Shrinkable label film, a shrinkable label and a method for providing a shrinkable film and a label
The invention relates to a shrink face film and a shrink label comprising said face film. According to an embodiment the shrink face film includes a core layer comprising propylene random copolymer(s) and a modifier which is at least one of the following: olefinic plastomer, olefinic elastomer and ethylene-octene block copolymer. The invention further relates to a method for providing a shrink face film and a method for labelling of an item with a shrink label comprising said face film.
1. A shrink face film for a label capable to shrink under exposure to external energy, the face film comprising a first skin layer, a second skin layer and a core layer in between the first skin layer and the second skin layer, wherein
the core layer consists of between 50 and 70 wt. % of propylene random copolymer(s) of propylene-ethylene or propylene-butylene, and total amount between 30 and 50 wt. % of a modifier which is ethylene-octene block copolymer or at least one of ethylene/octene elastomer and ethylene/butene elastomer.
2. A shrink face film according to claim 1 , wherein the first skin layer and the second skin layer include at least one of the following propylene terpolymers: 1-butene/propylene/ethylene, propylene/ethylene/1-hexene and propylene/ethylene/1-butene.
3. A shrink face film according to claim 2 , wherein an amount of the terpolymer(s) is between 1 and 99 wt. %.
4. A shrink face film according to claim 1 , wherein the first skin layer and the second skin layer include at least 50 wt. % of propylene terpolymer(s) and further at most 50 wt. % of heterophasic propylene-ethylene copolymer(s) and/or propylene random copolymer(s).
5. A shrink face film according to claim 1 , wherein the first skin layer and the second skin layer include between 50 and 98 wt. % of propylene random copolymer(s).
6. A shrink face film according to claim 5 , wherein the first skin layer and the second skin layer further comprise at most 50 wt. % of heterophasic propylene-ethylene copolymer(s).
7. A shrink face film according to claim 1 , wherein the face film is uniaxially oriented comprising an uniaxial orientation ratio between 2 and 10.
8. A shrink face film according to claim 1 , wherein the face film has a shrinkage at least 15%, preferably at least 25%, or at least 35% above temperature of 65° C.
9. A shrink label capable to shrink under exposure to external energy comprising a face film according to claim 1 .
10. A method for manufacturing a shrink face film,
providing a multilayer face film comprising a first skin layer, a second skin layer and a core layer in between the skin layers, wherein the core layer consists of between 50 and 70 wt. % of propylene random copolymer(s) of propylene-ethylene or propylene-butylene, and total amount between 30 and 50 wt. % of a modifier which is ethylene-octene block copolymer or at least one of ethylene/octene elastomer and ethylene/butene elastomer;
stretching of the multilayer face film uniaxially at temperature between 50 and 130° C. so as to provide an uniaxially oriented multilayer face film;
cooling the uniaxially oriented multilayer face film so as to provide shrink potential for the face film in the stretching direction.
11. A method for labelling of an item with a shrink label comprising a shrink face film according to claim 1 :
cutting the face film into desired length of the shrink label;
wrapping the cut face film around a mandrel;
seaming the cut face film around the mandrel so as to form the shrink label;
applying the shrink label around the item, wherein the uniaxial orientation direction of the multilayer face film of the shrink label is extending circumferentially around the item; and
heating the shrink label at temperature between 65 and 140° C. so as to form a tight fitting label around the item.
12. A combination of an item and a shrink label according to claim 9 , wherein the label is shrunk around the item.