The physical properties of pallet shrink wrap supplier have some effects on the thermal forming of films
In fact, the physical properties of pallet shrink wrap are quite special, because many factors need to be considered in the thermal forming process, so we may need to consider according to the actual situation of the product.As the physical properties of the stretch film are different, so we need to consider some potential factors, let the following small make up to give you a brief introduction, exactly what physical properties will affect the thermal forming of the stretch film.
The permissible thickness error of stretch film for thermal forming should not exceed 4≤8%.The greater the thickness error, the longer the heating time.In addition, it is assumed that the thickness used for molding has changed, and it is necessary to consider extending or shortening the heating time of thermoforming accordingly.Just make sure you get a good product with even heating temperature.If the thickness error is too large, it is possible to separate the thinnest parts.
Viscosity or melting index of the resin used
Given that the viscosity of the data used in each stretch film varies greatly, there is a simple problem with thermoforming, particularly with polyolefin plastics.Due to melt viscosity (or melting index) changes, the thermoforming temperature should change accordingly.High melt viscosity (low melt index) plastic thermal strength is relatively high, thermal molding temperature is higher than high melt viscosity plastic.
With the increase of the density of tensile film data, the corresponding shortening rate, tensile strength, hardness and resistance also increase, and the thermal forming conditions should also change.
Generally, certain orientation exists in extruded and stretched films. The longitudinal orientation of the unstretched stretch film is about 12≤15%, and the longitudinal orientation of the transverse stretch film is about 2≤5%.When there is a certain orientation, the same tolerance can be obtained, because its strain can be maintained and stable.
Thermoforming of plastics has a wide temperature plan.In order to shorten the molding cycle, its temperature can be close to the lower limit of the temperature planning, because it can shorten the heating time.
There are many factors influencing the thermoforming of stretch film. Some properties and physical parameters of stretch film have great influence on the action and process of film formation.Therefore, we need to take different treatment methods according to different factors, so we must first distinguish the types of elements, and then better prescribe the right drugs.