{"id":5064,"date":"2026-07-04T08:07:58","date_gmt":"2026-07-04T08:07:58","guid":{"rendered":"https:\/\/wolorin.com\/?p=5064"},"modified":"2026-07-04T08:07:58","modified_gmt":"2026-07-04T08:07:58","slug":"lamination-bond-strength-low-uneven","status":"publish","type":"post","link":"https:\/\/wolorin.com\/es\/blog\/lamination-bond-strength-low-uneven\/","title":{"rendered":"\u00bfPor qu\u00e9 la resistencia de la uni\u00f3n de laminaci\u00f3n de los envases flexibles es baja o irregular?"},"content":{"rendered":"
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\u00bfPor qu\u00e9 la resistencia de la uni\u00f3n de laminaci\u00f3n de los envases flexibles es baja o irregular?<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Low bond strength in flexible packaging laminates may affect the full web, one side, the edges, or only a few local areas.<\/p>

The laminate may peel apart too easily. One edge may lift after slitting. A narrow weak band may remain in the same position across several rolls. In other cases, the laminate looks acceptable when it leaves the line but still fails after curing.<\/p>

These patterns usually point to different parts of the process. Overall weakness is more often linked to adhesive preparation, coat weight, wetting, or curing. A fixed weak band or a clear edge-to-center difference makes transfer, metering, and nip contact more relevant.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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Start with Where the Bond Is Weak<\/h2>\r\n\r\n

Take samples from the left, center, and right side of the web. Use the same peel-test method and the same curing time for each sample.<\/p>\r\n\r\n

The purpose is to see the pattern across the width.<\/p>\r\n\r\n

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\r\n \r\n \r\n \r\n \r\n <\/colgroup>\r\n\r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n
Lo que ves<\/th>\r\n Where to start<\/th>\r\n <\/tr>\r\n <\/thead>\r\n\r\n
Most of the width is weak<\/td>\r\n Adhesive mixing, coat weight, wetting, drying, and curing<\/td>\r\n <\/tr>\r\n\r\n
One side is weaker<\/td>\r\n Cross-web coating, surface treatment, web position, or nip contact<\/td>\r\n <\/tr>\r\n\r\n
Both edges are weaker than the center<\/td>\r\n Edge coating, wetting, surface treatment, or edge contact<\/td>\r\n <\/tr>\r\n\r\n
One edge lifts after slitting or winding<\/td>\r\n Local contamination, poor edge transfer, or uneven nip contact<\/td>\r\n <\/tr>\r\n\r\n
Small dry areas appear<\/td>\r\n Particles, local contamination, poor wetting, or unstable transfer<\/td>\r\n <\/tr>\r\n\r\n
A weak band stays in one machine position<\/td>\r\n Metering, transfer, treatment profile, or roller condition<\/td>\r\n <\/tr>\r\n\r\n
Bond remains low after curing<\/td>\r\n Mix ratio, curing, residual solvent, ink, or interface failure<\/td>\r\n <\/tr>\r\n <\/tbody>\r\n <\/table>\r\n <\/div>\r\n <\/div>\r\n\r\n

A single peel value from the center may look acceptable while one edge is already failing. Keep the test position and curing time with each result.<\/p>\r\n <\/section>\r\n\r\n

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When Most of the Web Is Weak<\/h2>\r\n\r\n

If most of the width is weak, start with the adhesive layer itself.<\/p>\r\n\r\n

Check the adhesive batch, actual mix ratio, mixing method, and the time between mixing and coating. Then compare the real coat weight, drying condition, and curing history.<\/p>\r\n\r\n

Using the correct adhesive product does not guarantee that the batch was prepared correctly. A ratio error, incomplete mixing, a long delay after mixing, or a change in adhesive condition can affect the full roll.<\/p>\r\n\r\n

The machine setting also does not prove that the expected amount of adhesive reached the film. Actual coat weight may change during start-up, speed changes, stops, restarts, or adhesive replenishment.<\/p>\r\n\r\n

If adhesive remains on both peeled surfaces but splits within the adhesive layer, mixing and curing should be checked before changing the nip.<\/p>\r\n <\/section>\r\n\r\n

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Poor Wetting Can Leave a Weak Interface<\/h2>\r\n\r\n

Sometimes the adhesive amount is enough, but it does not spread properly over one surface.<\/p>\r\n\r\n

If most of the adhesive stays on one side after peeling, while the other side looks clean or only partly covered, the weak point is probably at that interface.<\/p>\r\n\r\n

The film may have entered the laminator on the wrong side. Surface treatment may be weak or may have dropped during storage. Dust, oil, moisture, slip additives, or poorly dried ink can also stop the adhesive from wetting the surface evenly.<\/p>\r\n\r\n

Printed areas deserve a closer look. If the weak bond follows one ink color, one printed lane, or one film roll, the problem is more likely linked to the material or printing than to the full machine width.<\/p>\r\n\r\n

Surface-treatment readings can help, but they should match the actual weak area. The peeled surfaces usually show more clearly where the bond failed.<\/p>\r\n\r\n

For rollers that directly touch adhesive, ink, solvent, or cleaning liquid, check whether the roller surface has become sticky, swollen, shiny, or difficult to clean. These changes can affect adhesive pickup and release.<\/p>\r\n\r\n

See Rubber Rollers for Ink, Adhesive, and Solvent Contact<\/a> for the separate material-contact review.<\/p>\r\n <\/section>\r\n\r\n

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Why One Side Is Weaker Than the Other<\/h2>\r\n\r\n

When one side is consistently weaker, something is changing across the machine width.<\/p>\r\n\r\n

Compare the weak side with the coat-weight profile, surface treatment, web position, nip pressure, temperature, and nearby roller condition.<\/p>\r\n\r\n

If the weak band stays on the same machine side after changing the film roll, check the coating, metering, transfer, and nip areas on that side.<\/p>\r\n\r\n

If the weak area moves with the film roll or printed lane, check the film, ink, and treated surface first.<\/p>\r\n <\/section>\r\n\r\n

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Check the Metering and Transfer Area<\/h2>\r\n\r\n

Los rodillos dosificadores y de transferencia cobran importancia cuando la banda d\u00e9bil se alinea con una posici\u00f3n fija en la superficie del rodillo.<\/p>\r\n\r\n

Dried adhesive, local contamination, uneven wear, scratches, or one edge running differently from the other can disturb the adhesive layer. A roller may still look usable while one part of its surface no longer picks up or releases adhesive evenly.<\/p>\r\n\r\n

If the roller controls adhesive amount, check the Rodillos dosificadores<\/a> position.<\/p>\r\n\r\n

If the roller picks up and transfers adhesive to the web, check the Rodillos de transferencia<\/a> position.<\/p>\r\n <\/section>\r\n\r\n <\/div>\r\n<\/section>\r\n\r\n