the same trestle position;

- The pieces of different size in the same trestle position are separated by spacers.
In assigning trestles it is necessary to take into account existing physical limits, such as:
- The maximum number of trestle sides active at the same time in the cutting area;
- The number of pieces that can be put on a trestle, in the same position, according to the width of the platform;
- The coverage limit on the surface of the previous piece to avoid warping problems;
- The minimum number of supports each piece must rest on (usually two or three) and the distances between supports;
- The maximum weight of the material that can be placed on the trestle.

Since each trestle loading sequence automatic determination influences the optimization algorithm to minimize wastage, Perfect Rack allows working in two ways:
• Optimizing and then assigning pieces to trestles so that scraps are not penalized;
• Optimizing according to the weight (priority) indicating to the optimizer the level of trestle loading sequence optimization to be performed. Setting this parameter it is possible to balance scraps minimization and pieces handling on trestles, differently from other software available on the market that simply allow enabling / disabling this function.

The optimizer, taking into consideration all different kinds of available trestles, assigned during the stage of project description, and all specific management parameters, will try to establish the sequence of cutting layouts so to avoid the reallocation on trestles of pieces to be passed to double-glazing or to shipment, but only when scrap is not too penalizing. On demand, the software can "engage" assigned trestles in the stock, so that these trestles can not be used again for processing another project until they are available again.
To simplify even further the job of operators, it is possible to indicate, on the cutting layout, the trestle code and the progressive position of each piece on the layout itself.