Introduction of Weeton 823A/828B
WeetonTM823A/828B is a two-component solvent-free polyurethane adhesive for various film/film, film/metalized film and film /foil laminates, widely used in the packaging of food, medicine, daily use chemical, industrial packages. It has low viscosity, good wettability, long pot life, high peeling strength and high laminating speed (450m/min).
Typical applicable structure is as follows+:
+: Film should get appropriate surface tension by corona treatment.
I. Typical Characteristics
II. Directions for use
1. Mixing Ratio: Standard mass ratio of 823A:828B is 100:60. Adjust the ratio according to product properties, printing inks, raw materials, production conditions.
2. Coating: 823A/828B is applied on special laminating machines with multi roller application system.
3. Coating Weight: Depending on the film or foil combination and the end use of the laminate, the adhesive weight may range from 0.9–2.5 g/m² (dry). For printed laminates the weight has to be adjusted accordingly.
4. Dosing: The adhesive is continuously added in the gap of the application station with a two-component dosing and mixing unit. The amount of adhesive in the gap should be kept at the lowest possible level.
5. Pot Life: The pot life of mixed 823A/828B at 40°C is 40min. The viscosity of 823A/828B mixing at 40°C vs. time are shown in fig.1.
6. Laminating conditions: Precise web tension control together with a suitable winding program avoids delaminations as well as telescoping and curling effects.
7. Cleaning: In case of a machine stop (for more than 30 minutes) the coating unit has to be cleaned with solvents/plasticizer-mixture and the 2 component dosing unit has to be washed. The same cleaning procedure has to follow at the end of the run.
8. Curing: The laminates may be rewound and slit after 1-2 days at 35-45°C. Manufacture of triplex laminates is possible 2 hours after duplex production. Complete curing will be achieved after 24 hours at 25-45°C or 3-5 days at room temperature
III. Typical use parameters
Storage barrel: 823A: 40-45°C
Transport hose: 40°C
Metering roller: 37-40°C
Coating roller: 45-50°C
Pot life: over 30min (mixed)
Coating weight: 0.9-2.5g/m2
Coating temperature: 40–55°C
Coating speed: 100-450m/min
IV. Product Certification
823A/828B is in compliance with FDA175.105 and GB9685–2008
1. Storage: 823A/828B have a storage life of 9 months a room temperature when stored in the original unopened containers. Opened containers have to be closed immediately and the material should be consumed within a short period.
2. Transport: Details can be obtained from the corresponding safety data sheets.
VI. Packing Specifications
When using HT 823A and HT 828B an efficient exhaust hood has to be installed to the coating unit due to safety reasons. The exhaust efficiency has to be checked prior to production by gas analysis for isocyanate concentration in the air. Safety regulations with regard to handling of isocyanates have to be followed as per the guide line issued by the International Isocyanates Institute. Please also refer to the local safety instructions as well as our safety data sheet and contact Huitian for analytical support.
VIII. Other information
Film additives-particularly the types and content of slip agent, film thickness, packed goods, printing inks, pre-treatment and film coating are of significant importance to the end use of the laminates and may affect the performance properties either directly or indirectly.
Laminates of high slip containing films, EVA films, CPA films and white pigmented PE films bear the risk of migration of monomeric MDI. This can cause negative influences on the filling good and may lead to antiseal effects. Therefore, practical laminating tests as well as proper checks on the laminates are necessary before going into full scale production.
The Information provided herein, especially recommendations for the usage and the application of our products, is based upon our knowledge and experience. Due to different materials used as well as to varying working conditions beyond our control we strictly recommend to carry out intensive trials to test the suitability of our products with regard to the required processes ad applications. We do not accept any liability with regard to the above information or with regard to any verbal recommendation, except for cases where we are liable of gross negligence or false intention.
Introduction of Huitian
Established in 1977, Huitian is now one of the biggest adhesive manufacturers in China. There are four manufacturing bases in total, providing high performance adhesives for different industries.
Huitian has two fully automatic productions lines and the capacity is 24,000MT/Year just for flexibile packaging adhesives.
Huitian's products has been well received by domestic and international end users.
Besides flexible packaging adhesives, Huitian also provides many others kinds of products for different industries, transportation, electronics, photovaltaic, etc..
Huitian is your reliable partner and satisfy your need of adhesives!