1、Vertical bag delamination crease
1.Phenomenon description
A vertical milk powder bag with a structure of PET12/VMPET12/PE80 was used in supermarkets for six months,and non ink layer delamination occurred between PET and VMPET.
2.Cause analysis
The vertical bag packaging is for small bags of milk powder,so the chemical properties of the packaging contents will not affect the quality of the packaging bag.However,due to the weight of the packaging contents being 450g,during the supermarket placement process,the wrinkled areas of the vertical bag are prone to delamination.Upon checking the production records,it was found that the surface of the bag was coated with high brittleness quick drying adhesive from the previous order.Brittle adhesive is not resistant to bending,so it is necessary to choose a composite adhesive with suitable hardness and softness.
2、Low composite strength of composite film
1.Phenomenon description
The anti heat adhesive packaging bag with BOPP28/VMCPP25 structure is printed in two colors,without a full white ink backing,and has low peel strength and delamination after lamination.
2.Cause analysis
The peel strength is very low in both the red and green ink areas.The reason is that in the ink,the original yellow ink shows a slightly positive polarity,the original red ink has a negative polarity,and the original blue ink has a negative polarity.Therefore,the polarity of the green film composed of original yellow and original blue is neutral,and its composite strength is relatively low.However,the low peel strength of the red ink here is mainly due to the large amount of red wax added by the ink supplier,which affects the composite strength due to precipitation.Therefore,it is recommended to use ink or printing surface(ink surface)from regular manufacturers for corona discharge once and composite within 8 hours.
3、Composite bubble phenomenon
1.Phenomenon description
The structure is PET12/AL17/NY15/MIPE60 electronic product packaging bag.During the production process,on the first day of compounding PET and AL,no bubbles appeared;The next day,NY and MIPE were continuously compounded without any bubble problems;After production,it was placed at room temperature in the workshop for 2 days without any quality issues observed;Then it was sent to the curing room for 48 hours of curing.On the 6th day of bag making,it was found that the surface of the composite film had a strip-shaped foaming phenomenon,and the bubbles occurred between nylon and pure aluminum.
2.Cause analysis
By checking the production records,it was found that the adhesive used between PET/AL composite film and NY was not deteriorated,ruling out the possibility of adhesive deterioration caused by the use of expired adhesive and the generation of bubbles.Further careful analysis of the distribution of bubbles reveals no periodic pattern and eliminates the possibility of bubbles being generated due to clogging of the mesh holes of the mesh rollers.After communicating with the adhesive supplier,it was found that the initial adhesion of the adhesive is low.It is recommended to enter the curing room immediately after compounding.PET/AL is a rigid material.NY is a peristaltic material that uses adhesive with relatively low initial adhesion,which has poor resistance to material creep and generates vacuum bubbles.
1.Phenomenon description
A vertical milk powder bag with a structure of PET12/VMPET12/PE80 was used in supermarkets for six months,and non ink layer delamination occurred between PET and VMPET.
2.Cause analysis
The vertical bag packaging is for small bags of milk powder,so the chemical properties of the packaging contents will not affect the quality of the packaging bag.However,due to the weight of the packaging contents being 450g,during the supermarket placement process,the wrinkled areas of the vertical bag are prone to delamination.Upon checking the production records,it was found that the surface of the bag was coated with high brittleness quick drying adhesive from the previous order.Brittle adhesive is not resistant to bending,so it is necessary to choose a composite adhesive with suitable hardness and softness.
2、Low composite strength of composite film
1.Phenomenon description
The anti heat adhesive packaging bag with BOPP28/VMCPP25 structure is printed in two colors,without a full white ink backing,and has low peel strength and delamination after lamination.
2.Cause analysis
The peel strength is very low in both the red and green ink areas.The reason is that in the ink,the original yellow ink shows a slightly positive polarity,the original red ink has a negative polarity,and the original blue ink has a negative polarity.Therefore,the polarity of the green film composed of original yellow and original blue is neutral,and its composite strength is relatively low.However,the low peel strength of the red ink here is mainly due to the large amount of red wax added by the ink supplier,which affects the composite strength due to precipitation.Therefore,it is recommended to use ink or printing surface(ink surface)from regular manufacturers for corona discharge once and composite within 8 hours.
3、Composite bubble phenomenon
1.Phenomenon description
The structure is PET12/AL17/NY15/MIPE60 electronic product packaging bag.During the production process,on the first day of compounding PET and AL,no bubbles appeared;The next day,NY and MIPE were continuously compounded without any bubble problems;After production,it was placed at room temperature in the workshop for 2 days without any quality issues observed;Then it was sent to the curing room for 48 hours of curing.On the 6th day of bag making,it was found that the surface of the composite film had a strip-shaped foaming phenomenon,and the bubbles occurred between nylon and pure aluminum.
2.Cause analysis
By checking the production records,it was found that the adhesive used between PET/AL composite film and NY was not deteriorated,ruling out the possibility of adhesive deterioration caused by the use of expired adhesive and the generation of bubbles.Further careful analysis of the distribution of bubbles reveals no periodic pattern and eliminates the possibility of bubbles being generated due to clogging of the mesh holes of the mesh rollers.After communicating with the adhesive supplier,it was found that the initial adhesion of the adhesive is low.It is recommended to enter the curing room immediately after compounding.PET/AL is a rigid material.NY is a peristaltic material that uses adhesive with relatively low initial adhesion,which has poor resistance to material creep and generates vacuum bubbles.
