Labels that survive the plant: heat, oil, dust and handling

A label that looks flawless on an office shelf can be unreadable a month later on a machine, a mould, a rack near a furnace or a bin beside a press. Labels cost little to print and a lot to replace. If one label in ten will not scan, the count turns into a manual one. Choosing the right label means matching three things to the place where the item lives: the material, the adhesive and the protection.

Read the environment first

Walk the plant, and note the following for each area rather than for each item.

• Heat: near furnaces, ovens and hot machine surfaces. Compare the working temperature range stated by the supplier with the temperature measured at that very spot, not with the room temperature.
• Oil, grease, coolant and solvents: they make many labels smear or soften.
• Dust and dirt: contrast drops, and wiping rubs the surface.
• Abrasion and impact: forklifts, cart wheels, hands and tools scrape labels on corners and edges.
• Cold, damp and condensation: cold stores, outdoor yards and the area near doors in winter.
• Cleaning: areas that are washed or wiped with cleaning agents.

Mark these on the floor plan. Grouping the areas into three or four environment types leaves you with three or four label types.

Material, printing and protection

• Polyester or polyimide labels suit heat, oil and chemicals. Paper labels belong to dry, clean, short-lived uses, such as cartons that leave within weeks.
• Thermal transfer printing with a resin ribbon withstands smearing, solvents and heat better than a wax ribbon. Direct thermal labels, printed without a ribbon, darken or fade with heat, light and time, so do not use them where a label must last more than a few months.
• A clear protective overlay on the printed face shields the print from abrasion and oil.
• Size and contrast matter too. Print the barcode large enough to read from the real scanning distance, with a clear margin around it. If the margin is damaged, the label will not scan even though the bars are intact.

Adhesive and surface

• Oily, powder-coated, rough, curved and cold surfaces each need a different adhesive. Tell the supplier what the surface is and ask which adhesive suits it.
• Clean the surface with a suitable cleaner and let it dry. Apply the label at a reasonable temperature, not onto cold, wet steel. Press firmly, and allow the time the supplier states for the adhesion to settle before using the item.
• Choose a flat area, and avoid corners and places where hands grab.
• Do not peel a label off and stick it somewhere else; its adhesive is weakened.
• For curved or rough surfaces, use wrap-around labels, or a tag plate fixed with a cable tie.

A one-week durability test

1. In each area, pick the three harshest spots.
2. Apply 10 labels of each candidate type.
3. Leave them for a week while the plant runs normally, or longer for important items.
4. Run a scan test (how many of the 10 scan at the working distance), a peel test (can a fingernail lift an edge) and a wipe test (rub with a cloth soaked in the cleaner or oil used there).
5. Record scans, lifted edges and smears for each type.

For illustration, beside the press only 4 of 10 paper labels scan, while all 10 polyester labels with an overlay do. The result goes into your label standard.

Replacing labels

At every count, record how many labels cannot be read. If the rate passes a level fixed in advance, say 2%, find the cause before printing again. Keep spare labels and a portable printer so that replacements can be made on the spot, print the replacement with the same number, and log that it was replaced.

Summary

The right label for a plant is not the expensive one but the one chosen for heat, oil, dust and handling. Smart Inventory brings label printers, prints new labels on site for items and shelves that have none or have damaged ones, and recommends a small trial in the harshest spots before a large labelling job.