Study on Disposable Degradable Tableware Coating (Part 2)

Currently, there are only local and national standards for disposable degradable tableware in terms of product quality, and there is no standard for fast food box coatings. We refer to GB 18006.1-1999 "General technical conditions for disposable degradable tableware"; GB/T 5009.60--1996 "Analysis method for hygienic standard of polyethylene, polystyrene and polypropylene molded products for food packaging" GB11677-89 "Sanitary standard for water-based modified epoxy cans inner wall coating"; General emulsion product standard: SH/T 1154-1999 "Determination of total solid content of synthetic rubber latex"; SH/T1150-1999 "Synthetic rubber latex "Measurement of PH value"; SH/T 1152-1999 "Determination of viscosity of synthetic rubber latex" selected the following three aspects of mass measurement:

I. Determination of General Properties of General Emulsions

1. Determination of emulsion pH requires that the emulsion is preferably near neutral.
2. The emulsion viscosity was measured because the viscosity had a great influence on the coating performance of the dishes.
3. Determination of solid content, high solid content will help reduce drying time and improve production efficiency.

Second, the determination of emulsion health indicators

4. Determination of Evaporation Residue (mg/L): After the emulsion film was dried, it was soaked with four liquids to measure the amount of residue. Specific conditions are:

4 g of paint (solid 50%) is uniformly coated on a glass plate with a glass plate area of ​​320 cm2 (equivalent to the inner surface area of ​​a 600 ml round bowl), baked at 130°C for 5 minutes, and baked in different media after baking. ( Add 2ml of liquid per 1cm2 of surface area. See GB/T5009.60-1996 for operation. All four extracts must not exceed the standard. Distilled water, 60°C, 2hr: Simulated water soaking. 4% acetic acid, 60°C, 2hr: Simulated vinegar soaked condition. 65% ethanol, 20°C, 2hr: Simulated wine soaking. n-Hexane, 20°C, 2hr: Simulated oil soaking condition.
5. Potassium permanganate consumption (mg/L): Distilled water, 60°C, 2hr: Determination of the dissolution of residual monomers and organics, not exceeding the standard.
6. Heavy metal content (Pb): The heavy metal content must not exceed the standard.
7. Decoloration: Soybean salad oil, ethanol, and soaking liquids are used for decolorization. There should be no decolorization of the coating film.

Third, the performance of the emulsion after coating on the snack box.

8. Water resistance test: The paint is applied to the bowl according to the coating process used in the actual factory. After the drying, adding 100° C. water to the bowl requires at least 2 hours of water resistance.
9. Adhesion performance: After fast-food box coating emulsion is dried, the fast-food box is not deformed; the paint and snack box have certain adhesive properties; after water is added, the film does not fall off and does not change.

3 test results

4 Promotion and Application

The project has been produced by specialized manufacturers, acrylic emulsion snack box special paint has been promoted and applied in many fast food box factories, and has passed the appraisal of relevant experts. The product features are as follows: (1) The product meets the requirements for food hygiene, (2) The biodegradable proportion is artificially controllable, and (3) The color can be adjusted manually. Products can be applied to: (1) plant fiber cutlery; (2) starchy cutlery; (3) cardboard coated tableware; (4) biodegradable industrial packaging







Author/Zhao Ke Sun Peiqin Sun Shaohui Liu Dazhuang

(School of Chemical Engineering, Zhengzhou University, Zhengzhou 450002)