Mobile phone accessories pulp molding how to customize

Table of Contents

To customize mobile phone accessories via pulp molding, design molds with CAD, blend 70% recycled paper with 30% bamboo fiber, and dry at 140-160°F for optimal results.

Design Specification

The design specification stage is vital when customizing mobile phone accessories via pulp molding. At this point, the exact dimensions, physical features, and accessories’ functionality must be defined, ensuring that the case, stand, or similar accessory will perfectly fit the specific brand-model mobile device. Thus, when customizing a phone case for the i-phone series, the accessory’s dimensions will be the same as the target phone. In the case of the latest i-phone, the specifications are 146.7 x 71.5 x 7.65 mm. These specifications will include correct cutouts as well as exact button and camera locations to make the pulp molded case as a precise extension of the device.

When the target mobile device is thoroughly examined, the design of the accompanying accessory can be customized to enhance customer experience. For example, the client could request a stand for use on the plane and similar products, asking for a lightweight but robust product suitable for watching videos on mobile devices. The design requires a slight incline, with the tilt being on average about 30 to 45 degrees. These angles were found by Cousins et al.

to be the best ergonomics for the average user height when using a monitor or a mobile phone on a desk. Furthermore, the pulp mold mixture requires the right mix of plastic and bamboo to add strength and environment-friendliness. Currently, most pulp mold combinations include 80% recycled paper and 20% bamboo fibers since this balance makes the final product light and sturdy. Moreover, this exact composition produces a smooth surface, ensuring high-quality digital printings. The longevity of this product must also be considered, and the proper manufacture of a 2 mm-thick phone case can protect the product from drops of even 1.5 meters on concrete.

After the accessory is produced in the proper specifications, a final adjustment can be added if necessary due to user feedback. They will often note that the case can slip through the hand. In this case, a proper feature for the phone case will be a longitudinal edge pattern that will ensure consistency. Moreover, the final calculation of the price of the phone case will involve accurate measures. For a standard phone case in the described specifications, the cost of materials is around $0.50 per piece. With large-scale production, market price will be around $15, equaling an appropriate share of equipment, operation, and distribution.


Mold Creation

The preparation process of molds used in the manufacturing of pulp molded mobile phone accessories is quite challenging and requires innovative technology and precision to produce. The process of mold creation typically begins with a 3D model of the accessory – designed by the expert developers in advanced Computer-Aided Design software. Once the design and specifications are submitted to the next section, the designer prepares a 3D model of the accessory based on the inputs received in the preceding phase. The 3D model is relevant to fine tune the design for optimum precision and fit and also for visualization of the accessory to be created.

This model is later to be sent to the experts working with CNC machines, who will fabricate the actual mold based on the model prepared by the designer. The use of CNC machines is a prerequisite for the machinery’s ability to produce extremely fine cuts essential for molds used for the creation of mobile phone accessories. The models of the phone cases typically have camera cutouts and indents for buttons or volume controls, all of which need to be manufactured with precision. The technology used can achieve 0.005-inch tolerances, and in practice even mobile phone cases can be accurately made to the dimensions of the phone.

Aluminum is the preferred material as it ensures that pulp dries evenly and for its superior life. It can be used to produce hundreds and thousands of copies of the accessory without much wear and tear, unlike hardened plastics, which are cheaper but soon lose their quality in a short time. Another niche detail to consider is where the holes for ventilation are to be placed – these holes allow for the pulp to dry faster. Placed too close to the edge, the entire accessory may be deformed by the suction force when the dried pulp is removed from the mold.

The ventilation holes are prepared using CNC machines which ensure the optimal dimensions for the efficient drying of the product. The cost of the aluminum molds used can range from $3,000 to $5,000 per mold – which is later offset by its durability and requirement to produce hundreds and thousands of parts from the mold, thus reducing in practice the cost of creating this part to a very minuscule level.


A strong and necessary step in the creation of mobile phone accessories with pulp molding is to develop a prototype. This is a step that allows the company to evaluate product functionality and customer acceptance of this product. The goal is to reach a mass market using small-scale production to make necessary changes to the reference, ensure compatibility of form factor and technical capabilities of the product. The first prototype should not replace the production cycle. According to RAYMOND, “the main prototype is usually made of four or five batches/ deliveries”. The final prototype can also be tested.

At this stage, the first molds are used, and the first small-scale production is recorded. This batch consists of several prototypes, each of which can be thinner or denser, more or less binding, or slightly different in terms of the references form factor. The first option has modifications of bamboo fibers concentration, allowing customers to test the product’s resistance and select the best option. The second option does not use flexible paper surface fibers as an option, allowing you to make the material smoother and better able to print.

This stage includes tests in both mechanical and real terms. At the same time, mechanical tests may include dropping a mobile phone from different heights to avoid damage or deformation. During this stage of testing includes as finished products on the original reference. The product’s compatibility and convenience are evaluated in terms of the existence of each button cutout, its shape, and size. In real terms, companies can use real devices and find a test group of potential customers who test the aesthetic side of the product and evaluate their solvency. At this stage, companies may have to comply with the terms of the reference or its approval.

A sunny day, a customer can test flexibility as a prototype for the main consumer of mobile phone accessories and buy. If it is too slippery or if the colors are too blurry, the first group must determine which version of the material requires practical changes. Moreover, according to EPPLE, “Cost requirements are gaining considerable importance at the production level”. However, material cost savings and compromise in finishes and colours are becoming apparent to customers.


