New PP Applications: Packaging, Blending and Compounding

Basell North America (Basel)'s two new polyethylene resins pose a challenge for PS, PET, PVC and Other PP series plastics as transparent and rigid packaging materials for thermoplastic molding, stretch blow molding and injection molding On the formation of a new balance of performance.

Basell has a new third PP family, this function resin has a variety of effects, as a dispersant for plastic flame retardant, as a compatibilizer for engineering thermoplastic blending, as a coupling agent is used in Reinforced polyolefin composites.

Transparent and rigid material

Basell's new family of PPs, called Adstif, has a wide range of consumer packaging customers. The materials are basell for use in cast film, sheet, and thermoforming Spheripol processes. (The earlier Adstif grades were produced by the Catalloy process as blended resins for the production of automotive injection molded parts.) Due to the wide molecular weight distribution of the new materials, these resins improved significantly in impact, stiffness, and heat distortion temperatures compared to standard PP. . They also equal or exceed PS, PET, and PVC in terms of transparency and toughness balance.

There are currently four grades available: Adstif X83-1 is a 3.5 MFR homopolymer used in the production of turnover containers, beverage cups and lids; X34-1 and X65-1 are considered typical reaction body grades and contain 15 % Rubber and 3.5 MFR impact copolymer; X34-1 is designed for frozen milk and ice cream containers; X-65-1 is suitable for sports cups and hollow corrugated cardboard.

Adstif X786-1 is a 4 MFR impact copolymer with less than half the rubber content of traditional impact copolymers and is designed for refrigerator storage packages such as milk tubes, yogurt cups and serving containers.

Basell claims that Adstif thermoplastic containers are superior to PS containers in transparency and impact resistance in lightweight packaging. For example, a 230cc deep-formed beverage cup produced using Adstif X83-1 resin has better impact resistance, top loading strength and transparency than PS cup, and the PP cup is reduced from 3.9g of PS to 2.1g, although the weight is reduced by 46%. , but performance is still better than PS.

Similar results were obtained for the moderately shaped cheese cups, where the weight of Adstif was 32% less than the HIPS/GPPS mix and 17% lighter than the standard PP homopolymer.

In multilayer cast film packages such as bread bags, Adstif is said to have better strength, toughness, and barrier than standard PP. In addition, Adstif's production efficiency is very obvious. In the high-speed packaging line, Adstif resin production speed up to 350 bags per minute without losing strength, the traditional PP material began to lose strength when the speed exceeds 310 bags.

Metallocene PP (mPP) Challenge PET/PE/PS

Basell introduced new injection molding and blow-molding molding grades with better transparency and low extractive flow, and the mPP family has expanded.

Metocene X50182 is an 18 MFR grade for directional bottles. It competes with PET and HDPE on hot-fill packages and can be used for bottles with fruity water, sports drinks, chilled juices and applesauce. This resin was tested on a two-step Sidel repeated heating stretch blow molding machine to obtain transparency equivalent to a PET bottle (haze of 1.5%), which was higher than that of conventional PP.

Metocene X70293 (40 MFR) and X50109 (60 MFR) are two new injection molding resins designed specifically for medical test vessels and disc cartridges. In addition to high transparency, low extract flow, and dimensional stability, these grades also meet FDA and USP Class VI standards. When making CD-ROM cartridges, Metocene saves 40% more weight than translucent PS materials, has a 10% faster cycle time, has greater crack resistance and lower tooling costs. Metocene plastic box has a good overall connectivity and side stretch to prevent the box from splaying. Transparent Metocene resin coloring is also very easy.

Other uses include household goods, consumer product packaging, and thin-walled cups and containers. Many items that can use PS, such as containers and hangers, Metocene reduces the weight by 15% because of the low density of the resin. It is said that the appearance of the Metocene hanger and the hanger made of the GPPS/HIPS blend are not only 35% lighter, but also have higher breakage resistance and better processability.

New functional PP

Basell's new multi-purpose Oxy-PP material is a polar functional PP resin capable of producing oxygen components as flame retardant dispersants and coupling agents/affinity agents in engineering thermoplastic blends and reinforced polyolefins. design. Bottles made with Metocene X50182 mPP by repeated heating and blowing method can achieve the transparency of PET bottles (haze of 1.5%), and the gloss is higher than that of conventional PP.

To produce oxyPP, basell uses the same proprietary technology used to make high melt strength resins, and the company currently plans to produce oxyPPs with different MFR ranges and functional levels.

The initial emphasis was on flame retardant materials. oxyPP is said to reduce halogen and non-halogen FRs with its dispersant but does not affect flame retardancy. When OxyPP is blended with brominated FR compound, it is injection-molded into a household plastic part such as a TV cover, which can achieve the flame retardancy equivalent to UL94, and the halogen flame retardance is less than half of the original value.

An order product of OxyPP showed very high MFR, 30% higher strength than non-halogen FR-PP composites, and better surface appearance.

Basell states that oxyPP resins and their ionic polymers can work together with engineering thermoplastics to create an affinity alloy effect. For example, the combination of 25 to 75 oxyPP and nylon 6 resulted in a mixture of similar positive PP and nylon: 10% to 25% increase in tensile strength and flexibility, and a 4-fold increase in MFR and color stability.

The use of OxyPP as a coupling agent can be seen in the experiment of polypropylene containing 30% glass fiber: The addition of 10% oxyPP can effectively increase the glass fiber bottle exit rate, and can greatly improve the flexural modulus, tensile strength, bending Strength, impact resistance and heat distortion temperature. OxyPP can also achieve good results in glass fiber-containing PP materials.