For manufacturers of milk tea straws and bent straws, "stiffness" is the key to retaining customers. However, many manufacturers have long been troubled by batch differences: one batch of straws is soft and flat, making it difficult to insert into milk tea cups and prone to bending during drinking; the other batch is brittle and easy to break, especially the corrugated part of bent straws, which breaks with a little force. Despite using the same formula and equipment, it is impossible to produce products of uniform specifications, resulting in serious raw material waste and frequent customer loss. Machine operators repeatedly adjust the equipment but achieve little effect, falling into the dilemma of "being driven crazy by machine adjustment".

Many manufacturers check equipment and adjust processes but overlook a core factor — the Melt Flow Rate (MFR) of PP (polypropylene) raw materials. The hardness and stiffness stability of straws are closely related to PP MFR, which is also the fundamental reason for batch instability.

PP MFR is a core indicator for measuring the fluidity of polypropylene, directly determining the plasticizing effect of raw materials and the mechanical properties of final products. For straw production, stable MFR is the premise of uniform specifications: if the MFR is too high, the fluidity of raw materials is excessively strong, and the formed straws have a loose structure and insufficient stiffness, failing to meet usage requirements; if the MFR is too low, the raw materials are not fully plasticized, and the straws are brittle and lack toughness, prone to breaking — with more prominent hidden dangers at the corrugated part of bent straws.

Unstable PP MFR and uneven raw material mixing are the two core causes of the problem. On the one hand, the MFR of PP raw materials varies sharply between different batches. Some manufacturers choose low-quality raw materials or mix PP materials with different MFRs to control costs, leading to significant differences in raw material performance; on the other hand, the mixing process is non-standard and the equipment is backward, making it impossible for raw materials to fully blend, which further exacerbates the instability of straw stiffness.

Failing to meet stiffness standards brings huge losses to manufacturers. The catering industry has increasingly high requirements for straw quality. Especially for chain milk tea brands, there are clear standards for straw stiffness and toughness. Once problems occur, cooperation will be terminated directly, resulting in both customer loss and damage to the industry reputation. Machine operators repeatedly adjust equipment parameters, consuming manpower and material resources and seriously affecting production efficiency.

The core of solving the problem is to control the stability of PP MFR and the uniformity of raw material mixing. Manufacturers need to establish a strict raw material testing mechanism, test the MFR before raw materials enter the factory, and eliminate unqualified raw materials; optimize the mixing process, select mixing equipment with precise proportion control to ensure the full blending of raw materials; introduce advanced control systems to monitor and adjust process parameters in real time, reducing batch differences from the source.

Although straws are small, they are related to the survival and development of manufacturers. In the current fierce industry competition, the stability of product quality is the core competitiveness. For straw manufacturers troubled by stiffness problems, identifying PP MFR as the key, standardizing raw material control and production processes, can completely solve the pain points of unstable batches and difficult machine adjustment, produce milk tea straws and bent straws that meet standards and are recognized by customers, retain customers, gain a firm foothold in the market, get rid of the dilemma of "being driven crazy by machine adjustment", and achieve efficient and stable production.