Pulp Preparation

The preparation of pulp is the initial step in the process for the production of mobile phone accessories. It is initiated by selecting the appropriate mix of fibrous material and pulping it which will be used in molding the phone accessories. The selection of materials has a great effect not only on the physical properties of the product but also on the cost of production and the smallest possible environmental impact. The first step in this process is the selection of a principle fibrous material. Recycled paper is commonly selected for its cost-effectiveness and is an environmentally friendly option.

For durability, the manufacturer may need to add certain levels of the secondary fibrous material. For instance, bamboo or sugarcane fibers are added for a unique texture. A common ratio may here be 70% recycled paper and 30% bamboo fibers. This mix will provide a conducive balance tip of both weight and strength surface finish. The surface finish is among the most important properties owing to its adhesive adhesion to glue and how it contributes to how the accessories can be printed or branded to a higher quality. The second also has an influence on the performance of the product in actual use. Afterwards, the pulping is produced when the selected materials are disintegrated into water. The correct consistency is important; if the pulp similar to the slurry is too thick, it will not feed all of the details of the mold correctly.

If it is thin, the final product will be without strength. The suggested consistency is similar to heavy cream in that the detailed features of the mold will preserve the strength of the molded product. The additives can be added to this slurry to increase the final product properties. For example, a small amount of natural gelatin can be added 10 grams to produce a stronger bond between the fibers once dried. In the case of starch, the material weight includes a significant effect as increasing it at 5% of the overall pulp amount increases the mechanical strength of the resulting molded product.

To improve the long-term term performance of the product, the manufacturer could also choose for the biodegradable water repellent or natural dye in the slurry. The renewable materials will not be harmful to the recycling processes. The cost of manufacture can be very variable. The recycled paper is where the minimal cost is expected to be; it sells at around $150 per ton. On the other hand, premium secondary fibers like bamboo may add up to 20% to the cost of the product. The product with these fibers and a greater addition of performance additive could also on the other hand decently sell for higher prices.

Molding Process

The molding process is a vital step of production where prepared pulp becomes a final shape of a mobile phone accessory. It calls for the utmost care to ensure precision, efficiency, and high quality of the final accessories. The technique usually involves pouring the pulp mixture in a needed mold, pressing the products with the use of molds, and drying the items. To begin, the pulp slurry is poured on the already formed mold that corresponds in shape to the finished accessory. For example, molds may be anodized to ensure uniform drying due to the good heat conductivity or even cobalt-based molds to give more detail to the accessory’s shape. The mold has to be filled completely to create the desired form and cover specific details of the phone accessory, for instance, a camera location or button placement in a phone case.

Later, the excess of water needs to be removed. This follows two main approaches: the first one is to apply vacuum pressure, while the second is mechanical pressing, or these methods can be combined. The vacuum usually removes bulk of the water, making the pulp dense enough to stay in shape of the mold. Mechanical presses are then used to apply pressure directly with force of 200 – 500 psi.

The pressing step defines the density and strength of the accessory; this ensures press time of about 30 minutes for most of the products. Finally, phone accessories must dry for a longer time to gain their shape and become solid. The drying techniques vary; however, dried packing is widely used as it fastens the drying process. Manufacturers have to be very careful controlling the temperature and humidity; if the temperature is too high, the pulp may warp and crack.

If the temperature is set too low, pulp stays long with moisture and becomes weak. As for present times, the acceptable temperature amounts to 140 – 160 F as based on the time when the pulp dries perfectly without becoming damaged. The drying and pressing times vary, but as evidenced by the example of use of dried pumpage, power, and time are best spent on 160 F when dried in 30 – 120 minutes. The speed of the molding process directly influences the cost and timeline of production.

A single cycle of mold which includes mold filling, pressing, and drying takes from 30 minutes to few hours based on the complexity and size of the accessory. For such products as molded pumpage, the production time can be up to two hours while one and a half is perfect for molded packing or cases. The timeline can be best cut using multi-cavity molds, a new technology which allows for a production of several items in a single mold. The approach cuts up to 50% of time and power compared to single cavity molds.

Drying and Finishing

When the molded mobile phone accessories are produced from the pulp, they enter into an essential drying and finishing process that requires careful handling to ensure the appropriate strength, texture, and the overall appearance of the final product. As some of the cellulose fibers from the pulp accessories still retain moisture at this point, allowing the time for them to dry is critical. The first step in the dry and finishing process is usually drying set to remove all the water retained by the molded pulp products. For this purpose, drying is carried out in industrial ovens or kilns which supply products with controlled heat.

The heat must be around 140 to 160 degrees Fahrenheit and remain steady at this level to provide mold products with even drying without warping or shrinking. The time it takes to dry the molded pulp product depends on the thickness of the object – however, it is usually done in a matter of hours. It is recommended to use rapid drying measures to ensure the process is completed faster. Conveyor belt ovens in the drying units allow the products to dry continuously, which decreases the time for drying by nearly 30 percent as opposed to a drying in static racks. Such rapid drying is especially appropriate for manufacturers who need to produce mold pulp accessories in a large quantity safely while not worrying about timing issues.

After the drying process is completed, finishing touches can be performed in order to provide products with the required texture and ensure that molded pulp mobile phone accessories look appealing. Finishing of the products may include sanding their edges to provide a smoother touch. Sealants or varnishes can also be applied to facilitate their use, such water resistance. Moreover, certain products can be provided with either matte or glossy appearance, depending on market trends and customer wishes.

Another option that allows the producer to customize the finishing of the molded pulp accessories incorporate color dyeing or direct printing which is usually achieved with digital or screen printing. Finishing of products also adds some of the production cost to the molded accessories, though usually not exceedingly so – for example, a water-resistant coating can add extra 0.10 or 0.20 per product, which is usually a very small amount compared to the overall production costs.

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